Cervical laminoplasty is a well-established surgical approach for managing various cervical spine pathologies, including cervical spondylotic myelopathy, spinal canal stenosis, and ossification of the posterior longitudinal ligament. Among the available laminoplasty techniques, the use of Hydroxyapatite spacers secured with screws is common for maintaining the expanded interlaminar space. However, one potential complication is screw back-out, which, although recognized, has rarely been documented in the literature. We present a rare case of delayed screw migration culminating in skin perforation in a 76-year-old woman who underwent cervical laminoplasty for cervical spondylotic myelopathy. During the index procedure, Hydroxyapatite spacers were placed and secured with screws into the lamina. Seven years postoperatively, gradual subcutaneous migration of the screw from the lamina of the fourth cervical vertebra was observed, ultimately resulting in complete skin penetration 9 years after the initial surgery. The patient underwent surgical removal of the protruding screw along with surrounding granulation tissue. The surgical site was thoroughly irrigated with copious saline, and the wound was closed primarily with sutures. Postoperative recovery was uneventful. Stitches were removed on day 11 after confirming complete wound healing. This case underscores an exceptionally rare but clinically significant late complication of cervical laminoplasty with Hydroxyapatite spacers -complete screw extrusion through the skin. To our knowledge, this is the first documented case of its kind. The prolonged asymptomatic nature of screw migration in this patient highlights the importance of long-term surveillance following laminoplasty, even in the absence of clinical symptoms, to detect hardware-related complications at an early stage.

Solitary plasmacytoma is a hematologic malignancy in which about 50% of cases progress to multiple myeloma within 10 years. Local radiation therapy is effective for solitary plasmacytoma treatment, but there are cases of spinal cord paralysis due to osteolytic pathological fractures in the spine. Here, we report a 63-year-old male with spinal cord injury caused by pathologic fracture progression after radiotherapy. A 63-year-old male presented with neck pain and left hemiplegia. Imaging studies revealed a pathological fracture of the C5 vertebral body, and biopsy confirmed the diagnosis of solitary plasmacytoma. Radiation therapy temporarily improved symptoms, but progressive quadriplegia developed 2 months later. Cervical spinal cord compression due to an additional vertebral bone fracture was confirmed. Aggressive lesionectomy and fixation using simultaneous anterior and posterior combined approaches were performed. Postoperatively, paralysis completely recovered. No local recurrence or transition to multiple myeloma was observed even after 7 years of follow-up at age 70. Surgical treatment may be effective for spinal cord injury associated with pathologic fracture progression after radiotherapy for solitary plasmacytoma.

Flow diverters have revolutionized the treatment of large and giant cerebral aneurysms. However, aneurysms with branch vessels originating from the aneurysm sac remain challenging for flow diverter monotherapy. We present five cases demonstrating favorable outcomes following combined treatment with overlapping flow diverter with coiling. The study cohort included five female patients with a mean age of 72.8 years. The mean aneurysm diameter was 8.1 mm. Triple antithrombotic therapy (dual antiplatelet therapy plus short-term anticoagulation) was administered to prevent ischemic complications due to posterior communicating artery occlusion in the perioperative period. Complete or near-complete occlusion (O'Kelly-Marotta grade C or D) was achieved in all cases. Follow-up angiography (mean follow-up time: 17.2 months) revealed preserved patency of the posterior communicating artery in four of five cases. In one case, the posterior communicating artery arising from the aneurysm was occluded at its origin but was supplied retrograde from the posterior circulation. Follow-up digital subtraction angiography of most cases showed caliber changes, with the posterior communicating artery diameter reducing and the P1 segment of the posterior cerebral artery increasing. No ischemic or hemorrhagic complications occurred perioperatively or during follow-up. Overlapping flow diverter with coiling combined with low-dose and short-term triple antithrombotic therapy might be a safe and effective treatment for fetal-type posterior communicating artery aneurysms, offering a viable alternative for complex aneurysms. Further studies with long-term follow-up data from a larger patient cohort are required to validate the efficacy and safety demonstrated in this case series.

To investigate whether oral contraceptives induce acute ischemic stroke in patients with moyamoya disease. We retrospectively reviewed female patients with moyamoya disease who were taking oral contraceptives during their reproductive years (12-49 years of age) at the time of diagnosis or during follow-up. The patients' detailed clinical history, including the time course of oral contraceptive usage and acute ischemic stroke occurrence, was evaluated. For patients with radiological evidence of acute ischemic stroke, the imaging pattern of stroke was assessed to investigate the underlying mechanisms. Among 589 female patients, 12 patients took oral contraceptives at some point during the period from 2012 to 2023; 5 patients were taking oral contraceptives at the time of diagnosis, and 4 of them were diagnosed with moyamoya disease after acute ischemic stroke. Among the 7 patients who started oral contraceptives during follow-up, 2 patients developed acute ischemic stroke several months after starting oral contraceptives. Notably, none of the hemispheres that developed acute ischemic stroke previously underwent revascularization, and none of the 5 hemispheres with prior revascularization developed acute ischemic stroke. The imaging pattern of acute ischemic stroke in 7 patients suggested the contribution of a thromboembolic mechanism. Oral contraceptives may increase the risk of acute ischemic stroke via thromboembolic mechanisms in patients with moyamoya disease, but its risk might be manageable in hemispheres with prior revascularization and stable disease conditions for years. Active education of patients regarding the possible risk of oral contraceptives and close communication with gynecologists seem necessary to provide the best treatment strategies for female patients with moyamoya disease who require contraception or treatment of menstrual disorders.

Cardioembolic stroke caused by tumor emboli is a rare form of cancer-associated stroke. We report a case of a patient with cardiac metastasis of extraskeletal chondrosarcoma who developed left internal carotid artery occlusion due to embolic stroke. Extraskeletal chondrosarcoma is an extremely rare subtype of soft tissue sarcoma characterized by a tendency for local recurrence and metastasis. Endovascular thrombectomy was performed using a combined technique, achieving complete revascularization. Histopathological analysis of the retrieved cell mass confirmed that the embolic source was the preexisting extraskeletal chondrosarcoma.

Diffuse midline glioma, H3K27-altered, is a rare and aggressive central nervous system tumor that typically affects children, whereas adult cases are uncommon and less well characterized. We report a 43-year-old woman who experienced progressive lightheadedness for 10 months and was diagnosed with orthostatic hypotension on the basis of a positive tilt-table test result. Despite treatment with midodrine, her symptoms worsened, and dysarthria, dysphagia, sensory disturbance, and gait instability later developed. Magnetic resonance imaging confirmed an intra-axial mass in the dorsal medulla oblongata. Partial resection was performed, and histopathological examination with immunohistochemistry confirmed the diagnosis of H3K27-altered diffuse midline glioma. The patient subsequently received adjuvant chemoradiotherapy. Although her motor function improved postoperatively, severe orthostatic hypotension persisted, leading to recurrent syncopal episodes that significantly hindered rehabilitation. The solitary nucleus in the dorsal medulla plays a central role in the baroreflex by relaying sympathetic and parasympathetic signals within the central autonomic network. Disruption of this network by medullary tumors can impair blood pressure regulation, causing orthostatic hypotension. Although orthostatic hypotension has been reported in association with various medullary tumors, gliomas are rarely implicated. To our knowledge, this is the first reported case of medullary diffuse midline glioma presenting with orthostatic hypotension under the current World Health Organization molecular classification. This case highlights the importance of considering brain magnetic resonance imaging in patients with newly developed or severe orthostatic hypotension, particularly when accompanied by neurological symptoms, to enable timely diagnosis and management.

Myxoid glioneuronal tumor is a newly included entity in the 2021 World Health Organization classification of central nervous system tumors, based on both pathological and molecular evidence, characterized by platelet-derived growth factor receptor alpha mutations. A 23-year-old female presented with intermittent visual field abnormalities and dizziness. Magnetic resonance imaging revealed a 2-cm mass occupying both foramens of Monro, leading to non-communicating hydrocephalus. Endoscopic surgery via the transcortical approach achieved gross total resection of the tumor. Postoperatively, she developed cognitive dysfunction involving recent memory disturbance and progressive ventricular dilation, necessitating a ventriculoperitoneal shunt, which led to significant cognitive recovery. Histopathological analysis confirmed myxoid glioneuronal tumor with a platelet-derived growth factor receptor alpha p.K385L mutation. A review of 23 cases, including ours, indicates that surgical resection is the preferred treatment and is generally associated with a favorable prognosis. However, recurrence and meningeal dissemination have been reported in some cases, emphasizing the need for long-term follow-up. Myxoid glioneuronal tumor is frequently located close to critical structures like the fornix, so careful surgical planning is essential to balance maximal resection with functional preservation. Endoscopic techniques offer advantages for deep-seated lesions by minimizing cortical damage while allowing adequate tumor resection. Further studies are needed to establish the optimal treatment strategies and clarify the long-term prognosis of myxoid glioneuronal tumor.

Spinal arachnoid cysts are relatively uncommon lesions, broadly classified as either congenital or acquired. Acquired cysts may develop following trauma, hemorrhage, or post-infectious inflammation. Depending on their location, these cysts can cause a range of symptoms, including quadriplegia, pain, sensory disturbances, and gait impairment. Surgical resection may be indicated in cases with significant neurological symptoms. We report the case of a 77-year-old woman who presented with persistent bilateral leg numbness and pain. Magnetic resonance imaging revealed a suspected intradural spinal arachnoid cyst or arachnoid web at the Th7-8 level, and surgery was planned to relieve the symptoms.

A laminectomy was performed, revealing a cystic, membrane-like structure in the subdural space. By injecting a crystal violet staining solution into the cyst, we enhanced the visibility of the boundary between the normal arachnoid membrane and the cyst, allowing for complete resection. Postoperatively, the patient experienced improvement in leg pain and numbness. This case demonstrates that crystal violet staining can facilitate clear boundary recognition during arachnoid cyst resection, enabling more precise cyst removal.

We report a case of successful diaphragm pacing in a patient with severe traumatic spinal cord injury resulting in complete ventilator dependence. A 29-year-old man sustained a traumatic cervical spinal injury at the C3 level. On admission, he exhibited tetraplegia, complete sensory loss below the C6 dermatome, and acute respiratory failure. Emergency spinal decompression surgery was performed; however, neurological deficits showed no improvement. Despite intensive respiratory rehabilitation, the patient remained fully dependent on mechanical ventilation. Diaphragm pacing implantation was planned approximately 17 weeks post-injury. Intraoperative electrical stimulation revealed no responsiveness in the left diaphragm, whereas the right diaphragm demonstrated sufficient contractility. After estimating that adequate tidal volumes could be achieved through unilateral right diaphragmatic stimulation, bilateral diaphragmatic electrodes were laparoscopically implanted. Diaphragm pacing was initiated on postoperative day one, gradually increasing pacing duration daily while maintaining exertion levels below the Borg scale 4. By day 46 post-implantation, the patient achieved complete independence from mechanical ventilation despite persistent left diaphragmatic paralysis. Enhanced right diaphragmatic function was confirmed by increased diaphragmatic thickness and thickening fraction. Additionally, improved sputum clearance allowed withdrawal from cough-assist therapy and subsequent closure of tracheostomy. At 1-year follow-up, the patient maintained independent respiration without device-related complications. This case highlights the potential efficacy of early diaphragm pacing implantation in patients with high cervical spinal cord injury, demonstrating favorable respiratory outcomes even in the presence of unilateral diaphragmatic dysfunction.

Marfan syndrome presents unique challenges for mechanical thrombectomy in acute ischemic stroke due to vascular fragility and complex aortic anatomy, often from prior surgeries. We describe the case of a man in his 50s with Marfan syndrome, total aortic arch replacement, mechanical valve replacement, and extensive chronic dissections, who presented with acute ischemic stroke due to right internal carotid artery occlusion. Conventional transfemoral access failed due to anomalous prosthetic brachiocephalic artery graft anatomy. Consequently, mechanical thrombectomy was performed via direct surgical exposure and puncture of the right common carotid artery. Despite initial avoidance of a stent retriever due to Marfan syndrome-related vessel fragility, an stent retriever was ultimately used in a combined technique with aspiration in the third pass, achieving partial recanalization (thrombolysis in cerebral infarction 2a) and retrieval of a fibrin-rich thrombus. This case highlights direct carotid access as a feasible alternative in Marfan syndrome patients with prohibitive conventional access and suggests stent retrievers can be used cautiously.

Abusive head trauma in infants and young children can have a significant impact on neurological outcomes and, in severe cases, may be life-threatening. We report 3 cases of abusive head trauma that presented with acute subdural hematomas on computed tomography scans, accompanied by extensive low-density areas and parenchymal brain swelling. All patients exhibited impaired consciousness due to brain injury and underwent craniotomy for hematoma evacuation as well as extensive decompressive craniectomy. Despite the severity of the initial presentation, hemiparesis was mild and gradually improved over several months. Postoperative magnetic resonance imaging revealed widespread parenchymal injury but preservation of the corticospinal tract, including the precentral gyrus. In the acute phase, diffusion-weighted imaging showed no irreversible infarction in the motor cortex, and arterial spin labeling demonstrated increased perfusion in peri-motor regions of the affected hemisphere. These findings suggest that preserved corticospinal pathways and compensatory hyperperfusion may correlate with favorable motor recovery even in the presence of extensive parenchymal damage. These cases highlight the radiological features and short-term neurological outcomes of abusive head trauma, demonstrating preserved motor function despite extensive parenchymal damage.

Choroid plexus cysts are typically benign lesions found within the ventricular system during prenatal imaging and are usually asymptomatic. Intraparenchymal choroid plexus cysts, especially in adults, are exceptionally rare, with very few reported cases. This case report aims to present a rare instance of a symptomatic, intraparenchymal choroid plexus cyst in an adult patient and to discuss the diagnostic and surgical considerations involved. We present the case of a 50-year-old man with complaints of lower extremity weakness and imbalance who was found to have a bilobulated cyst in the frontal cortex causing significant mass effect and midline shift. The patient underwent cyst fenestration through endoscope-assisted open craniotomy, with marked postoperative reduction in cyst size and resolution of neurological symptoms. Histopathology confirmed the diagnosis of a choroid plexus cyst. This case highlights the importance of considering rare pathologies such as choroid plexus cysts in the differential diagnosis of cystic brain lesions with mass effect in adults.

Aneurysms of the meningohypophyseal trunk are rare and usually asymptomatic, but because of the close anatomical relationship between the meningohypophyseal trunk and cranial nerves within the cavernous sinus, they can cause neurological deficits. We describe an 80-year-old woman who presented with acute horizontal diplopia exacerbated on rightward gaze. Neurological examination revealed isolated right abducens nerve palsy. Magnetic resonance angiography demonstrated an aneurysm arising from the right meningohypophyseal trunk in close proximity to the abducens nerve. Endovascular coil embolization was performed under dual antiplatelet therapy, and the aneurysm was successfully occluded while preserving meningohypophyseal trunk patency. The procedure was uneventful, although postoperative diffusion-weighted imaging revealed multiple small cerebral infarctions suggestive of distal embolism. The patient remained neurologically stable, and her diplopia gradually improved. At the 6-month follow-up, she exhibited complete recovery of abducens nerve function. This case highlights the anatomical vulnerability of the abducens nerve to compression by meningohypophyseal trunk aneurysms and underscores the importance of considering vascular lesions in the differential diagnosis of isolated cranial nerve palsies. Despite radiographic evidence of silent embolic infarction, endovascular coil embolization resulted in full clinical recovery, supporting its role as a safe and effective therapeutic option in appropriately selected symptomatic meningohypophyseal trunk aneurysms.

Although rare, thrombosed vertebral artery aneurysms can lead to severe symptoms and are challenging to treat due to their proximity to vital structures. The location of a thrombosed aneurysm on the anterior aspect of the brainstem poses a significant challenge to conventional microscopic approaches. We herein report a 78-year-old man with a thrombosed right vertebral artery aneurysm who developed progressive quadriparesis, dysphagia, and respiratory failure despite prior interventions, including flow diverter stent placement, parent artery occlusion, and microscopic thrombectomy. Given worsening medullary compression and poor clinical status, intra-aneurysmal thrombectomy was performed using an exo-endoscopic 2-step approach. The procedure involved reopening the previous suboccipital craniotomy, partial condylectomy, and C1 hemilaminectomy. Exoscopic thrombus de-bulking was followed by endoscopic evacuation of the residual thrombus compressing the ventral brainstem. Postoperatively, no complication was observed, and the patient demonstrated gradual neurological improvement, including recovery of spontaneous respiration and the ability to wean from mechanical ventilation within 3 weeks. Follow-up imaging confirmed resolution of medullary compression without thrombus recurrence. The exo-endoscopic 2-step approach is a viable option for surgical decompression of thrombosed vertebral artery aneurysms that cause brainstem compression. This enhances surgical access and visualization, particularly in the ventral brainstem, while potentially minimizing brainstem manipulation. Further investigation is warranted to better define the indications, efficacy, and safety of the management of complex thrombosed aneurysms.

This report presents 2 cases demonstrating how a foraminal block served as both a diagnostic tool and an effective treatment for small far-lateral lumbar disc herniation at L5-S1 in elite athletes. The patients were a male swimmer in his early 20s and a female figure skater in her late teens, both of whom developed activity-related low back pain, with symptoms acutely exacerbated by the high flexion and extension loads inherent to their sports, which compromised their ability to compete at the highest level. A fluoroscopy-guided foraminal block was performed in each case; the key technical component was careful paraneural needle placement, stopping just short of the nerve root to minimize the risk of iatrogenic injury while targeting the inflammatory environment throughout the foramen. The diagnosis was confirmed in both athletes by reproducing their specific pain during injection. This non-operative intervention provided pain relief that was sufficient for successful participation in a major international competition in one case and continuation of a critical qualifying season for a premier global event in the other. This approach represents a critical diagnostic and therapeutic strategy that can avoid the need for surgery and preserve an elite athlete's immediate career goals.

This report discusses the case of a 70-year-old male orthopedic surgeon with multilevel lumbar foraminal stenosis and degenerative scoliosis (Cobb angle 21°) who presented with right leg radiculopathy and foot drop. To accommodate his inability to take extended leave and his desire to avoid fusion, we performed a staged transforaminal full-endoscopic lumbar foraminotomy, consisting of one procedure per level, under local anesthesia. The procedures targeted the L5/S1, L4/5, and L3/4 levels sequentially at 1-month intervals. The patient's foot drop resolved immediately after the first surgery. At the 3-month follow-up after the final procedure, his motor deficits showed marked improvement, and his Oswestry Disability Index score decreased from 12% to 8%. He returned to his clinical duties the day after each discharge and was able to continue managing his private clinic without interruption. He resumed playing golf 2 months after the final surgery. A staged, non-fusion transforaminal full-endoscopic lumbar foraminotomy approach under local anesthesia was a safe and effective strategy for multilevel foraminal stenosis, even in the presence of deformity, providing excellent functional recovery with minimal disruption to the patient's professional life.

Dural laceration is a critical complication in full endoscopic spinal surgery. We need to recognize precise surgical anatomy to avoid it. Recently identified dorsal meningovertebral ligaments, connecting the dorsal spinal dura mater to the ligamentum flavum, may contribute to this risk, but their role remains unclear. We present 2 cases of lumbar spinal canal stenosis treated with full endoscopic laminectomy. In both cases, dorsal meningovertebral ligaments anchored the dura to the ligamentum flavum and were visible through high-resolution endoscopy. Attempts to remove ligamentum flavum fragments caused dural traction via the dorsal meningovertebral ligament, nearly resulting in laceration. We modified our approach by detaching the dorsal meningovertebral ligament before flavectomy, preventing dural injury and ensuring uneventful recoveries. These cases highlight the importance of recognizing dorsal meningovertebral ligament as a potential risk factor for dural laceration during full endoscopic laminectomy. Although the presence of dorsal meningovertebral ligament cannot be predicted preoperatively, the enhanced visualization provided by full endoscopic spinal surgery allows for intraoperative identification. We recommend careful inspection for dorsal meningovertebral ligament before flavectomy during full endoscopic laminectomy. If identified, these ligaments should be detached prior to ligamentum flavum removal to minimize the risk of dural injury. This approach can significantly enhance the safety of the full endoscopic laminectomy procedure and potentially reduce the incidence of dural complications in full endoscopic spinal surgery.

Acute thrombosis is often observed following the rupture of an intracranial aneurysm, and optimal coil selection during endovascular coiling is challenging. A 75-year-old woman presented with a subarachnoid hemorrhage. Computed tomography angiography revealed aneurysms at the right anterior cerebral artery A2/3 junction and the right middle cerebral artery. Based on vessel wall imaging, the anterior cerebral artery aneurysm was diagnosed as the rupture site. Initial digital subtraction angiography demonstrated a 4.4 × 3.4 × 3.4 mm aneurysm with a 1.6 mm neck. Coil embolization was performed 1 day after diagnostic angiography. Preprocedural angiography revealed significant lumen shrinkage to 2.0 mm, probably due to aneurysmal thrombosis. A 4 mm framing coil was selected based on the initial digital subtraction angiography findings. Contrast extravasation occurred after coil deployment. Immediate protamine administration, blood pressure reduction, and coil embolization with smaller coils in the opacified aneurysm dome achieved hemostasis. Final angiography confirmed complete occlusion, without residual filling or distal thrombus migration. Postoperative computed tomography showed an intracerebral hematoma in the left frontal lobe, which subsequently resolved. The patient recovered without focal neurological deficits and was transferred to a rehabilitation hospital on day 18 with mild attention deficits. This case demonstrates the risk of intraprocedural rupture when coil sizing is selected based on pre-thrombosis dimensions rather than current lumen visualization in rapidly thrombosing aneurysms. When thrombosis reduces the lumen, selecting the coil size based on pre-thrombosis dimensions may increase the risk of intraoperative rupture. Coil size selection should match the currently visualized lumen.

Immature teratomas of the pineal region are a subtype of non-germinomatous germ cell tumors typically associated with early recurrence. Ultra-late recurrence decades after initial treatment is exceedingly uncommon. We report an immature teratoma case in the pineal region that recurred 35 years after subtotal resection and chemoradiotherapy, showing somatic-type malignant transformation into adenoid cystic carcinoma-like adenocarcinoma.

A 16-year-old boy initially underwent ventriculoperitoneal shunting followed by tumor resection, after the pathological confirmation of an immature teratoma (grade 2 according to the ovarian teratoma grading system). A small residual lesion remained, and the patient's condition remained stable for more than a decade, but he was lost to follow-up. At 51 years of age, the patient presented with obstructive hydrocephalus and tumor regrowth. Preoperative serum and cerebrospinal fluid tumor markers levels were normal. An endoscopic biopsy revealed poorly differentiated adenocarcinoma. Resection through an occipital transtentorial approach indicated tumor infiltration into the bilateral thalamus. Histology showed glandular and cartilaginous components with marked atypia and immunohistochemical features resembling adenoid cystic carcinoma, whereas germ cell markers were negative, thus establishing a diagnosis of teratoma with somatic-type malignant transformation. Despite ifosfamide, carboplatin, and etoposide chemotherapy (all at 50% dose) and stereotactic radiosurgery, the disease progressed with leptomeningeal dissemination, and the patient died 613 days after he underwent the second surgery.

This case represents the longest reported interval of recurrence for a central nervous system immature teratoma and highlights the possibility of long-term tumor dormancy followed by malignant transformation. Lifelong surveillance is therefore warranted in patients with residual immature teratomas.

Surfer's myelopathy is a rare, nontraumatic spinal cord injury affecting novice surfers. Although spinal ischemia is considered the primary mechanism, whether the initial insult is arterial or venous remains controversial. We report a case of surfer's myelopathy with magnetic resonance imaging findings suggestive of venous congestion-radiological features that, to our knowledge, have not been previously described.

A previously healthy 23-year-old man developed acute low back pain, progressive lower limb weakness, and bladder and bowel dysfunction after his first surfing experience. Magnetic resonance imaging on admission showed longitudinal T2 hyperintensity from T8/9 to the conus medullaris without abnormalities on diffusion-weighted imaging. On day 2, repeat magnetic resonance imaging again demonstrated no diffusion-weighted imaging changes, whereas the apparent diffusion coefficient map revealed hyperintensity, indicating vasogenic edema. These findings were more consistent with venous rather than arterial ischemia. The patient was treated with antiplatelet and anticoagulation therapy along with rehabilitation and ultimately achieved complete neurological recovery.

This case may represent the first description of magnetic resonance imaging findings suggestive of venous congestion in surfer's myelopathy. Apparent diffusion coefficient hyperintensity in the absence of diffusion restriction may reflect reversible venous ischemia. Incorporating diffusion-weighted imaging and apparent diffusion coefficient maps into routine magnetic resonance imaging protocols for suspected surfer's myelopathy could provide valuable insight into pathophysiology and prognosis.

Ossification of the ligamentum flavum is a pathological condition that can cause progressive myelopathy or severe radiculopathy. Standard surgical management involves direct decompression via posterior resection of the ossification. However, there is a substantial risk of complications, including dural tears and iatrogenic instability. We report a rare case of lumbar ossification of the ligamentum flavum with degenerative spondylolisthesis treated solely by full-endoscopic trans-Kambin's triangle lumbar interbody fusion, aiming for indirect decompression and stabilization, without direct resection of the ossification. A 68-year-old woman had progressive low back pain, bilateral lower extremity radiculopathy, and severe neurogenic claudication, limiting ambulation to 100 m. Imaging revealed Meyerding Grade I L4-L5 spondylolisthesis with dynamic instability and significant canal stenosis due to ossification of the ligamentum flavum, measuring 4.06 mm in maximal thickness. She underwent single-level Kambin's triangle lumbar interbody fusion at L4-L5. Postoperatively, rapid improvement was observed (visual analog scale low back pain: 7→1, leg pain: 8→0; Oswestry Disability Index: 52%→10% at 3 years). Follow-up computed tomography/magnetic resonance imaging demonstrated progressive regression of the ossification, from 4.06 mm to 3.2 mm at 1 year and 1.46 mm at 3 years (64.0%). This case suggests that Kambin's triangle lumbar interbody fusion with indirect decompression is an effective surgical option in lumbar ossification of the ligamentum flavum with segmental instability. The remarkable regression of the ossification suggests that spinal stabilization may suppress pathological mechanical stress, shifting bone remodeling toward resorption, and supports a mechanistic hypothesis. Further prospective studies are warranted to validate this pathophysiological mechanism.

Essential tremor is the most common adult movement disorder, typically presenting with kinetic and postural tremor that interferes with daily activities. For patients unresponsive to medications, surgical options such as radiofrequency thalamotomy, deep brain stimulation, and magnetic resonance-guided focused ultrasound can provide therapeutic benefit.

Magnetic resonance-guided focused ultrasound, an incisionless lesioning modality, has gained clinical use; however, accurate targeting of the ventral intermediate nucleus remains challenging because the nucleus cannot be directly visualized on routine magnetic resonance imaging and exhibits substantial individual variability.

This report describes 2 cases of medication-refractory essential tremor treated with magnetic resonance-guided focused ultrasound ventral intermediate nucleus thalamotomy under structurally complex conditions. One patient had a thick skull with a low skull density ratio, and the other exhibited marked thalamic distortion. In both cases, individualized ventral intermediate nucleus targeting was performed using multimodal imaging that combined a stereotactic planning platform, dentatorubrothalamic tract tractography, and Fast Gray Matter Acquisition T1 Inversion Recovery. The Fast Gray Matter Acquisition T1 Inversion Recovery sequence, which enhances gray-white matter contrast, provided relative contrast of intrathalamic structures, including signal patterns corresponding to the internal medullary lamina. When integrated with connectivity-based dentatorubrothalamic tract tractography, this approach provided complementary information to support anatomically guided targeting.

Stepwise sonication with intraoperative thermal monitoring resulted in substantial tremor reduction without new neurological deficits. These observations suggest that combining Fast Gray Matter Acquisition T1 Inversion Recovery with tractography offers practical, complementary guidance for ventral intermediate nucleus targeting, including in settings without access to advanced commercial integration software. Although limited to 2 patients, this work suggests the value of accessible multimodal imaging for improving confidence in anatomy-informed targeting in magnetic resonance-guided focused ultrasound and potentially other lesioning procedures.

Intracranial schwannomas account for approximately 8% of all primary brain tumors, and the majority arise in the cerebellopontine angle. Ectopic schwannomas that originate from non-cranial nerve sites, such as the dura mater or brain parenchyma, are rare, representing less than 1% of all intracranial schwannomas. These lesions often mimic meningiomas on neuroimaging, making preoperative diagnosis challenging. A woman in her 50s was referred to our department after a brain check-up incidentally revealed a mass lesion extending both above and below the tentorium. Neurological examination was unremarkable. Magnetic resonance imaging demonstrated a well-defined, heterogeneously enhancing extra-axial mass widely attached to the tentorium, suggestive of meningioma. The lesion was completely resected via a suboccipital approach. Histopathological examination revealed spindle-shaped tumor cells with palisading nuclei, positive for S-100 protein and negative for epithelial membrane antigen, confirming the diagnosis of schwannoma. The MIB-1 (Ki-67) labeling index was below 5%, consistent with a benign lesion. Postoperative magnetic resonance imaging confirmed total resection, and the patient's postoperative course was uneventful. No recurrence was observed during a 7-month follow-up period. Tentorial ectopic schwannoma is an extremely rare entity that can closely resemble meningioma both radiologically and intraoperatively. Awareness of this entity is important when evaluating tentorial extra-axial tumors. Although the clinical course is generally favorable following complete resection, careful preoperative evaluation is essential for accurate diagnosis and appropriate management.

Perimedullary arteriovenous fistulas at the craniocervical junction are rare, frequently present with subarachnoid hemorrhage, and require accurate identification of the shunt point―particularly in lesions involving the anterior spinal artery―to achieve durable cure. A 64-year-old man presented with dense posterior fossa subarachnoid hemorrhage caused by a high-flow craniocervical junction arteriovenous shunt supplied predominantly by a markedly enlarged right C2 radiculomedullary artery. Selective catheterization was unsuccessful. On day 1, suboccipital craniectomy with C1 laminectomy enabled posterior flow control by clipping the dominant feeder; however, the ventral shunt point could not be safely visualized. Postoperative angiography demonstrated persistent shunting with prominent anterior spinal artery contribution. One month later, definitive transoral anterior obliteration was performed in a hybrid operating room. Intraoperative digital subtraction angiography and intra-arterial indocyanine green angiography demonstrated caudal-to-rostral flow reversal from the anterior spinal artery into the ascending anterior spinal vein at the shunt point, located within the anterior median fissure on the ventral pial surface. The shunt was directly obliterated by simultaneous clipping of the anterior spinal artery branch and draining vein, with additional coagulation of minor feeders. Halo immobilization followed by delayed posterior C1-2 fixation was performed. Final angiography and serial magnetic resonance angiography confirmed complete cure, and the patient returned to work 10 months postoperatively, maintaining functional independence for more than 5 years. This case illustrates that, in carefully selected anterior spinal artery-involved high-flow craniocervical junction perimedullary arteriovenous fistulas, a staged strategy combining posterior flow control and definitive anterior direct obliteration can provide a safe and durable solution.

Sphenoid wing dysplasia is a recognized diagnostic feature of neurofibromatosis type 1, yet it rarely occurs in isolation. We present the case of a girl who had pulsatile exophthalmos since birth and was diagnosed with sphenoid wing dysplasia at 1 year and 2 months of age, with no clinical or familial evidence of neurofibromatosis type 1 identified during long-term follow-up. Progressive herniation of the temporal lobe into the left orbit prompted surgical intervention at age 12. Using a 3-dimensional printed skull base model, a patient-specific, hand-bent titanium mesh was preoperatively fabricated and implanted via a frontotemporal approach to reconstruct the superior orbital wall and restore separation between the cranial and orbital compartments. Postoperatively, the pulsatile exophthalmos resolved completely, and a transient abduction deficit recovered within 6 months. Follow-up imaging confirmed stable mesh positioning and durable compartment separation, with satisfactory cosmetic results maintained at 2 years. This case expands the clinical spectrum of sphenoid wing dysplasia by illustrating a neurofibromatosis type 1-negative phenotype and supports 3-dimensional model-assisted, patient-specific titanium mesh reconstruction as an effective strategy for correcting spheno-orbital defects and eliminating pulsatile exophthalmos. Accumulation of similar cases is needed to refine surgical indications, optimize timing, and assess the long-term durability of implant materials.

Chiari malformation type I is a structural anomaly of the posterior fossa characterized by cerebellar tonsillar herniation through the foramen magnum, often associated with disrupted cerebrospinal fluid dynamics and elevated intracranial pressure. Papilledema is a rare ophthalmic manifestation in Chiari malformation type I, typically linked to increased intracranial pressure. Isolated visual symptoms without signs of intracranial pressure in pediatric Chiari malformation type I are particularly rare and poorly understood. We report a rare pediatric case of Chiari malformation type I in a 9-year-old girl presenting solely with bilateral papilledema and visual impairment, without typical symptoms of raised intracranial pressure such as headache. Magnetic resonance imaging revealed cerebellar tonsillar descent and cervical syringomyelia. Due to progressive visual decline and the absence of alternative diagnoses, the patient underwent foramen magnum decompression with C1 laminectomy. Postoperatively, visual acuity significantly improved, although papilledema persisted at 9 months. This case challenges the conventional view that papilledema in Chiari malformation type I is solely caused by elevated intracranial pressure. Alternative mechanisms, such as localized venous congestion, mechanical stress on the optic nerve, or regional cerebrospinal fluid flow disturbances, may contribute to papilledema. Persistent papilledema despite clinical improvement supports the hypothesis of localized rather than global intracranial pressure elevation. Pediatric presentations may differ from adult cases in symptomatology and pathophysiology, requiring careful diagnostic and therapeutic considerations. Surgical decompression may lead to functional visual recovery even if anatomical signs such as papilledema persist. This case underscores the need for further research into atypical presentations and underlying mechanisms of Chiari malformation type I, especially in pediatric populations.

Cardiac sarcoidosis elicits cardiac disorders due to granuloma formation in cardiac tissue; it can lead to cerebral infarcts. We encountered a 72-year-old Japanese male with isolated cardiac sarcoidosis diagnosed after a cardiogenic cerebral infarction. He suffered a sudden-onset disturbance of consciousness, aphasia, and right hemiparesis. His National Institutes of Health Stroke Scale score was 17. The diagnosis was left middle cerebral artery occlusion due to cardiogenic embolism. Percutaneous thrombectomy achieved thrombolysis and recanalization of the cerebral infarction; his National Institutes of Health Stroke Scale score improved to 0. Cardiac ultrasonography revealed an enlarged left atrial diameter, a thinned inferior ventricular wall, a ventricular aneurysm, and left ventricular systolic dysfunction. During the clinical course, ventricular tachycardia was noted; sarcoidosis was suspected as the underlying disease. As no definitive diagnosis could be made, he was discharged on the 54th day of hospitalization. 18F-fluorodeoxyglucose positron emission tomography in the outpatient department showed localized abnormal accumulation in the left ventricle, and he was diagnosed with isolated cardiac sarcoidosis. Steroid treatment was added to anticoagulation therapy. There have been no recurrent cerebral infarctions or lesions in other organs. Cardiac sarcoidosis can be 1 cause of cardiogenic cerebral infarction.

Jugular foramen dural arteriovenous fistulas are exceedingly rare vascular abnormalities, with only 10 cases documented so far. Their complex angioarchitecture and the risk of postoperative complications necessitate carefully planned treatment strategies. We present the case of an 82-year-old man who presented with transient dizziness. Digital subtraction angiography revealed a Cognard type V dural arteriovenous fistula at the right jugular foramen, fed by the neuromeningeal branch of the right ascending pharyngeal artery and draining into the perimedullary veins of the brainstem and spinal cord via a single right inferior petrosal vein. The lesion was successfully treated in a hybrid operating room using a multimodal approach. The procedure involved continuous neurophysiological monitoring and endoscopic disconnection of the draining vein, guided by superselective intra-arterial indocyanine green videoangiography. Complete disconnection was confirmed intraoperatively by digital subtraction angiography. To our knowledge, this is the first report of endoscopic disconnection of a jugular foramen dural arteriovenous fistula, specifically performed using intra-arterial indocyanine green videoangiography in a hybrid operating room. The combination of minimally invasive neuroendoscopy with superselective intra-arterial indocyanine green videoangiography provides both safety and effectiveness in the treatment of dural arteriovenous fistulas. This approach may be particularly advantageous for lesions in rare and anatomically complex regions such as the jugular foramen.

Superior articular process-pedicle impingement may be an underrecognized mechanical pain generator in posture-dependent axial low back pain. We report a case of a 32-year-old male professional football player who presented with low back pain that was provoked by forward flexion and right lateral bending and was refractory to conservative measures. Radiographs and computed tomography scans showed near-elimination of the osseous interval between the right S1 superior articular process and the caudal aspect of the right L5 pedicle, with reactive cortical change. Targeted infiltration of local anesthetic at the suspected impingement interface produced immediate pain relief, and facet-preserving full-endoscopic bony decompression led to sustained improvement at 3 months. We propose that superior articular process-pedicle impingement should be considered in patients presenting with posture-dependent axial low back pain. The following 3 features serve as a practical diagnostic triad: concordant provocation; radiographic or computed tomographic evidence of superior articular process-pedicle contact or near-contact; and an immediate response to targeted local anesthesia. Facet-preserving full-endoscopic decompression is a reasonable option for refractory cases.

Floppy infants caused by craniocervical instability in childhood are extremely rare. Furthermore, due to underdeveloped bone structures, treatment for it is extremely difficult.

The patient was a 2-year-old boy who was referred at the age of 1 year for psychomotor developmental delay. The cause was unknown, so he was placed under observation. At the age of 2 years, he remained a floppy infant and had not yet acquired motor skills, so he was referred again. Neurologically, he was in a state of progressive motor paralysis of the limbs. Magnetic resonance imaging revealed damage to the medulla oblongata, and he was diagnosed with orthotopic os odontoideum. A C1 laminectomy was performed, with posterior fixation from a C2 translaminar screw to the occipital bone. The progression of the condition has halted, and the patient is currently undergoing rehabilitation.

Here, we report the pathological diagnosis, surgical treatment, and orthotopic os odontoideum timing, a condition presenting with progressive craniocervical instability in infants.

Anti-neutrophil cytoplasmic antibody-associated vasculitis is an autoimmune disorder characterized by inflammation of small vessels, with potential for multi-organ involvement. Anti-neutrophil cytoplasmic antibody-associated vasculitis can affect blood vessels throughout the body, but involvement of cerebral vessels is relatively rare. We report a case of anti-neutrophil cytoplasmic antibody-associated vasculitis complicated by a subarachnoid hemorrhage due to the rupture of a cerebral artery pseudoaneurysm, which was successfully managed with endovascular intervention. A 61-year-old man presented with headache, purpura on the extremities, profound fatigue, and diffuse myalgia. Computed tomography revealed subarachnoid hemorrhage. Based on clinical, laboratory, brain magnetic resonance imaging, and cerebral angiography findings, the patient was diagnosed with anti-neutrophil cytoplasmic antibody-associated vasculitis and subarachnoid hemorrhage secondary to the rupture of pseudoaneurysm formed in perforating branch arising from the vertebral artery. Parent artery occlusion of the vertebral artery resulted in the complete obliteration of the aneurysm and no rebleeding occurred during the course. Despite intensive care management, the patient developed renal and putaminal hemorrhages, resulting in a fatal outcome. Anti-neutrophil cytoplasmic antibody-associated vasculitis may involve the cerebral vessels, and in cases complicated by ruptured aneurysms, implementing appropriate re-rupture prevention alongside adequate treatment of anti-neutrophil cytoplasmic antibody-associated vasculitis may help improve clinical outcomes.

We report a rare case of an isolated superior sagittal sinus dural arteriovenous fistula successfully treated by transcranial direct puncture transvenous Onyx embolization using a steerable microcatheter. With reduced arterial inflow and sinus balloon protection, Onyx injection through the steerable catheter achieved complete occlusion of the shunted pouch without complications. The patient showed marked improvement in cortical venous dilatation and cerebral edema. This case highlights the feasibility and safety of combining transarterial flow reduction, sinus balloon protection, and steerable microcatheter navigation for the curative embolization of isolated sinus dural arteriovenous fistulas.

Spinal neuromas related to chronic irritation or remote trauma may arise from unrecognized repetitive minor injury to the spinal cord or nerve roots, yet detailed descriptions with precise preoperative imaging findings are rare. We report a 59-year-old man with a 6-month history of severe dysesthesia and numbness in the neck and left upper limb, followed by progressive weakness over 2 months. He had undergone splenectomy after a traffic accident 23 years earlier. Computed tomography revealed ossification of the posterior longitudinal ligament, osteophytes, and a disc herniation at the left C5/C6 level. Magnetic resonance imaging demonstrated a slightly enhancing peripheral mass compressing the spinal cord. The differential diagnosis included meningioma and sequestrated cervical disc herniation. During surgery, only the swollen, non-functioning C6 ventral root filaments were resected, while functioning filaments were preserved. Histopathological examination confirmed a neuroma composed of disorganized axonal bundles consistent with chronic irritation- or remote trauma-related changes. The patient showed mild postoperative improvement. Chronic irritation appears to be the predominant contributor. Irritation-related neuromas should be considered in the differential diagnosis of intradural extramedullary lesions arising from C6 ventral root filaments, even when the trauma history is remote.

Classification of neuroendocrine tumors in the paranasal sinuses is difficult, and the management of olfactory neuroblastoma with epithelial differentiation remains unclear. Recently, a group of tumors that exhibit neuroectodermal differentiation while maintaining distinct epithelial characteristics has been proposed as olfactory carcinoma, with reports indicating that these tumors have distinct clinical features and a worse prognosis than olfactory neuroblastoma. Here, we present a rare case in which an initial biopsy from the nasal cavity yielded a diagnosis of cylindrical cell papilloma, but surgical resection via combined transnasal endoscopic and transcranial approaches ultimately revealed a diagnosis of olfactory carcinoma. An accurate diagnosis is of the utmost importance for paranasal sinus tumors because it significantly impacts the treatment strategies and prognosis. In cases of olfactory carcinoma, sampling the glandular structure only may result in a misdiagnosis of papillary epithelial neoplasm. Therefore, sufficient tissue samples must be collected, and the entire tumor must be evaluated.

Anterior choroidal artery aneurysms, in which the anterior choroidal artery arises from the aneurysmal sac, pose significant therapeutic challenges, as treatment risks include branch occlusion and devastating ischemic complications, including hemiplegia and hemianopia. We report a patient in their 70s with an incidentally diagnosed 12.2 mm unruptured right anterior choroidal artery aneurysm, in which three-dimensional angiography demonstrated that the anterior choroidal artery originated from the center of the aneurysm dome. During conservative observation, the aneurysm enlarged to 14.1 mm, necessitating intervention. We employed overlapping flow diverters (2 Pipeline Shield devices) with minimal loose coiling to facilitate controlled thrombosis. To prevent rapid aneurysm thrombosis and subsequent anterior choroidal artery occlusion, we administered modified triple antithrombotic therapy comprising dual antiplatelet agents (prasugrel 3.75 mg and aspirin 100 mg) and reduced-dose rivaroxaban (10 mg daily) for 30 days postoperatively. At 12-month follow-up, angiography demonstrated near-complete aneurysm occlusion (O'Kelly-Marotta grade C3) and a significant reduction in aneurysm size. Critically, during gradual aneurysmal shrinkage, the orifice of the anterior choroidal artery progressively migrated toward the aneurysm neck, allowing branch preservation while the sac underwent organized thrombosis. No perioperative or delayed ischemic complications occurred, and magnetic resonance imaging confirmed the absence of new infarction. This controlled thrombosis strategy combining mechanical flow diversion with time-limited pharmacological modulation successfully achieved aneurysm occlusion while preserving the sac-originating branch through gradual vascular remodeling. This approach addresses the fundamental therapeutic dilemma posed by anterior choroidal artery aneurysms with incorporated branches. It may represent a paradigm shift from acute treatment to controlled, gradual occlusion strategies for similarly challenging lesions.

A 50-year-old male who had undergone ventriculoperitoneal shunt for hydrocephalus following acoustic neurinoma surgery 18 months earlier presented with progressive fatigue and loss of appetite. Three months prior to visiting our hospital, he fell off his bicycle and sustained a skin laceration just above the tube on the right clavicle. He exhibited tenderness in the right upper quadrant but no other neurological symptoms. A contrast-enhanced abdominal computed tomography scan revealed a large well-defined lesion in the right lobe of the liver, with the shunt tube having migrated into the lesion. Ultrasound-guided percutaneous drainage was performed, resulting in a diagnosis of liver abscess. Culture of the drainage fluid confirmed the presence of methicillin-resistant Staphylococcus aureus, and vancomycin therapy was initiated. Later, an increased cell count, predominantly neutrophils, was observed in his cerebrospinal fluid. We then removed the entire shunt system and administered linezolid, after which the cerebrospinal fluid cell count normalized within almost one month. Liver abscesses as a complication of ventriculoperitoneal shunt are rare, with only 11 cases reported in the previous literature. This is possibly the first case associated with traumatic skin injury occurring long after ventriculoperitoneal shunt placement. With proper management of the shunt tube and administration of the appropriate antibiotic treatment, a favorable prognosis can be expected.

Eight years after resection of hypopharyngeal carcinoma with neck dissection and ligation of the left internal jugular vein, a man in his 50s presented with an incidentally discovered isolated left transverse sinus dural arteriovenous fistula. Transvenous embolization was performed to achieve complete obliteration. The patient likely developed venous hypertension due to stenosis of the left transverse sinus, limiting contralateral drainage and the absence of collateral communication between the internal jugular vein and the suboccipital cavernous sinus. A retrospective review of serial imaging revealed progression of venous drainage from the initial development of transverse sinus dural arteriovenous fistula to an eventual isolated sinus configuration. Although dural arteriovenous fistula formation is associated with venous hypertension, this case suggests that anatomic venous variants may predispose individuals to delayed dural arteriovenous fistula formation, with abrupt alterations in venous flow serving as triggers. The serial imaging demonstrates the progressive nature of this pathology. Assessment of venous anatomy in patients undergoing planned occlusion of major venous pathways may help predict long-term complications.

Isolated middle cerebral artery dissection is a rare cause of acute ischemic stroke, accounting for approximately 2.4% of anterior circulation events. Due to its rarity, no optimal management strategy has been established, and evidence regarding the safety and efficacy of endovascular therapy remains limited. We report a 26-year-old male who presented with sudden-onset headache, vomiting, right hemiparesis, and aphasia. Magnetic resonance imaging revealed multiple faint diffusion-restricted lesions in the left hemisphere (DWI-ASPECTS 7), and magnetic resonance angiography demonstrated occlusion of the left middle cerebral artery (M2 segment). Emergency mechanical thrombectomy using a combined stent retriever and aspiration technique achieved complete recanalization (Thrombolysis in Cerebral Infarction 3), although significant residual stenosis persisted. Balloon angioplasty restored satisfactory luminal patency without stent placement. Postoperative contrast-enhanced vessel wall imaging showed mural thickening and marked enhancement of the left M2 segment, confirming arterial dissection. The patient recovered well, and no infarct progression or re-occlusion occurred during the 6-month follow-up. The present case suggests that endovascular therapy employing mechanical thrombectomy as the first-line strategy may be one of the therapeutic options for acute middle cerebral artery occlusion secondary to arterial dissection. The procedural strategy and device selection should be individualized to minimize vessel injury. Furthermore, given the potential for dynamic vascular changes, long-term radiological surveillance remains essential.

Neurogenic pulmonary edema is a rare but severe complication of acute central nervous system injury, such as subarachnoid hemorrhage, typically presenting with immediate onset. This report describes an uncommon case of delayed-onset neurogenic pulmonary edema following subarachnoid hemorrhage. A 68-year-old man with subarachnoid hemorrhage, caused by a ruptured left posterior communicating artery aneurysm, developed tachypnea and hypoxemia with bilateral pulmonary infiltrates 96 hours after symptom onset. Echocardiography was normal, ruling out cardiogenic causes, and neurogenic pulmonary edema was diagnosed. The patient improved rapidly with fluid restriction and diuretic therapy, and subsequently underwent successful aneurysm coil embolization. Neurogenic pulmonary edema is thought to result from an excessive sympathetic activation leading to pulmonary vasoconstriction, increased capillary pressure, and endothelial injury. Delayed cases may involve secondary sympathetic surges due to intracranial pressure fluctuations, vasospasm, or inflammatory injury. This case highlights the need for clinicians to consider delayed neurogenic pulmonary edema when respiratory deterioration occurs several days after subarachnoid hemorrhage to ensure timely diagnosis and life-saving management.

Calvarial hemangiomas are rare benign vascular tumors originating from the skull bones, most commonly observed in the frontal and parietal bones of the cranium. Although most cases are asymptomatic, they can present with headache, cosmetic deformity, or, rarely, neurological deficit. The lesions are usually solitary; multicentric involvement and dural invasion are exceedingly rare phenomena. Here, we report a 22-year-old male patient who presented with frontal headache and a palpable scalp swelling. Imaging revealed two separate expansile lytic lesions in the right and left frontal bones with no connection between them. Surgical resection was planned. Intraoperatively, the lesion on the left side demonstrated findings highly suggestive of dural invasion, and both lesions were completely resected. This case highlights the rarity of the combination of multicentric involvement with dural invasion in the literature.

Idiopathic normal pressure hydrocephalus is a disease of unknown cause that occurs in people aged 60 years or older and causes gait disturbance, cognitive decline, and urinary problems. A 63-year-old man with untreated diabetes presented with unsteady gait and amnesia. Head magnetic resonance imaging revealed disproportionately enlarged subarachnoid-space hydrocephalus and brain herniation into the para-superior sagittal sinus arachnoid granulation. Although the patient experienced generalized convulsions immediately before surgery, a lumbo-peritoneal shunt was performed, and symptoms improved. These brain herniations into the arachnoid granulation might accelerate the pathology, and idiopathic normal pressure hydrocephalus with brain herniation into the arachnoid granulation of the lateral lacuna of the superior sagittal sinus is extremely rare and has not been reported previously.

Detailed evaluation of language function is important in the management of dominant temporal lobe lesions. Although spoken language is routinely evaluated in patients, disturbances in written language may remain undetected without detailed assessment. The Japanese writing system, consisting of logographic Kanji and phonographic Kana, provides a unique framework for identifying selective impairments of the ventral language stream. We report a 51-year-old right-handed Japanese male who presented with selective agraphia for Kanji following a left posterior temporal subcortical hemorrhage. Upon admission, spontaneous speech was fluent, and auditory comprehension was preserved, with no clinically apparent aphasia. However, comprehensive neuropsychological assessment revealed a profound impairment in Kanji writing. Although standard language scores improved significantly by the chronic phase (Day 87), qualitative assessment revealed persistent deficits in Kanji retrieval, characterized by frequent non-responses and morphologically related errors. Conversely, Kana writing and reading abilities were largely preserved. This case demonstrates that selective impairment of written language (pure agraphia for Kanji) may occur in association with posterior temporal lesions, despite preserved spoken language. Unlike typical cortical lesions that destroy the orthographic representation itself, we propose that this specific subcortical hemorrhage caused a transient disconnection within the ventral language stream, selectively disrupting the semantic access pathway to Kanji. From a functional and clinical perspective, systematic evaluation of writing function is essential for neurosurgeons and clinicians to prevent overlooked disabilities.

Posterior condylar canal dural arteriovenous fistula is rare, and cases of posterior condylar canal dural arteriovenous fistula directly related to trauma have been reported even less frequently. We describe a case of posterior condylar canal dural arteriovenous fistula that presented with tinnitus soon after head trauma and was successfully treated with transarterial embolization. A 60-year-old man presented with right-sided tinnitus that had persisted for 2 weeks after sustaining a right temporal injury. Digital subtraction angiography revealed a posterior condylar canal dural arteriovenous fistula with venous drainage from the posterior condylar vein to the suboccipital cavernous sinus, without cortical venous reflux. The shunt was supplied by a single feeder, the jugular branch of the occipital artery. Transarterial embolization using N-butyl cyanoacrylate and coils achieved complete occlusion of the shunt. The patient's tinnitus resolved immediately after the procedure, and follow-up angiography demonstrated persistent complete occlusion of the fistula, with no evidence of recurrence. Posterior condylar canal dural arteriovenous fistula is a rare lesion that may occur following head trauma. Bone-window three-dimensional angiographic reconstruction is useful for diagnosis, as it clearly delineates the relationship between the skull base canal and the shunt. Transarterial embolization can be a curative treatment option when performed with a thorough understanding of the relevant vascular anatomy and potentially hazardous anastomoses.

Endodermal cysts typically occur in intradural regions of the ventral spine or posterior cranial fossa. However, they are rarely found in supratentorial regions, especially within the frontal bone. Here, we report a rare case of an intraosseous endodermal cyst in the frontal convexity and discuss its potential pathogenesis in this unusual location. A 54-year-old woman presented with a gradually enlarging, soft, elastic mass in the left frontal region. Neurological abnormalities were not observed. Computed tomography revealed a cystic lesion within the left frontal bone, associated with a bulging contour. The cyst contents appeared hyperintense on T1-weighted magnetic resonance and showed a hypointense component on T2-weighted magnetic resonance imaging. The cyst wall was not enhanced with gadolinium. The cyst and its mucinous content were completely excised from the frontal bone. Intraoperatively, the cyst wall was completely separated from the frontal sinus by a thin bony structure. Histopathological examination revealed that the cyst wall consisted of inflammatory granulation tissue with a ciliated columnar epithelium, consistent with a diagnosis of endodermal cyst. Although the pathogenesis of supratentorial endodermal cysts remains unclear, the location of the cyst in the frontal convexity, as opposed to the anterior cranial base, may suggest a distinct pathogenesis for each endodermal cyst in terms of embryological aspects.

Currarino syndrome is a rare congenital disorder characterized by a triad of sacral agenesis, presacral mass, and anorectal malformation. Although it is typically diagnosed in infancy or childhood, adult presentation is rare and poses unique diagnostic and surgical challenges. We present the case of a 45-year-old woman diagnosed with Currarino syndrome during pregnancy after incidental discovery of a presacral mass associated with tethered spinal cord and sacral agenesis. Over time, the mass enlarged, causing rectal obstruction and abdominal pain. A combined neurosurgical and gastrointestinal surgical approach was used to perform tethered cord release and mass resection without cerebrospinal fluid leakage, owing to autologous omental flap placement. There were no postoperative complications except for transient urinary retention and numbness in the left foot. Adult cases of Currarino syndrome require individualized, multidisciplinary surgical management. A combined neurosurgical and gastrointestinal surgical approach, incorporating preventive techniques such as autologous omental flap placement, can result in favorable outcomes with minimal complications.

Cervical calcification of the ligamentum flavum is a relatively rare disease that causes myelopathy due to calcification within the ligament. We recently encountered a patient with rapid progression of cervical calcification of the ligamentum flavum after anterior fixation surgery, resulting in spinal cord symptoms. An 81-year-old woman had a history of anterior decompression and fixation surgery (Williams-Isu method) at C3-4 and C5-6 at the age of 58 years, with no sequelae. Eighteen months preoperatively, the patient developed walking difficulties, arm pain, and weakness in both arms. Magnetic resonance imaging showed C4-5 anterior spinal cord compression, and C4-5 anterior decompression and fixation surgery were performed. Postoperatively, the patient's condition improved, and she was discharged from the hospital, able to walk unaided. However, 17 months postoperatively, the patient rapidly developed right arm pain, walking difficulties, and urinary and rectal incontinence. There was a rapid progression within 18 months in cervical calcification of the ligamentum flavum at the C6-7 level on magnetic resonance imaging and severe compression of the spinal cord; therefore, urgent laminectomy was performed. Postoperatively, the symptoms improved, and there was no recurrence for 3 years. In addition to the previously performed C3-4 and C5-6 fusion procedures, the addition of a C4-5 fusion resulted in a longer fusion spanning from C3 to C6, and it is thought that mechanical stress was concentrated on the adjacent intervertebral space of C6-7. Although the cause of cervical calcification of the ligamentum flavum has not been determined, this case strongly suggests that mechanical stimulation may exacerbate the condition.

Inflammatory pseudotumor involving the cranial nerves is extremely rare, and delayed diagnosis may cause irreversible neurological deficits. To our knowledge, this represents the third reported case of an inflammatory pseudotumor involving the cavernous sinus with extension along the oculomotor nerve. A 56-year-old woman presented with a visual field defect in her left eye, and her condition was initially managed conservatively because of her mild clinical presentation. Initial magnetic resonance imaging revealed a homogeneously enhanced dumbbell-shaped mass lesion extending from the left cavernous sinus through the superior orbital fissure into the intraconal orbital space. At 3-year follow-up, the patient's condition worsened during routine outpatient visits, with left visual acuity decreasing to light perception. Surgical biopsy revealed a fibrous mass involving the cisternal portion of left oculomotor nerve and extending into the cavernous sinus. Histopathological examination and laboratory findings confirmed the diagnosis of an immunoglobulin G4-related inflammatory pseudotumor. Oral corticosteroid therapy caused marked radiological regression of the lesion; however, visual impairment was not alleviated. This case highlights that delayed histopathological confirmation may produce irreversible neurological deficits despite a favorable radiological response to corticosteroid therapy.

Aneurysms associated with arteriovenous malformations occur in up to 20% of cases, but distal anterior inferior cerebellar artery aneurysms associated with arteriovenous malformations are extremely rare. We report a case of a ruptured distal anterior inferior cerebellar artery aneurysm associated with a cerebellar arteriovenous malformation in a 71-year-old man presenting with subarachnoid hemorrhage. Digital subtraction angiography revealed a cerebellar arteriovenous malformation supplied mainly by the right anterior inferior cerebellar artery and a fusiform aneurysm located at the meatal loop within the internal auditory canal. The aneurysm was considered the most likely rupture point based on the hemorrhage distribution and angiographic findings. Endovascular treatment was attempted to prevent re-rupture. Due to challenging distal catheterization and unattainable complete coil embolization of the aneurysm, the aneurysm and a short proximal segment of the parent artery were occluded. Postoperatively, the patient developed a mild hearing loss without brainstem infarction. Subsequent arteriovenous malformation resection via lateral suboccipital craniotomy led to complete obliteration. Parent artery occlusion reduced arteriovenous malformation flow and served as preoperative embolization to facilitate safe surgical removal. This case highlights the importance of individualized treatment strategies for rare distal anterior inferior cerebellar artery aneurysms associated with arteriovenous malformations and suggests that parent artery occlusion with subsequent staged arteriovenous malformation resection can be an effective approach.