Tarlov cysts (TCs) rarely cause clinical symptoms, such as leg pain, buttock pain, and bladder/bowel dysfunction. Surgery is considered when these symptoms persist despite medical treatments. Among several surgical procedures, microsurgical wrapping (MSW) is a relatively novel, simple technique with few complications, including cerebrospinal fluid leakage. Herein, we report a case of multiple TCs treated with MSW and present the mechanism of symptoms generated by TC and the procedure's limitations. A 58-year-old man complained of severe right leg and buttock pain for 3 months and was admitted to our hospital. His symptoms aggravated with sitting and standing and improved with the prone position. Spinal magnetic resonance imaging (MRI) demonstrated multiple sacral cysts containing intense cerebrospinal fluid. The cysts connect to the right S3 and S4 nerve roots. He was treated conservatively with medications; however, his symptoms were not improved. Therefore, MSW was performed for TCs connected to the S3 and S4 roots. The postoperative course was uneventful, and cerebrospinal fluid leakage did not occur. MRI performed 1 year after the operation demonstrated no recurrence of the TCs, and his leg pain was completely relieved; however, the buttock pain remained. MSW for TCs is effective for symptoms of adjacent nerve root compression; however, repairing the damaged nerve root in TCs is sometimes difficult. This may be a limitation of present surgical interventions because these symptoms may be difficult to treat even with other interventions.

Isolated superior petrosal sinus dural arteriovenous fistula (SPSdAVF) is a rare condition for which transvenous embolization is a safe treatment, even if accessing the isolated sinus can be challenging. A 39-year-old female patient with dizziness and right facial palsy underwent magnetic resonance imaging, revealing a venous infarction at the posterior fossa and a dural arteriovenous fistula. Digital subtraction angiography showed an isolated SPSdAVF. The shunt point was posterior to the isolated superior petrosal sinus, and the shunt flowed only through the petrosal vein. Contrast-enhanced magnetic resonance imaging showed thrombosis at the anterior segment of the superior petrosal sinus. Transvenous embolization was successfully performed via the thrombosed anterior segment of the superior petrosal sinus without associated complications. This case shows that transvenous embolization through a thrombosed superior petrosal sinus is an alternative treatment option for isolated SPSdAVF.

Moyamoya disease (MMD) is a rare idiopathic cerebrovascular disorder that causes transient ischemic attack (TIA) and ischemic stroke in the pediatric population. Herein, we report an extremely rare case of Moyamoya syndrome (MMS) and late-onset idiopathic aqueduct stenosis, a unique form of non-communicating hydrocephalus. A 17-year-old female presented with an intractable headache and occasional faintness. Pertinent medical history included a fourth ventricle epidermoid cyst without any evidence of aqueduct stenosis, which was surgically removed when she was two years of age. The patient subsequently experienced a TIA and was diagnosed with MMD at 14 years of age. Under the definitive diagnosis of MMS associated with a brain tumor, the patient underwent surgical revascularization of the symptomatic right hemisphere without complications. Although the ischemic symptoms resolved postoperatively, a medically intractable headache with occasional faintness persisted. Serial magnetic resonance imaging ultimately revealed newly developed non-communicating hydrocephalus due to acquired aqueduct stenosis at the age of 17. After careful exclusion of the development of either or both a periventricular anastomosis and vault moyamoya vessels along the surgical route using cerebral angiography, we performed an endoscopic third ventriculostomy (ETV) via the right anterior horn without complications. A complete resolution of her chronic headache with the shrinkage of the third ventriculomegaly was observed postoperatively. In cases of MMS associated with symptomatic aqueduct stenosis, transdural collaterals on the cranial vault and periventricular collaterals should be meticulously evaluated preoperatively using cerebral angiography to safely perform an ETV.

Meningiomas originating within the bones of the skull are rare and have been reported as primary intraosseous meningiomas (PIOM). Moreover, PIOMs with a skull base location or malignant pathology are predisposed to recurrence; however, recurrence is quite rare among PIOMs characterized by a convexity location and benign pathology. Here, we present a case of extensive recurrence of a convex intraosseous meningioma with benign pathology. A 72-year-old woman presented with a headache to our hospital. Gd contrast-enhanced magnetic resonance imaging revealed an enhanced tumor in the left frontal to the parietal region extending through the calvarial bone and invading the subdural space and subcutaneous tissue. Skull radiograph and computed tomography identified a remarkable osteolytic change in the lesion. Macroscopic complete resection (MCR) of the tumor and the surrounding tissues was performed. The tumor was histopathologically diagnosed as a transitional meningioma (World Health Organization grade 1). Seven years after the surgery, the patient presented with dysarthria, and the recurrence of the tumor was identified as massive lesions extending through the calvarial bone to the orbital bone, partially protruding into the brain and scalp. MCR was performed again, with the reconstruction of the skull for an extensive calvarial area using a titanium plate. This case is unique due to the extensiveness of the recurrent tumor and its rarity. Here, we report the details of the clinical course and discuss the characteristics of this case.

We compare two cases of primary spinal atypical teratoid/rhabdoid tumor (AT/RT), which rarely occurs in adults marked by SMARCA4 inactivation, and SMARCB1 inactivation for pediatric cases. AT/RT represents a highly malignant neoplasm comprising poorly differentiated constituents and rhabdoid cells, with SMARCB1 (INI1) or infrequently SMARCA4 (BRG1) inactivation. These tumors are predominantly found in children but are rare in adults. While AT/RT can arise anywhere in the central nervous system, spinal cord localization is comparatively scarce. Despite mutation or loss of SMARCB1 at the 22q11.2 locus serving as the genetic hallmark of AT/RTs, infrequent cases of SMARCA4 inactivation with intact SMARCB1 protein expression are significant. We present each case of primary spinal tumors in a child and an adult, showing loss of the SMARCB1 and SMARCA4 proteins, respectively. Both tumors met the AT/RT diagnostic criteria. The histopathology demonstrated the presence of rhabdoid cells in both cases. Diagnosing primary spinal AT/RT with SMARCB1 protein loss remains a challenge. Nevertheless, the presence of SMARCB1 positivity alone must be noted to be insufficient to exclude the possibility of AT/RT diagnosis. In cases in which the diagnosis of AT/RT is highly suspected clinically, additional testing is warranted, including SMARCA4 analysis.

Spinal cord stimulation (SCS) is widely performed to treat several types of intractable chronic pain. To maintain lasting SCS, epidural electrode leads must be replaced sometimes due to problems like lead breakage. However, in lead replacement, guiding the new lead to the original position may be difficult because granulation tissue sheath forms around the lead. We encountered a surgical case where we inserted new leads through tissue sheaths forming around the old leads from the epidural space to the thoracolumbar fascia; the lead was smoothly introduced to the original place. This procedure is simpler than previously reported techniques. Here, we report the detailed surgical procedure and review the relevant literature.

Hemorrhagic changes in a dural arteriovenous fistula are typically associated with cortical venous reflux and occur as intracerebral or subarachnoid hemorrhages. A convexity dural arteriovenous fistula (DAVF) usually flows directly into the cortical veins and exhibits cortical venous reflux. Herein, we report a rare case of a convexity DAVF without cortical venous reflux presenting with a pure acute subdural hematoma. A 19-year-old man complaining of headache without any history of head injury was diagnosed with a left acute subdural hematoma on magnetic resonance imaging (MRI) and referred to our hospital. The patient was conscious and exhibited no neurological signs. The MRI did not reveal any possible abnormalities leading to hemorrhage. Cerebral angiography revealed a dural arteriovenous fistula in the left parietal cranium with a feeder from the middle meningeal artery and a drainer into the main transverse sinus via a diploic vein. Part of the shunt blood flowed into the superior sagittal sinus from the meningeal vein; however, there was no reflux into the cortical vein or stasis of the cerebral vein, suggesting venous hypertension. A convexity DAVF was diagnosed as the source of bleeding, and transarterial embolization was performed. The patient recovered without any neurological deficits. In the absence of trauma, an acute subdural hematoma requires an appropriate evaluation of the vascular lesions and a treatment plan.

Intramedullary spinal cord abscess is a rare and severe infectious disease characterized by devastating neurological deficits. We report a case of cervical intramedullary spinal cord abscess in a 74-year-old diabetic male with a 3-day history of neck pain and weakness in the right lower extremity. Magnetic resonance imaging revealed a ring-shaped contrast lesion in C3-C6 of the cervical spinal cord with extensive edema. Further, 1 day after admission, he became comatose (Glasgow Coma Scale E1VtM1), and a computed tomography head scan revealed hydrocephalus. Despite emergency ventricular drainage, the patient's level of consciousness remained unchanged. Magnetic resonance imaging performed 1 day after surgery revealed bilateral intracranial extension of the abscess into the thalamus and caudate nucleus. The patient died 19 days after admission. Our report is the first case of extensive brain abscess development over a short period. Based on our experience, prompt administration of antibiotics and emergency abscess drainage of the cervical cord (and ventricular drainage, if necessary) are recommended in cases of neurological deterioration in patients with cervical intramedullary spinal cord abscess.

Stereotactic electroencephalography (SEEG) is an increasingly popular surgical modality for localizing the epileptogenic zone. Robot-guided stereotactic electrode placement has been covered in Japan by National Health Insurance since 2020. However, several surgical devices, such as the anchor bolt (a thin, hollow, metal shaft that serves as a guide screw or fixing for each electrode), have not been approved. A 14-year-old female who underwent SEEG for intractable epilepsy and required additional surgery to remove a retained depth electrode from the skull after the SEEG monitoring was finished. She had uncontrolled focal seizures consisting of nausea and laryngeal constriction at the onset. After a comprehensive presurgical evaluation, robot-guided stereotactic electrode implantation was performed to evaluate her seizures by SEEG. Nine depth electrodes were implanted through the twist drill hole. The electrodes were sutured to her skin for fixation without anchor bolts. When we attempted to remove the electrodes after 8 days of SEEG monitoring, one of the electrodes was retained. The retained electrode was removed through an additional skin incision and a small craniectomy under general anesthesia. We confirmed narrowing of the twist drill hole pathway in the internal table of the skull due to osteogenesis, which locked the electrode. This complication might be avoided if an anchor bolt had been used. This case report prompts the approval of the anchor bolts to avoid difficulty in electrode removal. Moreover, approval of a depth electrode with a thinner diameter and more consistent hardness is needed.

Tuberculum sellae meningiomas commonly present as bitemporal hemianopia and loss of visual acuity due to optic nerve compression. Two female patients (48 and 58 years old) presented with a small scotoma at the lower visual field center due to tuberculum sellae meningioma (25 and 10 mm, respectively). Despite the fact that their visual field defect was not very large, daily activities, including walking or reading were hindered. By the total removal of the tumors in both patients, the scotoma was cured and daily activities recovered. When patients exhibit visual deficits, especially in the lower center fields, surgical removal should be considered even if the tumors are small and visual deficits are limited because improvement of both vision and daily activities can be achieved.

Although true subarachnoid hemorrhage (SAH) is an atypical complication owing to suicide by hanging, pseudo-SAH can often develop because of hypoxic encephalopathy. Therefore, differentiating pseudo-SAH from true SAH using brain computed tomography (CT) is often challenging. In Japan, an individual's cause of brain death must be determined to be eligible for organ donation, regardless of whether true SAH is involved or not. Herein, we report a case of SAH confirmed by magnetic resonance imaging (MRI) in a patient with brain death owing to hypoxic encephalopathy following suicide by hanging. A 48-year-old man attempted suicide by hanging. Upon arrival at the hospital, he developed pulseless electrical activity with apnea. Although spontaneous circulation returned within a few minutes of his arrival, spontaneous breathing did not recover. The patient was in deep comatose state without response to pain stimulation, brainstem reflexes, or electrical activities on an electroencephalogram. Consequently, the patient met diagnostic criteria for clinical brain death based on the Japanese organ transplantation law. Brain CT revealed global hypoxic injury and high density in the basal cisterns and subarachnoid space. Brain MR T2*-weighted imaging revealed low intensity at the left Sylvian fissure underlying the hematoma. These findings indicated brain death owing to hypoxic encephalopathy following hanging, and incidental true SAH was confirmed by MRI. Donor surgery and organ transplantation were performed. Spontaneous SAH can often develop secondary to hanging, and brain MRI can effectively determine whether the cause of brain death involves true SAH.

Carotid webs cause ischemic stroke in young people and are associated with a high rate of stroke recurrence. Histopathological examination is crucial for clarifying the pathogenesis and mechanisms underlying the occurrence of carotid webs, although the mechanisms generally remain unclear. Here, we report a case of a symptomatic carotid web in a woman in her 50s who had a medical history of two ischemic strokes. She was diagnosed with a right carotid web and underwent carotid endarterectomy 18 days after the second stroke. Histopathological examination clearly revealed several phases of intimal hyperplasia. Furthermore, a thrombus attached to the carotid web showed invasion by fibroblasts and capillaries, and organization had begun. We presume that after the appearance of the carotid web, the thrombus formed by stagnant flow and became organized, causing the carotid web to grow and change in shape.

We report a rare case of adult-onset sacral meningocele where compression triggered a specific headache. A 46-year-old woman presented with a headache, which worsened when she was in a sitting or supine position. A subcutaneous mass was observed on her left buttock, the compression of which also induced headache. No neurological deficits were evident. Lumbar and sacral magnetic resonance imaging demonstrated a meningocele in the left dorsal buttock, connecting to the sacral cerebrospinal fluid (CSF) space, and spinal computed tomography revealed sacral dysplasia. Initial meningocele resection improved the patient's headache, but the cyst recurred 2 years later. Following repeated surgery to reinforce the meningocele orifice, the headache was relieved and has been absent for more than 6 years. The headache was due to intracranial pressure fluctuations due to CSF influx into and drainage from the meningocele. Meningocele development in adulthood can be owing to a spinal bone defect and pressure load on the spinal dura. Surgical resection can improve symptoms resulting from meningocele, and reinforcement of the orifice using an artificial surgical membrane effectively prevents recurrence.

A 24-year-old woman with hemorrhagic onset moyamoya disease received bilateral indirect bypass surgery 11 years ago. She presented with a life-threatening atraumatic acute right subdural hematoma with temporal lobe intracerebral hemorrhage due to a transdural anastomosis (TDA) aneurysm rupture. We reviewed six cases of rare TDA aneurysms, all of which occurred around the temporal base. TDA aneurysms may occur near the main trunk of the middle meningeal artery (MMA) where hemodynamic stress is high. Therefore, we must pay attention to skull base aneurysms that form near the MMA; otherwise, the prognosis would be poor if such an aneurysm ruptured.

Capillary hemangiomas are benign tumors comprising a lobulated proliferation of capillary vessels frequently located in the soft tissues of the neck and head. Spinal intradural capillary hemangiomas are rare, particularly intramedullary lesions. To our knowledge, only 31 cases of spinal intramedullary capillary hemangiomas have been reported. Here, we describe a rare case of a thoracic capillary hemangioma comprising extramedullary and intramedullary components. A 51-year-old male patient presented with bilateral lower extremity numbness and subsequent paraparesis, sensory disturbance, and bladder-bowel dysfunction with a subacute clinical course. Magnetic resonance imaging revealed a mass lesion with intramedullary and intradural extramedullary components at the Th9-10 vertebrae level and widespread spinal cord edema. Contrast-enhanced computed tomography revealed abnormal vessels on the dorsal spinal cord surface. Spinal angiography revealed a light-stained mass lesion fed by the radiculopial artery from the right Th11 intercostal artery. The tumor was resected en bloc, and the histological diagnosis was a capillary hemangioma. Postoperatively, the spinal cord edema diminished, and the patient was discharged from the convalescent rehabilitation ward. Although intramedullary capillary hemangioma is a rare spinal tumor and its preoperative diagnosis is difficult, it should be considered in the differential diagnosis of spinal intramedullary tumors.

Brain tuberculoma and its occurrence within the subarachnoid cisterns is rare in Japan. Serological and cerebrospinal fluid (CSF) examinations and imaging findings lack specificity; thus, preoperative diagnosis is often challenging. This report presents the case of a 70-year-old woman admitted to our hospital with a one-month history of low-grade fever and altered mental status. Based on the CSF analysis and her history of latent tuberculosis infection seven years ago, she was strongly suspected of suffering from tuberculous meningitis (TBM). Consequently, the patient was enrolled in a clinical trial for antituberculosis treatment (ATT). CSF soluble interleukin-2 receptor level decreased from 2,926 U/mL on day 1 to 225 U/mL 42 days after initiating ATT. Her condition improved after five weeks; however, contrast-enhanced T1-weighted magnetic resonance imaging (MRI) revealed multiple enhanced lesions within the basal subarachnoid cisterns 25 days after admission. As the number and size of these lesions increased, a biopsy confirmed brain tuberculoma diagnosis, and the treatment was continued. In conclusion, when intracisternal scattered mass lesions are identified during TBM treatment, we should consider the possibility of tuberculoma developments arising from a paradoxical response (PR) during the treatment. Serial MRIs are crucial in monitoring PR development in cisternal tuberculomas, an extension of severe TBM. Finally, a PR can be effectively managed by continuing ATT with adjunctive corticosteroids.

M1 fenestration of the middle cerebral artery is rare. We present two patterns of acute thromboembolic conditions in M1 fenestrations treated with mechanical thrombectomy. Case 1 was a male in his 60s presenting with right hemiparesis and aphasia. Angiography showed acute left M1 proximal occlusion; the first direct aspiration revealed two parallel routes, and the second aspiration achieved complete recanalization of the left M1 fenestration. Case 2 was a male in his 70s presenting right hemiparesis and aphasia. Angiography revealed a sudden stair-like narrowing of the left M1 in the intermediate part, and a retrograde blood flow cavity was observed on the upper side of the distal part. Mechanical thrombectomy was performed to diagnose the upper limb occlusion of the left M1 fenestration, and successful recanalization was achieved through direct aspiration. Anatomical variations, such as fenestration, should be considered to reduce complication risks.

A dissecting aneurysm in the P4 segment of the posterior cerebral artery (PCA) is extremely rare, and its treatment is sometimes challenging. Endovascular parent artery occlusion (PAO) was performed for an unruptured P4 segment dissecting PCA aneurysm presenting with ischemic stroke and rapid growth. A 70-year-old man was rushed to our emergency department due to a right-sided headache and a visual field defect. Head magnetic resonance imaging showed a right occipital lobe ischemic stroke, with right PCA occlusion and aneurysm formation in the P4 segment. The diagnosis was PCA dissection in the calcarine artery, and oral aspirin was started. Within a week, the dissecting aneurysm had enlarged progressively to 6.2 mm in diameter. Thus, PAO with coils was performed as a preventive measure against aneurysm rupture, assuming that complication risks were low because the tributary area of the dissecting PCA had already infarcted. A 6-Fr guiding sheath was introduced from the right brachial artery to the right vertebral artery, and a microcatheter/microguidewire was placed into the true lumen of the calcarine artery distal to the aneurysm. PAO with coils was performed, and the blood flow to the aneurysm was completely obliterated. After the treatment, the known infarction in the right occipital lobe was enlarged, but no new neurological symptoms developed. The patient was discharged independently on postoperative day 3. Treatment for a distal PCA dissecting aneurysm is challenging. PAO with coils is one of the reasonable choices, especially when a visual field defect has already developed.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a peripheral neuropathy caused by immune-mediated demyelination, causing tremors in 3.9%-58% of affected patients. This neuropathic tremor may persist after treatment and is known to be refractory to conventional medication. We present two cases of neuropathic tremor due to CIDP in which deep brain stimulation (DBS) over a long-term period led to marked improvement. Case 1: A 66-year-old woman presented with severe 2-3-Hz resting, postural, and kinetic tremors of both hands. The tremor was refractory to medication but improved well after bilateral VIM-DBS. However, 2 months after the procedure, the tremor worsened and was accompanied by sensory disturbance in the extremities. A diagnosis of CIDP was made, and treatment with corticosteroids and intravenous immunoglobulin achieved remission 6 months later. Although there was residual tremor after CIDP remission, it has been well controlled by DBS for the last 10 years. Case 2: A 56-year-old man presented with a 6-year history of CIDP after developing sensory dullness and tremors in the extremities. The CIDP had gone into remission 1 year previously and the sensory deficits had improved, but the tremors had gradually worsened: severe 8-12-Hz postural, kinetic, and resting tremors were present in both upper extremities. Right VIM-DBS was performed and the tremors on the left side showed marked improvement. Over the next 8 years, the tremors were well controlled and there were no relapses of CIDP. DBS may achieve long-term improvement of neuropathic tremor caused by CIDP if the CIDP is in remission.

To improve optic nerve function in a patient with progressive visual dysfunction, performing early decompressive and debulking surgery for a metastatic tumor located in the optic canal is essential. The endoscopic endonasal approach could be a practical and effective alternative for lesions in the inferomedial part of the optic canal. A 66-year-old man with a right visual eye field deficit had multiple lesions in the pineal gland, occipital lobe, and right inferomedial optic canal. The optic nerve was distorted by a tumor compressing against the falciform ligament. Although a systemic examination suggested the presence of primary lung cancer, the patient only complained of progressive visual impairment in the right eye. We planned surgery with endoscopic transethmoidal and transsphenoidal approaches to restore visual function and make a pathological diagnosis. During the procedure, we drilled the sella floor, tuberculum sellae, and optic canal and successfully removed the tumor underneath the dura mater. The patient's visual function improved rapidly following surgery, and no complications were observed, such as cerebrospinal fluid leakage. After confirming the pathological diagnosis, the patient subsequently received whole-brain radiotherapy. The endoscopic endonasal skull base approach to the optic canal region could be a practical alternative for treating symptomatic metastatic tumors.

Rheumatoid meningitis (RM) is a rare but serious extra-articular manifestation of rheumatoid arthritis. Due to the absence of specific biomarkers, imaging findings, or guidelines for its detection, the diagnosis of RM is difficult. This report describes a patient of RM diagnosed with an open biopsy and discusses the utility of anticyclic citrullinated peptide antibodies (ACPA) levels in the serum and cerebrospinal fluid (CSF), and contrast-enhanced (CE) fluid-attenuated inversion recovery (FLAIR) images for screening and monitoring RM. A 65-year-old woman presented with a 2-month history of headaches. Imaging studies showed asymmetric meningeal and leptomeningeal involvement seen on brain magnetic resonance imaging (MRI). An open biopsy of the meninges and leptomeninges depicted palisaded and necrotizing granulomatous inflammation, which suggests rheumatoid nodules. Treatment with prednisolone and tocilizumab led to symptom improvement and reduced lesion intensity on follow-up MRI. Throughout the treatment, the ACPA index in her serum and CSF, and the findings of CE-FLAIR images, rather than the CE T1WI, reflected disease activity. For 6 months, the patient has been stable without symptom recurrence. The ACPA index and the CE-FLAIR images were useful for the diagnosis and monitoring of RM. To validate these findings, further studies are necessary.