Initial three-dimensional computed tomography and cerebral angiography fail to identify any aneurysm in 20% of cases of subarachnoid hemorrhage. Basilar artery (BA) perforator aneurysms are rare, and approximately 30%-60% were not identified by initial angiography. A 71-year-old male was transferred with a sudden onset of headache and loss of consciousness. Computed tomography demonstrated subarachnoid hemorrhage, but no ruptured aneurysm was detected. Repeat preoperative cerebral angiography indicated a bifurcation aneurysm of the circumflex branch of the superior cerebellar artery perforator, but microsurgical observation identified the BA perforator aneurysm. If the location of the BA perforator aneurysm cannot be clearly identified, as in this case, repeat angiography should be considered, and the treatment strategy should be decided based on a detailed consideration of the site of the aneurysm.

Idiopathic normal-pressure hydrocephalus (iNPH) is a neurological disorder that typically presents with gait disturbance, cognitive impairment, and urinary incontinence. Although most patients respond to cerebrospinal-fluid shunting, some do not react well because of shunt failure. A 77-year-old female with iNPH underwent ventriculoperitoneal shunt implantation, and her gait impairment, cognitive dysfunction, and urge urinary incontinence improved. However, 3 years after shunting (at the age of 80), her symptoms gradually recurred for 3 months and she did not respond to shunt valve adjustment. Imaging studies revealed that the ventricular catheter detached from the shunt valve and migrated into the cranium. With immediate revision of the ventriculoperitoneal shunt, her gait disturbance, cognitive dysfunction, and urinary incontinence improved. When a patient whose symptoms have been relieved by cerebrospinal-fluid shunting experiences an exacerbation, it is important to suspect shunt failure, even if many years have passed since the surgery. Identifying the position of the catheter is crucial to determine the cause of shunt failure. Prompt shunt surgery for iNPH can be beneficial, even in elderly patients.

Central poststroke pain is a chronic, intractable, central neuropathic pain. Spinal cord stimulation is a neuromodulation therapy for chronic neuropathic pain. The conventional stimulation method induces a sense of paresthesia. Fast-acting subperception therapy is one of the latest new stimulation methods without paresthesia. A case of achieving pain relief of central poststroke pain affecting both the arm and leg on one side by double-independent dual-lead spinal cord stimulation using fast-acting subperception therapy stimulation is presented. A 67-year-old woman had central poststroke pain due to a right thalamic hemorrhage. The numerical rating scale scores of the left arm and leg were 6 and 7, respectively. Using dual-lead stimulation at the Th 9-11 levels, a spinal cord stimulation trial was performed. Fast-acting subperception therapy stimulation achieved pain reduction in the left leg from 7 to 3. Therefore, a pulse generator was implanted, and the pain relief continued for 6 months. Then, two additional leads were implanted at the C 3-5 levels, and pain in the arm decreased from 6 to 4. Independent setting and adjustments of the dual-lead stimulation were required because the thresholds of paresthesia perception were significantly different. To achieve pain relief in both the arm and leg, double-independent dual-lead stimulation placed at cervical and thoracic levels is an effective treatment. Fast-acting subperception therapy stimulation may be effective for central poststroke pain, especially in cases where the paresthesia is perceived as uncomfortable or the conventional stimulation itself is ineffective.

A 78-year-old man underwent a tracheostomy after embolization for a dural arteriovenous fistula. Seventy days after tracheostomy, arterial bleeding appeared through the tracheal stoma. The bleeding stopped spontaneously. However, two days later, arterial bleeding reappeared, and he was diagnosed with a tracheo-innominate artery fistula (TIF). He then underwent urgent endovascular covered stent placement. After the procedure, there was no bleeding. TIF can be a fatal complication after tracheostomy and it is generally treated with open chest surgery. However, a successful endovascular treatment for TIF has recently been reported and may yield better results.

Primary germ cell tumors of the central nervous system (CNS) typically occur in the neurohypophysis, hypothalamus, or pineal gland and rarely in the spinal cord. We report a case of a spinal intramedullary tumor, which was first detected on magnetic resonance imaging (MRI) 41 months after the initial symptoms, with a verified pathological diagnosis of germinoma. The initial symptom was an abnormal sensation in the left plantar region that gradually worsened, resulting in severe sensory disturbance, difficulty in standing, and even bladder rectal disturbance. Repeated MRI after the onset failed to provide an imaging diagnosis. The MRI was performed 41 months after the onset and revealed a previously undiagnosed, contrast-enhancing spinal intramedullary neoplastic lesion at the Th11-12 level. Gross total resection of the tumor was successfully performed, and the pathology confirmed the diagnosis of pure germinoma. Postoperative chemotherapy, followed by local radiation, was successfully administered. Among primary germinomas of the CNS, occult germinoma that lacks imaging findings suggestive of tumors in the early stages of onset and becomes apparent over time is often reported as a primary neurohypophyseal germinoma, particularly in adolescents presenting with diabetes insipidus. In the present case, the lesion appeared to correspond to a primary occult germinoma of the intramedullary spinal cord.

Blood blister aneurysms (BBAs) or pseudoaneurysms (PAs) in the internal carotid artery (ICA) have fragile necks; therefore, conventional neck clipping is difficult. The standard treatment for BBAs or PAs is trapping with high or low flow bypass. However, there is no consensus on whether or not anterior clinoidectomy should be performed together. Two patients with ruptured ICA PA (anterior protrusion) or BBA (posterior protrusion) were presented to our hospital. Complete trapping was safely performed for both types of aneurysms via extradural anterior clinoidectomy and the extradural approach with dural incision. The advantages of the procedure are 1) safe proximal clipping, 2) early identification of the ICA C3 portion, 3) minimized frontal lobe retraction, 4) optic canal opening to allow mobility of the optic nerve, and 5) dural ring incision to allow mobility of the ICA.

Several studies have reported the coexistence of chronic subdural hematoma (CSDH) and dural arteriovenous fistula (DAVF); however, the association between these two entities remains unknown. A case of coexisting CSDH and DAVF that was successfully treated with burr hole surgery and middle meningeal artery (MMA) embolization is reported herein. We visualized the positional relationship between CSDH and DAVF by fusion three-dimensional computer graphics images reconstructed from multimodal imaging studies, which revealed that the shunt point of the DAVF was far from the burr hole and was in contact with the CSDH membrane at the center of the CSDH. Additionally, the chronological development of CSDH in the presence of DAVF and the complete disappearance of both DAVF and CSDH after MMA embolization were also demonstrated. This study suggests a possible association between recurrent CSDH and DAVF.

The accessory meningeal artery (AMA) demonstrates various potential anastomoses with the external (ECA) and internal (ICA) carotid arteries. However, rarely does the AMA markedly dilate and compensate for ICA blood flow. A 52-year-old woman with nonspecific symptoms was diagnosed with multiple cerebral aneurysms and abnormal blood vessels observed on magnetic resonance angiography. Digital subtraction angiography revealed four aneurysms and anastomoses between the left AMA and inferolateral trunk (ILT). In addition, two sequential severe flexions were observed in the cervical portion of the left ICA. No ischemic lesions were detected on magnetic resonance imaging. In conclusion, we experienced a rare case in which the AMA-ILT anastomosis was highly developed. This case also presented with the unusual characteristics of an anomaly in the extracranial ICA and multiple aneurysms.

We report a rare case presenting radiculopathy caused by unilateral lumbosacral facet abnormality resembling facet interlocking. The patient was a 57-year-old man with no medical and traumatic history. He began to exhibit numbness below his left ankle followed by pain at the left buttock with no obvious causes. He visited our hospital approximately 1 year after the onset of his symptom. Preoperative images revealed a left lumbosacral facet abnormality resembling facet interlocking. His left S1 nerve root was compressed by the dislocated left L5 inferior articular process and bone fragment. His symptom was consistent with left S1 radiculopathy without an obvious stenosis of the left L5 intervertebral foramen; thus, we performed partial facetectomy of the left L5/S1, posterior decompression of the S1 nerve root tunnel, and removal of bone fragment. After the operation, his symptom completely disappeared with satisfactory result. There are several types of congenital facet anomalies in the lumbosacral facet joint; however, congenital unilateral lumbosacral facet abnormality resembling facet interlocking described in this paper has not been reported. His clinical symptom was completely recovered after simple decompression surgery. In this paper, we report the interesting and unique findings of facet abnormality resembling facet interlocking.

Internal carotid artery aplasia or hypoplasia above the cervical bifurcation is rare, occurring in less than 0.01% of the general population. Unilateral neurocristopathy complicated by unilateral internal carotid artery agenesis or hypogenesis has been reported, but bilateral internal carotid artery hypoplasia is rare and scarcely reported. Herein, we report a novel case of Treacher Collins syndrome complicated by bilateral internal carotid artery hypoplasia. A 94-year-old woman presented with complaints of headache and vomiting. Computed tomography revealed a subarachnoid hemorrhage and dysplasia of the bilateral zygoma, mandible, and external auditory meatus. The patient had severe hearing loss and visual impairment. Computed tomography angiography revealed bilateral internal carotid artery hypoplasia and multiple aneurysmal changes in the intracranial arteries. We diagnosed the patient with a ruptured anterior inferior cerebellar artery aneurysm and performed coil embolization. The patient's unique facial features were consistent with neurocristopathy, especially Treacher Collins syndrome. Developmental anomalies of neural crest cells can present as vascular abnormalities and craniofacial malformations. Special care is required for endovascular treatment and airway management in cases of neurocristopathy because of the specific craniofacial anomalies.

Nilotinib, one of the tyrosine kinase inhibitors, has been used to treat chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Nilotinib-associated cerebral arterial occlusive disease, which is treated with medicine with/without bypass surgery or stenting, has been sporadically reported to occur. The mechanism of the nilotinib-associated cerebral disease has not been clarified and is still controversial. Here we present the case of a 39-year-old woman with Ph+ ALL treated with nilotinib, which led to symptomatic intracranial arterial stenosis. We performed high-flow bypass surgery and observed the arterial stenotic change in the stenotic portion intraoperatively, whose findings strongly supported the theory of atherosclerosis and seemed to be irreversible.

Melanoma carries a high risk of brain metastasis. A small subset of metastatic melanomas, known as amelanotic melanomas, does not present black coloration, reflecting a lack of melanin pigmentation. Here, we report a case of B-Raf proto-oncogene (BRAF) V600E mutation associated with a metastatic brain tumor caused by the amelanotic melanoma. A 60-year-old man was transferred to our department following acute onsets of left upper limb paralysis and convulsion. In the brain imaging, multiple lesions in the right frontal lobe and left basal ganglia were detected, and the presence of an enlarged left axillary lymph node was revealed. Consequently, we removed the right frontal lesion and performed a biopsy of the left axillary lymph node. Histological analysis of both specimens indicated an amelanotic melanoma, and genetic testing revealed a BRAF V600E mutation. The residual intracranial lesions were treated with stereotactic radiotherapy and molecular-targeted therapy, with dabrafenib and trametinib as the systemic treatment. Based on the Response Evaluation Criteria in Solid Tumors, we determined that the patient achieved complete remission (CR) under uninterrupted molecular-targeted therapy over a period of 10 months. After the temporary withdrawal of dabrafenib and trametinib to avoid hepatic dysfunction, a new intracranial lesion appeared. CR of this lesion was achieved following reinstatement of the two drugs. These results suggest that, under limited conditions, molecular-targeted therapy can produce a sustained response against the intracranial metastasis of melanoma, and the therapy with reduced dose is still effective against a recurrent case after cessation of the therapy due to the toxicity.

Diffusely infiltrative midline gliomas are known to have a poor prognosis. The standard treatment for typical diffuse midline glioma in the pons is local radiotherapy as surgical resection is inappropriate. This case reports a brainstem glioma in which stereotactic biopsy and foramen magnum decompression were concomitantly performed to confirm the diagnosis and improve symptoms. A 23-year-old woman was referred to our department with a chief complaint of headache for six months. Magnetic resonance imaging (MRI) showed diffuse T2 hyperintense swelling of the brainstem with the pons as the main locus. Enlargement of the lateral ventricles was observed because of cerebrospinal fluid obstruction out of the posterior fossa. This was atypical for a diffuse midline glioma in terms of the longstanding slow progression of symptoms and patient age. Stereotactic biopsy was performed for diagnosis, and foramen magnum decompression (FMD) was concomitantly performed to treat the obstructive hydrocephalus. The histological diagnosis was astrocytoma, IDH-mutant. Post-surgery, the patient's symptoms were relieved, and she was discharged on the fifth day after surgery. The hydrocephalus was resolved, and the patient returned to normal life without any symptoms. The tumor size follow-up with MRI demonstrated no marked change for 12 months. Even though diffuse midline glioma is considered to have a poor prognosis, clinicians should contemplate if it is atypical. In atypical cases like the one described herein, surgical treatment may contribute to pathological diagnosis and symptom improvement.

Middle meningeal arteriovenous fistula (MMAVF) is a shunt between the middle meningeal artery and the vein surrounding the artery. We report an extremely rare case of spontaneous MMAVF; then, we evaluated the effectiveness of trans-arterial embolization for spontaneous MMAVF and the possible cause of spontaneous MMAVF.

A 42-year-old man with tinnitus, a left temporal headache, and pain surrounding the left mandibular joint was diagnosed with MMAVF on digital subtraction angiography. Trans-arterial embolization with detachable coils was conducted, which resulted in a fistula closure and symptoms' diminishment. The cause of MMAVF was thought to be the rupture of the middle meningeal artery aneurysm.

A middle meningeal artery aneurysm can be a cause of spontaneous MMAVF, and trans-arterial embolization might be an optimal treatment.