Serum perampanel levels in patients with seizures are not affected by hemodialysis.

Perampanel belongs to a novel class of antiseizure medications (ASMs). Studies examining the effect of hemodialysis on perampanel serum levels in clinical settings are lacking. We aimed to evaluate the changes in serum perampanel levels during hemodialysis. We studied patients with seizures who received oral perampanel between April 2020 and March 2023 and whose serum concentration of perampanel was measured before and after hemodialysis. We analyzed the serum concentrations of levetiracetam and lacosamide for comparison. Fourteen patients, with a mean age of 76.1 ± 7.88 years, were included. The dose of perampanel was 2.14 ± 1.27 mg. The hemodialysis clearance rate of perampanel, levetiracetam, and lacosamide was 0 ± 13%, 69 ± 11%, and 59.6 ± 8.2%, respectively. The post-dialysis CD ratio decreased significantly with levetiracetam but not with perampanel. Adverse but acceptable effects of perampanel were observed in two patients. The serum concentrations of several ASMs have been shown to be reduced during hemodialysis. Our study revealed that the serum perampanel concentration does not decrease during hemodialysis. Owing to the low rate of adverse effects and the stability of perampanel serum concentration during hemodialysis, perampanel could be a favorable choice as an ASM for patients with seizures undergoing hemodialysis. PLAIN LANGUAGE SUMMARY: Our study looked at how hemodialysis affects the serum levels of perampanel, a new type of medication for seizures. In 14 patients who started treatment between April 2020 and March 2023, perampanel serum levels did not decrease during hemodialysis, unlike other seizure medications. This shows that perampanel can be a good option for patients with seizures who need hemodialysis, with fewer side effects compared to other medications.

Ultrashort Echo Time Magnetic Resonance Angiography as an Alternative Tool to Digital Subtraction Angiography in the Follow-up of Stent-Assisted Coil Embolization Outcomes.

BACKGROUND: Follow-up of aneurysms treated with stent-assisted coil embolization has been performed using digital subtraction angiography (DSA) because in time-of-flight magnetic resonance angiography, metal artifacts from the stent often affect visualization. OBJECTIVE: To confirm whether ultrashort echo time (TE) MRA may be an alternative for DSA during follow-up. METHODS: Patients with unruptured aneurysms initially treated with stent-assisted coil embolization between April 2019 and March 2021 were enrolled. After 3 months of treatment, follow-up DSA and ultrashort TE MRA were performed. All images were independently reviewed by neurosurgeons to evaluate in-stent flow and rated from 1 (not visible) to 4 (excellent). Aneurysmal embolization status was assessed as complete obliteration, residual neck, or residual aneurysm. Ultrashort TE MRA findings were classified as evaluative or nonevaluative state based on the presence of metal artifacts. We investigated the types of aneurysms that were evaluative and the agreement between ultrashort TE and DSA. RESULTS: Overall, 89 aneurysms were examined, of which 74% (n = 66) were classified as evaluative on ultrashort TE. Significant differences were observed in size and stent type. Evaluative cases had an aneurysm size of <7 mm ( P = .0007) and a higher rate of Neuroform Atlas ( P = .0006). The rate of agreement between ultrashort TE with evaluative state and DSA was 95%. CONCLUSION: Ultrashort TE MRA could evaluate an embolization status treated with stenting, and the findings are in excellent agreement with those of DSA. Aneurysms measuring <7 mm and treated with Neuroform Atlas are evaluative on ultrashort TE, and DSA might not be necessary.

Gadolinium-enhanced MR improved motion sensitized driven equilibrium (iMSDE) for intracranial vessel imaging in giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) generally affects extracranial large and medium-sized vessels. It rarely causes intracranial vessel stenosis, presenting as cerebral infarction (CI). Consequently, accurate diagnosis of CI induced by GCA is often challenging. Improved motion-sensitized driven-equilibrium (iMSDE) is one of the advanced high-resolution magnetic resonance (MR) vessel wall imaging techniques that enables direct visualization of the vessel wall because of a strong reduction in blood flow artifacts, leading to higher quality images. Herein, we effectively used gadolinium-enhanced MR iMSDE imaging to diagnose a patient presenting with recurrent CI due to right intracranial internal carotid artery (ICA) stenosis as GCA. CASE DESCRIPTION: A 64-year-old man with polymyalgia rheumatica for several years and who had experienced CI due to moderate intracranial ICA stenosis one year ago, presented to the emergency room with dysarthria and left hemiparesis. Diffusion-weighted MR imaging showed high signals in the right centrum ovale, and MR angiography revealed severe stenosis of the right intracranial ICA. Gadolinium-enhanced MR iMSDE imaging showed marked concentric enhancement in the vessel wall of the right stenosed ICA, which led to a definitive diagnosis of GCA via biopsy from the right superficial temporal artery. The patient's symptoms gradually improved after initiation of steroid treatment. Three months later, gadolinium-enhanced MR iMSDE imaging revealed improvement in the contrast enhancement in the vessel wall and vascular stenosis. CONCLUSION: Gadolinium-enhanced MR iMSDE imaging is useful to diagnose and evaluate GCA with intracranial vessel involvement.

Characterization of Moyamoya and Middle Cerebral Artery Diseases by Carotid Canal Diameter and RNF213 p.R4810K Genotype.

OBJECTIVES: It is sometimes difficult to differentiate middle cerebral artery disease from moyamoya disease because the two can present similarly yet have different treatment strategies. We investigated whether the presence of a narrow carotid canal and the RNF213 mutation can help differentiate between the two phenotypes. POPULATION AND METHODS: We analyzed 78 patients with moyamoya disease, 27 patients with middle cerebral artery disease, and 79 controls from 2 facilities. The carotid canal diameter was measured using computed tomography. The p.R4810K mutation was genotyped by TaqMan assay. A receiver operating characteristics analysis was performed to assess the significance of the carotid canal diameter for the accurate diagnosis of moyamoya disease. RESULTS: The carotid canal diameter was significantly narrower in patients with moyamoya disease than in controls. The optimal cutoff values were 5.0 mm for adult males and 4.5 mm for adult females and children (sensitivity: 0.82; specificity: 0.92). Among the patients with middle cerebral artery disease, 18.5% and 25.0% of the affected hemispheres had the p.R4810K mutation and narrow canal (i.e., below the cutoff), respectively, whereas only 3.1% of those had both. Contrastingly, 68.8% of the affected hemispheres in patients with moyamoya disease had both these characteristics. Among the patients with moyamoya disease, those with the p.R4810K mutation tended to have narrower carotid canals. CONCLUSIONS: Although the presence of a narrow carotid canal or the p.R4810K mutation alone could not be used to distinguish those with moyamoya disease from those with middle cerebral artery disease, the combination of these factors could better characterize the two phenotypes.

Plasticity of the bony carotid canal and its clinical use for assessing negative remodeling of the internal carotid artery.

BACKGROUND AND OBJECTIVE: It has long been believed that the bony carotid canal has no plasticity and that a small canal represents a hypoplastic internal carotid artery. We aimed to show whether the carotid canal can narrow according to morphological changes in the internal carotid artery. MATERIALS AND METHODS: The carotid canal diameter was longitudinally measured in seven individuals who underwent carotid artery ligation. As moyamoya disease is known to be associated with negative remodeling of the internal carotid artery, the carotid canal diameter was measured in 106 patients with moyamoya disease, and an association with the outer diameter of the internal carotid artery or a correlation with the disease stage was investigated. The carotid canal was measured by computed tomography (106 patients), and the outer diameter of the artery was measured by high-resolution magnetic resonance imaging (63 patients). The carotid canal area was calculated by the product of the maximum axial diameter and its perpendicular diameter. RESULTS: All seven patients who underwent carotid artery ligation showed narrowing of the carotid canal, and the carotid canal area decreased by 12.2%-28.9% during a mean follow-up period of 4.2 years. In patients with moyamoya disease, the carotid canal area showed a linear correlation with the outer area of the internal carotid artery (r = 0.657, p < 0.001), and a negative correlation with the disease stage (ρ = -0.283, p < 0.001). CONCLUSION: The bony carotid canal has plasticity, and its area reflects the outer area of the internal carotid artery, therefore, it can be used to assess the remodeling of the carotid artery. A narrow carotid canal may not necessarily indicate hypoplastic internal carotid artery.

Fenestration of the cavernous internal carotid artery associated with a persistent primitive trigeminal artery.

Fenestration of the cavernous segment of the internal carotid artery (ICA) is an extremely rare variant with unknown clinical significance. We present two cases of this variant, both of which were associated with a persistent primitive trigeminal artery (PPTA). Large dual channels of the ICA were seen extending from the part immediately distal to the origin of the PPTA to the C3 segment of the ICA. We speculate that coexistence of the two vascular anomalies might be due to failed regression or a remnant of the primitive arterial network during the same early gestation period in which development of the PTA takes place (3-5 mm crown-rump length stage).

The use of 5-aminolevulinic acid to assist gross total resection of pediatric astroblastoma.

PURPOSE: Astroblastoma is an uncommon pediatric neuroepithelial tumor. The prognosis and appropriate treatment of astroblastoma were not well understood. Previous reports suggested the best treatment for astroblastoma is surgical total resection. The authors report a case of pediatric astroblastoma that underwent gross total resection with the use of fluorescent guidance by 5-aminolevulinic acid (5-ALA). CASE REPORT: A 13-year-old girl presented with the tumor that was well-circumscribed cystic and solid mass with marked gadolinium enhancement in the right occipital lobe. At surgery, fluorescence of the tumor was clearly distinctive from the normal cerebral tissue. All fluorescent tissue including residual cyst wall was removed. Postoperative MRI showed gross total resection of the tumor. No serious side effect or complications occurred. The histopathologic diagnosis was suggestive of astroblastoma. The patients had no evidence of recurrence of tumor without adjuvant radiotherapy during the last 1 year of follow-up time. CONCLUSION: 5-ALA is useful to achieve gross total resection including cystic lesion of pediatric astroblastoma. A larger prospective study is warranted to establish the use of 5-ALA in pediatric brain tumor.

Cauda Equina Syndrome Due To Dural Sac Shift with Engorgement of the Epidural Venous Plexus: Rare Complication After Lumbar Microdiscectomy.

BACKGROUND: Several postoperative complications related to lumbar microdiscectomy have been reported, including cauda equina syndrome. However, to the best of our knowledge, postoperative cauda equina syndrome resulting from dural sac shift with engorgement of the epidural venous plexus is yet to be reported. CASE DESCRIPTION: A 71-year-old male patient was referred to our hospital with a chief complaint of pain and sensory disturbance due to the lumbar disc herniation of L5-S1. Microdiscectomy was performed to treat the lumbar disc herniation, and his sensory disturbance improved. However, from postoperative day 2, he started to complain of motor weakness, sensory disturbance of S2, and difficulty in urination. Magnetic resonance imaging showed the dural sac shifted to the bone window of L5-S1 with engorgement of the ventral epidural venous plexus. The dural sac shift was thought to be the cause of postoperative cauda equina syndrome, and laminoplasty was chosen to return the dural sac shift into the spinal canal. Cauda equina syndrome completely resolved after laminoplasty. Postoperative magnetic resonance imaging showed the reduction of the dural sac into the spinal canal. The patient was discharged from the hospital without any residual clinical symptoms. CONCLUSION: We report a rare case of postoperative cauda equina syndrome due to dural sac shift and discuss the nascent mechanism of the dural sac shift focusing on anatomic features of the dural sac. We also propose laminoplasty as an option to treat dural sac shift with engorgement of the epidural venous plexus.

Onyx extravasation during embolization of a brain arteriovenous malformation.

During Onyx embolization to treat brain arteriovenous malformation (AVM), carefully observing the penetration of Onyx to the nidus is important in order to avoid complications such as hemorrhage, ischemia, and difficulty with microcatheter removal. We encountered a case of Onyx extravasation during embolization of a cerebellar AVM confirmed by surgical resection and pathological analysis. The patient was a 44-year-old man with Spetzler-Martin grade I cerebellar AVM who underwent Onyx embolization prior to resection of the brain AVM. While injecting Onyx into the nidus using the "plug-and-push" technique, Onyx extravasation was observed. Onyx injection was paused and subsequently restarted, thereby allowing continuation of embolization. An oblate Onyx cast that was entirely covered in cerebellar tissue was removed during total resection of the AVM, performed the same day. The surgically removed oblate Onyx cast did not contain brain tissue or vessel wall, and immunohistochemical staining against glial fibrillary acidic protein (GFAP) showed Onyx penetration into GFAP-positive cerebellar tissue. Onyx extravasation was confirmed based on intraoperative findings during resection as well as pathological findings. The patient has been followed for four years postoperatively, and adverse events caused by Onyx extravasation have not been observed. Unexpected cast of Onyx, remote from the vascular architecture of the AVM, may represent an intra-parenchymal extravasation.

Bilateral Chronic Subdural Hematoma is Associated with Rapid Progression and Poor Clinical Outcome.

Chronic subdural hematoma (CSDH) has been recognized as a benign disease, but its clinical outcome is not well documented. This study aims to expand the knowledge base regarding the outcome of CSDH. We retrospectively reviewed clinical characteristics of CSDH operated in the Kobe City Medical Center General Hospital between June 2005 and June 2012. Variants included age at onset, sex, laterality, presence of headache, consciousness level, and risk factors for hemorrhage such as malignancy or intake of anticoagulants. A total of 368 cases were analyzed. Six patients (1.4%) had a poor outcome, defined as any morbidity or mortality at 7 days postoperatively. Bilateral hematoma was significantly associated with a poor outcome (p = 0.041). Warfarin use and malignancy, albeit statistically not significant, were more frequently observed in patients with a poor outcome. Bilateral CSDH was observed in 53 patients (14.4%). Age at onset, sex, history of malignancy, anticoagulant use, and antiplatelet use did not differ between bilateral and unilateral CSDH. Recurrence rate was not different between bilateral and unilateral CSDH (14.2% vs. 11.3%), but poor outcome as a result of brain herniation was significantly higher in bilateral than in unilateral hematomas (5.7% vs. 0.3%, p = 0.01). Bilateral CSDH was associated with rapid progression and showed worse outcome as a result of brain herniation in comparison with unilateral CSDH. Urgent trephination surgery for decompression of hematoma pressure may be recommended for bilateral CSDH.

Familial schwannomatosis with a germline mutation of SMARCB1 in Japan.

Schwannomatosis is the third major form of neurofibromatosis (NF) and is distinct from NF1 and NF2. The disease is not well recognized in Asian countries and the role of germline SMARCB1 mutations requires investigation. A 35-year-old Japanese man complaining of headache underwent an MRI examination, which showed a cystic tumor at the left cerebellopontine angle. The tumor was surgically removed and diagnosed as vagus nerve schwannoma. He had a past medical history of multiple schwannomas of the neck, groin and intercostal nerves, which were also treated surgically. He had a family history of multiple schwannomas for his father and sister. Systemic examinations of these family members ruled out a diagnosis of NF1 or NF2, and thus schwannomatosis was suspected. Genetic analysis revealed a germline mutation (c. *82C > T) of SMARCB1, and a somatic mutation of NF2 without loss of heterozygosity at the chromosome 22 locus. This is the first report of familial schwannomatosis associated with a germline mutation of SMARCB1 in an Asian country.

[Cryptococcus Neoformans Var. Gattii meningoencephalitis with cryptococcoma in an immunocompetent patient successfully treated by surgical resection].

Cryptococcosis is a fungal infection, which mainly invades the lungs and central nervous system. In Japan, most cases of cryptococcosis are caused by Cryptococcus neoformans(C. neoformans). Until now, only three cases which the infectious agent was Cryptococcus neoformans var. gattii(C. gattii)have been reported. As compared with cryptococcosis caused by C. neoformans, which is often observed in immunocompromised hosts, cryptococcosis caused by C. gattii occurs predominantly in immunocompetent hosts and is resistant to antifungal drugs. Here, we report a case of refractory cerebral cryptococcoma that was successfully treated by surgical resection of the lesions. A 33-year-old man with no medical history complained of headache, hearing disturbance, and irritability. Pulmonary CT showed a nodular lesion in the left lung. Cerebrospinal fluid examination with Indian ink indicated cryptococcal meningitis, and PCR confirmed infection with C. gattii. C. gattii is usually seen in the tropics and subtropics. Since this patient imported trees and soils from abroad to feed stag beetles, parasite or fungal infection was, as such, suspected. Although he received 2 years of intravenous and intraventricular antifungal treatment, brain cryptococcomas were formed and gradually increased. Because of the refractory clinical course, the patient underwent surgical resection of the cerebral lesions. With continuation of antifungal drugs for 6 months after the surgeries, Cryptococcus could not be cultured from cerebrospinal fluid, and no lesions were seen on MR images. If cerebral cryptococcosis responds poorly to antifungal agents, surgical treatment of the cerebral lesion should be considered.