Comparative Analysis of Patients Undergoing Microvascular Decompression for Trigeminal Neuralgia Caused by Solely Arterial or Solely Venous Compression.

OBJECTIVE: Trigeminal neuralgia (TN) due to venous compression is far less common than that due to arterial compression, and its pathogenesis is less clear. We investigated the clinical and imaging features of TN caused by solely venous compression by measuring the morphologies of the posterior cranial fossa (PCF) and the trigeminal nerve. METHODS: We retrospectively reviewed records of TN patients who underwent microvascular decompression at our institution and extracted cases with solely arterial or solely venous compression. Preoperative magnetic resonance imaging was used to find the length (Y), width (X), height (Z), and volume (V) of the PCF, the angle between the trigeminal nerve and pons, and the distance between Meckel's cave and the root entry zone of the trigeminal nerve. RESULTS: Of 152 patients, 24 had TN caused solely by venous compression. The value of Y was significantly smaller in the venous group than the arterial group (P < 0.01). The trigeminal nerve and pons was significantly smaller in the venous group (P < 0.01). We hypothesized that TN patients with solely venous compression had a characteristic PCF morphology with a short anteroposterior diameter (Y), such that age-related changes in brain morphology could alter the course of the trigeminal nerve and cause compression by a vein. CONCLUSIONS: The morphological features of the PCF differed between patients with TN of venous and those with TN of arterial etiology. Age-related changes in brain morphology and changes of course of the trigeminal nerve may also add to the possibility of developing TN, especially of venous etiology.

Histopathological Examination of a Symptomatic Carotid Web: A Case Report.

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.

Long-term efficacy and safety of perampanel as an add-on therapy in patients with epilepsy.

BACKGROUND: Perampanel (PER) is a newly developed amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor antagonist that has been globally approved for the treatment of both focal and generalized seizures. The efficacy and safety of PER have only been reported over short periods of treatment so far. This study aims to clarify the long-term efficacy and safety of PER as an add-on therapy. METHOD: This retrospective observational study investigated 176 epilepsy patients who received PER as add-on medical therapy in two Japanese epilepsy centers between June 2016 and July 2022. The adherence, seizure frequency, and plasma concentration of PER were evaluated at three time points: 6 months, 12 months, and 24 months or longer after the start of adjunctive PER treatment. RESULTS: 112 patients undergoing PER treatment were evaluated at 6 months, 86 were evaluated at 12 months, and 52 were evaluated at 24 months or longer. Overall, 42.9 % (48/112), 45.4 % (40/86), and 44.2 % (23/52) of the patients were seizure-free at 6, 12, and 24 months or longer, respectively. The rate of PER tolerance was 78.3 %, 69.9 %, and 54.7 % at 6, 12, and 24 months or longer, respectively. At the latest timepoint, the seizure-free group was taking a significantly lower dose of PER than the seizure-remnant group, and the number of anti-seizure medications (ASMs) was associated with seizure outcomes. In addition, the seizure-free rate was significantly higher in patients who received PER as a first add-on than in those who received it as a late add-on. No significant difference was found in the plasma concentration of PER between the seizure-free and seizure-remnant groups at 24 months or longer. Among the patients receiving PER at dose of 2 mg, however, the plasma concentrations were significantly higher in the seizure-free group than in the seizure-remnant group (282.7 ± 109.8 µg/ml vs 94.7 ± 54.9 µg/ml, p = 0.0024). CONCLUSION: This long-term retrospective observational study provides evidence of the efficacy and safety of PER over 2 years treatment period in Japan. Notably, patients who started on PER as the first add-on showed a better seizure outcome than those who received it as a late add-on over the long term. Measured plasma concentrations may provide valuable guidance for the management of patients. Higher plasma concentration at low dose PER may suggest the better seizure control.

Long-term prognosis of 452 moyamoya disease patients with and without revascularization under perfusion-based indications.

OBJECTIVES: To evaluate the long-term outcomes of patients treated under our perfusion-based strategy and assess whether conservative treatment without surgical treatment under our strategy is acceptable. MATERIALS AND METHODS: A total of 315 adult and 137 pediatric MMD patients (follow-up period ≥ 3 years from 2001 to 2020) were included. Follow-up events in each patient group (pediatric or adult, surgically treated or conservatively treated) were evaluated and compared to each other using a log-rank test. Risk factors for stroke and nonstroke events were also investigated using a multivariate Cox proportional hazard model. RESULTS: In adult-onset patients, the stroke event rates (person-year %) were not different between surgically treated patients and conservatively treated patients (2.00 % vs. 1.59 %, p = 0.558); however, conservative patients showed a higher stroke rate than surgically treated hemispheres (0.34 %; p = 0.025) and hemorrhagic stroke was the major type (18/26, 69.2 %). Hemorrhagic onset was associated with increased risk of stroke in adults (hazard ratio (95 % confidence interval) = 2.43 (1.10-5.36)). In pediatric-onset patients, no conservatively treated patients experienced stroke; however, nonstroke events occurred more frequently than in surgically treated hemispheres (4.86 % vs. 1.71 %, p = 0.020 for transient ischemic attack; and 7.91 % vs. 1.31 %, p < 0.001 for asymptomatic progression on magnetic resonance angiography). CONCLUSIONS: In adult patients, conservatively treated patients experienced stroke more frequently, especially hemorrhagic stroke. An additive strategy to prevent stroke in hemorrhagic-onset patients without hemodynamic disturbance seems to be needed. Pediatric patients with mild hemodynamic disturbance can be safely observed without initial surgical intervention, but close follow-up for disease progression is necessary.

Ischemic Stroke with Multiple Cerebral Artery Stenosis in a Patient with an Anaplastic Astrocytoma during Bevacizumab Treatment: A Case Report.

It has been reported that bevacizumab, an agent administered as an adjuvant therapy for high-grade gliomas, causes thromboembolic complications. We report a cerebral infarction with newly developed cerebral artery stenosis occurring during treatment with bevacizumab for an anaplastic astrocytoma. A 48-year-old female underwent excision surgery for an anaplastic astrocytoma on the right temporal lobe and received radiation therapy and chemotherapy with temozolomide. Twenty months after the maintenance therapy, treatment with bevacizumab was introduced for tumor recurrence. After the 14th course of bevacizumab at 6 months, 27 months after radiation therapy, the patient began experiencing mild right hemiparesis. Magnetic resonance imaging revealed scattered cerebral infarcts on the left frontal lobe and diffuse cerebral artery stenosis of the bilateral internal carotid artery system both inside and outside the radiation-treated area. Antiplatelet medication was commenced, and there was no recurrence of ischemic stroke. The morphological transition of the cerebral arteries should be carefully monitored via magnetic resonance angiography during post-radiation treatment with bevacizumab.

[A Rare Case of Radiation-Induced Meningioma that Occurred Only 3 Years and 6 Months after Radiation Therapy for Oligodendroglioma].

We describe an adult case of radiation-induced meningioma(RIM)that was identified within a short interval from the initial treatment for brain tumor. A 45-year-old woman, who had tumor resection followed by radiation therapy for right frontal oligodendroglioma, showed a small enhanced lesion on the right frontal region 3 years and 6 months after the initial radiation therapy. The pathological diagnosis was meningioma(World Health Organization(WHO)grade I)and the Ki-67 labeling index was 3.2%. Most RIMs occur after a long period of time(18.7-24.0 years on average)following radiation therapy. Several studies have suggested that the period before the occurrence of RIM is correlated with both the age of a patient and the radiation dose at the time of radiation therapy. A patient that receives a higher dose of radiation at a younger age has a higher risk of RIM occurrence. In this case, the patient was middle aged;however, she was exposed to a high dose of radiation(54 Gy). High-dose radiation might induce the early onset of RIM. Recently, treatments for glioma have been developed, thus resulting in an increased long-term survival rate among patients. Physicians must pay attention not only to the recurrence of gliomas but also to the occurrence of RIMs.