Koichi Oki

Musashi1 as a marker of reactive astrocytes after transient focal brain ischemia

The synthesis of glial-fibrillary acidic protein (GFAP) or the re-expression of progenitor markers such as Nestin increases in reactive astrocytes after brain ischemia. We investigated the dynamics of reactive astrocytes after transient focal brain ischemia by examining the expression of Musashi1 (Msi1), an RNA-binding protein and another marker of neural stem/progenitor cells. In ischemic striatum induced by middle cerebral artery occlusion (MCAO), an increase in Msi1-immunoreactivity was observed from 2 days after MCAO, persisting until 14 days. The proliferation of Msi1-positive cells was observed from 4 days after MCAO and reached a peak at 7 days. These Msi1-positive cells were regarded as reactive astrocytes based on their co-expression with GFAP or Nestin and their morphology. Msi1-positive cells were located in the peri-infarct area in a region similar, but not identical, to that of Nestin-positive cells. The Msi1(+)Nestin(+) cells were located much closer to the ischemic core than the Msi1(+)Nestin(-) cells. The present study revealed that Msi1-expression, similar to Nestin, is induced after brain ischemia and may be involved in the reactivation of astrocytes, including their proliferation. However, the difference in the distributions of Msi1 and Nestin suggests that some of their features may differ in reactive astrocytes.

Effects of Surgery and Antiplatelet Therapy in Ten-Year Follow-Up from the Registry Study of Research Committee on Moyamoya Disease in Japan

BACKGROUND Despite the common practice of surgery and antiplatelet therapy for the prevention of recurrent stroke in patients with moyamoya disease, the benefit of these treatments is controversial. We analyzed the stroke recurrence rate in the Registry Study of Research Committee on Moyamoya Disease in Japan funded by the Health, Labor and Welfare Ministry of Japan. METHODS An annual follow-up study of the registered cases was continued for 10 years. The rate of recurrent stroke, including cerebral infarction and hemorrhage but not transient ischemic attack and seizure, was evaluated with Kaplan-Meier analysis. RESULTS The proportion of childhood-onset cases decreased in recently registered cases (within 10 years, n = 541) compared to remote cases (> 10 years, n = 735). Among types at disease onset in adult-onset cases, intracerebral hemorrhage decreased recently. In recent cases, the rate of subsequent cerebral hemorrhage was much higher in the hemorrhagic group (10.9 ± 3.3%/5 years) than in the ischemic group (2.0 ± .9%/5 years). The recurrence rate of cerebral infarction was lower in the surgery group (1.8 ± .9%/5 years) than in the nonsurgery group (3.8 ± 2.2%/5 years). In the adult-onset ischemic group, the proportion of surgically treated patients increased and their recurrence rate was lower than that of nonsurgery patients. In the ischemic group, the rate of cerebral infarction was not significantly different between the antiplatelet subgroup and the non-antiplatelet subgroup, whereas the rate of cerebral hemorrhage was higher in the non-antiplatelet subgroup than in the antiplatelet subgroup. CONCLUSIONS Our results suggest revascularization surgery may suppress recurrent ischemic attacks in patients with moyamoya disease.

Metronidazole‐induced encephalopathy and myoclonus: Case report and a review of the literature

We describe a 36‐year‐old man with metronidazole‐induced encephalopathy in the course of alcoholic liver cirrhosis who developed periodic myoclonus on the head and fixed eye position with ocular myoclonus in the vertical direction. Involuntary movements are rare in patients with metronidazole‐induced encephalopathy, because neurological manifestations of metronidazole‐induced encephalopathy usually include ataxic gait, dysarthria and confusion. Involuntary movements including myoclonus should be considered as the clinical manifestation of metronidazole‐induced encephalopathy. In addition, we review the literature of metronidazole‐induced encephalopathy patients who developed myoclonus with regard to the clinical characteristics.

Clinical utility of triptans in the management of headache attributed to dural arteriovenous fistula involving the cavernous sinus.

• Triptans may be effective in alleviating headache attributable to dural arteriovenous fistula involving the cavernous sinus.

Serial changes of corticospinal tract hyperintensity on magnetic resonance imaging from the preclinical stage in amyotrophic lateral sclerosis

Serial changes of corticospinal tract hyperintensity on magnetic resonance imaging from the preclinical stage in amyotrophic lateral sclerosis Tsubasa Takizawa, Gen Shiihashi, Junki Maehara, Koichi Oki, Mayuko Osaka, Hirokazu Fujiwara, Hidenori Ojima, Yuichi Ichinose, Mamoru Shibata, Shinichi Takahashi and Norihiro Suzuki Departments of Neurology, 2 Pathology, 3 Diagnostic Radiology, Keio University School of Medicine, and Department of Internal Medicine, International Catholic Hospital, Tokyo, Japan

The first report of a japanese case of seipinopathy with a BSCL2 N88S mutation

Seipinopathy is an autosomal dominant neurodegenerative disease caused by mutations of the Berardinelli-Seip Congenital Lipodystrophy 2 (BSCL2) gene. We report the first Japanese case of seipinopathy with a heterozygous mutation of p.N88S in the BSCL2 gene. The patient showed bilateral hyperreflexia of the biceps, triceps, brachioradialis, and knee, as well as the pes cavus and distal dominant weakness and atrophy of both arms and legs, suggesting the involvement of both upper and lower motor neurons. Mutations of the BSCL2 gene have been known to cause motor neuron degeneration through endoplasmic reticulum stress. Seipinopathy should be considered in patients with symptoms mimicking amyotrophic lateral sclerosis.

Ipsilateral Facial Tactile Hypesthesia in a Patient with Lateral Medullary Syndrome

BACKGROUND Various sensory impairments have been reported in patients with lateral medullary syndrome, also known as Wallenberg syndrome. The typical sensory impairments experienced by patients with this condition are ipsilateral facial and contralateral trunk and limb thermal hypesthesia and hypoalgesia. Tactile (light touch) sensation is not generally diminished. Here we report the case of a 35-year-old man with lateral medullary infarction who had atypical sensory impairment. METHODS We examined the results from the neurological examination of the patient as well as findings from computed tomography of the head and magnetic resonance imaging. RESULTS Magnetic resonance imaging showed left lateral medullary infarction caused by left posterior inferior cerebellar artery dissection. Neurological examination revealed both tactile and thermal/pain hypesthesia on the left side of the patients face, and thermal/pain hypesthesia on his right upper and lower limbs. CONCLUSION There are two types of tactile sensation: epicritic and protopathic. Facial tactile sensation is usually thought to be associated with epicritic tactile sensation, which travels through principal sensory nuclei of the trigeminal nerve. The protopathic pathway travels down through the spinal tract via the trigeminal nerve and is not considered a primary pathway. However, in this case the protopathic tactile sensation pathway might be involved, and it caused facial tactile hypesthesia. Because most of previous case reports and literature reviews focused only on thermal/pain hypesthesia, we believe that this case provides critical information on the brainstem neuroanatomy, especially for the protopathic tactile sensation pathway in patients with stroke.

Epidemiology of Moyamoya Disease

Moyamoya disease has a high incidence in East Asian countries, and many large-scale epidemiological surveys of this disease have been conducted in East-Asian countries such as Japan and Republic of Korea.

Predictive actors for prolongation of dysphagia in acute stroke

Dysphagia is a common and disabling symptom in stroke patients, and prediction of prolongation of dysphagia in its acute stage is very important from several standpoints, including selection of the treatment strategy, planning of care, and the QOL of the patients.We retrospectively analyzed the data of 33 stroke patients in whom videofluoroscopy (VF) had been performed to check for the swallowing function, and investigated the predictive factors for dysphagia after stroke. Of the 33 patients, 25 patients had had ischemic stroke and 8 had had hemorrhagic stroke. Twenty patients (39%) could take their regular meals orally by the 30th hospital day, while 12 patients (36%) developed pneumonia during the first 30 days of hospitalization. Predictive factors of taking regular diet by oral feeding were 1) consciousness level, 2) location of lesions, and 3) severity of dysphagia as assessed by VF. While a predictive factor for pneumonia was advanced age of the patient. Dysarthria was not a predictor of dysphagia.Comprehensive evaluation of the swallowing function by detailed clinical evaluation and VF should be conducted in acute stroke patients, to enable timely identification and management of dysphagia in these patients.