[Postoperative hyperperfusion in a patient with a dural arteriovenous fistula associated with intracerebral hemorrhage: a case report].

A 60-year-old male complained of a severe headache and developed generalized convulsions. He was drowsy at the time of admission and a neurological examination revealed aphasia and right hemianopsia. Plain computed tomography (CT) revealed an intracerebral hematoma in the left occipital lobe. He was treated conservatively, the hematoma passed without increasing and his symptoms gradually improved. Angiography showed a dural arteriovenous fistula (dAVF) in the left occipital region, which was classified as type IV based on Cognard and a varix of the draining vein. He was treated with direct surgery and obliteration of the draining vein. The color of the red vein changed to blue after disconnection of the fistulas by electrocoagulation. However, he experienced aphasia and loss of memory 2 days after the operation. CT and MRI revealed no change, but postoperative I-IMP SPECT demonstrated temporal hyperperfusion in this region. The present report describes a case of transient hyperperfusion occurring after treatment for a dAVF associated with an intracerebral hemorrhage.

Short latency afferent inhibition associated with cortical compression and memory impairment in patients with chronic subdural hematoma.

OBJECTIVE: To evaluate the cortical excitability in patients with mild cortical compression. METHODS: The present study used short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and short latency afferent inhibition (SAI) to evaluate motor cortex excitability in 16 chronic subdural hematoma (CSDH) patients with memory impairment and compared the data with those of 16 healthy controls. RESULTS: SAI was reduced in patients compared with controls (99±14 vs. 47±11% of the test size; p<0.0001, unpaired t-test). CSDH patients tended to have a high resting motor threshold and less pronounced SICI and ICF than controls, but these differences were not significant. Treatment of hematoma improved memory impairment and SAI in CSDH patients with wide individual variations that ranged from an increase of 74% to 17% of test size. CONCLUSION: These findings suggest that measuring SAI may provide a means of probing the integrity of cortical cholinergic networks in a compressed human brain.

Cognitive alteration after carotid revascularization is correlated with cortical GABA(B)-ergic modulations.

The present study evaluates the hypotheses that a GABAergic mechanism underlies neurobehavioral sequelae of carotid stenosis and that it can be reversed by carotid revascularization. We used the Rivermead Behavioural Memory Test (RBMT), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), long interval intracortical inhibition (LICI), and cortical silent period (CSP) to evaluate cognitive function and cerebral cortical excitability in 16 carotid artery stenosis patients with cognitive impairment before carotid arterial stenting (CAS) and 1 month later. We compared the pre- and post-CAS results and those of 16 healthy controls. CSP was prolonged in patients compared with controls (195.8±18ms vs. 157.8±13.9ms; p<0.0001, unpaired t-test). Patients tended to a have high resting motor threshold and less pronounced SICI and ICF than controls, but differences were not significant. Decreased RBMT score was correlated with hyperperfusion and CSP increase after CAS. RBMT score increase was correlated with CSP normalization. LICI showed positive correlation with CSP. CSP may provide a means of probing the integrity of GABA(B)-ergic networks in an ischemic human brain. CSP and LICI are potential tools to explore neuronal function for improvement as well as impairment after carotid revascularization.

Homocysteine levels are associated with hippocampus volume in type 2 diabetic patients.

BACKGROUND: Elevated total plasma homocysteine (tHcy) levels are associated with cognitive dysfunction, in which changes in the hippocampus plausibly play a pivotal role. We tested the hypothesis that elevated tHcy levels are correlated with hippocampus volume and insulin resistance in nondementia patients with type 2 diabetes. MATERIALS AND METHODS: The study included 43 nondementia patients with type 2 diabetes, who were divided into two groups: a high tHcy group (age: 65 ± 8 years, mean ± standard deviation, n = 16) and a normal tHcy group (64 ± 9 years, n = 27). Hippocampus volume was quantified with a computer-assisted analysis using a magnetic resonance imaging (MRI) voxel-based specific regional analysis system developed for the study of Alzheimer's disease (VSRAD), which yields a Z-score as the end point for the assessment of hippocampal volume. Results The Z-score was higher in the high tHcy group compared to the normal tHcy group (P < 0·0001). The fasting plasma glucose (P < 0·01) and insulin (P < 0·0001) concentrations and the homoeostasis model assessment (HOMA) index (P < 0·0001) were higher in the high tHcy group than in the normal tHcy group. Multiple regression analysis showed that the main factors that influenced tHcy levels may be the Z-score and the HOMA index. CONCLUSIONS: Our results indicate that the elevated levels of tHcy in Japanese nondementia patients with type 2 diabetes are characterised by hippocampal atrophy and insulin resistance and that the Z-score and HOMA index may be the primary factors that influence tHcy levels.

Transcranial direct current stimulation decreases convulsions and spatial memory deficits following pilocarpine-induced status epilepticus in immature rats.

PURPOSE: Transcranial direct current stimulation (tDCS) is a recently available, noninvasive brain stimulation technique. The effects of cathodal tDCS on convulsions and spatial memory after status epilepticus (SE) in immature animals were investigated. METHODS: Rats underwent lithium-pilocarpine-induced SE at postnatal day (P) 20-21 and received daily 30-min cathodal tDCS for 2 weeks at P23-36 through a unilateral epicranial electrode at 200µA. After tDCS, convulsions over 2 weeks were estimated by 20-h/day video monitoring. The rats were tested in a water maze for spatial learning at P50-53 and the brains were examined for cell loss and mossy fiber sprouting. RESULTS: Long-term treatment with weak cathodal tDCS reduced SE-induced hippocampal cell loss, supragranular and CA3 mossy fiber sprouting, and convulsions (reduction of 21%) in immature rats. The tDCS treatment also rescued cognitive impairment following SE. CONCLUSIONS: These findings suggested that cathodal tDCS has neuroprotective effects on the immature rat hippocampus after pilocarpine-induced SE, including reduced sprouting and subsequent improvements in cognitive performance. Such treatment might also have an antiepileptic effect.

Electroconvulsive seizure-induced VEGF is correlated with neuroprotective effects against cerebral infarction: Involvement of the phosphatidylinositol-3 kinase/Akt pathway.

The present study demonstrates the cytoprotective effect of electrical convulsive stimulation (ECS) as a potential neuroprotective vascular endothelial growth factor (VEGF) inducer against ischemic insult. Phosphatidylinositol-3 kinase/Akt (PI3K/Akt) is thought to be an important factor that mediates neuroprotection. However, the signaling pathways in the brain in vivo after ECS remain unclear. We measured and compared infarction volumes to investigate the effect of ECS on cerebral infarction induced by permanent middle cerebral artery occlusion in rats. We evaluated the effects of pretreatment with Wortmannin (Wort), a specific PI3K inhibitor of ECS-induced neuroprotection against infarction volumes. To clarify the relationship between PI3K/Akt activation and neuroprotection, we used immunoblot analysis to determine the amounts of p-Akt and VEGF proteins present after ECS with or without Wort treatment. Neuroprotective effects of ECS (pretreatment with a single ECS 6h before ischemia) were prevented by Wort pretreatment, which indicates that the PI3K/Akt pathway may mediate ECS-dependent protection. ECS induced p-Akt and VEGF and ECS pretreatment enhanced ischemia-induced VEGF, both of which were prevented by Wort pretreatment. These results suggest that a single ECS induces p-Akt and that ECS plays an important role in neuroprotection against the cerebral ischemia through VEGF induction.

Cerebral vasculitis associated with amyloid angiopathy: case report.

A 78-year-old female presented with coexisting primary angiitis of the central nervous system (CNS) and cerebral amyloid angiopathy (CAA) manifesting as motor aphasia caused by a left frontal lobe lesion. Magnetic resonance imaging revealed an enhanced lesion with moderate surrounding edema.Technetium-99m propylene amine oxime single-photon emission computed tomography showed decreased cerebral blood flow (CBF) in the lesions, and high serum soluble-interleukin-2 level was detected, suggesting intravascular lymphoma of the CNS. Cerebral biopsy revealed CAA with secondary florid vasculitic appearance. The CBF and neurological symptoms, such as aphasia and dementia, recovered following steroid treatment. Cerebral vasculitis associated with CAA should be included in the differential diagnosis of an unusually enhanced lesion, because timely diagnosis and aggressive treatment are critical to successful recovery in such elderly patients.

The phosphatidylinositol-3 kinase/Akt pathway mediates geranylgeranylacetone-induced neuroprotection against cerebral infarction in rats.

Previous studies demonstrated the cytoprotective effect of geranylgeranylacetone (GGA), a heat shock protein inducer, against ischemic insult. Phosphatidylinositol-3 kinase/Akt (PI3K/Akt) is thought to be an important factor that mediates neuroprotection. However, the signaling pathways in the brain in vivo after oral GGA administration remain unclear. We measured and compared infarction volumes to investigate the effect of GGA on cerebral infarction induced by permanent middle cerebral artery occlusion in rats. We evaluated the effects of pretreatment with 5-hydroxydecanoate (5HD), a specific mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel inhibitor; diazoxide (DZX), a selective mitoK(ATP) channel opener and wortmannin (Wort), a specific PI3K inhibitor of GGA-induced neuroprotection against infarction volumes. To clarify the relationship between PI3K/Akt activation and neuroprotection, we used immunoblot analysis to determine the amount of p-Akt proteins present after GGA administration with or without Wort treatment. Neuroprotective effects of GGA (pretreatment with a single oral GGA dose (800 mg/kg) 48 h before ischemia) were prevented by 5HD, DZX and Wort pretreatment, which indicates that the selective mitoK(ATP) channel and the PI3K/Akt pathway may mediate GGA-dependent protection. Oral GGA-induced p-Akt and GGA pretreatment enhanced ischemia-induced p-Akt, both of which were prevented by Wort pretreatment. These results suggest that a single oral dose of GGA induces p-Akt and that GGA plays an important role in neuroprotection against cerebral ischemia through the mitoK(ATP) channel opening.

Visualization of subdural electrodes with fusion CT scan/MRI during neuronavigation-guided epilepsy surgery.

Neuronavigation in epilepsy surgery enables surgeons to accurately resect deep targets inside the brain, especially lesions that are unable to be visually differentiated from adjacent normal brain. The usefulness of visualizing subdural electrodes with postimplantation fusion CT/MRI was investigated. The use of platinum subdural electrodes made it possible to obtain postimplantation MRI. The postimplantation MRI and CT scans were fused on the surgical navigation system workstation to form three-dimensional (3D) images, and the epileptogenic regions were marked using the visualized electrodes. Immediately after a craniotomy was performed, the subdural electrodes were removed and the epileptogenic region was successfully resected using the neuronavigation guide. During neuronavigation-guided surgery to target deep brain epileptogenic lesions adjacent to eloquent areas, which are often invisible, we found visualization of the subdural electrodes with postimplantation fusion CT/MRI very useful.

Superficial temporal artery-to-middle cerebral artery anastomosis with encephalo-duro-myo-synangiosis as a modified operative procedure for moyamoya disease.

BACKGROUND: Various types of revascularization surgery have been performed for moyamoya disease. Although the efficacies of these operations are well recognized, the optimal operative procedure remains undecided. In this report, we describe our modified surgical revascularization procedure for moyamoya disease and retrospectively analyze the results of such surgeries on six sides in six adult patients. METHODS: Our operative procedure, combining direct and indirect bypasses, is a superficial temporal artery to middle cerebral artery anastomosis with encephalo-duro-myo-synangiosis. The encephalo-duro-myo-synangiosis is an indirect bypass combining the encephalo-duro- and encephalo-myo-synangioses. This operative procedure has been used routinely in adult patients since 2002. RESULTS: Perioperative complications were noted in one of the six operations. This complication was transient and no attributive lesions were detected on CT or MRI. Revascularization was seen in cerebral blood flow studies in all patients, and the clinical outcomes were excellent or good. Effective neovascularization through the grafts was observed in all patients in follow-up angiographies. CONCLUSIONS: This operative procedure provides needed revascularization and prevents ischemic deficits. This modified procedure is useful for responding to subsequent additional ischemia in the area of the anterior cerebral artery and should be considered one of the optimal procedures for treating moyamoya disease.

A hemispherotomy for intractable startle epilepsy characterized by infantile hemiplegia and drop attacks.

Startle epilepsy is provoked by unexpected sensory stimuli, mainly auditory, and reveals subsequent tonic posturing of the limbs. We present a case of intractable startle epilepsy with infantile hemiplegia and discuss the indications for a hemispherotomy.

Edaravone, a free radical scavenger, retards the development of amygdala kindling in rats.

This study evaluated the antiepileptogenic effects of edaravone, a newly developed radical scavenger, on the amygdala kindling rats. The afterdischarge duration (ADD), AD threshold (ADT), and seizure severity in animals were measured to study the anticonvulsant effects of edaravone (2mg/kg or 20mg/kg i.p. for 7 days) on fully kindled seizures. Furthermore, for the study of antiepileptogenesis effects of the drug (2mg/kg or 20mg/kg i.p. for 7 days), not only ADD and seizure severity during kindling but also both the pre- and post-kindling ADT were measured. Edaravone neither induces nor inhibits fully kindled seizures regardless of the dose; however high-dose edaravone (20mg/kg) retarded kindling development together with shortened ADD and elevated ADT. The present data suggest that high-dose edaravone has an antiepileptogenic drug effect for the prevention of epilepsy. However, other chronic models and clinical trials are needed to confirm the effects of edaravone on the prevention of human epilepsy.

Intracranial infiltration by recurrent scalp dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) of the scalp is a rare soft tissue sarcoma. A 22-year-old male with DFSP, who had undergone several surgical excisions and radiotherapy, presented with a mild left lower-limb paresis. An MRI scan demonstrated a huge mass extending throughout the frontoparietal convexity. A macroscopically complete removal of the mass was performed. Despite this, there were several recurrences; thereafter, the patient underwent surgery, stereotactic radiosurgery and chemotherapy. The histological findings demonstrated a DFSP that both abutted and occasionally invaded the adjacent brain cortex, while extending along the Virchow-Robin spaces. Due to the highly infiltrating characteristics of DFSP, another approach, such as the use of molecular-targeted agents, will be required to significantly improve the clinical outcome.

A rosette-forming glioneuronal tumor of the spinal cord: the first case of a rosette-forming glioneuronal tumor originating from the spinal cord.

Rosette-forming glioneuronal tumors of the fourth ventricle are rare brain tumors, and only 19 such lesions have been previously reported. This report presents the first case of a rosette-forming glioneuronal tumors arising from the spinal cord. A 44-year-old woman presented with a 15-year history of dissociated sensory disturbance of the lower extremities that gradually spread through her upper extremities. She also experienced continuing motor disturbance. Magnetic resonance imaging demonstrated a mass in the cervicothoracic spinal cord that suggested an intramedullary spinal tumor. A total gross resection of the tumor was performed. As is typical of rosette-forming glioneuronal tumors of the fourth ventricle, this spinal cord example manifested neurocytic and astrocytic components. Neurocytic rosettes were detected in the neurocytic component, and the center of rosettes showed positive immunostaining for synaptophysin. The astrocytic component showed characteristic features of a pilocytic astrocytoma, as is often the case in the fourth ventricle examples.

Induction of collateral circulation by hypoxia-inducible factor 1alpha decreased cerebral infarction in the rat.

BACKGROUND: We recently reported that hypoxia-inducible factor 1alpha (HIF-1alpha), HIF-2alpha and cyclooxygenase 2 naked DNA induced angiogenesis in a rat indirect bypass model. In this work, we investigated whether the collateral circulation induced by HIF-1alpha DNA affected the cerebral infarction. METHODS: We utilized a rat encephalomyosynangiosis (EMS) model and inoculated HIF-1alpha DNA onto the brain surface. These treatments were performed before the cerebral infarction occurred. We thereafter performed middle cerebral artery occlusion on the fifth or tenth day after EMS. RESULTS: A histological section treated with HIF-1alpha DNA for 10 days showed a well-developed collateral circulation (p<0.05) and a reduction in the infarction volume in comparison to the control DNA (p<0.01). CONCLUSION: These results suggest the feasibility of a novel approach for the treatment of cerebral ischemia via the development of therapeutic collateral circulation, in which neovascularization may be indirectly achieved using a transcriptional regulatory strategy.

Possible involvement of interferon beta in post-operative vasculitis restricted to the tumour bed: a case report.

Cerebral vasculitis is a very rare complication after brain tumour surgery. We herein report a case and discuss the origins of this complication. A 52-year-old female was admitted because of motor aphasia due to a left frontal lobe brain tumour. The magnetic resonance imaging (MRI) study revealed a non-enhanced tumour. A partial resection of the tumour and the placement of an Ommaya's reservoir were performed. The pathological diagnosis was an oligoastrocytoma. The patient recovered well without any neurological deficits. Post-operative radiotherapy and the intravenous injection of interferon beta were performed. During these treatments, the patient showed a continued high fever. An MRI scan revealed multiple enhanced lesions in the residual tumour, thus raising suspicions about a post-operative infection. We therefore performed a tumour biopsy and the removal of the exogenous materials. The histopathological diagnosis was vasculitis in the residual tumour. The patient's consciousness and neurological symptoms recovered quickly with the steroid treatment. Following the radiotherapy (50 Gy total), complete remission of the tumour was rapidly obtained and no recurrence was observed. Cerebral vasculitis confined to the tumour bed is an unusual complication; however, this special condition was of critical importance for a successful tumour regression in this patient.

Invited article: surgical management of Moyamoya disease.

OBJECTIVE: Various types of revascularization surgery have been performed for moyamoya disease, and there have been controversies about the surgical procedures. In this report, we introduce our surgical strategy of moyamoya disease and discuss the various surgical procedure options. METHODS: The subjects consisted of 13 consecutive patients (8 children, 5 adults) with moyamoya disease who were surgically treated between 2004 and 2007. The onset symptoms were ischemia (11 patients), hemorrhage (1 patient), or headache (1 patient). We performed modified standard encephalo-duro-arterial-synangiosis on 16 sides in the 8 children and superficial temporal artery-to-middle cerebral artery anastomosis with encephalo-duro-myo-synangiosis combining direct and indirect bypasses on 5 sides in the 5 adult patients. RESULTS: Perioperative complications were noted in 12 (9 patients) of 21 operations (13 patients). Most complications were transient and no attributive lesions were detected on CT or MRI. The clinical outcome was excellent or good and revascularization was seen in cerebral blood flow studies. Effective neovascularization through the grafts was observed in follow-up angiography. CONCLUSIONS: The surgical management of moyamoya disease has various aspects depending on the individual subject and very specific surgical management might be required.

Functional brain mapping during recitation of Buddhist scriptures and repetition of the Namu Amida Butsu: a study in experienced Japanese monks.

BACKGROUND: The invocation Namu Amida Butsu (Nembutsu), voices the hope of rebirth into Amida's Pure Land. In the Nembutsu, Buddhists imagine that they are absorbed into Amida's Pure Land. Shiritori, a Japanese word chain game, is a common task used to activate language related regions in Japanese. The purpose of this study was to identify the regions activated during praying of the Namo Amida Butsu (Nembutsu), and the reciting of Buddhist scriptures (Sutra). MATERIAL AND METHOD: Functional MRI (fMRI) was used to identify the regions activated by the Nenbutsu, the Sutra and the Shiritori in eight highlytrained Japanese monks. RESULTS: The task of repeating the Nenbutsu activates the medial frontal gyrus, which is mainly related to mental concentration and visuospatial attention, similar to the areas activated by meditation. The task of reciting the Sutra activates the left lateral middle frontal gyrus, the right angular gyrus, and the right supramarginal gyrus, which are related to visuospatial attention also involved in the area activated by meditation. CONCLUSION: These results suggest that different types of meditation in Japanese Buddhism showed different brain regional activation. The Nenbutsu activated the prefrontal cortex, and the Sutra activated the left dorsolateral prefrontal cortex and right parietal cortex.

Neuroprotective and antiamnesic effect of donepezil, a nicotinic acetylcholine-receptor activator, on rats with concussive mild traumatic brain injury.

In this study we evaluated the effect of donepezil on the neurodegeneration and behavioral impairments induced by mild traumatic brain injury (MTBI). Donepezil is an acetylcholinesterase inhibitor that is used to treat Alzheimer's disease. Donepezil was given orally to rats subjected to MTBI. Treatment with a single oral dose of donepezil (12mg/kg) immediately after injury significantly attenuated MTBI-induced neuronal death and cognitive impairment as measured by preservation of neurons in the CA1 region of the hippocampus and a water maze test respectively. However, these neuroprotective effects were prevented by concomitant injection of mecamylamine, a nicotinic acetylcholine-receptor (nAChR) antagonist, indicating that protection is mediated by nAChR activation.