Minoru Fujiki

Long-term outcomes of pediatric moyamoya disease treated by encephalo-duro-arterio-synangiosis.

To investigate the efficacy of encephalo-duro-arterio-synangiosis (EDAS) for the treatment of pediatric moyamoya disease, we analyzed 11 patients who were followed up for more than 100 months. Among 22 sides in 11 patients, we performed EDAS on 16 sides in 10 pa- tients, encephalo-duro-arterio-myo-synangiosis (EDAMS) on 5 sides in 4 patients and encephalo-myo-synangiosis (EMS) on 1 side. Of the 11 patients, 8 patients showed normal development and had no neurological deficit. The remaining 3 patients showed mild to moderate neurological deficits, but in these cases, pre- and perioperative insults were considered to be attributable to the morbidities. Of 13 sides treated by EDAS, well-developed neovascularization was observed in 12. However, well-developed neovascularization was observed in only 3 out of 6 sides treated by EMS or EDAMS. These data might indicate that EDAS is a therapeutic alternative for the surgical treatment of pediatric moyamoya disease.

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.

Astroglial activation accompanies heat shock protein upregulation in rat brain following single oral dose of geranylgeranylacetone.

Geranylgeranylacetone (GGA), more commonly known as an antiulcer agent, reportedly induces the heat shock protein 70 (HSP70) family in the gastric mucosa, liver and heart of rats. However, it has not been reported whether HSPs, and other factors that contribute to neuroprotection, are inducible in the brain following a single oral dose of GGA. The present study evaluated the consequences of oral GGA on astrocytic activation and the expression of HSP and revealed that a single oral dose caused a transient increase in the immunoreactivity (IR) of HSP70 and glial fibrillary acidic protein (GFAP) in the hippocampus of the rat brain.

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.

Neuroprotective effect of donepezil, a nicotinic acetylcholine-receptor activator, on cerebral infarction in rats.

This study evaluated the potential effect of donepezil, which is known as an acetylcholinesterase inhibitor used for treatment of Alzheimers disease, against cerebral infarction induced by permanent left middle cerebral artery (MCA) occlusion. Donepezil was given orally in various regimens, prior to MCA occlusion in rats. Pretreatment with a single oral dose of donepezil (12 mg/kg), 2 h before ischemia, significantly attenuated cerebral infarction volume (165.5 +/- 105.3 vs. 377.1 +/- 48.5 mm(3); P < 0.05). These neuroprotective effects were prevented by coinjection with mecamylamine, a nicotinic acetylcholine-receptor (nAChR) antagonist, indicating that protection was mediated by nAChR activation.

Corticospinal direct response to transcranial magnetic stimulation in humans

The corticospinal motor evoked potential (MEP) response to transcranial magnetic stimulation of the motor cortex was investigated in comparison with the direct (D) response to electrical stimulation of the exposed motor cortex from the spinal epidural space in 7 neurologically normal patients during brain tumor surgery. The D response during operation was obtained by transcranial magnetic stimulation of the scalp over the areas of the cerebral motor cortex, the hand or arm areas. The magnetic induced D response showed a conduction velocity of 50.5-72.7 m/sec and was resistant to anesthesia and unaffected by muscle relaxants and tolerant to high frequency (500 Hz) paired magnetic stimulus, and the latencies of magnetic MEPs corresponded to those with direct electrical stimulation. Thus, recordings of the D response by transcranial magnetic stimulation are useful for not only identifying the location of the motor cortex during intracranial surgery but also for non-invasive recording of pyramidal tract activity during extracranial surgery under general anesthesia.

Geranylgeranylacetone, a noninvasive heat shock protein inducer, induces protein kinase C and leads to neuroprotection against cerebral infarction in rats

Previous studies demonstrated the cytoprotective effect of geranylgeranylacetone (GGA), a heat shock protein (HSP) inducer, against ischemic insult. Protein kinase C (PKC) is thought to be an important factor that mediates the expression of heat shock protein 70 (HSP70) in vitro. 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 (MCA) occlusion in rats. To clarify the relationship between PKC induction and HSP70 expression, we determined the amounts of HSP70 and PKC proteins after GGA administration by immunoblotting. We evaluated the effects of pretreatment with chelerythrine (CHE), a specific PKC inhibitor, on expressions of PKC and HSP70 proteins with immunoblotting. Neuroprotective effects of GGA (pretreatment with a single oral GGA dose (800 mg/kg) 48 h before ischemia) were prevented by CHE pretreatment, which indicates that PKC may mediate the GGA-dependent protection. Oral GGA-induced HSP70 expression induced PKC delta, and GGA pretreatment enhanced ischemia-induced HSP70, both of which were prevented by CHE pretreatment. These results suggest that a single oral dose of GGA induces PKC delta and promotes HSP70 expression in the brain and that GGA plays an important role in neuroprotection against cerebral ischemia.

Comparison of Multiple Parameters Obtained on 3T Pulsed Arterial Spin-Labeling, Diffusion Tensor Imaging, and MRS and the Ki-67 Labeling Index in Evaluating Glioma Grading

BACKGROUND AND PURPOSE: Pulsed arterial spin-labeling, DTI, and MR spectroscopy provide useful data for tumor evaluation. We evaluated multiple parameters by using these pulse sequences and the Ki-67 labeling index in newly diagnosed supratentorial gliomas. MATERIALS AND METHODS: All 32 patients, with grade II (3 each of diffuse astrocytoma, oligodendroglioma, and oligoastrocytoma), grade III (3 anaplastic astrocytomas, 4 anaplastic oligodendrogliomas, and 1 anaplastic oligoastrocytoma), and grade IV (14 glioblastomas and 1 glioblastoma with an oligodendroglioma component) cases underwent pulsed arterial spin-labeling, DTI, and MR spectroscopy studies by using 3T MR imaging. The following variables were used to compare the tumors: relative cerebral blood flow, fractional anisotropy; ADC tumor/normal ratios; and the Cho/Cr, NAA/Cho, NAA/Cr, and lactate/Cr ratios. A logistic regression and receiver operating characteristic analysis were used to assess parameters with a high sensitivity and specificity to identify the threshold values for separate grading. We compared the Ki-67 index with various MR imaging parameters in tumor specimens. RESULTS: Significant correlations were observed between the Ki-67 index and the mean, maximum, and minimum ADC, Cho/Cr, and lactate/Cr ratios. The receiver operating characteristic analysis showed that the combination of the minimum ADC and Cho/Cr ratios could differentiate low-grade and high-grade gliomas, with a sensitivity and specificity of 87.0% and 88.9%, respectively. The mean and maximum relative cerebral blood flow ratios were used to classify glioblastomas from other-grade astrocytomas, with a sensitivity and specificity of 92.9% and 83.3%, respectively. CONCLUSIONS: Our findings indicate that pulsed arterial spin-labeling, DTI, and MR spectroscopy are useful for predicting glioma grade. Additionally, the parameters obtained on DTI and MR spectroscopy closely correlated with the proliferative potential of gliomas.

Reduced short latency afferent inhibition in diffuse axonal injury patients with memory impairment.

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 diffuse axonal injury (DAI) patients with memory impairment and compared the data with those of 16 healthy controls. SAI was reduced in patients compared with controls (92+/-12 versus 39+/-11% of the test size; p<0.0001, unpaired t-test). DAI patients tended to have a high resting motor threshold (RMT) and less pronounced SICI and ICF than controls, but these differences were not significant. A single oral dose (3mg) of donepezil, an acetylcholinesterase inhibitor that is commonly used to treat Alzheimers disease (AD), improved SAI in DAI patients with wide individual variations that ranged from an increase of 77-18% of test size. These findings suggest that measuring SAI may provide a means of probing the integrity of cholinergic networks in an injured human brain.

Effect of spinal cord stimulation on cerebral blood flow in cats.

Effects of electric spinal cord stimulation (SCS) on cerebral blood flow (CBF) were investigated in anesthetized adult cats. SCS was performed under various stimulus conditions for 1 h via a wire electrode inserted into the dorsal epidural space at various levels in the spinal cord. CBF was measured in the subcortex of the parietal lobe by hydrogen clearance method before, during, and after SCS. After the start of SCS in the high cervical cord with a frequency of 20 Hz, CBF gradually increased up to 140% of the pre-SCS value, and remained high for 15 min after the end of SCS. SCS of the low cervical or midthoracic cord under the same condition caused no significant increase in CBF. Nor did SCS of the high cervical cord with frequencies of 200 and 2,000 Hz increase CBF. No CBF increase was observed after SCS of the high cervical cord with 20 Hz when the dorsal column was sectioned at the medullo-cervical junction. These results suggest that the ability of SCS to increase CBF is peculiar to high cervical cord stimulation with moderately low frequencies.