Kimiko Fukui

Effects of Sevoflurane and Isoflurane on Electrocorticographic Activities in Patients With Temporal Lobe Epilepsy

To compare the neuroexcitatory effects of sevoflurane and isoflurane, we recorded electrocorticograms (ECoG) during wakefulness and during sevoflurane and isoflurane anesthesia in six patients with temporal lobe epilepsy (TLE). These patients had subdural grid electrodes chronically implanted in the temporal region. During sevoflurane anesthesia at 1.5 minimum alveolar concentration (MAC) of the combination with 67% nitrous oxide (N2O), a marked increase in interictal paroxysmal activities was observed in four patients. Two patients had a slight increase in paroxysmal activities. Activated areas were widely distributed, not being confined to the ictal onset zone of spontaneous seizures. However, isoflurane anesthesia at 1.5 MAC of the combination with 67% N2O was associated with less increased paroxysmal activity. While the neuroexcitatory properties of sevoflurane proved greater than those of isoflurane, the widespread irritative response to sevoflurane administration was not helpful in localizing the epileptogenic area.

Fetal germinal matrix and intraventricular haemorrhage diagnosed by MRI

Abstract Subependymal germinal matrix haemorrhage and intraventricular haemorrhage (GMIVH) is a common complication of delivery in preterm neonates but has rarely been observed in the fetus. We report two cases of GMIVH in fetuses of 36 weeks gestation, clearly demonstrated by antenatal MRI. In both cases progressive ventriculomegaly was observed, and ventriculoperitoneal shunts were placed at 19 and 6 months of age, respectively. Prenatal GMIVH may be a cause of congenital hydrocephalus, for which no aetiology has yet been found.

Corpora Amylacea Replace the Hippocampal Pyramidal Cell Layer in a Patient with Temporal Lobe Epilepsy

Summary: A 39‐year‐old woman, with a 23‐year history of medically intractable seizures of the complex partial type, underwent a left anterior temporal lobectomy and hippocampectomy. Histologic examinations revealed a massive occurrence of corpora amylacea, neuronal loss, and gliosis in the pyramidal cell layer of the hippocampus. The distribution of corpora amylacea in this case was quite distinctive and unlike the patterns of “nonspecific” corpora amylacea formation seen in aging or other neurodegenerative conditions. The pathogenetic aspects of the accumulation of these peculiar bodies are discussed in relation to hippocampal sclerosis.

Gait disturbance in patients with low pressure hydrocephalus

Using criteria of the classification recently described by Nutt et al., we examined gait disorder in five patients with normal pressure hydrocephalus (NPH). Their cerebrospinal fluid (CSF) pressures were in the normal range, and trials of CSF removal produced temporary improvement of symptoms. Surgical procedures to relieve hydrocephalus improved gait disorders in all patients. No patient showed spasticity, sensory ataxia, cerebellar ataxia, extrapyramidal signs, or limb apraxia. All walked slowly with a wide base and a short stride. The arm swing normally associated with walking was preserved. In standing, patients were unsteady and fell easily when pushed. Four patients showed hesitation in initiating walking and in turning. These clinical features fit Nutts criteria for frontal gait disorder and frontal disequilibrium. Unlike findings in Parkinsons disease, where similar gait disorders may occur, other extrapyramidal signs, Myersons sign, and upper limb dysfunction were absent in NPH, and arm swing while walking was preserved. We suspect that ventricular dilatation disturbs neuronal connections between the supplementary motor area and the globus pallidus in NPH patients.

Callosal anomalies in patients with spinal dysraphism: Correlation of clinical and neuroimaging features with hemispheric abnormalities

Abstract Dysgenesis of the corpus callosum can occur in association with spinal dysraphic lesions. Clinical and neuroimaging features were reviewed in 23 patients (12 male, 11 female; mean age 11.3 years) with caudal spinal dysraphism (myeloschisis in eight, meningomyelocele in 10, and lumbosacral lipoma in five) to characterize types and degrees of callosal and other cerebral anomalies. T1- and T2-weighted magnetic resonance images were obtained, and the total midsagittal cross-sectional area of the corpus callosum was determined. The corpus callosum appeared normal in nine patients and was abnormal in 14. In five patients the corpus callosum was narrow, with all regions present; the cerebral hemispheres were hypoplastic. Two patients with dysgenesis of frontal, parietal, and occipital lobes had a small, partly agenetic corpus callosum. In the remaining seven patients the posterior third of the corpus callosum was absent or hypoplastic; six of them had ventriculomegaly that selectively affected the occipital horns (colpocephaly). All callosal anomalies were accompanied by hemispheric ones. This supports a disordered developmental relationship between the corpus callosum and the hemispheres as a cause. Spinal dysraphism can no longer be considered a single developmental abnormality, given the frequent association of other defects. [Neurol Res 2002; 24: 463-467]

Temporal lobe epilepsy and corpora amylacea in the hippocampus: Clinicopathologic correlation

Abstract Corpora amylacea (CoA) have been found in about 60% of neurosurgical specimens showing hippocampal sclerosis (HS). To determine clinical and neuroimaging differences between HS with and without CoA, we studied 29 patients (21 male, 8 female; age at surgery, 12 to 49 years0 who underwent anterior temporal lobectomy for intractable medical temporal lobe epilepsy. No CoA were noted in the hippocampus of 11 cases, and deposition of CoA was mild and limited to the subependymal and vestigial hippocampal sulcus regions in nine cases; in nine cases, moderate to marked deposition was noted in the pyramidal cell layer, accompanying severe neuronal loss. No significant differences were evident between these three groups for age at onset, frequency and duration of epileptic seizures, the average age at surgery, or surgical results. Hippocampal hyperintensity in fluid-attenuated inversion recovery magnetic resonance images tended to increase with increasing hippocampal deposition of CoA. Formation of CoA appears to be a response to neuronal loss in the pyramidal cell layer, being related to the epileptogenic process as a consequence rather than a cause. [Neurol Res 2002; 24: 563-369]

Temporal lobe epilepsy associated with hippocampal sclerosis and a contralateral middle fossa arachnoid cyst

We report on a 13-year-old boy with temporal lobe epilepsy associated with left hippocampal sclerosis and a contralateral arachnoid cyst in the middle cranial fossa (ACMCF). Chronic intracranial recording from subdural grid electrodes showed the left medial temporal lobe to be the ictal onset zone. After left anterior temporal lobectomy with hippocampectomy, seizure control was improved. ACMCF was not considered the direct cause of epilepsy; instead the seizures were attributed to hippocampal sclerosis.

Unilateral striatal damage following status epilepticus of ipsilateral frontal lobe origin

A 35-year-old man with an old contusional haematoma in the right frontal lobe developed status epilepticus (SE) of right frontal origin. On magnetic resonance (MR) images 10 days after SE, the right striatum showed signal enhancement with Gd-DTPA administration. Subsequent MR imaging 1 month later indicated prolonged T1 and T2 relaxation times in the right striatum. Prolonged seizure activity in the frontal lobe may have induced excitatory neurotoxicity in the ipsilateral striatum, with occurrence of delayed neuronal damage as a result.

Surgical management of intractable epilepsy associated with neuronal tumor

Neuronal tumors, such as gangliocytoma/gangliogliomas and cerebral neurocytomas, are slow-growing, indolent tumors consiting of neoplastic neuronal cells. They are likely to be present with seizures, often medically intractable epilepsy. During surgery for neuronal tumors associated intractable epilepsy, an enlargement of a resection area beyond the tumor boundaries, with recordings of intraoperative and/or chronic electrocorticography, may improve the postoperative seizure outcome, since tumor surrounding areas may have ‘cerebral microdysgenesis’ and may thus be epileptogenic. In addition, when the mesiotemporal lobe structures are involved with the tumor on the neuroimaging and have epileptiform electrocorticography activities, tumor removal and additional removal of the hippocampus are recommended.