Biomedical subjects
Publications and source records attributed to O Kanazawa.
One patient with frequent spike-waves in EEG was studied by a neuropsychological test. The spike-waves caused an obvious prolongation of cognitive processing. This delay was considered to be caused not only by motor inhibition but also by impaired cognitive function.
Two children with status epilepticus were treated successfully by the rectal administration of valproate (VPA), and complete seizure control was obtained in one patient without severe side effects. In addition, there was no essential difference in pharmacokinetics between rectal and oral administration of VPA as determined by computerized simulation of plasma concentration data of VPA after rectal administration in two healthy adults or an epileptic child. Although these findings suggest that the early absorption of VPA within 30 minutes of rectal administration is slightly more rapid than that of oral administration, rectal VPA seems to be unsuitable for the first choice in the treatment of status epilepticus, since it has not so immediate effects as intravenous administration of DZP.
99mTc-hexamethylpropylenamine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) was performed in a patient with alternating hemiplegia during 2 episodes of the disease. The regional cerebral blood flow patterns correlated with the clinical manifestations during both episodes. Hyperperfusion of the contralateral hemisphere was suggested by asymmetric 99mTc-HMPAO uptake, whereas symmetric 123I-N-isopropyl-p-iodoamphetamine uptake was detected during the interictal period. The results suggested that alternating hemiplegia in infants represents an atypical manifestation of epilepsy, despite the lack of paroxysmal electroencephalographic abnormalities during the episodes. 99mTc-HMPAO SPECT appears to be a useful method for detecting transient regional cerebral blood flow alterations during paroxysmal events because the tracer is rapidly available for emergencies and retains a fixed distribution for 5-8 hours, sufficient time to allow for SPECT acquisition.
Continuous oculoclonic status epilepticus occurred for 90 min in a 4-year-old girl. The seizure consisted of continuous contralateral horizontal nystagmus concurrent with left occipital spike discharges, occasional vomiting and no loss of consciousness. Oculoclonic status epilepticus may be a variant form of versive status epilepticus.
Cognitive functions of patients showing slow spike-wave discharge in EEG without obvious absence seizures were investigated using tachistoscopic stimuli triggered by spike-waves. Response times obtained during spike-waves and during non-spike-waves were compared for three tests (tapping, simple reaction, and morphological discrimination). We present one case of Lennox-Gastaut syndrome in which the test results could be statistically confirmed. The tapping test was interrupted by the occurrence of spike-waves. Response times during spike-waves were more delayed than during non-spike-waves in both the simple reaction tests and morphological discrimination tests. The differences in response times measured during spike-waves and during non-spike-waves were significantly greater in the morphological discrimination test than in the simple reaction test. The positive correlation between the length of spike-waves and response time in the discrimination test was significantly more pronounced than in the reaction test. These results were also confirmed in two other patients with Lennox-Gastaut syndrome. We conclude that spike-wave discharges may impair cognitive processing more intrinsically than motor functions.
Two cases of discontinuous status epilepticus (SE) characterized by repetitive asymmetrical atonic episodes associated with diffuse but asymmetrical spike waves are reported. Both patients also had partial seizures and interictal rolandic discharges. Dynamic EEG topography was performed to investigate the location or propagation of each ictal discharge overlying the scalp during status and showed immediate bilateral spread of discharges originating from a primary epileptogenic focus from a rolandic area.