峯 清一郎

Dipole sources of interictal epileptiform activities recorded by conventional electroencephalogram (EEG) were estimated using the dipole tracing method. Four cases of temporal lobe epilepsy with medial temporal lesions were studied. Two patients with hippocampal sclerosis, one patient with granulation in the hippocampus and one patient with cavernous angioma were involved in the study. Interictal epileptiform activities were classified into two patterns according to the topography of spikes. They were widespread spikes over the parasagittal electrodes (parasagittal spikes) and restricted spikes at the temporal electrodes (temporal spikes). Dipole sources of parasagittal spikes were localized in the medio-basal temporal lobe with vertically orientated vector moment. Dipole sources of temporal spikes were localized in the medio-basal temporal lobe with horizontally orientated vector moment. Locations of dipoles and directions of vector moments were consistent with topography and polarity of spikes. The difference in the two patterns of interictal epileptiform activities was derived from the difference in the direction of the vector moment of dipole sources. There was no difference in the location of dipole sources. Both the dipole sources and the lesions were localized in the same medio-basal temporal lobe. Dipole tracing was very useful in localizing the dipole sources of interictal epileptiform activities and in understanding the neurophysiological background.

This study was conducted to determine risk factors for poor outcome in the natural history of arteriovenous malformation (AVM). We statistically analysed the correlation between clinical or angiographical findings and clinical outcomes for 55 cases of untreated AVM. Subsequent haemorrhage from AVMs was the only significant risk factor for poor outcome (P &lt 0.0001). The odds ratio was 44.56 with a 95% confidence interval (CI) from 4.80 to 413.90. Risk factors for subsequent haemorrhage from AVMs were also determined. The size (P = 0.0483) and location (P = 0.0147) of an AVM were significant risk factors for subsequent haemorrhage. The odds ratios were 3.97 with a 95% CI from 1.18 to 13.33 and 3.89 with a 95% CI from 1.10 to 13.72, respectively. AVMs of more than 60 mm, and deep or infratentorial AVMs had more chance of subsequent haemorrhage, and hence of a poor outcome. We propose using an aggressive multidisciplinary approach to treating these AVMs. (C) 2000 Harcourt Publishers Ltd.

The expressions of mRNAs encoding G protein α subunits were analyzed in the cerebral cortex of amygdaloid kindled rats. A remarkable increase in G(sα) mRNA were observed on the bilateral cerebral cortex at 24 h after the last generalized seizure and persisted 3 weeks on the unstimulated side. G(i2α) mRNA level was also increased on the stimulated side at 24 h and persisted 3 weeks. These result suggest that dysfunction of G(s) and G(i2) might relate to the basic mechanisms of seizure generation and the maintenance of epileptogenesis.

34 patients with indirect traumatic optic neuropathy were studied to identify factors affecting outcome and surgical indications. 12 cases (13 eyes = group A) underwent surgery and 24 patients (24 eyes = group B) were managed without surgery. Age, optic canal fracture, visual acuity before treatment (initial visual acuity) and days until surgery (only group A) were employed as variables. Visual acuity improved significantly more in patients with initial visual acuity, hand movement (HM) or better than in those with initial visual acuity for light perception (LP) only or worse. When initial visual acuity was HM or better, vision improved significantly more in patients with surgery than in those without surgery (p = 0.0003 by Mann-Whitney U test). Days until surgery were correlated with visual improvement in patients with visual acuity HM or better. Age and optic canal fracture did not affect visual improvement or influence the decision for or against surgery.