Decrement of N20 amplitude of the median nerve somatosensory evoked potential in Creutzfeldt-Jakob disease patients.

We studied somatosensory evoked potentials (SSEPs) in eight Creutzfeldt-Jakob disease (CJD) patients presenting with subacute progressive dementia, generalized myoclonus, and characteristic periodic sharp wave complexes in EEG. Somatosensory evoked potentials were elicited by median nerve stimulation at the wrist. We compared SSEP findings with EEG and the clinical stage proposed by the Japanese Slow Virus Infection Research Committee (stage 1: early stage to stage 5: terminal stage). Until clinical stage 3, short-latency SSEPs showed normal findings despite the severely abnormal EEG. With the progression to clinical stages 4 and 5, however, the amplitude of N20 began to decrease and finally disappeared without prolongation of the latency of N20, whereas other short-latency components were preserved. We recorded giant SSEPs in two of three patients in stage 4, when the periodic sharp wave complex in EEG began to decrease in amplitude. The giant SSEPs decreased in amplitude with the progression of the illness. These findings suggest that the short-latency SSEP is relatively preserved until the middle phase of the disease but that it is eventually affected in the terminal phase. We conclude that our results are compatible with the CJD pathologic findings and that the amplitude of N20 reflects the extent of cortical damage in CJD patients.

[The relationship between MR images and clinical findings in neuronal migration disorders].

Among the variable manifesting conditions of neuronal migration disorders, mental retardation, motor disturbance and epilepsy are the main features of developmental disabilities. We analyzed the relationship between clinical symptoms and magnetic resonance (MR) images, including surface anatomy scan (SAS). Thirty nine patients (23 males, 16 females; mean age 6.1 years) with neuronal migration disorders were studied. The diagnoses were cerebral palsy in 23 cases, mental retardation in 4. West syndrome in 4, Fukuyama type congenital muscular dystrophy (FCMD) in 6. Walker-Warburg syndrome in 1 and Dubowitz syndrome in 1. Cortical dysplasias were classified into the following 7 groups, mainly based on the SAS findings: complete agyria (AG 1), mixture of agyria and pachygyria (AG 2), bilateral complete pachygyria (BP 1), diffuse pachygyria with marked widening of the bilateral superior frontal gyrus (BP 2), unilateral pachygyria with hemispheric atrophy or hemimegalencephaly UP), focal cortical dysplasia (FP) and other findings such as solitary schizencephaly (Others). Most cases of AG 1 and AG 2 showed spastic quadriplegia (6/7) and symptomatic generalized epilepsy (5/7), whereas cases of BP1 showed spasticity only in 1/8 and epilepsy in 7/8. Hemiplegia was observed in 6/7 of UP, 2/8 of FP and 2/4 of Others. Partial epilepsy was observed in 2/7 of UP and 1/8 of FP. Intellectual level was variable in BP 1, UP, FP and Others, but all cases showed severe mental retardation in AG 1, AG 2 and BP 2. BP 2 was observed in all cases of typical FCMD (5/5). The birth weight was less than 2,500 g in 6/7 of UP. The structural findings well correlated with clinical symptoms and epileptic seizure types. The surface anatomy scan was a very useful technique for detecting cortical dysplasias.

Dihydropteridine reductase deficiency: diagnosis by leukocyte enzyme assay.

An assay procedure for dihydropteridine reductase in peripheral leukocytes is described. The assay utilizes the tetrahydropterin-dependent reduction of ferri-cytochrome C in the presence of NADH and requires a smaller number of cells than assays described for cultured skin fibroblasts. Dihydropteridine reductase activity was not detectable in the peripheral leukocytes nor in the cultured skin fibroblasts from two adolescent patients with malignant hyperphenylalaninemia. The parents of the patients showed approximately 50% of normal dihydropteridine reductase activity in their peripheral leukocytes. Immunochemical experiments using antibodies against bovine liver dihydropteridine reductase suggest that normal leukocytes and skin fibroblasts contain dihydropteridine reductase which is immunologically similar to that of human liver. The present studies indicate that the determination of dihydropteridine reductase activity in peripheral leukocytes can be used to diagnose hyperphenylalaninemia due to a defect in dihydropteridine reductase.

Childhood epilepsy uncontrolled by phenytoin: clinical and electroencephalographic study.

Nine cases of childhood epilepsy manifesting motor convulsions uncontrolled despite high levels of phenytoin (PHT) were studied clinically and electroencephalographically. These cases consisted of five cases of partial seizures without impairment of consciousness, two cases of partial seizures (occasionally generalized seizures beginning locally), one case of predominantly unilateral seizures, and one case of generalized tonic-clonic seizures. the onset of seizures was at a rather early age, between 3 months and 9 years, and under 3 years of age in eight cases. All cases had single or multiple, cortical epileptic foci in EEG. The projection of spikes was localized to a rather limited area. Seizures of these patients were frequent. All cases, except one, did not respond to other medication. Convulsive seizures with cortical focal spike foci in EEG uncontrolled despite high levels of PHT were thought to have poor responsiveness to not only PHT itself, but also to other anticonvulsants.

Immediate changes of the electroencephalograms after intravenous injection of clonazepam and their relation to its effect on clinical fits in children with minor seizures.

Immediate EEG changes after intravenous administration of clonazepam and a correlation between the EEG changes and the effect of oral administration of the drug were studied in 21 children with minor seizures whose interictal EEG showed a paroxysmal abnormality. In 13 cases of infantile spasms whose EEG showed hypasrhythmia, paroxysmal discharges were completely or remarkably suppressed in 4 cases, partially suppressed in 3 cases, but not improved in 6 cases. Suppression bursts pattern was less improved. In 5 cases of Lennox syndrome, paroxysmal discharges were markedly improved in 3 cases. In a case of petit mal absence, parxoxysmal discharges were completely suppressed. In all 5 cases whose EEGs were completely improved, paroxysmal discharges reappeared 7 to 30 min after the intravenous injection. In 2 out of the 5 cases, paroxysmal discharges became severer at reappearance than before the injection. Among 12 cases whose EEG showed an improvement after the intravenous injection, their clinical seizures were improved in 9 cases, but the clinical effect was mostly transient. In the majority of the cases whose EEGs were not improved, no clinical effect was observed. There was a highly significant correlation between immediate EEG changes and clinical effect of clonazepam (p less than 0.02 by the chi-square test).

Electroencephalograms in a case of maple syrup urine disease: their relation to serum levels of branched-chain amino acids.

During dietary treatment of a case of maple syrup urine disease, it was found that abnormal EEGs were observed when serum levels of leucine were abnormally high while those of valine and isoleucine were normal, and also when serum levels of valine and isoleucine were abnormally high while serum leucine levels were normal.

Electroencephalographic study of an infant with phosphoribosylpyrophosphate synthetase deficiency.

In a hypouricemic and mentally retarded infant due to a defect of 5-phosphoribosylpyrophosphate synthetase, electroencephalograms were recorded at the age of 4, 7, 10 and 11 months. Hypsarrhythmia was first observed at the age of 10 months, and markedly improved after ACTH therapy with concomitant increase in the enzyme activity of erythrocytes.

Globoid cell leukodystrophy: the first case with antemortem diagnosis in Japan.

A Japanese boy was diagnosed as globoid cell leukodystrophy on the basis of a marked decrease in the galactocerebroside beta-galactosidase activity in the leukocytes and the serum when one year and two months old. At autopsy when 1 year and 10 months, microscopic findings were characteristic for those of globoid cell leukodystrophy. Galactocerebroside beta-galactosidase activities of leukocytes and sera of his father and mother were found to be half those of control subjects, thus it suggested the parents being heterozygotes of the disease.

Electroencephalographic findings in a case of globoid cell leukodystrophy.

An increased slow wave pattern of the EEG basic waves without epileptogenic discharges was observed in an early stage of a case of Krabbe's disease. In the later stage of the illness, spikes and sharp waves were mixed with. The peculiar runs of fast activity which were described by Kliemann et al. (1969) were not observed during the course of our patient.