Noriyuki Ohtsuki

Serial magnetic resonance imaging in children with postinfectious encephalitis

We analyzed follow-up magnetic resonance images (MRI) in eight children with clinical postinfectious encephalitis (PIE), and discussed their pathogeneses. Three categories of MRI findings were apparent: (1) multifocal lesions in the white matter with/without basal ganglia involvement consistent with acute disseminated encephalomyelitis (ADEM) (three patients); (2) single or multifocal lesions localized only in the gray matter (two patients); and (3) localized lesions in the brain stem, basal ganglia or cerebellum. Some lesions in the patients in Categories 1 and 2 migrated or were resolved quickly, sometimes within 10 days. Gadolinium caused linear or spotty enhancement in the patients in Category 2. These findings suggest that Categories 1 and 2 are a self-limiting allergic angiopathy without demyelination. In contrast, the lesions in the patients in Category 3 were fixed, and not resolved within 6 months (three patients). The pathogenesis of Category 3 is not known. All except one patient had no prednisolone (PSL) therapy, however; all lesions were resolved completely or markedly reduced in size, which indicates PSL therapy is not always necessary in patients with PIE.

Acute confusional migraine and migrainous infarction in childhood

We report two children with acute confusional migraine (ACM) and another with migrainous infarction (MI), aged 7-12 years. There was a family history of migraine in all patients. The patients, who were all right-handed, all manifested sudden onset of consciousness disturbance and other neurological deficits as the first aura in their life. The symptoms in all cases almost completely resolved spontaneously within 24 h, but transient occipital slowing on EEG with laterality corresponding to the side of migrainous origin lasted more than 24 h. In the cases of ACM in the critical phase, although MRI and MR angiography showed no abnormal findings, IMP-SPECT performed within 48 h of migraine attacks revealed a regional change in cerebral blood flow, which is one particular case demonstrated hypoperfusion in the left posterior cerebral artery (PCA) territory. Therefore, although ACM was diagnosed clinically by exclusion, SPECT was thought helpful for the diagnosis of ACM. We speculated that transient hypoperfusion affecting the dominant-sided PCA territory involving the medial temporal structures was responsible for the confusion with amnesia in ACM, in contrast to the lack of confusion or amnesia in the case of MI showing cystic encephalomalacia in the right thalamic and hippocampal regions.

Transcranial magnetic stimulation in benign childhood epilepsy with centro-temporal spikes

Motor cortical excitability was studied using transcranial magnetic stimulation (TMS) in 10 age-matched controls, and 13 children with benign childhood epilepsy with centro-temporal spikes (BECT), with a mean age of 11.2 +/- 2.0 years (five untreated, and eight treated with sodium valproate (VPA) and well controlled). Motor evoked potentials (MEPs) elicited by TMS through a circular coil were recorded from the first dorsal interosseous muscle (FDI) while relaxed. There was no significant difference in latency or duration of MEPs, or central motor conduction time among controls, untreated and treated patients. The threshold intensity for TMS in the untreated patients (63.0 +/- 14.8%, mean +/- SD) was similar to that in controls (63.0 +/- 12.5%), while the threshold intensity in the treated patients (79.4 +/- 11.8%) was significantly higher than that in the other groups. A significant increase in threshold intensity (15 +/- 4.1%) was also observed in the untreated patients retested after starting VPA treatment. No adverse effects occurred during TMS in any subjects. Thus, motor cortical hyperexcitability in BECT was not recognized in the present TMS study, while VPA was confirmed to have an effect on the threshold intensity for TMS.

Fukuyama-type congenital muscular dystrophy and the Walker-Warburg syndrome

We compared the neuropathological findings in two cases of the Walker-Warburg syndrome (WWS) with those in 6 of Fukuyama-type congenital muscular dystrophy (FCMD). Remarkable differences were noticed between the two conditions. The central nervous system (CNS) dysplasia in WWS, which involved diffuse agyria and hydrocephalus, was more severe than that in FCMD. In WWS the septum pellucidum was absent, and the corpus callosum, basal ganglia and thalami were markedly hypoplastic. The cerebellum was severely hypoplastic and the vermis was partly absent. The pyramidal tracts could not be identified. On the other hand, the general configuration of the CNS was well preserved in FCMD. The cerebral cortices exhibited diffuse or focal micropolygyria with or without a few pachygyric lesions, but the severity was variable. The cerebellum was not hypoplastic, but exhibited focal micropolygyria. The pyramidal tracts were aberrant. WWS and FCMD, however, did not show any distinct differences on microscopic analysis of the cerebral cortices. There was leptomeningeal glio-mesenchymal overgrowth, and the horizontal lamination of the nerve cells was distorted throughout by proliferating gliovascular bundles or septa. We found in this study that the CNS pathology in WWS was compatible with type II lissencephaly, and thus differed from that in FCMD. Hypoplasia of the cerebellum and a partial absence of the vermis also seemed to be predominant features of WWS, which can be used to differentiate WWS from FCMD. In this study, we concluded that FCMD and WWS are different disease entities because they differ in their clinical manifestations, including eye lesions and CNS pathology, and because no familial concomitance of FCMD and WWS has been reported.

Alternating hemiplegia of childhood : report of a case having a long history

We examined a patient with alternating hemiplegia of childhood (AHC) who had over a 23-year history of AHC to investigate the origin of the neurological deterioration with increasing age. Hemiplegic attacks had occurred consistently at a frequency of a few per week since infancy, and he first experienced attacks of cerebellar ataxia at the age of 23 years. Intellectual impairment, dysarthria, dystonic posturing, and a wide-based gait had been slowly progressive, but they had been stable since he turned twenty. The electromyographic response to transcranial magnetic stimulation was normal between attacks and showed reversible alteration during an attack. MRI revealed slight dilatation of the lateral ventricles, and MR angiography showed normal cerebral blood flow. Proton MR spectroscopy between attacks showed normal peak area ratios for N-acetyl groups, choline-containing compounds, and creatine and phosphocreatine, and it also demonstrated no lactic peak. 123I-IMP SPECT between attacks demonstrated diffuse cerebral hypoperfusion despite no evidence of ischemic change in the above MR study. These results suggest that the slowly progressive neurological deficits are due to the primary underlying pathology rather than the secondary neuronal loss as a result of frequent ischemic attacks.

Effect of digitalis on conduction dysfunction in Pelizaeus-Merzbacher disease

We studied the effect of digitalis on nerve conduction dysfunction in Pelizaeus-Merzbacher disease (PMD). The patients were three Japanese boys with PMD, aged 7-10 years. Digitalis was administered orally in a daily dose of 0.06 mg/kg for 2 consecutive months, and the obtained serum concentrations ranged from 0.33 to 0.55 ng/ml. The digitalis therapy induced slight improvement of severe dysarthria and cognitive dysfunction in the two older patients. Electrophysiological examinations revealed the following results: In brainstem auditory evoked potentials (BAEPs), while waves II (or III) to V were absent before treatment, on treatment all waves of BAEPs except a wave IV were restored in all patients. While visual evoked potentials (VEPs) in response to transient flash stimulation showed markedly prolonged latencies before treatment, digitalis produced a mild, although not statistically significant, shortening of the latency of N160. There were also no significant changes in inter-peak amplitudes of VEPs. Transcranial cortical magnetic stimulation continued to fail to elicit motor evoked potentials of the first dorsal interosseous muscles in all patients. Thus, although the serum concentrations were insufficient to elicit favorable therapeutic effects, digitalis therapy provided slight relief of clinical symptoms with evidence of improvement of conduction dysfunction. It is suggested that patients with PMD may respond to symptomatic treatment modulating nerve conduction.