Mitsugi Takahashi

Electroencephalographic Study of Rat Hyperthermic Seizures

Summary: The behavior and EEG of rat hyperthermic convulsions was studied. We found that a long run of high‐voltage slow waves without convulsions, high‐voltage irregular activity consisting of spikes and waves with intermittent myoclonus, and rapid spike and wave bursts accompanied by generalized clonic convulsions occurred sequentially. This behavioral and EEG activity is analogous to human febrile convulsions and supports the usefulness of this model for studies of human febrile convulsions. Rats frequently showed arrest of locomotion concurrently with paroxysmal EEG theta bursts before development of generalized convulsions. We speculate that this paroxysmal activity is a type of seizure discharge.

Hyperthermia-induced seizures with a servo system: Neurophysiological roles of age, temperature elevation rate and regional GABA content in the rat

A servo system including a microwave generator was applied to raise a rats body temperature at a pre-set rate. Using this system the effects of age and the temperature elevation rate upon febrile seizures in rats were studied. The relationship between the brain GABA content and hyperthermia was also studied. From the results of the present study, the seizure occurrence rate was found to be highest at the age of 20 days, brain damage was speculated to be severe after hyperthermia-induced seizures with a slow temperature rise, and the regional GABA concentration in subcortical structures was found to increase during hyperthermia. These data indicate that a servo system with a microwave generator is useful for experimental febrile convulsions, and that GABA neurotransmission in subcortical structures might contribute to feed-back regulation against seizures during hyperthermia.

A case of multiple sclerosis with multi-ring-like and butterfly-like enhancement on computerized tomography

We report a case of multiple sclerosis in which CT showed multiple ring-like enhancement and butterfly-like distribution of a low density area with marginal enhancement. The latter finding is found in other demyelinating disorders but is less common in tumors or abscesses. Therefore, it seems to have some diagnostic value in multiple sclerosis.

ESTIMATING BONE CHANGE IN PATIENTS WITH SEVERE DISABILITY

To evaluate bone change in severely disabled patients, bone density was assessed on X‐ray pictures by the microdensitometry (MD) method, and urinary hydroxyproline (U‐HYP), urinary glycosaminoglycans (U‐GAG) serum calcium (S‐Ca) and serum alkaline phosphatase (S‐AP) were assessed in 43 patients (mean age 16 years) at the National Sanatrium Ehime Hospital. On division of the severity of bone change into grades 0 to 3 using the MD method, U‐HYP was found to be significantly higher in grades 2 and 3 than in controls. Tendencies were similar for U‐GAG and S‐AP. U‐HYP in immobile patients was significantly higher than in mobile patients. Immobilisation was one of the most important contributors to the development of bone change and results obtained using the MD method, U‐HYP and U‐GAG were valuable indices of the bone change in severely disabled patients.

Impaired muscle fiber type differentiation in a child with nemaline myopathy

SINCE NEMALINE MYOPATHY was first described by Shy et al., 1 a n u m b e r of cases have been reported. The disorder is charac ter ized clinically by generalized muscle hypotonia f rom early infancy and by muscle weakness predominant ly involving the neck and face. Al though the presence of rod (nemal ine) bodies in the small-cal ibered fibers is a character is t ic and diagnostic finding in nemal ine myopathy, the n u m b e r of rod bodies per se is occasionally out of proport ion to the clinical severity. In additon, most of t h e pat ients have shown abnormal fiber type distribution, including hypoplast ic type 1 fibers and type 1 fiber p redominance . The abnormal muscle histochemistry, probably induced by an impaired neural influence on the developing muscles, and muscle fiber immatur i ty have been assumed to generate muscle weakness. 2-6 We describe an incidence of nemaline myopathy t ha t followed a typical course but produced extremely severe neck muscle weakness. In addit ion to the presence of numerous rod bodies in the muscle fibers, most (96%) of the fibers behaved as type 2C on ATPase staining, indicat ing impaired muscle fiber differentiat ion from immature type 2C fibers into ei ther ma tu re type 1, 2B, or 2A fibers.

The Orcadian Rhythm of Spike-Wave Discharges in Patients with Typical Absence Seizures

Absence seizures are characterized by the suppression of all mental functions, usually to the point of complete abolition of awareness, responsiveness and memory. The majority of attacks last for less than 10 seconds and the clinical manifestations are often minimal and easily missed. In recent years, long-term electroencephalographic (EEG ) monitoring, by cable telemetry (T/EEG) or with a cassette tape recorder (C/EEG), of attacks has been conducted. There have been several reports concerning the absence seizure frequency as ,monitored by C/EEG. The purpose of this study was to determine the relationship between the clinical symptoms of absence seizures and paroxysmal discharges (PD) seen on EEG and the circadian rhythm of the duration of PD by means of video-T/EEG.

Infantile sudanophilic leukodystrophy: computed tomography demonstration

SummaryWe report a female case of infantile sudanophilic leukodystrophy whose evolution was followed by CT