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Biomedical subjects

T Okuma

Publications and source records attributed to T Okuma.

At least 73 records · Page 4Linked to original sources
PubMed1981

Flickering light spot as a tracking target for the study of smooth pursuit eye movements in schizophrenics--a new method.

Smooth pursuit eye movements (SPEM) were studied in 26 schizophrenics and 20 normal controls. A light spot on a screen of cathode ray oscilloscope was used as a tracking target. In order to induce SPEM disorder easily, the subjects were required to track a light spot which flickered in various frequencies. This new method devised by the authors has clearly demonstrated that the SPEM in schizophrenic was more profoundly disturbed by the flickering of the tracking target than that in the normal control subjects. It was supposed that poor tracking of a flickering light spot in schizophrenics may be due to the inadequate concentration of attention to visual stimuli, and/or inability to predict the movements of a tracking target.

Acute Disease↗
PubMed1981

Natural history and prognosis of epilepsy: report of a multi-institutional study in Japan. The group for the study of prognosis of epilepsy in Japan.

A multi-institutional study on the prognosis of patients with epilepsy was performed in Japan from 1975 to 1977, including 20 institutions. The outcome of epileptic seizures and social adjustment 10, 5, and 3 years after the onset of the illness was studied in three different groups of epileptic patients, respectively. The number of successfully followed-up cases was 1,868 in total, follow-up rate being 42%. The data were analyzed statistically by use of analysis of variance. The rate of remission of seizures in all was 58.3% and the rate of normal social adjustment 62.6%. The remission rate showed no significant difference among the 10-, 5-, and 3-year outcome groups. The study on the outcome of seizure control indicated that the prognosis of seizure control is more favorable (a) in idiopathic than in residual or symptomatic epileptics; (b) in patients with onset before 10 years of age than in those with onset after 10 years; (c) in patients with less frequent seizures; (d) in sleep epilepsy than in waking and diffuse epilepsies; (e) in patients who started treatment within 1 year of onset of seizure; (f) in patients with single-type partial seizures than in those with partial seizures combined with tonic-clonic seizures; (g) in patients without high grade EEG background abnormality; and (h) in patients without neurological symptoms, intellectual deficits, personality disturbances, or psychotic symptoms. Factors that determine the prognosis of social adjustment were almost similar to those for remission of seizures. There was a close correlation between the outcome of seizure control and that of social adjustment. Correlation coefficient between follow-up rate and remission rate in 15 of the 20 collaborated institutions was 0.55 (p less than 0.05), showing a tendency that the remission rate becomes higher as the follow-up rate is raised.

Adolescent↗
PubMed1981

Smooth pursuit eye movements in epileptics under antiepileptic medication.

1) Smooth pursuit eye movements (SPEM) were recorded in 18 normal, 20 schizophrenic and 50 epileptic subjects. Most of the schizophrenic and epileptic subjects were under medication, antipsychotic drugs in the former and antiepileptic drugs in the latter. 2) In schizophrenics and epileptics, rate of the saccadic component in SPEM was higher than that of normal controls. The rate of large amplitude saccades was higher in epileptics than in schizophrenics. 3) Though small amplitude saccades were usually superimposed on SPEM in schizophrenic patients, both large and small amplitude saccades superimposed irregularly on the smooth tracking curve were observed in epileptics, and overshoots or undershoots were also seen frequently. 4) SPEM disorder in epileptics was observed in more than half of patients receiving antiepileptic medication, especially in patients with a long period of treatment. SPEM disorder in epileptics tended to occur frequently in patients who received phenytoin in doses higher than a certain level; i.e. approximately 150 mg per day for a long period of time. 5) It is conceivable that the SPEM disorder represents a latent or subclinical cerebellar dysfunction due to phenytoin medication. It is suggested that the SPEM measurement is a useful tool to find out subclinical side effects of antiepileptic drug in the treatment of epilepsy.

Adult↗
PubMed1980

Multi-institutional study on the teratogenicity and fetal toxicity of antiepileptic drugs: a report of a collaborative study group in Japan.

A multi-institutional collaborative study was conducted concerning the course of pregnancy and delivery and the incidence of abnormal infants delivered of epileptic women. Of 657 women receiving antiepileptic drugs, 73% delivered live infants, 14% had miscarriage or stillbirth, and 13% underwent induced abortion. In contrast to the above findings, 80% of 162 patients not receiving antiepileptic drugs delivered live infants and 4% had miscarriage or stillbirth. The latter outcome was significantly increased in the medicated patients. In this series, 63 (9.9%) of 638 live births were malformed, 55 (11.5%) being from medicated mothers and 3 (2.3%) from nonmedicated mothers. The incidence of fetal malformation in medicated mothers was thus five times as high as that in nonmedicated mothers. Cleft lip and/or palate and malformations involving the cardiovascular system were found frequently in the infants from medicated mothers. General background factors that might exert teratogenic effects on pregnant patients with epilepsy were studied, and the potential toxicity of antiepileptic drugs to the fetus was also analyzed. In this regard, consideration should be given to whether the patient has partial epileptic seizures, whether the patient herself exhibits any malformation, or whether her previous pregnancy resulted in an abnormal outcome. The incidence of fetal malformation was the highest (12.7%) in the medicated patients who had epileptic seizures during the pregnancy. It is presumed on the basis of the results of analysis of the data that a combination of more than three drugs and a daily dose greater than a certain minimal level is likely to produce malformed infants.

Abnormalities, Drug-Induced↗
PubMed1978

Model insomnia, noise, and methylphenidate, used for the evaluation of hypnotic drugs.

Experimental sleep disturbance (model insomnia) was produced by intermittent white noise and the administration of 10 mg of methylphenidate (MPD). The effects of flurazepam (FZP) 15 mg and triazolam (TZM) 0.25 mg on these models was investigated. All night sleep polygraphy was performed on 8 normal male subjects under each of the following 9 conditions: baseline, TZM 0.25 mg, FZP 15 mg, white noise alone, noise and TZM, noise and FZP, MPD alone, MPD and TZM, and MPD and FZP. A reduction in total sleep time and stage were (S-REM) and an increase in the wakening stage were observed with both noise and MPD. Stage 4 sleep was reduced only by MPD. Administration of TZM or EZP did not cause any significant change in sleep parameters. These drugs in combination with noise or MPD resulted in almost complete recovery of the sleep disturbance induced by noise or MPD, except for a reduction in S-REM. These results indicate that model insomnia, particularly MPD insomnia, will assist in the evaluation of hypnotic drugs.

Adult↗
PubMed1976

Sensitivity to chlorpromazine effects on brain function of schizophrenics and normals. A preliminary report.

For the purpose of quantitative demonstration of the sensitivity to chlorpromazine (CPZ) effects on brain functions of schizophrenics and normal subjects, polygraphic recordings of electroencephalogram (EEG) and electrodermal response (EDR) were performed before and 3 h after oral administration of 25 mg of CPZ: percent time waking EEG (per cent W-EEG) and number per minute of EDR were measured during the resting period and the period of calculation. In 10 normal adult subject, both per cent W-EEG and number of EDR showed remarkable decrease after CPZ administration. In 22 schizophrenics, however, per cent W-EEG showed no significant decrease after CPZ administration. Number of EDR in schizophrenics during the period of calculation did not show any significant decrease. The neural mechanism underlying the lower sensitivity to CPZ effects in schizophrenics was discussed.

Adolescent↗
PubMed1975

A case of Déjerine-Sottas disease with schizophrenic symptoms. A clinical and pathological study.

A case of hypertrophic interstitial neuritis with a disturbance of intelligence and schizophrenic symptoms was reported. The patient, a 41-year-old male, showed monologia at the age of 14 and auditory hallucination at the age of 21. He was diagnosed as schizophrenia. Torsion of the head to the right side and muscular atrophy were also noticed at 21 years. Atrophy of the muscles progressed gradually, particularly in the distal parts of the upper and lower extremeties. Psychiatric examination revealed schizophrenic symptoms such as auditory hallucination, thought disorder, lack of spontaneity, autism, apathy, etc. There was also a disturbance of intelligence (imbecility). In neurological examination, the torsion of the head to the right side, slight exaggeration of the peripheral reflexes, muscular atrophy in the distal parts of the extremeties were noted. The bilateral ulnar nerves were markedly hypertrophied. The biopsy of the right ulnar nerve revealed a remarkable thickening of the endoneuria and "onion bulb" formations. A large amount of the interstitial accumulation of PAS positive substance, which showed metachromasia in cresyl violet staining, was also noted. Schwann cell processes were proved electron-microscopically to surround the myelin sheaths and some of them meandered and extended and into the metachromatic substance. The basement membrane of the sheath cell was hypertrophic in some portions and elongated into interstitium. The nucleus of the sheath cell was hyperchromic and showed marked atrophy. Histological examination of the biopsy specimen obtained from the gastrocnemius muscle suggested neurogenic muscular atrophy. The relationship among the hypertrophic interstitial neuritis, schizophrenic symptoms, disturbance of intelligence and torsion of the head was also discussed.

Adult↗
PubMed1975

Differential effects of chlorpromazine, imipramine, nitrazepam and amobarbital on REM sleep and REM density in man.

The effect of chlorpromazine (CPZ), imipramine (IMP), nitrazepam (NZP) and amobarbital sodium (AMOB) on the REM period of sleep (REMP) was investigated on four subjects by means of all-night sleep polygraphy with the schedule PPPDDDPP where P is placebo and D active drug. CPZ 25 mg resulted in a slight increase in %REMP, and no significant change in REM density (1 second fraction method) and total REM activity during the drug and withdrawal nights. IMP 25 mg produced moderate decrease in %REMP in the three drug nights, whereas REM density decreased only in the first drug night. NZP 5 mg resulted in a slight parallel suppression of %REMP, REM density and total REM activity during the drug nights. AMOB 200 mg produced a slight decrease in %REMP and marked decrease in REM density during the drug nights. Rebound increase of %REMP and a tendency of carry over decrease of REM density were observed in the withdrawal nights. Decrease in the REM density was more marked in AMOB than in NZP drug night. The importance of the simultaneous analysis of %REMP and REM density for the study of effects of psychotrophic drugs on sleep was emphasized.

Adult↗