Yukiteru Machiyama

An epidemiological study of tics

Abstract: We devised a questionnaire for estimation of each tic, and used a two‐step investigation procedure, first by a parent questionnaire with 1,218 responses and second by a confirmatory telephone interview for 197 positive responses. The average estimated values were 11.3% for boys and 5.2% for girls. The prevalences were–blinking: 4.2%, head‐jerking: 1.6%, shrugging: 1.2%, mouth‐twitching: 0.6%, face‐distortion: 0.5%, mouth‐opening: 0%, throat‐clearing: 2.7%, sniffing: 0.6%, and vocalization: 0.2%. According to the criteria in DSM‐III‐R, 5.1% of 1,218 had TTD, 2.2% had CMVTD, and 0.5% had Tourette disorder.

Aberrant judgmental pattern of schizophrenic patients in weight discrimination

Sixteen chronic schizophrenics and 16 normal controls were tested on a weight discrimination task in various categories and hand conditions. Schizophrenics made significantly more errors than normals when the ‘equal’ category was included, whereas schizophrenics’ performance could approximate the normals’ discriminations when the ‘equal’ category was excluded. In the former condition, the more inaccurate performance of schizophrenics was ascribed to the selective increase in the errors by the ‘equal’ judgments, which was not due to an increase in ‘doubtful’ judgments. These findings were assumed to reflect schizophrenics’ preference to equal judgments, which seemed to be their fundamental cognitive attitude, because the same tendency was found on the various discrimination tasks of other sensory modalities. Furthermore, the present results supported neither left hemisphere dysfunction nor interhemispheric transfer deficit in schizophrenia, because schizophrenics failed to show consistently more errors in the right hand and the bimanual conditions.

Estimation of Epileptic Foci Using the Dipole Tracing Method in Epileptic Seizures with Structural Lesions of the Brain

Abstract We estimated the position of the epileptic focus using the dipole tracing method (DTM) in three patients with epileptic seizures and structural lesions, and made comparisons between the foci and their lesions. Patient 1 had a large arachnoid cyst in the right temporal lobe, patient 2 had a tumor in the right hippocampus, and patient 3 had a tumor in the right amygdala. In patient 1, the epileptic focus was estimated to lie in the lateral portion of the right temporal lobe just outside the cyst; in patient 2, in the right hippocampus just under the tumor; and in patient 3, one in the right hippocampus just behind the tumor, another in the right superior temporal gyrus (rSTG). Except for the focus of patient 3 on rSTG, the epileptic foci in all three patients were estimated to lie near the lesions. These estimations correlated with past reports that most foci of seizures caused by brain lesions were located near the lesions. The results of ECoGs in patient 3 were in close correlation with those of DTM. Therefore, we conclude that DTM is a highly accurate method in the estimation of the foci in patients with brain lesions associated with epileptic seizures.

Mapping Epileptic Foci by the Dipole Tracing Method in a Brain Tumor Patient with Olfactory Seizures: Comparison with Intraoperative Electrocorticograms

We estimated the position of the epileptic foci in a case of brain tumor with olfactory seizures using the Dipole Tracing Method (DTM) and compared the results with electrocorticograms (ECoGs) recorded during surgical resection. The case was a 24-year-old male. Electroencephalograms (EEG) showed frequent focal spikes in the right temporal area. Magnetic resonance imaging revealed a tumor in the right hippocampus region. We analyzed the spikes using DTM with a CDT-1000 EEG analyzer. The locations of two independent foci were analyzed; one was thought to be in the right hippocampus and the other in the right superior temporal gyrus. When the ECoG was taken, the results were in very close correlation with those of DTM, demonstrating the accuracy of DTM in the estimation of the location of epileptic foci in epileptic seizures with brain lesions.

Auditory Event-Related Potentials in Schizophrenia

A comparative study on the hemispheric differences was made between 12 righthanded patients with endogenous depression and 12 normal controls matched in age and sex. EEGs from the frontal and parietal regions of both hemispheres were analyzed by means of an FFT technique under the resting and non-loading baseline condition and auditory evoked potentials ( AEP) were recorded from the same portions of the brain under the same condition. The patient group showed a relative rightsided predominance of laterality index (L.I.) of peak alpha amplitudes in the frontal regions compared with that in the parietal regions, while the control group showed none of such L.I. differences between both regions. In the frequency of peak alpha, the patient group also showed the same trend as the amplitude but the difference was not statistically significant. Concerning the AEP amplitudes, a reversed relationship to the EEG amplitude was seen between both groups of subjects. There were no L.I. differences of P1-Nl amplitudes between the frontal and parietal regions in the patient group, in contrast to a relative right-sided L.I. predominance of the frontal region in the control group. These results consistently indicate a relative hypoactivation in the frontal region to the parietal region of the non-dominant hemisphere in Japanese depressive patients; just the opposite characteristics to the frontal activation of the non-dominant hemisphere reported with the subjects of Western countries.