Takuya Kojima

Eye movements in acute, chronic, and remitted schizophrenics ☆

Eye movements in 10 acute schizophrenics, 50 chronic schizophrenics, 20 remitted schizophrenics, 25 methamphetamine psychotics, 21 temporal lobe epileptics with left-sided spike focus (l-focus), 12 temporal lobe epileptics with right-sided spike focus (r-focus), and 50 normal controls were examined with an eye mark recorder while they viewed geometric figures. The eye movements while viewing an original S-shaped figure for 15 sec were analyzed. Each schizophrenic group and methamphetamine psychotics had significantly less eye fixations than the normal controls and temporal lobe epileptics (r-focus and l-focus). The chronic schizophrenics had significantly shorter mean eye scanning length (MESL) than the other six groups. Each subject was then shown two other figures slightly different from the original and was requested to compare them with the original. After comparing them, the subjects were asked the question, Are there any other differences? The 5-sec eye movements during the response to this question were scored using the Responsive Search Score (RSS). The schizophrenic groups had a significantly lower RSS than the nonschizophrenic patient groups and the normal controls. In the chronic schizophrenics, there was a significant negative correlation between the RSS and negative symptoms. These results suggest that the MESL can be an indicator of a chronic process of schizophrenia, and that lowering of the RSS may be a nosologically specific indicator for schizophrenia.

Age development and sex differences of various EEG elements in healthy children and adults — Quantification by a computerized wave form recognition method

The EEGs of 1416 healthy subjects aged 6-39 years were recorded and 1 min of background activity from Fp1, C3 and O1, was analyzed by a computerized wave form recognition method. Age development and sex differences of various EEG elements, which are employed in a conventional clinical EEG assessment, were statistically analyzed. The age developments of alpha and theta showed regional differences and were the most rapid in O1 and the slowest in C3. The delta amplitude, theta amplitude, theta continuity and percentage time of theta with an amplitude of 30 microV or more, which are important in a clinical EEG assessment, reached a stable level at 18-21 years of age in the 3 leads. The percentage time, amplitude and continuity of alpha in the 3 leads reached a stable level at 22-25 years of age. Including the low voltage theta in Fp1 and C3, all of the EEG elements reached the stable adult level at 26-29 years of age. Since there was a large interindividual variability in these age developments, the regression curves of the 10th and 90th percentiles of these EEG elements can be considered as quantitative standards for clinical EEG evaluation. As for sex differences, the percentage alpha time and alpha continuity were greater in males than in females after adolescence. The percentage theta time in Fp1 and C3 was greater in females than in males during childhood. The percentage beta time was higher in females than in males at all ages. But overall, these sex differences were minor compared with the differences associated with age developments of the EEG elements.

Epileptiform EEG Discharges in Healthy Children: Prevalence, Emotional and Behavioral Correlates, and Genetic Influences

Summary: Epileptiform discharges in 8 electrode waking EEGs at rest and during hyperventilation in 1,057 healthy children aged 6–12 years from an elementary school were studied: Epileptiform discharges, detected in 53 children (5.0%), consisted of centrotemporal spikes (37 cases), generalized spike ahd slow wave complexes (10 cases), occipital spikes (2 cases), frontal spikes (1 case), and a combination of multiple spike and slow wave complexes and focal spikes (2 cases). The occurrence of a positive past history of febrile convulsions was higher in children with epileptiform discharges (18.9%) than in those without epileptiform discharges (9.4%). Using the Rutter scales for teachers and parents, we compared the emotional and behavioral problems of children with epileptiform EEG discharges with those of children without epileptiform discharges. No statistically significant differences were noted, indicating that the emotional and behavioral problems existing are most probably coincidental and not directly related to the epileptiform discharges. A genetic basis for generalized epileptiform discharges was postulated because the occurrence of generalized discharges in siblings of probands with generalized discharges was higher (4 of 9, 44.4%) than the prevalence in all subjects. However, the occurrence of centrotemporat spikes in the siblings of probands with centrotemporal spikes was not higher (2/38, 5.3%) and an autosomaldominant genetic factor for centrotemporal spikes in waking EEGs of healthy children could not be confirmed.

Dynamic relationships between sleep spindles and delta waves during a NREM period.

All-night sleep EEGs from 7 normal young male adults were analyzed by a waveform recognition method using FFT-IFFT band pass filters. The total durations of sleep spindles and sleep delta waves in each 20-s epoch were measured and plotted on an X-Y graph with lines connecting the points in time sequence (dynamic two-component plot). The relationship between these two measures within a single NREM period showed three dynamic phases and one stationary period. In the first phase, spindles increased while delta remained at low level or increased slightly. In the second phase delta increased greatly while spindles decreased. In the third phase, delta decreased while spindles remained at a low level. There was a stationary period between the second and third phases, when delta maintained a higher level and spindles maintained a lower level. These dynamic descriptions reflect the underlying physiological mechanisms more directly than static sleep stages. They should also permit finer analyses of sleep in psychiatric and neurological disorders.

Exploratory eye movements in schizophrenic patients and patients with frontal lobe lesions

SummaryExploratory eye movements in 20 schizophrenics, 18 patients with frontal lobe lesions (9 right-sided and 9 left-sided) and 20 normal controls were examined with an eye mark recorder while they viewed stationary S-shaped figures. The eye movements made during the subjects first 15-s viewing of an original figure were analyzed. Patients with right frontal lobe lesions (RF) and schizophrenics (S) had lower scores than normal controls (NC) for the number of eye fixations, total eye scanning length and mean eye scanning length. Each subject was then shown two other figures slightly different from the original and was requested to compare them with the original. After comparing them, the subject wastasked the question, “Are there any other differences?” The eye movements made over the ensuing 5 s in response to this question were scored using the responsive search score (RSS). The RSS was low only in the S group. The subject was also asked to reproduce the original figure before and after making comparisons between the figures. The RF and S groups were poorer at reproduction than the NC group. These findings suggest that there is disordered function of the right frontal lobe in sehizophrenia, and that schizophrenia is due not only to localized damage to one part of the brain but to more widespread damage.

An epidemiological investigation of emotional and behavioural problems in primary school children in Japan

Summary1860 primary school children, aged from 6 to 12 years, from urban suburban and rural areas in Japan were assessed by their school teachers according to the Rutter scale. The prevalence of children with deviant scores in the general population was 3% and this figure was lower than that for any other country assessed by the same scale. Eighty-four percent of the deviants were of an antisocial type but only 7% were neurotic. The ratio of antisocial to neurotic was higher than those from other countries. The prevalence of children with deviant scores was higher in boys than in girls, and also higher in early and middle school years than in late school years. Area, family occupation, sibship size, birth order and one-parent family had only limited effects on the deviant behaviour of the children.

Eye Movement as an Indicator of Brain Function

Abstract: The level of consciousness between the alert and drowsy states was classified into four stages (Alert, Resting I, Resting II, Drowsy) by studying three factors of the EEG patterns on 23 normal subjects. The eye movements recorded by electro‐oculograph were divided into two groups, i.e. rapid eye movements (R type, r type) and slow eye movements (S type, s type). The occurrence of each type of eye movements was confirmed to change in close correspondence to the stages of consciousness.

Topographical changes in alpha power in medicated and unmedicated schizophrenics during digits span reverse matching test

The topographical distribution of alpha power reduction was compared in nine unmedicated schizophrenics (predominantly never-treated), 17 medicated schizophrenics, and 15 normal controls. The task involved four procedures: (1) listening to signal sound, (2) listening to digits for memorization, (3) after listening, and (4) listening to digits for recognition. The electroencephalograms (EEGs) during each procedure were analyzed with Fast Fourier Transformation and compared with EEGs at rest. While listening to the digits, medicated schizophrenics showed less alpha power reduction than normal controls and unmedicated schizophrenics. In addition, there were correlations found between the degree of alpha power reduction and medication dose, and score of chronic symptoms. These suggest that patients with different clinical backgrounds have differing cerebral activity.

A Multi‐Institutional Study on a New Five‐Axial Classification Sys‐ tem for Epileptic Psychoses.

Purpose: The pathophysiology and clinical phenomenology of epileptic psychoses are wide and varied, and an internationally accepted classification system has yet to be established. A multi‐axial classification should be developed to capture the complexity of clinicai situations and to describe the heterogeneity of individuals presenting with the same diagnosis. We propose a new 5‐axial classification system based on a review of the previous literature and evaluate its validity and applicability in Japan by a multi‐institutional design.

The long-term prognosis of patients with temporal lobe epilepsy for more than 20 years.

A recent community based prospective study’ on a long-term prognosis of temporal lobe epilepsy (TLE) revealed that onethird of patients showed full recovery, i.e., were supporting themselves socially and economically and were seizure free with no medication. This means that the diagnosis of TLE per se does not offer any information for a long-term prognosis. The clinical features of patients with TLE who show a poor long-term prognosis need to be specified. In 1989, a “Classification of Epilepsies and Epileptic Syndromes” was proposed by the International League Against Epilepsy. TLE is divided into two subtypes according to the classification-amygdalo-hippocampal seizures and lateral temporal seizures. The present paper aims to clarify the long-term outcome of TLE with respect to its subtypes.