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Biomedical subjects

Yasuhiro Kawasaki

Publications and source records attributed to Yasuhiro Kawasaki.

30 records · Page 2Linked to original sources
PubMed2004

Lack of normal gender differences of the perigenual cingulate gyrus in schizophrenia spectrum disorders. A magnetic resonance imaging study.

We have previously reported a lack of normal gender differences of the perigenual cingulate gyrus in patients with schizophrenia. The purpose of this study was to examine the perigenual cingulate gyrus morphology in patients with schizotypal disorder. We investigated volume of the gray and white matter of the perigenual cingulate gyrus in 26 patients with schizotypal disorder (14 males, 12 females) in comparison with 61 age- and gender-matched healthy controls (30 males, 31 females) and 58 schizophrenia patients (31 males, 27 females) using magnetic resonance imaging. The volumetric measures of the perigenual cingulate gyrus were compared among the three groups that were entered into the same multiple analysis of variance model. The gray and white matter volume of the perigenual cingulate gyrus in the schizotypal patients did not differ significantly from the values in the healthy controls or the schizophrenia patients. Similar to schizophrenia, however, the schizotypal patients showed a lack of normal gender differences of the perigenual cingulate gray matter seen in the healthy controls (females > males). These results suggest that both schizotypal and schizophrenia patients may share the same disruption of the normal pattern of gender differences of the perigenual cingulate gyrus.

Adolescent↗
PubMed2004

Event-related potentials elicited by non-target tones in an auditory oddball paradigm in schizophrenia.

It has been reported that in event-related potentials (ERPs) elicited by non-target tones in oddball paradigms, the superimposition of a negative component on the descending slope of N100 depends on subjects' attention to the task. We tested the possibility that this attention-related change is abnormal for patients with schizophrenia. ERPs induced by non-target, frequent tones were measured for 52 patients and 31 healthy controls under two oddball conditions: a passive condition where the subjects were told to disregard the tones, and an active condition where they were instructed to respond to infrequent tones. For both groups, a negative component was superimposed from the descending slope of N100 to the end of P150 (latency, 120-200 ms) for the active condition. The peak latency of this attention-related negative component was longer for the patients than for the controls, while the amplitude showed no group difference. In addition, the active P150 for the patients was more enlarged than that for the controls. Furthermore, the active P150 amplitude for the patients correlated positively with the score for the negative symptom factor of the Positive and Negative Syndrome Scale. These findings suggest that the enlargement of non-target P150 observed in conjunction with the latency prolongation of the attention-related negative component may be a biological marker for the severity of the negative symptoms in schizophrenia.

Acoustic Stimulation↗
PubMed2004

Multiple structural brain measures obtained by three-dimensional magnetic resonance imaging to distinguish between schizophrenia patients and normal subjects.

This study was designed to investigate the extent to which schizophrenia patients can be differentiated from normal subjects by structural brain measures. High-resolution magnetic resonance imaging scans were performed on 57 schizophrenia patients (30 males, 27 females) and 47 normal controls (25 males, 22 females). Significant enlargements of the left and right body of the lateral ventricle, the left and right sylvian fissure, and the third ventricle were observed in the male patients. Significant enlargements of the left inferior horn, and the left and right sylvian fissure, and a significant volume reduction of the right temporal lobe were observed in the female patients. Discriminant function analysis using brain anatomical measures as variables allowed correct classification of 80.0 percent of the male patients, 80.0 percent of the male controls, 77.8 percent of the female patients, and 86.4 percent of the female controls. These findings support the view that schizophrenia patients have structural deviations in multiple brain areas and that a combination of structural brain measures can distinguish between patients and controls.

Adolescent↗
PubMed2004

High-performance computing service over the internet for intraoperative image processing.

This paper presents a framework for a cluster system that is suited for high-resolution image processing over the Internet during surgery. The system realizes high-performance computing (HPC) assisted surgery, which allows surgeons to utilize HPC resources remote from the operating room. One application available in the system is an intraoperative estimator for the range of motion (ROM) adjustment in total hip replacement (THR) surgery. In order to perform this computation-intensive estimation during surgery, we parallelize the ROM estimator on a cluster of 64 PCs, each with two CPUs. Acceleration techniques such as dynamic load balancing and data compression methods are incorporated into the system. The system also provides a remote-access service over the Internet with a secure execution environment. We applied the system to an actual THR surgery performed at Osaka University Hospital and confirmed that it realizes intraoperative ROM estimation without degrading the resolution of images and limiting the area for estimations.

Arthroplasty, Replacement, Hip↗
PubMed2003

Decreased volume and increased asymmetry of the anterior limb of the internal capsule in patients with schizophrenia.

BACKGROUND: The anterior limb of the internal capsule (ALIC) contains the anterior thalamic peduncle connecting the medial and anterior thalamic nuclei with the prefrontal cortex and the cingulate gyrus. The purpose of this study was to detect the volumetric changes in the ALIC in view of the putative abnormal frontothalamic connectivity in schizophrenia. METHODS: High-resolution, three-dimensional magnetic resonance imaging was acquired from 53 schizophrenia patients and 48 age- and gender-matched control subjects. Volumetric analysis was performed using consecutive 1-mm-thick coronal slices rostral to the anterior commissure, on the ALIC, caudate nucleus, and lentiform nucleus. White matter concentration over the whole brain was compared using the voxel-based morphometry (VBM) with Statistical Parametric Mapping 99. RESULTS: The patients had significantly decreased volumes in the bilateral ALIC and showed significantly increased right-greater-than-left asymmetry of the ALIC; VBM revealed a reduction in white matter concentration of the bilateral internal capsule in patients. No volumetric difference was found in the rostral part of the caudate and lentiform nucleus between groups. CONCLUSIONS: Decreased volume found in the ALIC supports the hypothesis of abnormal frontothalamic connectivity in schizophrenia. Increased asymmetry of the internal capsule seems consistent with the notion of predominantly left-side pathology of schizophrenia.

Adult↗
PubMed2003

Perigenual cingulate gyrus volume in patients with schizophrenia: a magnetic resonance imaging study.

BACKGROUND: Anterior cingulate gyrus abnormalities have been suggested to be involved in the pathophysiology of schizophrenia; however, little is known about morphologic changes in the perigenual cingulate gyrus in schizophrenia patients. METHODS: We investigated perigenual cingulate gyrus volume in 40 schizophrenia patients (20 men, 20 women) and 40 age- and gender-matched normal controls using magnetic resonance imaging. Volume of both gray and white matter of the perigenual cingulate gyrus was measured on consecutive axial 1-mm slices. RESULTS: Total (left and right) perigenual cingulate gray matter volume was significantly reduced in female schizophrenia patients compared with female controls. There was no significant difference in the gray matter volume of the perigenual cingulate gyrus between male patients and male controls. Left perigenual cingulate white matter volume was significantly reduced in the patient compared with the control group. Furthermore, significant gender differences were found in the total gray and white matter volume of the perigenual cingulate gyrus in control subjects (women > men), although these gender differences were not significant in the patient group. CONCLUSIONS: Our findings suggests volume reduction of the perigenual cingulate gyrus in schizophrenia patients, especially women and that gender differences in perigenual cingulate morphology among normal subjects are, as has been suggested for other parts of the brain, reduced in schizophrenia patients.

Adolescent↗
PubMed2003

Auditory P300 amplitude as a state marker for positive symptoms in schizophrenia: cross-sectional and retrospective longitudinal studies.

The amplitude of the P300 component of the auditory event-related brain potential (ERP) is consistently reduced in schizophrenia. To determine whether this P300 abnormality can be used as a state marker to reflect the severity of symptoms, we examined both cross-sectionally and longitudinally the relationship between auditory P300 amplitude and symptom severity in patients with schizophrenia. For the cross-sectional study, ERP was elicited by an auditory oddball paradigm, and symptom severity was quantitatively measured by means of the Positive and Negative Syndrome Scale in 93 patients with schizophrenia or schizophreniform disorder (DSM-III-R). For the longitudinal study, ERP and psychopathology measured twice at an average interval of 238 days for 20 patients were retrospectively analyzed. The cross-sectional data showed that P300 amplitude correlated negatively with the positive but not with the negative syndrome scale score. The longitudinal data also showed a significant negative correlation between changes in P300 amplitude and in the positive syndrome scores of the first and second tests. In particular, P300 amplitude recorded at the left, but not right, posterior temporal region significantly correlated with the positive syndrome in both the cross-sectional and longitudinal studies. These findings support the hypotheses that auditory P300 amplitude recorded in the left hemisphere can be used as a state marker to reflect the severity of the positive symptoms and that the positive symptoms may be caused by a possible left-hemisphere deficit in schizophrenia.

Adult↗
PubMed2002

Lack of self-control as assessed by a personality inventory is related to reduced volume of supplementary motor area.

The present study was performed to examine the relationship between schizophrenia-related personality and brain morphometry. Magnetic resonance (MR) imaging and schizophrenia-related personality scales extracted from the Minnesota Multiphasic Personality Inventory (MMPI) were administered to 42 university students. Analysis of the relationships between the gray matter segmented from the MR images on a voxel-by-voxel basis through the use of the statistical parametric mapping technique and the schizophrenia-related personality subscale scores from the MMPI revealed that lack of self-control subscale scores were negatively related to the gray matter volume of the supplementary motor area (SMA). Furthermore, it was suggested that self-control including self-inhibition is associated with the density of the SMA, the precuneous and the cerebellar vermis, which govern voluntary movements and motor imagery. These results provide important clues to the neural basis for the disturbance of self commonly observed in schizophrenia spectrum disorders.

Adult↗
PubMed2002

Lack of normal structural asymmetry of the anterior cingulate gyrus in female patients with schizophrenia: a volumetric magnetic resonance imaging study.

We investigated anterior cingulate gyrus (ACG) volume in 40 patients with schizophrenia (20 males, 20 females) and 40 age-and sex-matched normal controls using three-dimensional magnetic resonance imaging (MRI). Volumes of the whole brain and both the gray and white matter of the ACG were measured on consecutive coronal 1-mm slices. There was no significant difference between the patients with schizophrenia and the normal controls in the whole brain volume. Right ACG gray matter volume was significantly reduced in the female patients with schizophrenia as compared with the female controls. Furthermore.in the female controls, ACG gray matter volume was significantly larger on the right than on the left, while this asymmetry was not significant in the female patients. ACG white matter findings were similar to those of the ACG gray matter in that the volume was significantly larger on the right in the female controls, and this normal structural asymmetry was reduced in the female patients. These results suggest that gender may play an important role in the structural asymmetry anomalies in schizophrenia.

Adult↗
PubMed2002

Regional changes in brain gray and white matter in patients with schizophrenia demonstrated with voxel-based analysis of MRI.

This study examined regional structural changes in the whole brain in 45 medicated patients with schizophrenia (23 males and 22 females), comparing with 42 age- and sex-matched healthy volunteers (22 males and 20 females). Automated voxel-based analysis on three-dimensional magnetic resonance imaging (MRI) was conducted using statistical parametric mapping (SPM). Compared with the controls, relative gray matter in the patients was significantly reduced in the left superior temporal, left middle and inferior frontal, right inferior frontal, and bilateral anterior cingulate and medial temporal areas. Gray matter reductions in the left superior temporal and prefrontal areas were found predominantly in the male patients, while the anterior cingulate gray mater reduction was more striking in the female patients. On the contrary, significant gray matter increases in the patients were found in the parietal areas and the cerebellum. In the white matter, significant reduction was found in the bilateral anterior limbs of the internal capsule and the superior occipitofrontal fasciculus, whereas the bilateral parietal white matter showed significant increases. These results suggest that a pathological process in schizophrenia predominantly affects the fronto-temporolimbic-paralimbic regions. Reduced white matter in the connecting bundles, which was first found in this study, may imply morphological substrates for abnormalities in the fronto-thalamic and fronto-temporolimbic connectivity in schizophrenia.

Adolescent↗
PubMed2002

Volumetric magnetic resonance imaging study of the anterior cingulate gyrus in schizotypal disorder.

Lack of normal structural asymmetry of the anterior cingulate gyrus (ACG) in patients with schizophrenia has been reported in our previous study. However, to our knowledge, no morphological studies of the brain have examined changes in ACG volume in patients with schizotypal features. We investigated the volume of the gray matter and the white matter of the ACG by three-dimensional magnetic resonance imaging (MRI) in 24 patients who met the ICD-10 criteria for schizotypal disorder (12 males, 12 females) in comparison with 48 age- and gender-matched healthy control subjects (24 males, 24 females) and 40 patients with schizophrenia (20 males, 20 females). As we reported previously, right ACG gray matter volume was significantly reduced in the female patients with schizophrenia compared with the female controls. On the other hand, the gray and white matter volume of the ACG in the patients with schizotypal disorder did not differ significantly from the values in the healthy controls or the patients with schizophrenia. However, the female patients with schizotypal disorder showed a lack of right-greater-than-left asymmetry of the ACG gray and white matter found in the female controls. These results suggest that both schizotypal and schizophrenic subjects share, at least in part, the same cerebral asymmetry abnormalities.

Adolescent↗