Thalamic volume in first-episode and chronic schizophrenic subjects: a volumetric MRI study.

OBJECTIVE: The thalamus, as a composite of several functionally very different nuclei, is a major relay and filter station in the CNS and is significantly involved in information processing and gating. The aim of our study is to investigate first-episode and chronic patients and controls to shed light on the potential pathogenetic role of the thalamus in schizophrenia and to assess the relationship between thalamic volumes and psychopathology ratings. METHODS: Forty-three male right-handed chronic and 25 male right-handed first-episode schizophrenic patients treated at the psychiatric hospital of the Ludwig-Maximilians University in Munich and 50 male control subjects were enrolled into the study. Demographic information and current symptom profile of all schizophrenic subjects were assessed using a semistructured interview, including a variety of measures relevant to the study. Volumetry of the thalamic gray and white matter was obtained with 1.5 T MRI, using the BRAINS software application. RESULTS: No significant differences regarding thalamic volumes were detected across groups. However, negative symptoms were significantly correlated with thalamic volumes in first-episode patients, whereas duration of illness and extrapyramidal symptoms were related to thalamic volumes in chronic patients. SUMMARY: Our findings indicate that, while the thalamus might be involved in the pathogenesis of negative symptoms, thalamic volume reduction is not a required element in the pathophysiology of the schizophrenic phenotype.

Dipole localization of P300 and normal aging.

At present, our understanding of how normal aging affects in vivo brain function is rudimentary. Therefore, the aim of the present study was to investigate age effects on auditory P300 topography. A recently developed dipole source model for P300 distinguishes overlapping P300 subcomponents and enhances reliability as well as validity of the measurement. 67 healthy subjects were examined using the P300 dipole model in addition to the scalp data measurement. The results show that P300 subcomponents reflect functionally different processes concerning age changes of P300 activities. Temporo-parietal P300 is smaller in older subjects, whereas frontal P300 is not attenuated. Age affected both P300 subcomponents' latencies. Therefore, the functionally different alteration of P300 subcomponents might be the reason for P300 topography changes with the P300 maximum more frontally in older age.

Adhesio interthalamica in male patients with schizophrenia.

OBJECTIVE: The authors investigated whether absence of the adhesio interthalamica in patients with schizophrenia constitutes a marker of early developmental neuropathological changes. METHOD: Thirty male patients with schizophrenia and 30 healthy male subjects were recruited for study. Magnetic resonance imaging was performed, and the presence or absence of the adhesio interthalamica was determined for each subject. The length and volume of the third ventricle were also measured. RESULTS: No differences in the presence or absence of the adhesio interthalamica were found between patients with schizophrenia and normal comparison subjects. Patients without the adhesio interthalamica had significantly higher scores for negative symptoms than patients with the adhesio interthalamica. There was no correlation between absence of the adhesio interthalamica and length and volume of the third ventricle in either patients or comparison subjects. CONCLUSIONS: The findings suggest that patients with schizophrenia who do not have the adhesio interthalamica are characterized by more severe negative symptoms.