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Neuroimage Analysis Center: Collaborations |
Psychiatry |
Our
laboratory's major focus over the last several years has been the investigation
of temporal lobe abnormalities in schizophrenia MR images represent an improvement
over CT images which are prone to "bone" hardening, particularly
in temporal lobe regions, and which, unlike MR, do not provide detailed contrast
between soft tissues such as gray matter, white matter and cerebrospinal
fluid (CSF) in the brain.
In the brains of schizophrenic patients, both post-mortem and structural studies seem to suggest that the temporal lobe may be implicated in the physiology of schizophrenia. More specifically, post-mortem investigations suggest that abnormalities pertaining to shape and size in the brains of schizophrenic patients show a selectivity to temporal lobe structures, especially limbic system, and especially pronounced on the left.
Shenton, Kikinis, Jolesz, et al... 1992
McCarley, Wible, Frumin, et al... 1999
Kwon, McCarley, Hirayasu, et al... 1999
Shenton, Dickey, Frumin, et al... 2001
SPD
is characterised by cognitive or perceptual distortions, an inability to
tolerate close friendships, and odd behavior, but not frank psychosis. The
hypothesis of a close link between schizotypal disorder (SPD) and schizophrenia
(SZ) is strongly supported by the presence of numerous phenotypic similarities,
including neurochemical and performance measures of attention and information
processing. Genetic-epidemiologic studies now suggest that the spectrum disorders
share a common heritability, and thus the presence of such a SPD-SZ link
implies that the schizophrenia spectrum abnormalities might be studied in
SPD without the complicating variables present in SZ. A pilot study has produced
striking findings suggesting that SPD patients indeed have many of the biological
characteristics of schizophrenics, including disorders of verbal memory and
lowered event-related potential, which shows processing of unusual stimuli.
Physiologically, these disorders can be seen in MRI volume reduction of gray
matter of amygdala/hippocampus and increase in CSF in the temporal horn of
the lateral ventricles, with both anomalies especially prominent on the left.