Functional and Anatomical Brain Imaging: Impact on Schizophrenia Research

Abstract

A group of related new technologies has made it possible to study the brain's regional changes in metabolism, blood flow, electrical activity, and neurochemistry. Positron emission tomography (PET) produces slice images of radioisotope density--brain metabolism or receptor concentration can be quantitated. Studies in schizophrenia have indicated relative metabolic underactivity of the frontal lobes of schizophrenics. Decreased activity in the basal ganglia, which can be reversed with neuroleptic treatment, is also seen in schizophrenia. PET studies are in the early stages; standard methodology for isotope selection, task during tracer uptake, and quantitative analysis is still developing. Cerebral blood flow studies have shown similar patterns in the cortical surface. The electroencephalogram provides a short time resolution approach which can assess attention and arousal, but lacks some of the anatomic exactness and depth capabilities of PET. Magnetic resonance imaging furnishes anatomical images of gray and white matter previously unavailable with x-ray computed tomography. Advances in methodology and clinical studies with imaging are making neuroanatomic theories of schizophrenia more directly testable than ever before.

Nicotine improves antisaccade task performance without affecting prosaccades

“…This finding is potentially relevant to understanding smoking patterns in schizophrenia. In schizophrenia, hypofrontality is perhaps the most frequently reported electrophysiological symptom (see Buchsbaum, 1990 for review), and impaired AS performance has been clearly demonstrated (Arolt et al, 1998;Crawford et al, 1995;Fukushima et al, 1988;Fukushima et al, 1990a;Fukushima et al, 1990b;Karoumi et al, 1998;Sereno and Holzman, 1995;Thacker et al, 1989). Furthermore, this population shows a much greater rate of cigarette smoking than the norm (deLeon, 1996;deLeon et al, 1995;Hughes et al, 1986;Lawrie et al, 1995;Lohr and Flynn, 1992;O'Farrell et al, 1983;Ziedonis et al, 1994).…”

Quantitative EEG in Schizophrenic Patients before and during Pharmacotherapy

“…Negative correlation between delta rhythm and cortical metabolism was also established [26], as well as positive correlation between delta activity and negative symptoms [27].…”

Ventricular Size, Cognitive and Psychomotor Performance, and Laterality in Schizophrenia

“…by the ven tricular brain ratio (VBR) [for review see Maser and Keith, 1983;Buchsbaum and Haier, 1987], Cognitive impairment, so-called negative symptoms and poor out come have been found to be related to atrophy in the majority of studies [Crow, 1985], Moreover, evidence from neuropsychological and other investigations sug gests lateralized abnormalities predominantly involving the left hemisphere in schizophrenia [Gruzelier, 1981[Gruzelier, , 1986Newlin et al, 1981;Wexler, 1980], Finally, there are indications for an increased sensitivity to parkinso nian side effects of neuroleptics in patients with brain atrophy [Bowers, 1985;Luchins et al, 1983]. Therefore, the present study focused on the possible relationship between indices of global (conventional VBR) and later alized (hemispheric VBR) brain atrophy and tests of per formance.…”