CT abnormalities in tardive dyskinesia

Many investigators have suspected neuropathology in tardive dyskinesia (TD) to center in the striatum. Previous computed tomographic (CT) studies of middle-aged and older subjects using linear measurements have reported primarily negative results. The present study attempts to identify neuropathological abnormalities in the periventricular region of young chronic schizophrenics using specific area measurements of in vivo brain imaging. A ratio of frontal horn area to maximal internal skull area (FHBR) was used in an effort to gain sensitivity and give a reliable measure of caudate atrophy. The ventricle-brain ratio (VBR) measurement and a cortical atrophy rating were also done. The TD and non-TD control groups did differ in the CT variables. Negative CT results do not rule out the possibility that more subtle neuropathological abnormalities may be present. Magnetic resonance imaging, with its superior gray/white matter differentiation and its ability to detect subtle differences in tissue, may discover abnormalities in TD.