Lateral ventricular size and drug-induced Parkinsonism.

Computed Tomography (CT) was used to assess lateral ventricular size in 20 psychiatric inpatients who had participated in at least 5 weeks of a fixed dose chlorpromazine (CPZ) trial. During treatment with CPZ, eight patients had required antiparkinsonian medication for treatment of rigidity. The ventricular brain ratio (VBR) of these eight patients was greater than that of either the 12 patients who did not require antiparkinsonian medication or a similarly aged control group of neurological patients, scanned for tension or migraine headaches. On the basis of these findings it is suggested that large lateral ventricular size may be associated with increased vulnerability to develop drug-induced parkinsonism.