Dyskinesia : An analysis of abnormal involuntary movement types among white psychiatric inmates of Town Hill Hospital, Pietermaritzburg.

Abstract

An overview of the varied clinico-neurological features of dyskinesias in

general is presented, and literature an the epidemiology af tardive dyskinesia since the introduction of antipsychotic drugs in 1950, reviewed. Furthermore reasons for the wide variations in previously

published prevalence figures have been critically highlighted, and

suggestions based upon the current state of clinical and experimental

knowledge put forward concerning the pathogenesis of drug induced

movement disorders.

The type and prevalence of abnormal or purposeless involuntary movements has been surveyed among a large sample of long term White patients

resident in Town Hill Hospital for a period of not less than 4 years, mast af whom were either currently receiving or had received neuroleptic

medication. This sample comprised 190 men and 98 women whose ages ranged from the third to the ninth decade. Patients manifesting abnormal

movements were grouped into 5 general diagnostic categories for analysis viz. schisophrenic disorders, affective disorders, organic brain disorders and syndromes, defective mental development and discrete

neurological disorder. The movements were clinically classified in terms

cf the areas of the body involved and semi quantitatively measured according to a standardised duration rating scale procedure.

Involuntary movements were noted to be present in a total o-f 83 patients examined, most o-f which were adjudged to correspond to the syndrome currently termed 'tardive dyskinesia'. Subtype analysis o-f movement

distribution indicated that 277. of cases manifested classical oro-facial

dyskinesia while 527. showed body dyskinesia o-f the type designated

' pseudaakathisia'; the balance o-f the patients presented combinations o-f

the two types.

Schizophrenic disorders constituted the commonest diagnostic category in the dyskinesia group up to the fifth decade. Functionally obtrusive

involuntary movements were observed in only some 77. of the patients with

dyskinesia. Prevalence overall was equal between the sexes, and no

correlations were discerned between age, sex, diagnosis or dyskinesia

subtype of cases and the rating scores obtained.

Prevalence rates obtained by this survey are favourably low by comparison with many results of overseas investigators, and are similar in this

respect to figures reported in the very few prevalence studies carried

out to date in South African institutions.