The inter-relationships of tardive dyskinesia, parkinsonism, akathisia and tardive dystonia: the Curaçao Extrapyramidal Syndromes Study II.

A study of the four extrapyramidal syndromes (EPS), tardive dyskinesia, parkinsonism, akathisia and tardive dystonia, was performed in the Netherlands Antilles, a well-defined catchment area with only one psychiatric hospital. The population under study (N = 194; mean age 53.1) was mainly Afro-Caribbean, and most patients were chronic. The severity of each EPS was measured with valid and reliable rating scales. The purpose was to study both the strength of the inter-relationships of EPS and the prevalence of combinations of EPS. The inter-relationships between the EPS were analyzed by means of logistic regression. The adjusted odds ratios between the various EPS revealed strong connections between the hyperkinetic syndromes (tardive dyskinesia, tardive dystonia and akathisia). Parkinsonism was found to be inversely related to tardive dyskinesia and to tardive dystonia. Almost 30% of the patients suffered from two or more EPS. The highest prevalence rates of combinations were: tardive dyskinesia combined with parkinsonism 12.9%, tardive dyskinesia combined with tardive dystonia 9.8%, and tardive dyskinesia combined with akathisia 5.2%. Our findings show a strong positive correlation between hyperkinetic forms of EPS. Furthermore, chronic psychiatric inpatients regularly suffer from combinations of EPS. Different treatment strategies are suggested for various combinations of EPS.