Extrapyramidal Symptoms As Predictors of Future TD

The neuroleptics produce a variety of acute, temporary neurological disorders referred to as extrapyramidal symptoms (EPS) in the great majority of patients. As described in chapter 3, drug-induced parkinsonism is one 

These acute EPS reactions often resemble TD, and indeed, the dystonias and akathisia can become tardive (persistent) disorders. All of them, including parkinsonism, result from neuroleptic effects on the dopaminergic neurotransmitter system in the basal ganglia. 

The question naturally arises, Do acute EPS increase the risk of TD If acute EPS do predict an increase in future TD, then the emergence of EPS indicates an increased need to terminate the medication. These questions have been debated over the years, but recent research gives the best-informed answer to date. In 2006 a prospective follow-up study of 9,298 patients by the European Schizophrenia Outpatient Health Outcomes (SOHO) Study found a statistically significant correlation between baseline EPS and later TD. According to Tenback et al. (2006), about half of the patients who developed tardive dyskinesia had earlier extrapyra-midal symptoms. They concluded that drug regimens... that increase extrapyramidal symptoms are likely to result in increased risk of tardive dyskinesia.  

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