Early extrapyramidal side-effects as risk factors for later tardive dyskinesia: a prospective study

To determine whether acute neuroleptic-induced parkinsonism and akathisia were risk factors for the later development of tardive dyskinesia (TD) in patients on typical neuroleptics.

Of 100 subjects examined for parkinsonism and akathisia after the initiation of typical neuroleptic medication, 78 were followed up for TD after a mean 41.2 months.

Nine (11.5%) subjects were diagnosed with TD, predominantly manifesting as oro-facial dyskinesia. They had greater severity of parkinsonism and akathisia at baseline, and a larger neuroleptic load, than those who did not develop TD. On regression analyses, parkinsonism at baseline was a significant predictor of later TD. Examined independently of parkinsonism, akathisia severity at 2 weeks was also a significant predictor of later TD.

Acute drug-induced parkinsonism and akathisia are both predictors of TD, with parkinsonism having greater predictive value. Acute and tardive extrapyramidal syndromes may share vulnerability factors.