[Severe treatment-resistant tardive dystonia: is deep brain stimulation a treatment option]

Severe tardive dyskinesia or dystonia (TD) are side-effects of dopamine-blocking agents, most of which are antipsychotics. A small subgroup of patients develop a severe debilitating treatment-resistant form of TD.

To assess the effects and side-effects of deep brain stimulation (DBS) in this subgroup of TD patients.

We searched PubMed and Embase using the search terms 'tardive' and 'deep brain stimulation'. We found 19 articles containing data referring to 52 patients. Using the Burke Fahn Marsden Dystonia Rating Scale (BFMDRS), the Abnormal Involuntary Movement Scale (AIMS) and the Extrapyramidal Symptoms Rating Scale (ESRS) we calculated the average improvement in the patients' condition.

On all the scales the improvement was statistically significant (p < 0.00001), the average improvement being 67% to 78%. In only 4% of the patients was there a deterioration in the psychiatric disorder.

DBS seems to be an effective treatment for treatment-resistant TD and the side-effects seem to be limited. However, the evidence is limited because our conclusion is based on case-reports and on small-scale trials without randomisation or blinding.