Cognitive outcome of pallidal deep brain stimulation for primary cervical dystonia: One year follow up results of a prospective multicenter trial.

ABSTRACT

BACKGROUND: Pallidal deep brain stimulation (DBS) is effective in alleviating motor symptoms of medication refractory cervical dystonia, but little is known about effects on cognitive functions. METHODS: As part of the first randomized, sham-controlled multicenter trial on DBS in medication-refractory primary cervical dystonia (ClinicalTrials.gov, number NCT00148889), a subgroup of 13 patients aged 39 to 69 underwent prospective neuropsychological long-term follow-up assessments. Various cognitive domains (memory, executive functions, attention, visual perception, mental arithmetic and verbal intelligence) were examined before and after 12 months of continuous DBS. RESULTS: Only the number of produced words in a verbal fluency task which included alternating categories decreased after stimulation (p = 0.020). All other cognitive domains remained unchanged. CONCLUSIONS: These findings indicate that long-term pallidal DBS for the treatment of primary cervical dystonia seems to be safe regarding global cognitive functioning.