To the Editor: In their randomized controlled trial, Dr Weaver and colleagues1 reported a significant improvement in the motor function of participants with advanced Parkinson disease (PD) treated with bilateral deep brain stimulation, compared with best medical therapy. Dementia is often cited as a contraindication to deep brain stimulation on practical grounds. This is particularly (but not exclusively) true when it is felt that the patient will be unable to cooperate during surgery.2 Indeed, participants with Mini-Mental State Examination (MMSE) scores of 24 or less were excluded from the trial. The prevalence of dementia in advanced PD may be greater than 70%.3 Therefore, treatment with deep brain stimulation may only be offered to a minority of patients with severe motor symptoms.
Genever RW. Deep Brain Stimulation for Patients With Advanced Parkinson Disease. JAMA. 2009;301(19):1985-1986. doi:10.1001/jama.2009.647