Intrepidly studying deep brain stimulation in patients with Parkinson's disease

Abstract

Of the previous five randomised controlled trials investigating the safety and efficacy of subthalamic nucleus DBS against best medical treatment, three were open-label studies,2,4,5 one involved masking the investigators to treatment,3 and one involved blinded video assessments of patients.6 The second important aspect of this double-blind study is that results compare favourably with those from previous trials. The difference in mean change from baseline visit to 3 months post-randomisation between the active and control groups in the mean number of waking hours per day with good symptom control and no troublesome dyskinesias as measured by patient diaries is the primary outcome of the present study10 and of previous US studies.3,5 Results are comparable, with an improvement of 4·4 h3 and 3 h5 in previous studies and an improvement of 3.03 h with subthalamic nucleus DBS in the present study.10 The worst mobility of the patients when their medication no longer works is measured by part 3 of the Unified Parkinson's Disease Rating Scale (UPDRS III) in the medications OFF phase. [...]the current study prompts considerations on potential biases, as investigators compared UPDRS III scores (medications OFF) at screening with those obtained at the baseline evaluation, post-implant but before device activation (stimulation OFF and medications OFF) to measure any potential microlesion effects.