Is DBS-STN appropriate to treat severe Parkinson disease in an elderly population?

To assess the role of age in the results of bilateral deep brain stimulation in the subthalamic nucleus (DBS-STN), we carried out a study of two groups of patients regarding age at time of surgery.

We compared, up to 2 years after surgery, the clinical effects, safety, and quality of life in parkinsonian patients younger than 65 years old (young patients) vs parkinsonian patients 65 years old or older (old patients).

The mean age was 57.4 +/- 4.9 years (n = 53) in young patients and 68.8 +/- 2.8 years (n = 34) in old patients. A dramatic improvement in motor complications was equally observed in both groups of patients. There was no significant difference between the groups regarding acute effects of DBS-STN on the motor score of the Unified Parkinson's Disease Rating Scale part III (UPDRS III). Time course evolution of UPDRS the motor score (p < 0.0001) and axial score (p = 0.0001) assessed postoperatively in "on" medication and "on" stimulation conditions appeared worse in old patients as compared to young patients. Improvement in the Schwab and England Scale score was better in young patients in "on" (p < 0.0003) and "off" state (p < 0.001). Quality of life assessed with the 39-item Parkinson's Disease Questionnaire showed an improvement in subscales evaluating mobility (p < 0.0001), activities of daily life (p < 0.0001), emotion and stigma (p = 0.0004), cognition (p < 0.0074), and communication (p = 0.0029) in young patients as compared to old patients. Side effects were similar in the two groups.

Although deep brain stimulation in the subthalamic nucleus reduces motor complications equally in both groups of patients, postoperative quality of life improved only in young patients.