Earlier versus later subthalamic deep brain stimulation in Parkinson's disease

Subthalamic nucleus deep brain stimulation (STN-DBS) has been recently compared to a possible "second therapeutic honeymoon" for Parkinson's disease, as it might prevent the development of severe motor complications and lessen the social adjustment associated to disease progression. This study aims to evaluate whether an early surgical treatment could result in better long-term outcomes, comparing the follow-up evolution of 203 parkinsonian patients, treated at different stages of the disease course.

The retrospective allocation to Early- or Late-Stimulated groups was performed in accordance to disease severity at the time of surgery and motor fluctuations duration. Then, the two groups clinical outcomes were compared after more than 8 years of follow-up by means of the Unified Parkinson's Disease Rating Scale, reporting the overall disability experienced by patients during the entire observational period.

Subjects receiving an earlier STN-DBS showed a sustained improvement in the activities of daily living and motor complications, never reaching the severe levels of disability reported by Late-Stimulated patients at the time of surgical selection. After ≥8 years of follow-up the Early-Stimulated group still reported a 28.7% lower impairment in activities of daily living and 43.8% lower duration of waking day spent in OFF compared to their pre-surgical basal scores.

Although the limitation of a retrospective study design should be considered in the interpretation of data, our findings suggest that an earlier STN-DBS treatment might result in a more precocious stabilization of motor complications, with beneficial effects on the patient's social and professional life autonomy.