Subthalamic DBS replaces levodopa in Parkinson’s disease: Two-year follow-up

To the Editor:

By optimizing stimulation parameters of PD patients who underwent subthalamic nucleus (STN) deep brain stimulation (DBS), Vingerhoets et al.1 minimized the amount of antiparkinsonian medication required, maintaining many study patients off medication. We are concerned that this paper will lead other centers to regard elimination of medications as a specific treatment objective, with potential harmful consequences.

Decreasing medications is desirable and may ameliorate side effects. However, stopping drugs can worsen motor signs, mood, and cognition.2,3⇓ Abrupt withdrawal of antiparkinsonian medications poses unnecessary risks; fortunately none of the patients in this study suffered more obvious severe motor complications of this approach. To support medication withdrawal, the authors state that DBS programming if patients are taking medication is suboptimal. However, we think medication cessation may adversely affect patients and in fact delay more effective programming adjustment.

In this study three patients suffered postoperative confusion, and three developed new-onset depression. The study noted a high incidence of dysarthria that may have been due to excessive drug withdrawal if limb symptoms were more effectively targeted by stimulation than orofacial symptoms. Induction of dysarthria might also suggest current spread to corticobulbar tracts, which could be treated by reducing stimulation measurements and increasing medication.

In the immediate postoperative period there may be significant clinical variability due to a microlesioning or insertional effect of the surgery. Attempts to optimize programming during this time are frustrating and not cost-effective as the patients’ symptoms vary from day to day. In contrast to the aggressive early programming (twice a day during the first week) applied in this study, we generally allow 3 weeks for postoperative outpatient recovery prior to programming. During this recovery period, when the microlesion and other nonspecific surgical effects are resolving, medications are reinstituted as needed to maintain comfort and function. …