Intraoperative decisionmaking with MER for STN DBS in PD and the potential relationship to patient selection

Abstract

Microelectrode recording (MER) techniques generally require experience and nuanced technical ability. In order for appropriate decisions in electrode placement to be made during DBS procedures, multiple variables need to be differentially weighed including patient-to-patient variability and differences encountered during each MER recording track. Moreover, most often the appropriate weightings of such variables are not well known. As such, MER for DBS is typical of a class of decision making exercises involving multiple variables of unknown weighting, common in surgical environments where Class I evidence is often lacking. This study identifies 9 categories of information used by surgeon and neurophysiologists during DBS in the STN for Parkinson's Disease, quantifies their occurrence, PPV, and NPV in 274 MER tracks across 75 consecutive patients and explores how they contribute to overall outcome in these patients. Although MER optimizes the ability to place the STN electrode accurately in these cases, it is not predictive in avoiding three categories of adverse outcome (gait and falling problems, worsened speech problems, or new psychiatric or cognitive problems). One conclusion as a result of this finding is the possibility that overall outcome, in terms of avoidance of unwanted side effects of DBS surgery, is unrelated to the decision making during surgery with MER, but is instead likely related to the ability to diagnose PD accurately at the outset. © Arle et al.