Determinants of Deep Brain Stimulation Candidacy Failure in Movement Disorders: A Multidisciplinary Analysis

BACKGROUND: Deep brain stimulation (DBS) is a common treatment offered for a variety of movement disorders refractory or resistant to medical management. It is important to confirm potential candidates possess a favorable risk-benefit ratio during screening. OBJECTIVE: To investigate the rates and reasons for failure when applying a multidisciplinary DBS candidacy approach for movement disorders including Parkinson's disease (PD), essential tremor (ET), and dystonia. METHODS: A retrospective chart review was conducted using the University of Florida INFORM database to identify consecutive patients referred for multidisciplinary evaluation of DBS candidacy. Patients who were either tabled (deferred for later consideration) or denied were defined as multidisciplinary evaluation failures (MEF) and further characterized using descriptive statistics to understand factors underpinning the decision not to pursue DBS. RESULTS: A total of 1758 patients underwent a multidisciplinary review for possible DBS therapy. Of these, 182 (10.4%) were MEF, with 117 (6.7%) denied and 65 (3.7%) tabled. Diagnostic breakdown of MEF included 129 (70.9%) patients with PD, 33 (18.1%) with ET and 18 (9.9%) with dystonia. A total of 13 possible reasons for MEF were identified; the three most common reasons were concern for excessive cognitive risk (62.1%), incongruent expectations for surgery (17.6%) and significant psychiatric concern (16.5%). CONCLUSIONS: Given the broad range of factors that may preclude approval for DBS in movement disorders, a multidisciplinary approach to candidate selection is essential.