Revisiting eligibility for deep brain stimulation: Do preoperative mood symptoms predict outcomes in Parkinson's disease patients?

Introduction: Anxiety and depression are common in PD, occurring in an estimated 30%-40% of PD patients. However, the extent to which these emotional symptoms interfere with Deep Brain Stimulation (DBS) outcomes is not well established. This study examined the association between pre-operative emotional well-being and postsurgical cognitive, emotional, and motor performance in PD.

Methods: Forty-nine PD patients underwent neurological, neuropsychological (global cognition, processing speed, language, visuospatial, memory), and emotional assessments pre- and post-DBS. Fifteen patients were administered the UPDRS. Patients were divided into Anxious (Anx; n = 21), Comorbid Anxious and Depressed (Anx + Dep; n = 15), and Emotionally Asymptomatic (EA; n = 13) based on BAI and BDI-II cutoffs, and compared on pre-post changes in neurocognitive, mood, and motor scores using analyses of covariance (ANCOVA), controlling for education, ethnicity, and disease duration.

Results: Pre-DBS, there were no significant differences between the three groups on any neuropsychological measure. Overall change from pre-to post-DBS revealed declines on multiple cognitive measures and lower symptom endorsement on the BAI among all participants. No group differences were observed on neurocognitive measures, mood, or UPDRS.

Conclusions: PD patients with mild-moderate anxiety or comorbid anxiety/depression pre-DBS do not show greater cognitive, emotional, and motor changes post-DBS compared to emotionally asymptomatic patients. These data emphasize the importance of discussing potential DBS outcomes, while keeping in mind that psychiatric comorbidity should not necessarily exclude patients from DBS. The notion that premorbid mood symptoms could disqualify a candidate for surgery would be a disservice, as this group performs comparably to asymptomatic peers.