Postoperative outcomes in patients with dementia undergoing deep brain stimulation: A retrospective matched cohort study

Background Deep brain stimulation (DBS) is an effective treatment for several movement disorders. Comorbid dementia is considered a contraindication for DBS. However, how preoperative dementia impacts specific DBS outcomes is not well understood. Objective To compare DBS outcomes between patients with dementia, mild cognitive impairment (MCI) and normal cognition. Methods We identified 16 patients with preoperative dementia from a database of patients undergoing DBS. Propensity score matching identified two patients with normal cognition and two with MCI for each with dementia. Outcomes including motor symptom control, postoperative delirium, complications, discharge disposition, one-year postoperative cognitive outcome, and length of stay were compared between groups using Chi-square and ANOVA tests. Multivariable regression evaluated the relationship between preoperative variables and each outcome. Results Motor symptom benefit did not differ between patient groups. Patients with dementia were more likely to be discharged to a higher level of care ( p corr =0.033), but this was not significant after we controlled for preoperative living setting. Patients with dementia had longer hospital stays ( p corr =0.017) and were more likely to have cognitive worsening at one-year follow-up ( p corr =0.045). Higher MMSE score and unilateral DBS were associated with lower chance of discharge to higher level of care (p=0.010 and p=0.016 respectively). Conclusions While patients with dementia had similar motor symptom benefit from DBS to those with MCE and normal cognition, they had longer hospital stays and greater chance of postoperative cognitive worsening. Individual risks and benefits should be carefully considered when evaluating patients with dementia for DBS.