Peri-Lead Edema in Deep Brain Stimulation: Long-Term Outcomes and Possible Etiological Correlates

BackgroundDeep brain stimulation (DBS) is an effective surgical procedure for the treatment of Parkinsons disease (PD) and other movement disorders. Immediate and delayed complications after DBS surgery have been described. Peri-lead edema (PLE) is a DBS-related complication whose etiology is still unknown. Moreover, PLE frequency and long-term effects are subjects of ongoing debate. ObjectivesTo elucidate the long-term clinical and neuropsychological effects of PLE and to find possible etiological correlates. MethodsWe retrospectively collected clinical and neuropsychological data from 51 PD patients before and one year after DBS. PLE visualized on FLAIR MRI sequence was manually segmented. Using appropriate statistical tests, continuous and categorical variables were compared between patients with and without PLE. A multivariate regression model was employed to analyze the contribution of clinical variables to edema volume changes. Results68.62% of patients presented PLE at the immediate postoperative MRI. Patients with PLE were significantly older (p<0.001) and had more frequent postoperative confusion episodes (p=0.025). Furthermore, more MER (microelectrode recording) tracks (p<0.001) were used in patients with PLE. Multiple MER tracks were directly correlated with edema volume and were the only significant predictors of edema volume changes in a multivariate regression model. No differences were found in other clinical and neuropsychological variables. ConclusionsPLE is a frequent post-surgical event and may cause transient postoperative confusion. It seems linked to older age and multiple MER tracks. Although it does not influence global motor and neuropsychological outcomes, PLE contributes to postoperative confusion episodes. To avoid PLE sequelae, using multiple MER tracks in older patients should be discouraged.