The incidence of seizures following Deep Brain Stimulating electrode implantation for movement disorders, pain and psychiatric conditions.

Deep Brain Stimulation (DBS) for neuromodulation is now commonplace. However little is known about the incidence of either procedural related seizures or epilepsy following chronic DBS. This study aims to provide estimates of these complications for movement disorders, pain and psychiatric conditions. A literature review was performed. Because searches using the terms seizure, epilepsy, and deep brain stimulation revealed only papers dealing with experimental and clinical application of DBS to treat chronic seizures disorders, a search strategy trawling through papers that described clinical case series of DBS was used. Thirty-two papers were reviewed that described stereotactic placement of DBS electrodes for movement disorders, pain syndromes and psychiatric conditions with cohorts of n > 5. Sixteen of these papers describing at least 1418 DBS electrode placements in 1254 patients did not mention seizures as a complication (i.e., it was not possible to know whether seizures had or had not occurred). In 16 papers, describing at least 2101 electrode placements in 1555 patients, seizures were described in 42 patients (incidence 2.7%). The range of seizure incidence varied from 0% (three series encompassing 317 patients and 576 electrode placements) up to 10% (n = 130) and 13% (n = 15). The reasons for this variance were not obvious. At least 74% of seizures occurred around the time of electrode implantation and many of these patients also suffered intracranial hemorrhage. Follow up times were variable (range 6 mths to 5 years). The analysis was complicated by multiple publications from some centres with duplication of some data. The quality of literature on seizures following DBS insertion for neuromodulation is highly variable. Analysis of the available data, after making corrections for publication of duplicate data, suggests strongly that the risk of seizures associated with DBS placement is probably lower than 2.4% (95% CI 1.7 to 3.3 %). The risk of postprocedural seizures associated with chronic deep brain stimulation is even lower with best estimates around 0.5% (95% CI .02 to 1.0%).