Deep brain stimulation (DBS) is an established and safe treatment option for selected movement disorders, such as idiopathic Parkinson's syndrome (IPS), essential tremor (ET) and dystonia. Although very rare, there are specific complications in DBS surgery. This study retrospectively investigates possible pre- and intraoperative conditions for their predictive value anticipating these complications. The investigated factors are disease duration, H/Y stage, UPDRS III score and non-disease-specific factors (age, diagnosis, secondary diseases, and duration of surgery).

Between January 2016 and October 2020, a total of 181 patients DBS were treated in our center with primary DBS implantation. Out of them, 160 were operated under general anesthesia and 21 patients underwent an awake procedure. We retrospectively reviewed patients" charts for surgical complications, such as intracranial hemorrhage, hematoma at the IPG site and infections. Neurological complications, such as postoperative delirium and mild cognitive impairment, were also included.

In the postoperative cCT, a hemorrhage was seen in 5 patients (3.1%, four SAH, one ICH), all asymptomatic not requiring additional treatment. Hematoma at the IPG side occurred in 8 patients (5%), none of them requiring surgical revision.

Infection and prolonged wound healing at the IPG site was found in 9 patients (5.6%) and electrode infections occurred in three patients (one intracerebral, two extracerebral (1.9%)). Neurological complications independent from stimulation were rare. Confusion was noted in 8 patients (5%), all of them following an awake procedure. Mild cognitive impairment was also seen following awake surgery only (two patients, 9.5%)

ICH was rare, all affected patients were asymptomatic and the hemorrhage was found in the routinely performed postoperative CT(3.1% vs. 0.2- 5.6% in the literature). Confusion and de novo mild cognitive impairment were only seen in awake DBS patients, casting doubt on the usefulness of awake DBS procedures.In this retrospective review in a large cohort of patients, we failed to identify specific predictors for complications in DBS de novo surgery. Larger prospective real-world data registers are required as effect sizes are small.