gms | German Medical Science

Objective: To assess adverse events (AE) associated with deep brain stimulation (DBS) in an unselected cohort.

Methods: Medical records (694 documents) of 105 consecutive patients (female 44; median age 63 years, range 17–75), who had undergone DBS between 2006 and 2011 were analyzed retrospectively. The indications were Parkinson's disease (66), dystonia (21), essential tremor (12), multiple sclerosis (4) and Tourette's syndrome (2). Electrodes were implanted into the subthalamic nucleus (65), ventrolateral thalamus (23), and internal globus pallidus (17). The follow-up period was > 6 months (median 23, min 6, max 54). AE were graded according to the guidelines of CTCAE.

Results: A total of 205 AE were recorded in 76 patients. These were life-threatening in 2 patients (urosepsis, gastric cancer), severe in 7 patients, moderate in 38 and mild in 60 patients. The adverse events were classified as operative (12), neurological (104), infectious (7), psychiatric (42), technical (17), problems of internal organisation (7) and others (16). The AE were regarded as related (24), probably related (78), possibly related (62), unlikely related (19), unrelated (21), or not rated (1). No significant correlation was found between the number of AE per patient and age (P > 0.05) as well as severity of complications and age (P > 0.05). 41% of neurological and psychiatric complications occurred during the first week after surgery, 31% between week 2 and week 10, and 28% beyond week 10 after DBS implantation. Urinary incontinence was observed in 6 patients. Among the severe surgical AE, there was one intracerebral hemorrhage (2 cm³) in the striatal region along the trajectory resulting in transient neuropsychological deterioration. DBS systems in three patients had to be removed due to infection after several months, and the stimulator was replaced in one patient several months later. In four patients, minor wound revisions had to be performed. One electrode had to be replaced because of impedance problems. In three patients, revisions were performed because of cable displacement at the stimulator site (2) or discomfort along the extensions cables (1).

Conclusions: Despite a relatively low rate of true surgical complications, stereotactic movement disorder surgery and long-term deep brain stimulation are associated with adverse events in the majority of patients. Detailed knowledge of possible AE is important to balance these against the improvement in quality of life attempted by DBS.