Prevalence of Twiddler's syndrome as a cause of deep brain stimulation hardware failure.

We reviewed our deep brain stimulation patient database to describe hardware complications which resulted from implantable pulse generator mobility, a phenomenon referred to as Twiddler's syndrome. A prospectively collected database of adverse events for all patients operated on at the University of Florida was queried searching for hardware malfunctions. Of 362 total leads implanted in 226 patients since 2002, there were 17 hardware malfunctions. Three of them were due to Twiddler's syndrome, representing 1.3% of patients (3 of 226 patients) and 1.4% of leads (5 of 362 leads). The subjects had characteristic presentations including re-emergence of symptoms, pain along the path of the hardware, abnormal impedances/current drain and radiographic signs of twisting/fracture. In all cases securing the implantable pulse generator within the chest pocket resolved the issue. Twiddler's syndrome in the population of movement disorder patients treated with deep brain stimulation is an uncommon but important adverse event. It possesses a characteristic presentation and with appropriate diagnostic evaluation it is treatable and future occurrences are preventable.