Position-Dependent Dysfunction of Deep Brain Stimulation in Tourette Syndrome: Diagnostic Clues

BACKGROUND: Detection of defective deep brain stimulation (DBS) contacts/electrodes is sometimes challenging. CASE REPORT: We report a patient with Tourette syndrome (TS), who presented with abrupt tic increase and mild generalized headache 9 years after DBS implantation. On the suspicion of a hardware defect, a fracture of the DBS electrode and extension lead was ruled out by radiography and standard implantable pulse generator readouts. Further investigation revealed position-dependent modifiable therapeutic impedances, suggesting an impaired contact of the extension lead/adaptor. After replacement normal impedances were recorded, and the patient fully recovered. DISCUSSION: In DBS dysfunction with inconspicuous hardware check, position-dependent defects might be suspected.