A case of tongue twisting during screening of STN DBS for parkinson’s disease: A unique form of pyramidal tract activation

Subthalamic nucleus deep brain stimulation (STN-DBS) is a safe and effective therapy for Parkinson´s disease (PD) in selected patients. However, various side effects such as paraesthesia, diplopia, ataxia, worsened akinesia, emotional changes, dysarthria, and muscle contractions can occur due to the current spread to the adjacent structures during the STN-DBS programming sessions. Muscle contractions result from the corticospinal and corticobulbar side effects, which can manifest due to the current spread to the pyramidal tract during DBS programming. Here, we report a case of tongue-twisting movement as a unique corticobulbar side effect of the STN-DBS programming in a patient with PD.