Intestinal Levodopa/Carbidopa Infusion as a Therapeutic Option for Unresponsive Freezing of Gait after Deep Brain Stimulation in Parkinson’s Disease

Background. Treatment of freezing of gait (FOG) is always challenging because of its unpredictable nature and multifactorial physiopathology. Intestinal levodopa infusion has been proposed in recent years as a valuable option for its improvement. FOG in Parkinson’s disease (PD) can appear after deep brain stimulation in patients who never had gait symptoms. Objective. To study the effects of intestinal levodopa/carbidopa infusion in unresponsive-FOG that appears in PD patients treated with subthalamic nucleus deep brain stimulation. Methods. We retrospectively collected and analyzed demographic, clinical, and therapeutic data from five PD patients treated with subthalamic nucleus stimulation who developed unresponsive-FOG and received intestinal levodopa/carbidopa infusion as an alternative therapy. FOG was measured based on scores in item 14 of the Unified Parkinson’s Disease Rating Scale before and after intestinal levodopa infusion. Results. Administration of intestinal levodopa caused improvement of FOG in the “ON” state in four patients (80%) by 2 or more points in item 14 of the Unified Parkinson’s Disease Rating Scale. The improvement was maintained for at least 12 months. Conclusions. Intestinal levodopa infusion may be a valuable therapeutic option for unresponsive-FOG developed after subthalamic nucleus deep brain stimulation.