Subthalamic deep brain stimulation effects on odor identification in P arkinson's disease

Background and purpose Olfactory dysfunction is common in Parkinson's disease ( PD ) and it is one of the earliest non‐motor symptoms. A few studies have suggested that deep brain stimulation of the subthalamic nucleus ( STN ‐ DBS ) could improve olfactory function. Our aim was to evaluate the acute effect of bilateral STN ‐ DBS on a commonly used smell test in PD patients. Methods Fifteen PD patients who underwent bilateral STN ‐ DBS and 15 controls were recruited. Patients and controls were tested for odor identification. Results No statistical differences were documented between ON and OFF STN ‐ DBS acute stimulation concerning olfaction. Controls presented a better performance for olfactory identification than patients. Conclusions Our exploratory study did not support that bilateral STN ‐ DBS could have an acute effect on olfactory function in PD patients.