Background: Subthalamic nucleus deep brain stimulation (STN-DBS) and levodopa/carbidopa enteral (Duodopa) infusion are two effective therapeutic options for the treatment of advanced Parkinson's disease (PD).

Methods: Retrospectively, this study compared the two procedures, evaluating 40 PD patients who underwent either STN-DBS or a percutaneous gastrostomy (PEG) for Duodopa infusion. Duodopa group comprised 20 patients, with a mean follow-up of ∼15 months, treated by Duodopa infusion rather than STN-DBS because of the presence of neurosurgical contraindications, age > 70 years-old, moderate cognitive impairment or patient's unwillingness to undergo neurosurgery. The STN-DBS group comprised 20 consecutive patients similar to the patients of the Duodopa group for age at the disease onset, age at the procedure, follow-up, and duration of motor complications. The only difference concerned neuropsychological functions, which were more impaired in the group of Duodopa patients. Clinical and neuropsychological data were compared at baseline and at follow-up for the two procedures.

Results: Both procedures showed a significant improvement in UPDRS-II, UPDRS-III, and UPDRS-IV and a considerable reduction in the percentage of waking day spent in "off," whereas only the STN-DBS group showed a significant improvement in dyskinesias duration and disability. STN-DBS was associated to a significant drop in the phonemic verbal fluency score, whereas Duodopa patients showed a milder worsening in this task. The procedure-related complications occurred more frequently with Duodopa.

Conclusion: STN-DBS and Duodopa showed a significant efficacy on motor symptoms, activities of daily living, and motor complications. The group of Duodopa-treated patients developed more procedure-related complications.