Background: Chronic bilateral subthalamic deep brain stimulation (STN-DBS)
is known to improve motor function in patients with Parkinson disease (PD).
However, the possible effects of STN-DBS on neuropsychological functions h
ave been studied less.
Objective: To investigate the effects of STN-DBS on neuropsychological func
tions in PD.
Design: Before-after trial.
Patients and Methods: Fifteen consecutive patients were assessed before and
3 months after implantation of stimulators for STN-DBS (postsurgical asses
sment with the stimulators switched on). Both assessments were performed wi
th patients in a drug-free condition. The neuropsychological battery consis
ted of tests measuring memory and visuospatial and frontal functions.
Results: The comparison between presurgical and postsurgical performance sh
owed a moderate deterioration in verbal memory and prefrontal and visuospat
ial functions, and a moderate improvement in a prefrontal task and obsessiv
e-compulsive traits. The motor state improved in all patients.
Conclusion: Therapy with STN-DBS improves motor symptoms in PD without any
clinically relevant neuropsychological deterioration.