Deep brain stimulation and cognitive functions in Parkinson's disease: A three-year controlled study

Area of Science:

• Neuroscience
• Neurology
• Neurosurgery

Background:

• Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a treatment for advanced Parkinson's disease (PD).
• The cognitive and behavioral effects of STN-DBS in PD patients remain a subject of debate.
• Long-term, naturalistic studies are needed to clarify these effects.

Purpose of the Study:

• To prospectively evaluate the long-term cognitive and behavioral effects of STN-DBS in advanced PD patients.
• To compare outcomes between patients who underwent STN-DBS and those who opted for alternative treatments.

Main Methods:

• A 3-year follow-up study enrolled 65 PD patients: 32 underwent STN-DBS (PD-DBS) and 33 served as a control group (PD-control).
• Motor and neuropsychological functions were assessed at baseline (T0) and 36 months (T36).
• PD-DBS patients had additional assessments at 1, 6, 12, and 24 months post-surgery.

Main Results:

• Short-term (T1) post-STN-DBS, patients showed declines in logical executive function and verbal fluency (FAS), with stable memory performance.
• Cognitive profiles returned to baseline levels by 12 months (T12) and remained stable through 36 months (T36).
• At T36, PD-DBS patients exhibited significantly worse FAS scores compared to the PD-control group.

Conclusions:

• STN-DBS for advanced PD leads to a transient worsening of frontal-executive functions.
• While verbal fluency shows a long-term decline, STN-DBS is generally considered safe from a cognitive perspective.
• This study provides long-term, naturalistic data on the cognitive impact of STN-DBS in Parkinson's disease.