Subthalamic nucleus stimulation and levodopa modulate cardiovascular autonomic function in Parkinson's disease

Area of Science:

• Neurology
• Cardiovascular Physiology
• Autonomic Neuroscience

Background:

• Parkinson's disease (PD) often involves cardiovascular autonomic dysfunction.
• Subthalamic nucleus stimulation (STN-S) and levodopa are key PD treatments.
• Understanding their combined effects on autonomic function is crucial.

Purpose of the Study:

• To investigate the distinct and combined effects of STN-S and levodopa on cardiovascular autonomic function in PD.
• To assess influences on blood pressure, heart rate variability, and baroreflex sensitivity.
• To explore modulation by orthostatic hypotension (OH).

Main Methods:

• Assessed 26 PD patients with bilateral STN-S under OFF-OFF, ON-OFF, and ON-ON conditions.
• Recorded continuous blood pressure, ECG, and respiration during rest, deep breathing, and head-up tilt tests.
• Analyzed baroreflex sensitivity and spectral data using trigonometric regressive spectral analysis.

Main Results:

• STN-S reduced systolic blood pressure during tilt-up, with further reduction by levodopa.
• STN-S and levodopa exhibited differential impacts on sympathetic and parasympathetic regulation.
• Levodopa decreased baroreflex sensitivity and RR interval in OH patients, but had opposite effects in non-OH patients.

Conclusions:

• STN-S and levodopa exert distinct influences on cardiovascular autonomic control in PD.
• The presence of orthostatic hypotension significantly modulates these treatment effects.
• Tailoring therapeutic strategies based on autonomic status is warranted.