Autonomic dysfunction in parkinsonian LRRK2 mutation carriers

Area of Science:

• Neurology
• Genetics
• Autonomic Neuroscience

Background:

• Parkinson's disease (PD) is a neurodegenerative disorder.
• Autonomic dysfunction is common in PD.
• LRRK2 gene mutations are a known cause of PD.

Purpose of the Study:

• To compare autonomic function between PD patients carrying LRRK2 mutations and those with idiopathic PD (iPD).

Main Methods:

• Studied 25 PD patients (12 LRRK2 carriers, 13 iPD).
• Assessed autonomic function using blood pressure/heart rate monitoring during tilt, Valsalva maneuver, deep breathing, sympathetic skin response (SSR), and cardiac MIBG scintigraphy.

Main Results:

• Fewer LRRK2 carriers (1/12) had orthostatic hypotension compared to iPD patients (3/13).
• LRRK2 carriers exhibited higher blood pressure increase during passive tilt and less pronounced arterial pressure overshoot during Valsalva maneuver compared to iPD.
• Cardiac MIBG uptake ratios were significantly higher in LRRK2 carriers (1.51 ± 0.28) versus iPD patients (1.32 ± 0.25).

Conclusions:

• LRRK2 mutation carriers with PD demonstrate less autonomic impairment than iPD patients.
• Higher cardiac MIBG uptake suggests potentially preserved cardiac sympathetic innervation in LRRK2-PD.
• Further large-scale studies are warranted to compare clinical, functional, and pathological characteristics.