Quantitative sudomotor abnormalities in clinically isolated rapid eye movement sleep behavior disorder

Area of Science:

• Neurology
• Autonomic Neuroscience

Background:

• Post-ganglionic sudomotor abnormalities are frequently observed in Parkinson's disease (PD).
• Limited data exists on sudomotor function in clinically isolated REM sleep behavior disorder (iRBD).

Purpose of the Study:

• To investigate the prevalence of sudomotor abnormalities in patients with iRBD.
• To compare sudomotor function in iRBD patients with those who have PD with REM sleep behavior disorder (PDwRBD) and PD without REM sleep behavior disorder (PDwoRBD).

Main Methods:

• Retrospective review of patients undergoing quantitative sudomotor axon reflex testing (QSART).
• Comparison of three groups: iRBD (n=20), PDwRBD (n=27), and PDwoRBD (n=23).

Main Results:

• Sudomotor abnormalities were found in 20% of iRBD patients, 67% of PDwRBD patients, and 35% of PDwoRBD patients.
• PDwRBD patients exhibited the most significant sudomotor abnormalities, followed by PDwoRBD and iRBD groups (p=0.015).

Conclusions:

• Sudomotor dysfunction is common in iRBD patients.
• Peripheral autonomic impairment appears to be an early feature in the disease course of iRBD, potentially preceding motor symptoms.