Autonomic dysfunction in patients with essential tremor

Area of Science:

• Neurology
• Autonomic Neuroscience
• Clinical Electrophysiology

Background:

• Essential tremor (ET) is a common neurological disorder.
• Autonomic nervous system (ANS) dysfunction has been anecdotally reported in ET patients.
• Comprehensive evaluation of ANS function in ET is lacking.

Purpose of the Study:

• To investigate autonomic function in patients diagnosed with essential tremor.
• To compare autonomic responses between ET patients and healthy controls.
• To identify potential electrophysiological markers of autonomic dysfunction in ET.

Main Methods:

• Electrophysiological assessments were conducted on 31 adult ET patients and 26 healthy controls.
• Autonomic function was evaluated using sympathetic skin response (SSR) and R-R interval variation (RRIV) tests.
• Statistical analysis compared SSR latency/amplitude and RRIV values between groups.

Main Results:

• ET patients exhibited significantly delayed SSR latency compared to controls (P=0.01).
• The mean amplitude of SSR was significantly lower in ET patients versus controls (P=0.001).
• No significant differences in R-R interval variation (RRIV) were observed between the groups.

Conclusions:

• Autonomic nervous system dysfunction, particularly sympathetic dysfunction, may be present in patients with essential tremor.
• Sympathetic skin response (SSR) tests are a sensitive method for detecting autonomic abnormalities in ET.
• These findings highlight the potential role of SSR in the clinical assessment of essential tremor.