Is hemifacial spasm affected by changes in the heart rate? A study using heart rate variability analysis

Area of Science:

• Neurology
• Cardiology
• Biomedical Engineering

Background:

• Hemifacial spasm (HFS) is typically attributed to arterial compression of the facial nerve.
• Arterial pulsatility is a known factor, but its direct association with HFS onset requires further investigation.

Purpose of the Study:

• To explore the relationship between heart rate variability and hemifacial spasm.
• To investigate if fluctuations in heart rate correlate with the occurrence of HFS episodes.

Main Methods:

• Simultaneous overnight recordings of facial electromyogram and electrocardiogram in 24 patients with HFS.
• Analysis of R-wave to R-wave intervals (RRIs) and heart rate variability (HRV) during HFS.
• Correlation of HFS episodes with sleep stages and heart rate fluctuations.

Main Results:

• A 5% fluctuation in RRIs at 0.1 Hz preceded HFS onset by seconds, indicating a heart rate increase.
• Heart rate variability analysis showed significantly enhanced heart rate fluctuations during HFS.
• HFS episodes were more frequent during wake or light sleep stages, suggesting autonomic nervous system involvement.

Conclusions:

• The etiology of HFS may involve more than mechanical compression, potentially including altered pulsatile frequencies of offending arteries.
• Heart rate fluctuations and autonomic activity appear to be associated with hemifacial spasm.