Finger tremor and the central nervous system

Area of Science:

• Neuroscience
• Human Physiology
• Biophysics

Background:

• Normal physiological tremor and alpha rhythm in electroencephalography (EEG) share a common frequency band around 10 Hz.
• The potential relationship between finger tremor frequency and EEG alpha rhythm requires investigation to understand physiological tremor.
• Establishing the underlying physiology of physiological tremor is crucial for clinical and research applications.

Purpose of the Study:

• To test the hypothesis that finger tremor and EEG alpha rhythm are frequency-related.
• To investigate the potential central control mechanisms of physiological tremor.
• To determine if tremor in the left and right hands exhibits a synchronous relationship.

Main Methods:

• Recorded bilateral occipital EEGs and simultaneous acceleration from the terminal phalanx of the middle finger in eight healthy subjects.
• Analyzed recorded data using power spectral densities to quantify signal characteristics.
• Employed coherence functions to identify common frequency elements between EEG and tremor signals.

Main Results:

• No evidence of frequency-related connections was found between physiological tremor and alpha rhythm in the EEG.
• Coherence analysis did not reveal common frequency elements shared by the two signal types.
• Tremor in the right and left hands did not demonstrate a synchronous relationship.

Conclusions:

• The findings suggest that physiological tremor is not under central nervous system control.
• The lack of frequency correlation implies independent physiological mechanisms for tremor and alpha rhythm.
• Asynchronous tremor between hands indicates localized or peripheral control mechanisms.