Voluntary motor function in patients with chronic fatigue syndrome

Area of Science:

• Neurology
• Neuroscience
• Human Physiology

Background:

• The underlying causes of chronic fatigue syndrome (CFS) are not fully understood.
• The role of the motor cortex and corticospinal system in CFS pathogenesis requires further investigation.

Purpose of the Study:

• To evaluate corticospinal function in patients with CFS.
• To investigate the relationship between fatigue, motor performance, and corticospinal excitability in CFS.

Main Methods:

• Transcranial magnetic stimulation (TMS) assessed motor-evoked potentials (MEPs) latency and threshold in thenar muscles.
• Reaction times and movement speed were measured using button presses in response to auditory stimuli.

Main Results:

• CFS patients reported higher fatigue than pain, anxiety, or depression.
• Patients demonstrated significantly longer simple reaction times and movement times compared to controls.
• No significant differences were found in MEP threshold or latency, indicating normal corticospinal excitability.

Conclusions:

• Despite increased fatigue and slower motor task execution, corticospinal conduction and excitability in CFS patients are within normal limits.
• These findings suggest that the subjective experience of fatigue and observed motor slowness in CFS manifest outside the corticospinal system.