A DGReview of :"Fatigue
in Multiple Sclerosis Is Associated with Abnormal Cortical Activation to
Voluntary Movement-EEG Evidence"
By James Adams
Abnormal cortical activation during voluntary movement may be responsible for fatigue in patients with multiple sclerosis, researchers find.
Cortical dysfunction results in hyperactivity during movement execution and failed inhibition after movement termination, according to the investigators from the Scientific Institute H. San Raffaele in Milan, Italy.
They compared changes in electroencephalogram (EEG) rhythms during voluntary movement in 15 multiple sclerosis (MS) patients with fatigue, 18 MS patients without fatigue and 14 normal controls. The two patient groups were similar in age, sex and duration of disease. None were disabled.
Event-related desynchronisation (ERD) of the 10 and 20 Hz frequency bands occurs during motor planning and execution, and event-related synchronisation occurs after movement termination.
Twenty-nine channel EEG was recorded as the patients carried out self-paced extensions of the right thumb.
Results showed similar onset latency and contralateral sensorimotor 10 and 18-22 Hz ERD in all three groups. However, ERD was more anteriorly widespread in the fatigued MS patients compared with normal controls.
Also, post-movement contralateral sensorimotor 18-22 Hz ERS was significantly lower in fatigued MS patients compared with normal controls and non-fatigued MS patients.
the investigators conclude, "are consistent with a central origin of fatigue
in MS and indicate cortical dysfunction even during a simple motor task,
resulting in hyperactivity during movement execution and failure of the
inhibitory mechanisms intervening after movement termination."
NeuroImage 2001; 13: 1186-1192. "Fatigue in Multiple Sclerosis Is Associated with Abnormal Cortical Activation to Voluntary Movement-EEG Evidence"