Muscle

In ME and CFS
Several of the key symptoms observed by Melvin Ramsay and a part of his Ramsay definition involved muscle including muscle fatigability along with muscle pain and clumsiness (ataxia). Patients also complain of muscle fasciculations.

Numerous abnormalities have been found in the skeletal muscle of Myalgic Encephalomyelitis patients including:


 * mitochondrial abnormalities found via muscle biopsy including: mitochondrial degeneration, deletions of mitochondrial DNA , the reduction of mitochondrial activity
 * Increased urinary creatine excretion during relapses
 * Increased creatine kinase (postviral fatigue syndrome)
 * Persistence of enteroviruses in muscle tissue

Studies

 * 1991, Mitochondrial abnormalities in the postviral fatigue syndrome - (Abstract)
 * 1995, Unusual pattern of mitochondrial DNA deletion in skeletal muscle of an adult human with chronic fatigue syndrome - (Abstract)
 * 1996, Sensory characterization of somatic parietal tissues in humans with chronic fatigue syndrome - (Abstract)
 * 2020, Altered muscle membrane potential and redox status differentiates two subgroups of patients with chronic fatigue syndrome - (Full text)
 * 2020, Skeletal Muscle Weakness Often Occurs in Patients with Myalgic Encephalomyelitis / Chronic Fatigue Syndrome ME/CFS - (Full text)