
ALT Post-acute COVID-19 syndrome (PACS) overlaps with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) but, due to frequent muscle pain and exertional intolerance, neuromuscular disorders are often suspected. We report the results of a comprehensive neuromuscular evaluation in 27 PACS patients (22F/5M; median age 41 ys). All patients developed chronic fatigue (>6 months), post-exertional malaise, and cognitive impairment, with muscle pain in 88% but no neuromuscular deficits at clinical examination. 18/27 patients were unable to work. All patients fulfilled established ME/CFS diagnostic criteria (CDC 1994, ICC 2011, Inst Medicine 2015, NICE 2021). Electrophysiological studies and CK levels were normal. Brain 18FDG-PET/MRI (14/27) showed posterior hypometabolism in 8/14. Muscle biopsy (7/27) showed moderate dysimmune changes in 2/7. Exploratory transcriptomic analyses performed in muscle biopsies from PACS patients and pre-COVID controls unveiled in PACS differentially expressed




























