{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T23:58:49Z","timestamp":1792022329037,"version":"4.4.0"},"reference-count":46,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T00:00:00Z","timestamp":1756857600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurosci."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Myalgic encephalomyelitis\/chronic fatigue syndrome (ME\/CFS) is a multisystemic disease characterized by exertional intolerance and fatigue which is often accompanied by muscle weakness and fatiguability. A study showed efficacy of the acetylcholinesterase inhibitor pyridostigmine on cardiac output in ME\/CFS patients. Pyridostigmine is currently used off-label in ME\/CFS and postural orthostatic tachycardia syndrome.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We evaluated the effect of pyridostigmine on hand grip strength in 20 patients with post-infectious ME\/CFS. Hand grip strength testing was performed ten times using an electric dynamometer and was repeated after 1\u202fh. In a second test, 30\u202fmg of pyridostigmine was given immediately after the first measurement. Orthostatic function was assessed using a passive standing test. Neurological examination and autoantibody testing were performed to rule out a diagnosis of myasthenia gravis.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>All patients had reduced maximum hand grip strength with a median of 16.45\u202fkg (IQR: 11.45\u202fkg\u201322.8\u202fkg). Hand grip strength was diminished by a median of 4.65\u202fkg after 1 h. In contrast, 1 h after pyridostigmine administration, patients showed an improvement in maximum hand grip strength with a median increase of 2.6\u202fkg. The maximum hand grip strength after exertion was about 1.5-fold higher with then without pyridostigmine (<jats:italic>p\u202f=<\/jats:italic> 0.01). The increase in heart rate from lying to standing was median 17 beats per minute without pyridostigmine (IQR: 13 beats per minute \u2013 23 beats per minute) and 13 beats per minute (IQR: 9 beats per minute \u2013 20 beats per minute) (<jats:italic>p<\/jats:italic>\u202f=\u202f0.017) with pyridostigmine. None of the patients tested positive for myasthenia gravis specific autoantibodies.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Pyridostigmine exerts an immediate effect on muscle strength and orthostatic function. This may be attributed to increased acetylcholine availability at neuromuscular junctions, and its augmentation of parasympathetic tone.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fnins.2025.1637838","type":"journal-article","created":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T06:19:29Z","timestamp":1756880369000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Pyridostigmine improves hand grip strength in patients with myalgic encephalomyelitis\/chronic fatigue syndrome"],"prefix":"10.3389","volume":"19","author":[{"given":"Ella","family":"Schl\u00f6mer","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elisa","family":"Stein","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claudia","family":"Kedor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rebekka","family":"Rust","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Brock","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kirsten","family":"Wittke","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carmen","family":"Scheibenbogen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Kim","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,9,3]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"17","DOI":"10.1038\/s41467-023-44432-3","article-title":"Muscle abnormalities worsen after post-exertional malaise in long COVID","volume":"15","author":"Appelman","year":"2024","journal-title":"Nat. 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