title: Acquired slow-channel syndrome.
abstract: We report the case of a 37-year-old man with clinical and electrophysiological features of hereditary slow-channel syndrome (SCS) and antibodies against acetylcholine receptors (AChR-Abs). He presented with weakness of shoulder and hand muscles. A supramaximal single stimulus to the motor nerves disclosed a double compound muscle action potential (CMAP). Repetitive stimulation of ulnar, suprascapular, and median nerves showed a CMAP decrement greater than 10%. The patient responded to pyridostigmine. This report confirms the importance of AChR-Ab titers in suspected cases of hereditary SCS because patients with positive AChR-Abs may have a better response to available treatments.
authors.affiliation: Neuromuscular Disorders Division, Hospital de Clinicas of Federal University of Parana, 181 General Carneiro Street, Curitiba 80.069-900, Brazil.
authors.forename: R H
authors.initials: RH
authors.lastname: Scola
authors.forename: L C
authors.initials: LC
authors.lastname: Werneck
authors.forename: F M
authors.initials: FM
authors.lastname: Iwamoto
authors.forename: E A
authors.initials: EA
authors.lastname: Comerlato
authors.forename: C K
authors.initials: CK
authors.lastname: Kay
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D009132:Muscles / Q000503:physiopathology*; D020294:Myasthenic Syndromes, Congenital / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology