Increased sensitivity to a nondepolarizing muscle relaxant in a patient with acquired neuromyotonia.
Neuromyotonia is a disorder of hyperexcitability of the peripheral nerve. It has electromyographic features of spontaneous, continuous, irregularly occurring doublets, or multiplets of motor unit potential discharges. Neuromyotonia is characterized by both myokymic and neuromyotonic discharges. To our knowledge, this is the first report in the literature to assess the sensitivity of skeletal muscle to a nondepolarizing muscle relaxant drug, rocuronium, in a woman with acquired neuromyotonia. She had a past medical history notable for prolonged postoperative paralysis following anesthesia. The patient showed increased sensitivity to the neuromuscular effects of rocuronium. This increase in sensitivity may be explained by downregulation of acetylcholine receptors in response to chronic high agonist (acetylcholine) concentrations. If patients with neuromyotonia receive anesthesia, we recommend that smaller doses of a nondepolarizing muscle relaxant be administered, accompanied by monitoring of neuromuscular function, so as to provide optimal muscle relaxation while avoiding overdose and prolonged postoperative recovery.
Ginsburg
Greg
G
Department of Anesthesia and Critical Care, Massachusetts General Hospital, Shriners Hospital for Children Harvard Medical School, 55 Fruit Street, Boston, Massachusetts 02114, USA.
Forde
Ryan
R
Martyn
Jeevendra A J
JA
Eikermann
Matthias
M
D000732:Androstanols; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D020386:Isaacs Syndrome / Q000473:pathology* / Q000503:physiopathology*; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000503:physiopathology; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium; D013997:Time Factors
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium