Cholinergic neuromuscular hyperactivity in patients with myasthenia gravis seropositive for MuSK antibody.
A 75-year-old man with severe oculobulbar myasthenia gravis (MG) treated with acetylcholine esterase inhibitors (AChEIs) was found to have muscle-specific tyrosine kinase (MuSK) antibodies. Neurophysiological examination displayed extra repetitive discharges after the compound motor action potential (CMAP) at low-frequency stimulation, possibly triggered by AChEI. This indicates an abnormal sensitivity to acetylcholine in patients with MuSK antibodies and may be a useful indicator of the adverse effect of AChEI treatment in these patients.
Punga
Anna Rostedt
AR
Department of Clinical Neurophysiology, University Hospital, S-75185 Uppsala, Sweden.
Flink
Roland
R
Askmark
Håkan
H
Stålberg
Erik V
EV
D000109:Acetylcholine; D000200:Action Potentials / Q000187:drug effects; D000368:Aged; D000906:Antibodies / Q000097:blood*; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D009157:Myasthenia Gravis / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000503:physiopathology*; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology*; D011950:Receptors, Cholinergic / Q000276:immunology*
D000906:Antibodies; D002800:Cholinesterase Inhibitors; D011950:Receptors, Cholinergic; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases; D000109:Acetylcholine