Clinical and Electrophysiologic Responses to Acetylcholinesterase Inhibitors in MuSK-Antibody-Positive Myasthenia Gravis: Evidence for Cholinergic Neuromuscular Hyperactivity
Journal of Clinical Neurology 2014³â 10±Ç 2È£ p.119 ~ p.124
½ÅÇÏ¿µ(Shin Ha-Young) - Yonsei University College of Medicine Department of Neurology
¹ÚÇüÁØ(Park Hyung-Jun) - Yonsei University College of Medicine Department of Neurology
ÀÌÈ¿Àº(Lee Hyo-Eun) - Yonsei University College of Medicine Department of Neurology
ÃÖ¿µÃ¶(Choi Young-Chul) - Yonsei University College of Medicine Department of Neurology
±è½Â¹Î(Kim Seung-Min) - Yonsei University College of Medicine Department of Neurology
Abstract
Background and Purpose: Patients with muscle-specific tyrosine kinase (MuSK) antibody (MuSK-Ab)-positive myasthenia gravis (MG) show distinct responses to acetylcholinesterase inhibitors (AChEIs). Although clinical responses to AChEIs in MuSK-Ab MG are reasonably well known, little is known about the electrophysiologic responses to AChEIs. We therefore investigated the clinical and electrophysiologic responses to AChEIs in MuSK-Ab-positive MG patients.
Methods: We retrospectively reviewed the medical records and electrodiagnostic findings of 17 MG patients (10 MuSK-Ab-positive and 7 MuSK-Ab-negative patients) who underwent electrodiagnostic testing before and after a neostigmine test (NT).
Results: The frequency of intolerance to pyridostigmine bromide (PB) was higher in MuSK-Ab-positive patients than in MuSK-Ab-negative patients (50% vs. 0%, respectively; p=0.044), while the maximum tolerable dose of PB was lower in the former (90 mg/day vs. 480 mg/day, p=0.023). The frequency of positive NT results was significantly lower in MuSK-Ab-positive patients than in MuSK-Ab-negative patients (40% vs. 100%, p=0.035), while the nicotinic side effects of neostigmine were more frequent in the former (80% vs. 14.3%, p=0.015). Repetitive compound muscle action potentials (R-CMAPs) developed more frequently after NT in MuSK-Ab-positive patients than in MuSK-Ab-negative patients (90% vs. 14.3%, p=0.004). The frequency of a high-frequency-stimulation-induced decrement-increment pattern (DIP) was higher in MuSK-Ab-positive patients than in MuSK-Ab-negative patients (100% vs. 17.7%, p=0.003).
Conclusions: These results suggest that MuSK-Ab-positive MG patients exhibit unique and hyperactive responses to AChEIs. Furthermore, R-CMAP and DIP development on a standard AChEI dose may be a distinct neurophysiologic feature indicative of MuSK-Ab-positive MG.
Å°¿öµå
myasthenia gravis, acetylcholinesterase inhibitor, muscle-specific tyrosine kinase, repetitive compound muscle action potential
KMID :
1130620140100020119
¿ø¹® ¹× ¸µÅ©¾Æ¿ô Á¤º¸
µîÀçÀú³Î Á¤º¸
À¯È¿¼º°á°ú(Recomendation)