High-temperature repetitive nerve stimulation in myasthenia gravis

✍ Scribed by Seward B. Rutkove; Jeremy M. Shefner; Annabel K. Wang; Michael Ronthal; Elizabeth M. Raynor

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 120 KB
• Volume: 21
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/(sici)1097-4598(199811)21:11<1414::aid-mus8>3.0.co;2-c

✦ Synopsis

High temperature enhances the decrement on repetitive nerve stimulation (RNS) in patients with myasthenia gravis (MG). However, the limit of this phenomenon at high temperature is unknown. Three-hertz ulnar RNS was performed in 7 patients with MG at a skin temperature of 32°C and then with the hand in a 44°C water bath. At 32°C, the mean decrement preactivation was 5% (range, 0-24%); after 1 min of exercise, the mean decrement reached a maximum of 11% (range, 1-34%) 2 min postactivation. At a hand temperature of 42°C, the mean decrement preactivation was 17% (range, 0-65%); after exercise, the mean decrement reached a maximum of 29% (range, 5-74%) 1 min postactivation. In 3 subjects, RNS was normal at 32°C, but a definite decrement developed with heating. These findings demonstrate that very high temperature can improve the sensitivity of ulnar RNS for postsynaptic neuromuscular transmission defects.