Single fiber electromyography of extraocular muscles: a sensitive method for the diagnosis of ocular myasthenia gravis.
We performed single fiber electromyography (SFEMG) in the superior rectus and levator palpebralis (SR-LP) muscles of 17 patients with pure ocular myasthenia gravis (MG) and 9 controls. Thirteen patients were also assessed with SFEMG in the orbicularis oculi (OO) muscle. All the MG patients but none of the control subjects showed abnormal SFEMG jitter in the SR-LP muscles. On the other hand, only 62% of the MG patients had abnormal SFEMG jitter in the OO muscle. The procedure was well tolerated by the patients, and complications were minor. We conclude that SFEMG of the SR-LP muscles is a safe and highly sensitive technique for the diagnosis of ocular MG.
Rivero
A
A
Raúl Carrea Institute of Neurological Research, Buenos Aires, Argentina.
Crovetto
L
L
Lopez
L
L
Maselli
R
R
Nogués
M
M
D000328:Adult; D000368:Aged; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D009801:Oculomotor Muscles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009915:Orbit / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed