Electroencephalographic changes in experimental autoimmune myasthenia gravis.
A number of reports have suggested that central disturbances of cholinergic function may occur in patients with myasthenia gravis. The present study was designed in order to examine cortical electroencephalographic (EEG) activity in Lewis rats with experimental autoimmune myasthenia gravis (EAMG). Experiments were performed on conscious rats with clinical EAMG and demonstrable antibodies against the acetylcholine receptor. The animals showed no gross changes in cortical EEG discharge in terms of cycles and durations of wake, desynchronized sleep, and synchronized sleep, as compared with control rats. However, abnormalities characterized by single spikes or waves, and by spike and wave complexes, were observed, most commonly during synchronization of the EEG. Use of computerized frequency analysis of the EEG records revealed the presence of three basic differences in EEG discharge in myasthenic animals: (1) additional high-amplitude, low frequency (< 4 Hz) activity was recorded, especially during synchronized sleep; (2) decreases in mid-range (4-7 Hz) activity were recorded, particularly during periods of wakefulness; and, (3) increases in high frequency (> 8 Hz) spike discharge were observed at all times, although this was most evident during periods of synchronized sleep. The data provide further evidence for alterations in central cholinergic function in myasthenia gravis.
Saphier
D
D
Department of Pharmacology, Louisiana State University Medical Center, Shreveport 71130-3932.
Birmanns
B
B
Brenner
T
T
D000200:Action Potentials; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D001327:Autoimmune Diseases / Q000503:physiopathology*; D004195:Disease Models, Animal; D004569:Electroencephalography; D005260:Female; D009132:Muscles / Q000503:physiopathology; D009157:Myasthenia Gravis / Q000276:immunology / Q000503:physiopathology*; D051381:Rats; D011917:Rats, Inbred Lew; D011950:Receptors, Cholinergic / Q000276:immunology*; D012016:Reference Values; D012044:Regression Analysis
D000888:Antibodies, Anti-Idiotypic; D011950:Receptors, Cholinergic