Autoimmune optic neuritis in the common marmoset monkey: comparison of visual evoked potentials with MRI and histopathology.
OBJECTIVE
To assess the use of visual evoked potentials (VEPs) for the in vivo detection of impaired visual function in a marmoset model of multiple sclerosis. The sensitivity of the VEP recordings was determined by comparison with magnetic resonance imaging (MRI) and histopathology.


METHODS
Baseline VEPs were recorded in six healthy marmoset monkeys in response to light-flash stimulation. Experimental autoimmune encephalomyelitis (EAE) was induced in four of the six monkeys. Clinical scores were assessed daily, and VEPs were recorded every second week. In vivo MRI and subsequent histopathology of the brains and optic nerves were performed at the end of the study.


RESULTS
After induction of EAE, all four marmosets exhibited clinical signs between day 26 and 38 after immunization. VEPs were normal during the induction phase of the disease, but deteriorated in amplitude with the occurrence of clinical symptoms in all animals. MRI revealed bilateral optic neuritis and signal alterations in the optic tracts and occipital subcortical white matter in two of the animals. In the remaining two animals, MRI detected signal alterations in the occipital subcortical white matter. Histopathologic results were concordant with the MRI findings.


CONCLUSIONS
VEPs are an easily accessible noninvasive tool for measuring visual function and diagnosing impairment of the visual pathway in a marmoset EAE model.
Diem
Ricarda
R
Neurologische Klinik der Universität des Saarlandes, Homburg, Saar, Germany. ricarda.diem@uniklinikum-saarland.de
Demmer
Iris
I
Boretius
Susann
S
Merkler
Doron
D
Schmelting
Barthel
B
Williams
Sarah K
SK
Sättler
Muriel B
MB
Bähr
Mathias
M
Michaelis
Thomas
T
Frahm
Jens
J
Brück
Wolfgang
W
Fuchs
Eberhard
E
D000818:Animals; D001327:Autoimmune Diseases / Q000175:diagnosis*; D002144:Callithrix; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000139:chemically induced / Q000175:diagnosis*; D005074:Evoked Potentials, Visual; D005260:Female; D008279:Magnetic Resonance Imaging; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D063308:Myelin-Oligodendrocyte Glycoprotein; D009900:Optic Nerve / Q000473:pathology*; D009902:Optic Neuritis / Q000175:diagnosis*; D010775:Photic Stimulation; D014786:Vision Disorders / Q000175:diagnosis; D014795:Visual Pathways / Q000473:pathology*
D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D063308:Myelin-Oligodendrocyte Glycoprotein