Neuromyelitis optica brain lesions localized at sites of high aquaporin 4 expression.
BACKGROUND
Neuromyelitis optica (NMO)-IgG is a specific autoantibody marker for NMO. It binds selectively to aquaporin 4 (AQP4), which is highly concentrated in astrocytic foot processes at the blood-brain barrier and is not restricted to optic nerve and spinal cord. Although it is conventionally believed that the brain is spared, brain imaging abnormalities are not uncommon in patients with NMO.


OBJECTIVE
To investigate the location of brain lesions that are distinctive for NMO with respect to the localization of AQP4 in mammalian brain.


METHODS
Observational, retrospective case series.


METHODS
Clinical serologic cohort of patients tested for NMO-IgG for whom brain MRI images were available.


METHODS
We identified 120 patients seropositive for NMO-IgG for whom brain magnetic resonance images were available.


METHODS
Magnetic resonance imaging abnormalities.


RESULTS
In 8 patients we observed recurring and distinctive magnetic resonance imaging abnormalities in the hypothalamic and periventricular areas that corresponded to brain regions of high AQP4 expression.


CONCLUSIONS
The distribution of NMO-characteristic brain lesions corresponds to sites of high AQP4 expression.
Pittock
Sean J
SJ
Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN 55905-0001, USA. Pittock.sean@mayo.edu
Weinshenker
Brian G
BG
Lucchinetti
Claudia F
CF
Wingerchuk
Dean M
DM
Corboy
John R
JR
Lennon
Vanda A
VA
D000293:Adolescent; D000328:Adult; D051401:Aquaporin 4 / Q000276:immunology / Q000378:metabolism*; D001323:Autoantibodies; D002552:Cerebral Ventricles / Q000378:metabolism / Q000473:pathology; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000378:metabolism / Q000473:pathology; D007074:Immunoglobulin G; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000378:metabolism* / Q000473:pathology*; D012189:Retrospective Studies
D051401:Aquaporin 4; D001323:Autoantibodies; D007074:Immunoglobulin G