Absence of cortical demyelination in neuromyelitis optica.
OBJECTIVE
To asses the presence of cortical demyelination in brains of patients with neuromyelitis optica (NMO). NMO is an autoimmune inflammatory demyelinating disease that specifically targets aquaporin-4-rich regions of the CNS. Since aquaporin-4 is highly expressed in normal cortex, we anticipated that cortical demyelination may occur in NMO.


METHODS
This is a cross-sectional neuropathologic study performed on archival forebrain and cerebellar tissue sections from 19 autopsied patients with a clinically and/or pathologically confirmed NMO spectrum disorder.


RESULTS
Detailed immunohistochemical analyses of 19 archival NMO cases revealed preservation of aquaporin-4 in a normal distribution within cerebral and cerebellar cortices, and no evidence of cortical demyelination.


CONCLUSIONS
This study provides a plausible explanation for the absence of a secondary progressive clinical course in NMO and shows that cognitive and cortical neuroimaging abnormalities previously reported in NMO cannot be attributed to cortical demyelination. Lack of cortical demyelination is another characteristic that further distinguishes NMO from MS.
Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
B F Gh
BF
Popescu
J E
JE
Parisi
J A
JA
Cabrera-Gómez
K
K
Newell
R N
RN
Mandler
S J
SJ
Pittock
V A
VA
Lennon
B G
BG
Weinshenker
C F
CF
Lucchinetti
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051401:Aquaporin 4 / Q000378:metabolism; D002525:Cerebellar Cortex / Q000378:metabolism / Q000473:pathology; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000378:metabolism / Q000473:pathology*; D055815:Young Adult
D051401:Aquaporin 4