Case Of the Week (COW) 14 February 2016
DEVIC S DISEASE Longitudinally extensive spinal cord lesion(LESCL):
Findings:
Long-segment involvement of the optic nerve with acute swelling extending posteriorly into the optic chiasm with diffusion restriction. LESCLs (3 vertebral segments) that preferentially involve spinal central gray matter ,acutely expand the cord.
Discussion:
Neuromyelitis optica is characterized by bilateral optic neuritis and myelitis, with blindness and paraplegia. Optic nerves appearing hyperintense on T2 weighted sequences, swollen and enhancement Bilateral involvement and extension of the abnormal signal back into the chiasm is particularly suggestive of NMO Spinal cord involvement is extensive, with high T2 signal extend over long distances (over three or more vertebral segments, often much more). Also helpful in distinguishing it from MS demyelination is the involvement of the central part of the cord (MS lesions tend to involve individual peripheral white matter tracts). NMO was thought to have normal intracranial appearance it is increasingly NMO-IgG binds selectively to aquaporin-4 (AQP4). AQP4 is a water-channel protein that assembles as homotetramers in cell membranes and plays a major role in fluid homeostasis of the CNS. AQP4 is found throughout the brain but is particularly abundant in the optic nerves and spinal cord.
DEVIC S DISEASE Longitudinally extensive spinal cord lesion(LESCL):
Findings:
Long-segment involvement of the optic nerve with acute swelling extending posteriorly into the optic chiasm with diffusion restriction. LESCLs (3 vertebral segments) that preferentially involve spinal central gray matter ,acutely expand the cord.
Discussion:
Neuromyelitis optica is characterized by bilateral optic neuritis and myelitis, with blindness and paraplegia. Optic nerves appearing hyperintense on T2 weighted sequences, swollen and enhancement Bilateral involvement and extension of the abnormal signal back into the chiasm is particularly suggestive of NMO Spinal cord involvement is extensive, with high T2 signal extend over long distances (over three or more vertebral segments, often much more). Also helpful in distinguishing it from MS demyelination is the involvement of the central part of the cord (MS lesions tend to involve individual peripheral white matter tracts). NMO was thought to have normal intracranial appearance it is increasingly NMO-IgG binds selectively to aquaporin-4 (AQP4). AQP4 is a water-channel protein that assembles as homotetramers in cell membranes and plays a major role in fluid homeostasis of the CNS. AQP4 is found throughout the brain but is particularly abundant in the optic nerves and spinal cord.