Nipah virus encephalitis: serial MR study of an emerging disease.
OBJECTIVE
To report the serial magnetic resonance (MR) imaging findings of the Nipah virus.


METHODS
Twelve patients underwent serial MR imaging. Eight patients were examined at the outbreak; 11, at 1 month; and seven, at 6 months. Contrast material-enhanced MR images, diffusion-weighted images, and single-voxel proton MR spectroscopic images were reviewed. Clinical and neurologic assessment, as well as analysis of the size, location, and appearance of brain lesions on MR images, were performed.


RESULTS
During the outbreak, all eight patients had multiple small foci of high signal intensity within the white matter on T2-weighted images. In six patients, cortical and brain stem lesions were also detected, and five patients had diffusion-weighted MR imaging-depicted hyperintensities. One month after the outbreak, five patients had widespread tiny foci of high signal intensity on T1-weighted images, particularly in the cerebral cortex. Diffusion-weighted images showed decreased prominence or disappearance of lesions over time. There was no evidence of progression or relapse of the lesions at 6-month follow-up. MR spectroscopy depicted reduction in N-acetylaspartate-to-creatine ratio and elevation of choline-to-creatine ratios.


CONCLUSIONS
The Nipah virus has findings unlike other viral encephalitides: small lesions that are primarily within the white matter, with transient punctate cortical hyperintensities on T1-weighted images.
Lim
C C Tchoyoson
CC
Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore. tchoyoson_lim@notes.ttsh.gov.sg
Lee
Kim En
KE
Lee
Wei Ling
WL
Tambyah
Paul A
PA
Lee
Cheng Chuan
CC
Sitoh
Yih Yian
YY
Auchus
Alexandra P
AP
Lin
B K Michael
BK
Hui
Francis
F
D000328:Adult; D000368:Aged; D000382:Agricultural Workers' Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D021821:Communicable Diseases, Emerging / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D004196:Disease Outbreaks; D018792:Encephalitis, Viral / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018184:Paramyxoviridae Infections / Q000175:diagnosis* / Q000453:epidemiology; D018098:Paramyxovirinae