[Animal model of facial neuritis induced by herpes simplex virus].
OBJECTIVE
To study the role of herpes simplex virus type 1 ( HSV-1 ) in facial paralysis by developing an experimental animal model of viral facial paralysis.


METHODS
Both sides of posterior auricular branch of facial nerve were anatomies and incised in 66 mice. The HSV-1 was inoculated into right ear branch and fetal bovine serum was inoculated into left ear branch as control. The symmetry of mouse face was observed and scored. The temporal bones were serially sectioned and stained with hematoxylin and eosin. The extratemporal facial nerves were stained with osmium tetroxide. HSV-1 DNA in bilateral facial nerve, brain stem, trigeminal ganglion and spinal cord was detected by the polymerase chain reaction.


RESULTS
Twenty-eight (42. 42%) mice developed right facial paralysis between 2 and 5 days after inoculation. Continuing 3-6 days, the facial paralysis recovered spontaneously. Thirty-eight mice had no signs of facial paralysis. Compared with the left, nerve swelling, inflammatory cell infiltration were manifested in right temporal facial nerve of paralyzed mice. The ratio of the cross-sectional area of the facial nerve to the facial canal ( FN/FC ) was significantly higher than that on the control side (P < 0.01). Demyelinated nerve fibers were seen in the right extratemporal facial nerve. Not only in paralyzed mice, but also in non-paralyzed mice, HSV DNA was detected in some nerve tissues.


CONCLUSIONS
Inoculating HSV-1 into posterior auricular branch of facial nerve can produce an acute and transient facial paralysis in mice. The possible pathophysiologic mechanism of the facial paralysis is viral invasion and transportation from distal branch to main trunk. Then the viral facial neuritis causes facial paralysis.
Liu
Wen
W
Department of Otorhinolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
Gao
Zhi-Qiang
ZQ
Shen
Ping
P
Ni
Dao-Feng
DF
Quan
Shi-Ming
SM
Ni
An-Ping
AP
Zhang
Yun
Y
D000818:Animals; D004195:Disease Models, Animal; D005154:Facial Nerve / Q000821:virology*; D005155:Facial Nerve Diseases / Q000821:virology*; D005260:Female; D006561:Herpes Simplex / Q000503:physiopathology*; D018259:Herpesvirus 1, Human; D051379:Mice; D008807:Mice, Inbred BALB C