Mechanisms of escape phenomenon of spinal cord and brainstem in human rabies.
BACKGROUND
Rabies virus preferentially involves brainstem, thalamus and spinal cord in human furious and paralytic rabies beginning in the early stage of illness. Nevertheless, rabies patient remains alert until the pre-terminal phase. Weakness of extremities develops only when furious rabies patient becomes comatose; whereas peripheral nerve dysfunction is responsible for weakness in paralytic rabies.


METHODS
Evidence of apoptosis and mitochondrial outer membrane permeabilization in brain and spinal cord of 10 rabies patients was examined and these findings were correlated with the presence of rabies virus antigen.


RESULTS
Although apoptosis was evident in most of the regions, cytochrome c leakage was relatively absent in spinal cord of nearly all patients despite the abundant presence of rabies virus antigen. Such finding was also noted in brainstem of 5 patients.


CONCLUSIONS
Cell death in human rabies may be delayed in spinal cord and the reticular activating system, such as brainstem, thus explaining absence of weakness due to spinal cord dysfunction and preservation of consciousness.
Juntrakul
Sasiwimol
S
Department of Medicine, Chulalongkorn University Hospital, Rama 4 Road, Bangkok, Thailand. c_sasiwimon@yahoo.com
Ruangvejvorachai
Preecha
P
Shuangshoti
Shanop
S
Wacharapluesadee
Supaporn
S
Hemachudha
Thiravat
T
D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D000956:Antigens, Viral / Q000032:analysis; D017209:Apoptosis; D001933:Brain Stem / Q000473:pathology* / Q000821:virology*; D002648:Child; D045304:Cytochromes c / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011818:Rabies / Q000473:pathology* / Q000503:physiopathology; D013116:Spinal Cord / Q000473:pathology* / Q000821:virology*
D000956:Antigens, Viral; D045304:Cytochromes c