Necropsy study of the olfactory portal of entry in herpes simplex encephalitis.

Two fatal cases of sporadic herpes simplex virus (HSV) encephalitis were seen and diagnosed at the Sir Charles Gairdner Hospital, Perth, between 1979 and 1981. Necropsy studies were directed to the possible portal of entry of HSV into the central nervous system. Viruses were present in the left olfactory nerve in one patient. No viruses were found in the Gasserian ganglia of either patient. The finding of HSV within an olfactory nerve provides further evidence of an olfactory portal of entry to the central nervous system in sporadic human HSV encephalitis.