Trichloroethylene cranial neuropathy: is it really a toxic neuropathy or does it activate latent herpes virus?

The mechanism of the cranial neuropathy associated with heavy exposure to trichloroethylene (or dichloroethylene) is unknown. In severe cases there is destructive spread of the neuropathic process from the Vth cranial nerve nuclei up and down the brain stem in a manner that is difficult to explain on accepted neurotoxicological principles. However, there is a close association reported of this form of trigeminal neuropathy with reactivation of orofacial herpes simplex that suggests the possibility that the chemical, which readily gains entrance into the nervous system, may be responsible for reactivating the latent virus. This novel hypothesis is discussed in the light of current understanding of latency in herpes simplex infection in nervous tissue.