HHV-6 Virus May Enter Brain via Nose 'Say Experts': Human herpes virus-6 (HHV-6), a member of the family of viruses that includes genital herpes as well as oral herpes, has been observed as the culprit for causing cold sores and often linked with various brain disorders, including multiple sclerosis, encephalitis and a form of epilepsy as well as causing roseola, a disease common among infants that results in high fever along with skin rashes.
Recently, experts at the Proceedings of the National Academy of Sciences have suggested that the common virus tends to slink into the brain through nose via nasal mucus and travels along olfactory cells right into the brain.
While explaining the findings of the study, Coauthor Steven Jacobson, of the National Institute of Neurological Disorders and Stroke in Bethesda, MD, claimed that everyone is exposed to this virus. In addition, Steven Jacobson also expressed disappointment that very little is known about the virus. Some studies have suggested that the virus may live in tonsils or in saliva. Further, other viruses such as herpes simplex, influenza A and rabies can invade the brain by shooting through the nose.
During the study course, researchers observed high levels of HHV-6 in the olfactory bulb, a smell-related part of the brain, in two of three autopsy brain samples. source