Hepatitis C virus (HCV) can damage not only the liver but also the brain, according to a new Canadian study.

"It has been a question for a long time," said study co-author Pornpun Vivithanaporn, a post-doctoral fellow in the University of Alberta's Faculty of Medicine and Dentistry. "It proves the virus has implications on neurological disease."

The study showed HCV "gets in [the brain], it infects, and it replicates," said lead author Dr. Christopher Power, a neurologist at the university. A buildup of HCV proteins in healthy brain cells eventually damages and kills the cells, as if the cells were drowning in their own refuse, he said.

"HCV core protein exposure caused neuronal injury through suppression of neuronal autophagy in addition to neuroimmune activation," the study concluded. "The additive neurotoxic effects of HCV- and HIV-encoded proteins highlight extrahepatic mechanisms by which HCV infection worsens the disease course of HIV infection."

Researchers already knew that severe liver damage can affect the patient's brain. The new findings support other studies showing that even when serious liver damage has not occurred, HCV patients might develop memory loss, trouble concentrating, apathy, and depression.

"It tells us we need to be vigilant for neurological problems for people who have hepatitis C," Power said. An HCV patient's treatment team might need to include a neurologist and a psychologist, as well as the liver specialist, he said.

The study, "Hepatitis C Virus Core Protein Induces Neuroimmune Activation and Potentiates Human Immunodeficiency Virus-1 Neurotoxicity," was published in Public Library of Science ONE (doi: 10.1371/journal.pone.0012856).