Central nervous system involvement in hepatitis C virus infection.

Hepatic encephalopathy is the most obvious neurological consequence of chronic hepatitis C virus (HCV) infection. There are also case reports of HCV-associated cerebral vasculitis. This review is concerned with the possibility of an effect of HCV on cerebral dysfunction, occurring at an early stage of chronic infection, prior to the development of cirrhosis and unrelated to vasculitis. There is emerging evidence of mild, but significant neurocognitive impairment in HCV infection, which cannot be attributed to substance abuse, coexistent depression, or hepatic encephalopathy. In vivo magnetic resonance spectroscopy and neurophysiological studies have suggested that a biological mechanism may underlie these cognitive findings. The recent detection of HCV genetic sequences in postmortem brain tissue raises the intriguing possibility that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment.