Numerous studies have reported associations between chronic hepatitis C virus (HCV) infection and fatigue, depression and impairments in health-related quality of life, which are independent of the severity of liver disease. Although there are a large number of potential explanations for these symptoms, including a history of substance abuse and associated personality types, or the effect of the diagnosis of HCV infection itself, there has been recent interest in the possibility of a biological effect of HCV infection on cerebral function. There is emerging evidence of mild, but significant neurocognitive impairment in HCV infection, which cannot be wholly attributed to substance abuse, co-existent depression or hepatic encephalopathy. Impairments are predominantly in the domains of attention, concentration and information processing speed. Furthermore, in-vivo cerebral magnetic resonance spectroscopy studies in patients with hepatitis C and normal liver function have reported elevations in cerebral choline-containing compounds and reductions in N-acetyl aspartate, suggesting that a biological mechanism may underlie the cognitive findings. The recent detection of HCV genetic sequences in post-mortem 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.
From the aLiver Unit, Division of Medicine, Faculty of Medicine, Imperial College London, St Mary's Hospital Campus, London, UK
bRobert Steiner MR Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, London, UK
cCognitive Drug Research Ltd., Goring-on-Thames, UK.
Correspondence to Daniel M. Forton, Hepatology Section, Faculty of Medicine, Imperial College London, 10th Floor QEQM Building, St Mary's Hospital, South Wharf Road, London W2 1NY, UK. Tel: +44 207 886 1247; fax: +44 207 724 9369; e-mail: firstname.lastname@example.org