Hepatitis C Virus (HCV) Infection and Neurocognitive Impairment in Subjects with Mild Liver Disease

Hepatitis C virus (HCV) infection is a leading cause of liver cirrhosis, hepatocellular carcinoma, and liver-related deaths. It is estimated that 40-74% of patients with hepatitis C will experience at least one extrahepatic manifestation within their lifetime. The finding of HCV-RNA sequences in post-mortem brain tissue raises the possibility that HCV infection may affect the central nervous system and be the source of subtle neuropsychological symptoms, even in non-cirrhotic. Our investigation aimed to evaluate whether asymptomatic, HCV-infected subjects showed cognitive dysfunctions. Twenty-eight untreated asymptomatic HCV subjects and 18 healthy controls were tested using three neuropsychological instruments in a random sequence: Symbol Digit Modalities Test (SDMT), Controlled Oral Word Association Test (COWAT), and Continuous Visual Attention Test (CVAT). We performed depression screening, liver fibrosis assessment, blood tests, genotyping, and HCV-RNA viral load. A MANCOVA and univariate ANCOVAS were performed to examine group differences (HCV vs. healthy controls) in four scores of the CVAT (omission errors, commission errors, reaction time-RT, and variability of RT-VRT), and the scores derived from the SDMT, and the COWAT. A discriminant analysis was performed to identify which test variables effectively discriminate HCV-infected subjects from healthy controls. There were no group differences in the scores of the COWAT, SDMT, and in two variables of the CVAT (omission and commission errors). In contrast, the performance of the HCV group was poorer than the controls in RT (p = 0.047) and VRT (p = 0.046). The discriminant analysis further indicated that the RT was the most reliable variable to discriminate the two groups with an accuracy of 71.7%. The higher RT exhibited by the HCV group may reflect deficits in the intrinsic-alertness attention subdomain. As the RT variable was found to be the best discriminator between HCV patients and controls, we suggest that intrinsic-alertness deficits in HCV patients may affect the stability of response times increasing VRT and leading to significant lapses in attention. In conclusion, HCV subjects with mild disease showed deficits in RT and intraindividual VRT as compared to healthy controls.