The overall study objective is to assess cerebral function with particular emphasis on cognitive functions in HCV patients (genotypes 1,2,3 and 4) by use of a neuropsychiatric test battery. Furthermore, the patients will be examined by MRI, including magnetization transfer, diffusion tensor and contrast perfusion, in order to perform measurements of cerebral volumetric and microstructure. Finally, HCV analysis, including viral sequences and cytokine profiles, in serum and cerebrospinal fluid will be carried out in the study population.