Objective: Involvement of the central nervous system (CNS) in patients with hepatitis C virus (HCV) mixed cryoglobulinemia (MC) is rare. The mechanism by which brain lesions are produced is unclear. We investigated these phenomena by clinical evaluation (neuropsychological tests) and cerebral magnetic resonance imaging (MRI) studies in patients with HCV-MC vasculitis.
Methods: This prospective study included 40 patients with MC vasculitis and chronic active HCV infection (HCV RNA+), 11 HCV controls without MC, and 36 healthy controls, matched for sex and age. A battery of 10 standardized neuropsychological tests was administered by one experienced neuropsychiatrist. All patients underwent cerebral MRI investigation.
Results: Twenty-four of the 27 (89%) evaluated patients with HCV-MC had a deficiency in one or more of the 10 cognitive domains examined. The most commonly involved domains were those of attention (70%), executive functions (44%), visual construction (37%), and visual spatial functions (33%). The number of impaired cognitive functions was significantly higher in patients with MC vasculitis than in HCV controls (2.18 +/- 1.84 vs 0.87 +/- 3.1; p < 0.05). MRI analysis showed that HCV-MC patients had a higher mean number of total (7.03 +/- 9.9 vs 0.90 +/- 1.81 and 2.03 +/- 3.1; p < 0.05) and periventricular (2.4 +/- 3.0 vs 0.38 +/- 0.5 and 0.8 +/- 1.4; p < 0.05) white matter high intensity signals than HCV controls and healthy controls, respectively.
Conclusion: The high frequency of impaired cognitive function and the extent of MRI brain abnormalities in patients with HCV-associated mixed cryoglobulinemia vasculitis strongly suggest specific inflammatory involvement of the CNS.