Peripheral neuropathy in Japanese patients with hepatitis C virus infection

OBJECTIVE: The aim of this study was to report a series of Japanese patients with neuropathic symptoms following HCV infection. PATIENTS AND METHODS: Fifteen patients with neuropathic symptoms and HCV infection were studied retrospectively (neuropathy group). We evaluated clinical and electrophysiologic findings. As a control group, we investigated prospectively 11 patients with chronic HCV hepatitis without neuropathic symptoms. RESULTS: In the neuropathy group, the peripheral neuropathy was a multiple mononeuropathy (MM) in 8 patients, a polyneuropathy in 4 patients, a single cranial neuropathy in 2 patients, and a cervical radiculopathy in one patient. Five patients with MM had relapsing symptoms. Two patients showed a progression of neurologic symptoms following varicella zoster virus infection. Mixed cryoglobulinemia was noted in 4 of 13 tested patients. Circulating immunocomplexes were detected in 3 of 10 tested patients, and low complement (C3, C4, or CH50) levels were noted in 10 of 13 tested patients. Nerve conduction study (NCS) showed abnormal findings in 10 of 13 investigated patients. In the control group, only the frequency of low CH50 was significantly lower than that in the neuropathy group. Abnormal findings of NCS were found in 3 of 11 patients. CONCLUSION: We showed the presence of various types of neuropathies in patients with HCV infection. Our results suggest that relapsing MM is common in HCV positive neuropathy with or without cryoglobulinemia, and that the virus may modulate neurologic manifestations of other viral infections. Subclinical neuropathy may be present in some patients with HCV infection without neurologic symptoms.