[Chronic inflammatory polyradiculoneuropathy and hepatitis C virus]

Recommendations on diagnostic strategies for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune mediated treatable peripheral neuropathy, the diagnosis of which is straightforward in more than half of cases. Numerous sets of electrophysiological criteria have been published. However, in some cases, electrophysiological data are not sufficient and patients that may benefit from treatment escape accurate diagnosis.

OBJECTIVE

To describe a step by step diagnostic procedure for neurologists facing a peripheral neuropathy of undetermined cause, to help make an accurate diagnosis of CIDP.

METHODS

A group of French experts was established, neurologists and neurophysiologists being recruited on the basis of personal experience with patients suffering from CIDP and also on publications in the field. A full literature review was conducted on the topic of diagnostic criteria and procedures for the diagnosis of CIDP, and meetings were scheduled to reach a consensus on the best diagnostic workup in different clinical situations.

RESULTS

Six meetings were conducted and a consensus was reached, based on the available literature and experience in the management of such patients. Discussions resulted in defining five clinical situations in which a diagnosis of CIDP may be considered, and procedures were detailed in each case, including the location of nerve biopsy and use of non-conventional electrophysiological testing and imaging procedures.

CONCLUSION

The guidelines in the diagnostic procedure reported here result from a consensus of French experts in the field of peripheral neuropathy and allow a diagnosis of CIDP to be made in the most frequently encountered situations. These recommendations may be of value for physicians as they rely on the rational use of available techniques in typical clinical situations.

Polyneuropathy with demyelinating features in mixed cryoglobulinemia with hepatitis C virus infection

Peripheral neuropathy can arise from various mechanisms during hepatitis C virus (HCV) infection, mainly involving associated mixed cryoglobulinemia. The frequency of demyelinating polyneuropathy is probably underestimated in these patients. We report two cases of demyelinating polyneuropathy in HCV-infected patients. The first case concerned a 76-year-old woman followed for hepatitis C associated with a mixed cryoglobulinemia (type II), who developed a chronic progressive distal motor weakness and sensory disturbances concomitant with a raise in serum aspartate aminotransferase (GOT/AST) and alanine aminotransferase (GPT/ALT) levels. Other laboratory studies were normal except for a decrease in the hemolytic fraction of complement to 75 IU (n = 400-520). The second case was a 68-year-old woman followed for hepatitis C associated with a mixed cryoglobulinemia (type II), who had sensory disturbances in the lower limbs. Laboratory studies were otherwise unremarkable. Cerebrospinal fluid studies showed a normal protein content without pleocytosis in both patients. In both cases nerve conduction studies were suggestive of a mixed axonal and demyelinating sensorimotor neuropathy. Sural nerve biopsy showed segmental demyelination and severe loss of large myelinated fibers as well as some onion bulb formation in both cases. The two patients subsequently improved, the first with an antiviral treatment and the second with oral steroids.

Neuropathies périphériques sans cryoglobulinémie révélatrices de l’hépatite virale C

INTRODUCTION

Peripheral neuropathies are the most common neurological complication of viral hepatitis C infection with mixed cryoglobulinemia.

CASES REPORT

We report five cases (three men, two women) of peripheral neuropathies revealing viral hepatitis C infection without cryoglobulinemia; the patients' mean age was 56 years. Paresthesias were the most frequent symptom. Electroneuromyographic examination found one case of polyneuropathy and four cases of multiplex mononeuropathies; the complement level was normal in all patients and the rheumatoid factor positive in two cases. Etiological investigations for peripheral neuropathy remained negative. Treatment and outcome were variable.

DISCUSSION

Negative cryoglobulinemia in cases of VHC infection with neurological features has been described in the last few years, suggesting the possibility of other mechanisms such as direct action of the virus on the nervous system. There is no consensus on the treatment and outcome is variable.

CONCLUSION

Peripheral neuropathy may reveal VHC infection, underscoring the need for VHC serology testing in etiological investigations for peripheral neuropathies.

Polyradiculonévrites inflammatoires démyélinisantes chroniques : stratégie diagnostique

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) comprises a group of dysimmune neuropathies easily diagnosed in more than half of the patients. Diagnosis is based on clinical, electrophysiological and biological clues. In some patients, diagnosis is unclear because of the debated value of the available clues. In such circumstances, dysimmune neuropathies may not be diagnosed, leading to insufficient treatment. This is an important category of patients because immunomodulatory drugs have proven efficacy. The CIDP spectrum includes a relatively wide range of diseases. Besides the easily recognized classic forms, there are many clinical variants, sometimes with a paucisymptomatic presentation leading to uncertain diagnosis. The French CIDP study group has established guidelines for diagnostic strategy in CIDP patients. The first part of this paper is devoted to the clinical aspects of the disease, classical forms and variants. In the second part, the results of electrophysiological studies are reported. In a third chapter, complementary examinations useful for diagnosis are discussed. The fourth chapter deals with the diagnostic strategy, discussed in relation to the different situations which may be encountered in clinical practice. details the technical modalities of appropriate electrophysiological studies and presents normal results together with those indicating demyelinating neuropathy. Nerve biopsy technique and results are given in appendix II.

[Peripheral neuropathy and hepatitis C virus infection: more than cryoglobulinemia]

PURPOSE

To study characteristics of peripheral neuropathies associated with hepatitis C virus infection.

METHODS

A study of two groups of four patients with peripheral neuropathy and infected with hepatitis C virus, and a literature review.

RESULTS

We observed four cases of peripheral neuropathy in patients with hepatitis C virus infection with persistent negativity of mixed cryoglobulinemia, and with no purpura, rheumatoid factor, or low C4 level. Neuropathy improved with treatment in three patients between 8 and 28 months after treatment was begun. We report four other observations of peripheral neuropathy with mixed cryoglobulinemia. Worsening of peripheral neuropathy was observed 2 to 13 weeks after initiation of interferon alpha despite improvement of hepatic parameters. After stopping interferon, peripheral neuropathy worsened (one case), stabilized (one case), or improved (two cases).

DISCUSSION

In patients infected with hepatitis C virus, peripheral neuropathy can be due to mixed cryoglobulinemia, periarteritis nodosa, and perhaps hepatitis C virus itself as suggested by our first observations. Low doses of interferon alpha may worsen peripheral neuropathy in patients with mixed cryoglobulinemia, as suggested in our later observations.