Corticosteroids for chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a progressive or relapsing and remitting paralysing illness probably due to an autoimmune response which should benefit from corticosteroids. Non-randomised studies suggest that corticosteroids are beneficial. Two commonly used corticosteroids are prednisone and prednisolone. Both are usually given as oral tablets. Prednisone is converted into prednisolone in the liver so that the effect of the two drugs is usually the same. Another corticosteroid, called dexamethasone, is more potent and is used in smaller doses.

OBJECTIVES

To evaluate the efficacy of corticosteroid treatment compared to placebo or no treatment for CIDP and to compare the efficacy of different corticosteroid regimes.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (20 February 2012), CENTRAL (2012, Issue 2), MEDLINE (January 1966 to February 2012), and EMBASE (January 1980 to February 2012) for randomised trials of corticosteroids for CIDP.

SELECTION CRITERIA

We included randomised or quasi-randomised trials of treatment with any form of corticosteroids or adrenocorticotrophic hormone for CIDP, diagnosed by an internationally accepted definition.

DATA COLLECTION AND ANALYSIS

Two authors extracted the data and assessed risk of bias independently. The primary outcome was intended to be change in disability, with secondary outcomes of change in impairment, maximum motor nerve conduction velocity, or compound muscle action potential amplitude after 12 weeks, and adverse events.

MAIN RESULTS

In one non-blinded randomised controlled trial (RCT) with 35 eligible participants, the primary outcome for this review was not available. Twelve of 19 participants treated with prednisone, compared with five of 16 participants randomised to no treatment, had improved neuropathy impairment scores after 12 weeks; the risk ratio (RR) for improvement was 2.02 (95% confidence interval (CI) 0.90 to 4.52). Adverse events were not reported in detail, but one prednisone-treated participant died.In a double-blind RCT comparing daily standard-dose oral prednisolone with monthly high-dose oral dexamethasone in 40 participants, none of the outcomes for this review were available. There were no significant differences in remission (RR 1.11; 95% CI 0.50 to 2.45 in favour of monthly dexamethasone) or change in disability or impairment after one year. Eight of 16 in the prednisolone, and seven of 24 in the dexamethasone group deteriorated. Adverse events were similar with each regimen, except that sleeplessness and moon facies (moon-shaped appearance of the face) were significantly less common with monthly dexamethasone.Experience from large non-randomised studies suggests that corticosteroids are beneficial, but long-term use causes serious side effects.

AUTHORS' CONCLUSIONS: Very low quality evidence from one small, randomised trial did not show a statistically significant benefit from oral prednisone compared with no treatment. Nevertheless, corticosteroids are commonly used in practice. According to moderate quality evidence from one RCT, the efficacy of high-dose monthly oral dexamethasone was not statistically different from that of daily standard-dose oral prednisolone. Most adverse events occurred with similar frequencies in both groups, but sleeplessness and moon facies were significantly less common with monthly dexamethasone. Further research is needed to identify factors which predict response.