The acute autoimmune polyneuropathy known as Guillain-Barré syndrome (GBS) is the most common cause of flaccid paralysis in developed countries and has an incidence rate of 1 to 1.5 per 100,000 persons. Most patients recover spontaneously within two weeks; however, symptoms, including paralysis, persist in a significant minority of patients. Standard treatment is based on intravenous immunoglobulin plus supportive therapy. After mixed results from clinical trials, a Cochrane review concluded that corticosteroids provided no benefit in the management of GBS. Positive results from trials of high-dose intravenous methylprednisolone in the treatment of other polyneuropathies led van Koningsveld and colleagues to study this treatment as an adjunctive therapy in GBS.

The authors recruited patients who had been admitted to 32 European health care centers over a six-year period with confirmed GBS that resulted in a score of at least 3 on a standardized disability rating scale. Patients had to be at least six years of age and to have had no prior episodes of GBS, serious concurrent conditions, or contraindications to the study treatments. The initial assessment included extensive testing of blood, urine, and cerebrospinal fluid to screen for abnormalities and alternative explanations of symptoms.

The 233 participants were randomly assigned to treatment after stratification for age because prognosis in GBS is strongly related to age. All patients received intravenous immunoglobulin (0.4 g per kg for five days) and 116 patients also received 500 mg of intravenous methylprednisolone (children received 8.0 mg per kg) for five days. The remaining 117 patients received an equivalent volume of saline as placebo. The patients were assessed weekly for eight weeks for cranial nerve dysfunction, GBS disability score, and a limb muscle function score (using the Medical Research Council sumscore). Patients were assessed every other week between weeks 9 and 14, then monthly until week 26. Patients were then reassessed one year after entry to the study. The primary end point was improvement in GBS disability score from baseline.

Overall, improvement of one or more grades on the GBS score was recorded in 76 patients (68 percent) treated with methylprednisolone and 63 patients (56 percent) in the control group. The difference did not quite achieve statistical significance (P = .06) in the intention to treat analysis. When results were based only on patients who adhered to the protocol, improvement was recorded in 71 patients (70 percent) in the treatment group and 58 patients (56 percent) in the control group. This difference was statistically significant (P = .03). The two treatment groups did not differ significantly in seven measures of secondary outcome (see accompanying table).

After adjustments for age and degree of disability, the odds ratio for treatment was 1.89. The groups did not differ significantly in adverse events. Four patients in the control group and six in the treatment group died. Urinary tract infections developed in 30 percent of patients in the control group and 16 percent in the treatment group. Significant rises in serum glucose levels were noted in 21 percent of patients in the treatment group compared with 6 percent in the control group. Hypertension was reported in 13 percent of patients in the control group compared with 2 percent in the treatment group.

The authors conclude that adjunct therapy with high-dose methylprednisolone did not provide consistent significant benefit in patients with GBS who received intravenous immunotherapy. Nevertheless, they believe the two treatments could be synergistic in selected patients and call for more research to identify subgroups of patients with GBS who could benefit from combination therapy.