Corticosteroids for parasitic eosinophilic meningitis.

Background: Angiostrongylus cantonensis (A. cantonensis) is the major cause of infectious eosinophilic meningitis. Dead larvae of this parasite cause inflammation and exacerbate symptoms of meningitis. Corticosteroids are drugs used to reduce inflammation caused by this parasite.

Objectives: To examine the effects and adverse events of corticosteroids in patients with eosinophilic meningitis.

Search Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 6), MEDLINE (1950 to July Week 4, 2012), EMBASE (1974 to July 2012), Scopus (1960 to July 2012), Web of Science (1955 to July 2012), LILACS (1982 to July 2012), and CINAHL (1981 to July 2012).

Selection Criteria: Randomised controlled trials (RCTs) of corticosteroids versus placebo for eosinophilic meningitis.

Data Collection And Analysis: Two review authors (SiT, SaT) independently collected and extracted study data. We graded the methodological quality of the RCTs. We identified and analyzed outcomes and adverse effects.

Main Results: One study involving 110 participants (55 participants in each group) met our inclusion criteria. The corticosteroid (prednisolone) showed a benefit in shortening the median time to resolution of headaches (five days in the treatment group versus 13 days in the control group, P < 0.0001). Corticosteroids were also associated with smaller numbers of participants who still had headaches after a two-week course of treatment (9.1% versus 45.5%, P < 0.0001). There was a reduction in median time of analgesics use in participants receiving corticosteroids (10.5 versus 25.0, P = 0.038). There were no reported adverse effects from prednisolone in the treatment group.

Authors' Conclusions: Corticosteroids significantly help relieve headache in patients with eosinophilic meningitis. However, there is only one RCT supporting this benefit and this trial did not clearly mention allocation concealment and stratification. Future well-designed RCTs may be necessary.