Corticosteroids for parasitic eosinophilic meningitis
Abstract
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.
PICOs
Plain language summary
Corticosteroids for the treatment of parasitic eosinophilic meningitis
Eosinophilic meningitis is an inflammation of the membrane covering the brain which can be broadly categorised into infectious and non‐infectious causes. Among infectious aetiologies, Angiostrongylus cantonensis, a rat lung worm, is the major cause of eosinophilic meningitis. It occurs principally in South‐East Asia and throughout the Pacific basin. However, this parasite has spread progressively beyond the Pacific basin and is now found in regions of North America due to intercontinental dissemination of infected ship rats. Severe headache, which is self‐limiting, is the main complaint. The headache is probably due to an immune response to the dead parasites. Other signs and symptoms include neck stiffness and pain, visual disturbances, nausea, vomiting, paraesthesia and hyperaesthesia.
Corticosteroids are drugs that reduce inflammation, which can occur in eosinophilic meningitis from dead larvae. Our review found only one randomised controlled trial that matched our criteria. This trial included 129 patients (63 in the treatment group, prednisolone 60 mg/day, divided into three doses for two weeks and 66 in the control group, placebo). However,19 patients were lost to follow‐up. It showed that the median time of resolution of headaches was lower in the group treated with prednisolone (10.5 days versus 25 days) and the number of patients who still had headaches after 14 days was lower in the prednisolone group compared to the control (9.1% versus 45.5%).
There were statistically significant differences, which favoured the treatment group in other outcomes including the frequency of acetaminophen use (median of number of times used) amongst those who still had headaches after 14 days of prednisolone treatment; mean time until complete disappearance of headache; the number of patients who needed repeat lumbar puncture was smaller in the treatment group; and the frequency of acetaminophen use (median of number of times) was lower in the treatment group. There were no reported adverse effects from prednisolone in the treatment group. However the trial authors did not report on allocation concealment which is one of the important issues when considering selection bias.
