Eleven RCTs (n=936), of which 5 were double-blind RCTs (n=368) and 6 were non-blinded randomised trials (n=568), were included in the review.
Five trials were rated as having good methodological quality, 1 was fair, 3 were fair or poor, and 2 were poor.
Neuroimaging outcome: enhancing lesions (5 studies).
Seventy-two per cent of patients treated with a cysticidal drug and 63% of untreated patients showed improvement on computed tomography (CT) scans. The chi-squared test for homogeneity was not statistically significant (P=0.19), but the I-squared statistic (34%) suggested marginal homogeneity. Using a random-effects model, there was no statistically significant difference between treatment groups for the number of participants without lesions (OR 1.18, 95% CI: 0.82, 1.71, P=0.38). When the one trial thought to be the cause of the heterogeneity was removed, the results were statistically significant in favour of the cysticidal drug (OR 1.93, 95% CI: 1.21, 3.08, P=0.006), and no significant statistical heterogeneity was detected.
Neuroimaging outcome: cystic lesions (6 studies).
Forty-four per cent of treated patients and 19% of untreated patients had complete resolution of all cystic lesions on CT scans or magnetic resonance imaging. The chi-squared test for homogeneity was not statistically significant (P=0.22), but the I-squared statistic (29%) suggested marginal homogeneity. When a random-effects model was used, there was a statistically significant difference between groups in favour of the treated group (OR 2.10, 95% CI: 1.10, 4.01, P=0.025).
Based on 5 studies, there was a greater reduction in the total number of cysts in treated patients than in untreated patients, but the difference was not statistically significant at the 5% level (random-effects OR 3.55, 95% CI: 0.81, 15.52, P=0.092). Removing one of the studies because it was thought to be the cause of statistical heterogeneity revealed a stronger relationship between a reduction in number of cysts and treatment with a cysticidal drug (OR 14.79, 95% CI: 10.16, 21.53, P<0.001), and no significant statistical heterogeneity was detected.
Seizure recurrence: enhancing lesions (4 studies).
There were statistically significantly fewer seizures during follow-up in the treated patients (14%) than in the untreated patients (32%) (OR 0.36, 95% CI: 0.21, 0.62, P<0.001). No significant statistical heterogeneity was detected (P=0.68, I-squared 0%).
Seizure recurrence: cystic lesions (2 studies).
One study, in which all patients had epilepsy, found that patients treated with albendazole showed a significant (67%) reduction in the rate of seizures involving loss of consciousness after the first month of treatment (P=0.003). In the other study, only some patients had epilepsy, and no information about the frequency or severity of recurrences in individual patients was provided.
Effects of corticosteroids on cysticidal drug efficacy.
One study found that albendazole plus a corticosteroid (dexamethasone) was no better than albendazole alone in terms of lesion resolution or risk of seizure recurrence during follow-up.
Safety of cysticidal drugs.
Adverse events related to treatment were poorly reported. Many patients reported mild headache, nausea, or abdominal discomfort. Some patients had a transient exacerbation of seizures during the trial, and a few developed signs of increased intracranial pressure. The occurrence of adverse events did not depend on the type of cysticidal drug used or whether patients were receiving corticosteroids.