Treatment of epilepsy in people with neurocysticercosis

Background

Neurocysticercosis is a common infection of the brain caused by the larvae of the pork tapeworm, migrating to the brain. Seizures are the most common symptom, although some people may present with headache, vomiting or other symptoms of brain swelling.

This review investigates the usefulness of antiepileptic drugs (AEDs) in preventing seizures in people who did not have seizures but presented with these other symptoms. We also examined the usefulness of the AEDs in people with epilepsy due to neurocysticercosis in terms of choice of drug, dosage, duration of treatment, cost, side effects and the quality of life.

Study characteristics

Four trials with a total of 466 participants were reviewed, focusing on the comparison of 'short duration' and 'long duration' of AEDs drugs in people with a single cerebral lesion. These trials compared various durations of AED therapy: six to 12 months as short duration and 12 to 24 months as long-duration therapy.

Key results

No statistically significant benefit of one duration of AED over the other (six, 12 or 24 months) could be demonstrated. In people with calcified cysts, longer duration of therapy may be preferable.

All four included trials, enrolled people with a single brain lesion. The findings of our review cannot be extrapolated to people with multiple cysts or with cysts in unusual parts of the brain.

The evidence is current to July 2019.

Authors' conclusions: 

Despite neurocysticercosis being the most common cause of epilepsy worldwide, there is currently no evidence available regarding the use of AEDs as seizure prophylaxis among people presenting with symptoms other than seizures. For those presenting with seizures, there is no reliable evidence regarding the duration of treatment required. There is therefore a need for large scale randomised controlled trials to address these questions.

Read the full abstract...
Background: 

Neurocysticercosis is the most common parasitic infection of the brain. Epilepsy is the most common clinical presentation, though it may also present with headache, symptoms of raised intracranial pressure, hydrocephalus and ocular symptoms depending upon the localisation of the parasitic cysts. Anthelmintic drugs, anti-oedema drugs, such as steroids, and antiepileptic drugs (AEDs) form the mainstay of treatment.

This is an updated version of the original Cochrane Review published in 2015, Issue 10.

Objectives: 

To assess the effects (benefits and harms) of AEDs for the primary and secondary prevention of seizures in people with neurocysticercosis.

For the question of primary prevention, we examined whether AEDs reduce the likelihood of seizures in patients who have neurocysticercosis but have not had a seizure.

For the question of secondary prevention, we examined whether AEDs reduce the likelihood of further seizures in patients who have had at least one seizure due to neurocysticercosis.

As part of primary prevention studies, we also aimed to examine which AED has been found to be beneficial in people with neurocysticercosis in terms of duration, dose and side-effect profile.

Search strategy: 

For the latest update of this review, we searched the following databases on 8 July 2019: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to July 05, 2019) and LILACS (1982- ). CRS Web includes the Cochrane Epilepsy Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), and randomised or quasi-randomised, controlled trials from Embase, ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (ICTRP). We also checked the references lists of identified studies, and contacted experts in the field and colleagues to search for additional studies and for information about ongoing studies.

Selection criteria: 

Randomised and quasi-randomised controlled trials.

Single-blind, double-blind or unblinded studies were eligible for inclusion.

Data collection and analysis: 

Two review authors screened all citations for eligibility (MS screened the initially identified 180 citations, MF and BDM screened the 48 citations identified for the purpose of this update).Two review authors independently extracted data and evaluated each study for risk of bias.

Main results: 

We did not find any trials that investigated the role of AEDs in preventing seizures among people with neurocysticercosis, presenting with symptoms other than seizures.

We did not find any trials that evaluated evaluating individual AEDs in people with neurocysticercosis.

We found one trial, comparing two AEDs in people with solitary neurocysticercosis with seizures. However, we excluded this study from the review as it was of poor quality.

We found four trials that compared the efficacy of short term versus longer term AED treatment for people with solitary neurocysticercosis (identified on computed tomography (CT) scan) presenting with seizures. In total, 466 people were enrolled. These studies compared various AED treatment durations, six, 12 and 24 months. The risk of seizure recurrence with six months treatment compared with 12 to 24 months treatment was not statistically significant (odds ratio (OR) 1.34 (95% confidence interval (CI) 0.73 to 2.47; three studies, 360 participants; low-certainty evidence)). The risk of seizure recurrence with six to 12 months compared with 24 months treatment was not statistically significant (OR 1.36 (95% CI 0.72 to 2.57; three studies, 385 participants; low-certainty evidence)).

Two studies co-related seizure recurrence with CT findings and suggested that persistent and calcified lesions had a higher recurrence risk and suggest longer duration of treatment with AEDs. One study reported no side effects, while the rest did not comment on side effects of drugs. None of the studies addressed the quality of life of the participants.These studies had certain methodological deficiencies such as a small sample size and a possibility of bias due to lack of blinding, which affect the results of this review.

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