Key points
- Course of treatment depends on multiple factors including clinical manifestation, and quantity, size, and location of cysticerci.
- Managing any neurological manifestations should be the focus of initial therapy.
- Oral albendazole and praziquantel are available for human use in the United States.
Treatment of Neurocysticercosis
The choice of treatment for neurocysticercosis depends on the clinical manifestations and the following characteristics of the cysticerci:
- Location
- Number
- Size
- Stage
Anthelminthic chemotherapy
Anthelminthic chemotherapy for symptomatic neurocysticercosis is almost never a medical emergency. The focus of initial therapy is the control of:
- Seizures
- Edema
- Intracranial hypertension
- Hydrocephalus
Anthelminthic therapy may increase symptoms acutely by killing viable cysts and triggering inflammation. Co-administration of corticosteroids that cross the blood brain barrier (e.g., dexamethasone) may mitigate these effects.
Surgery
Under certain circumstances, a ventricular shunt or other neurosurgical procedure may be indicated. Rarely, neurocysticercosis—especially large and/or subarachnoid (racemose) lesions—may present with imminent threat of intracranial herniation, a neurosurgical emergency.
Care precautions
Treatment in Pregnancy
Albendazole is a pregnancy category C drug. There are limited data on the use of albendazole in pregnant women. The available evidence suggests no difference in congenital abnormalities in the children of women accidentally treated with albendazole during mass drug administration (MDA) campaigns compared with those who were not. In MDA campaigns for which the World Health Organization (WHO) has determined that the benefits of treatment outweigh the risks, WHO allows use of albendazole in the 2nd and 3rd trimesters of pregnancy. However, healthcare providers should balance the risks of treatment for the fetus with the risks of disease progression in the woman in the absence of treatment.
Pregnancy Category C. Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal, or other) plus there are no controlled studies in women, or studies in women and animals are not available. Prescribe albendazole only if the potential benefits to the woman justify the potential risks to the fetus.
Treatment during lactation
Albendazole is minimally excreted in human milk. WHO has concluded that a single oral dose of albendazole can be given to lactating women.
Treatment in pediatric patients
The safety of albendazole in children less than 6 years old is not certain. Studies of the use of albendazole in children as young as one year old suggest that it is safe. According to WHO guidelines for MDA campaigns, children as young as one year of age (able to safely swallow tablets) can take albendazole. These campaigns have treated many children under six years old with albendazole, albeit at a reduced dose.
Treatment in Pregnancy
Praziquantel is a pregnancy category B drug. There are no adequate and well-controlled studies in pregnant women. However, the available evidence suggests no difference in adverse birth outcomes in the children of women who were accidentally treated with praziquantel during mass drug administration (MDA) campaigns compared with those who were not. In MDA campaigns for which the World Health Organization (WHO) has determined that the benefit of treatment outweighs the risk, WHO encourages the use of praziquantel in any stage of pregnancy. For individual patients in clinical settings, healthcare providers should consider the risk of treatment in infected pregnant women with the risk of disease progression in the absence of treatment.
Pregnancy Category B. Either animal-reproduction studies have not demonstrated a fetal risk plus there are no controlled studies in pregnant women, or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).
Treatment During Lactation
Praziquantel is excreted in low concentrations in breast milk. According to WHO guidelines for MDA campaigns, the use of praziquantel during lactation is encouraged. For individual patients in clinical settings, healthcare providers should consider the risk of treatment in infected breastfeeding women with the risk of disease progression in the absence of treatment.
Treatment in Pediatric Patients
The safety of praziquantel in children aged less than 4 years has not been established. WHO now recommends treating children at least 2 years of age with praziquantel during MDA campaigns for schistosomiasis control, citing evidence that praziquantel is safe in this age group. For individual patients in clinical settings, healthcare providers should consider the risk of treatment in children younger than 4 years old with the risk of disease progression in the absence of treatment.
Considerations
Although the heterogeneity of the clinical picture of neurocysticercosis requires individual tailoring of treatment and management, several general principles apply.
Anthelminthic therapy
Anthelminthic therapy is generally indicated for symptomatic patients with multiple, live (noncalcified) cysticerci.
Anthelminthic treatment will not benefit patients with dead (calcified) cysts.
Even when anthelminthic therapy is successful, continued use of anticonvulsant and other symptomatic medications may still be needed because the pathology may be irreversible.
Antihelminthic therapy may need to be deferred for certain presentations of neurocysticercosis (e.g., patients with increased intracranial pressure or diffuse cerebral edema).
Anticonvulsants
Conventional anticonvulsant therapy is the mainstay of management of neurocysticercosis-associated seizure disorders.
Decisions regarding discontinuation of anticonvulsant regimens must be made on an individual clinical basis, but data suggest that many patients can eventually be weaned from anticonvulsant therapy.
Steroids
Concomitant administration of steroids (e.g. dexamethasone) is often indicated to suppress the inflammatory response induced by destruction of live cysticerci.
Although our understanding of subarachnoid neurocysticercosis is evolving, treatment with both anthelminthics and corticosteroids is usually required. Ventricular shunting is often necessary as well.
Surgery
Intraventricular cysts should usually be treated by surgical removal (endoscopic if possible). Anthelminthics are relatively contraindicated because the resulting inflammatory response could precipitate obstructive hydrocephalus.
Medication options
In the United States, two oral antihelminthic medications are available for the treatment of neurocysticercosis, albendazole and praziquantel. Placebo-controlled trials confirm that albendazole treatment in appropriately selected neurocysticercosis patients is effective in decreasing the frequency of generalized seizures in long-term follow-up. Several studies suggest that albendazole (conventional dosage 15 mg/kg/day in two divided doses for 15 days) may be superior to praziquantel (50 mg/kg/day for 15 days) for the treatment of neurocysticercosis. In comparative clinical trials, albendazole was equivalent or superior to praziquantel in reducing the number of live cysticerci. Studies comparing combination therapy with albendazole and praziquantel to albendazole monotherapy have shown improved cyst resolution with combination therapy in patients with 3 or more parenchymal cysts. From this information, the Infectious Diseases Society of America (IDSA) and American Society of Tropical Medicine and Hygiene (ASTMH) have developed treatment guidelines that recommend initial monotherapy with albendazole for 1-2 viable parenchymal cysts or a single enhancing lesion due to neurocysticercosis and combination therapy with albendazole and praziquantel for >2 viable parenchymal cysts.
More prolonged treatment courses (e.g., 30 days of albendazole, which may be repeated) may be needed for extraparenchymal or extensive disease. Albendazole is more likely to be effective against extraparenchymal forms of the disease because of better penetration than praziquantel into the CSF.
Another possible contributing factor to the greater efficacy of albendazole is that serum and CSF metabolite levels appear to be potentiated by concomitant corticosteroids whereas praziquantel levels are depressed. Albendazole, unlike praziquantel, has been reported to be effective in giant subarachnoid cysticerci (racemose cysts) and in extraocular muscle cysts. However, some experts recommend using combination therapy with albendazole and praziquantel for subarachnoid cysticerci.
Both drugs appear to have a role in therapy, since cases that have not responded to one of the drugs have been reported to respond to the other, or a combination of the two.