Clinical management of neurocysticercosis

Abstract

Neurocysticercosis is the most common helminthic disease of the nervous system and a leading cause of acquired epilepsy worldwide. Differences in the number and location of lesions as well as in the severity of the immune response against the parasites, makes neurocysticercosis a complex disease. Therefore, a single therapeutic approach is not expected to be useful in every patient. Introduction of cysticidal drugs – praziquantel and albendazole – have changed the prognosis of thousands of patients with neurocysticercosis. While pioneer trials of therapy were flawed by a poor design, recent studies have shown that cysticidal drugs results in disappearance of lesions and clinical improvement in most cases. Nevertheless, some patients with parenchymal neurocysticercosis may be left with remaining cysts and may develop recurrent seizures after therapy, and many patients with subarachnoid cysts may need repeated courses of therapy. In addition, not all forms of the disease benefit from cysticidal drugs.

Keywords::

• albendazole
• cysticercosis
• cysticidal drugs
• epilepsy
• neurocysticercosis
• parasitic diseases
• praziquantel
• seizures
• Taenia solium

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Neurocysticercosis is a pleomorphic parasitic disease causing different pathological lesions and clinical syndromes. Therefore, a single therapeutic approach should not be expected to be useful in every patient.

• Proper characterization of neurocysticercosis according to the viability of cysts, severity of the host's immune response and location of lesions, is of paramount importance for a rational therapy.

• The first line of management of neurocysticercosis should be directed to control the clinical manifestations of a given patient and the pathogenetic mechanisms involved in their occurrence.

• Two drugs, praziquantel and albendazole, have been shown to have potent cysticidal effects and have improved the prognosis of thousands of patients with neurocysticercosis.

• The anecdotal nature of pioneer trials on cysticidal drugs created concern and it was postulated that these drugs do not modify the natural course of the disease.

• More recently, a number of double-blind, placebo-controlled studies have shown that the use of cysticidal drugs is associated with resolution of lesions and clinical improvement in most patients with parenchymal brain cysticercosis.

• Treatment of extraparenchymal neurocysticercosis is more complicated and many patients do not respond to medical treatment. In these cases, repeated trials of cysticidal drugs (or even surgical interventions) are often needed.

• Some forms of neurocysticercosis, like cysticercotic encephalitis, must not be treated with cysticidal drugs as their use exacerbates the inflammatory reaction against parasites and may cause seizures or intracranial hypertension.

• Calcifications should not be seen as inert lesions, as they represent permanent epileptogenic foci that may reactivate causing recurrent seizures. Long-term therapy with antiepileptic drugs is needed in most of these cases.