Neurocysticercosis: A natural human model of epileptogenesis

Abstract

Objective: To develop a better understanding of mechanisms of seizures and long-term epileptogenesis using neurocysticercosis.

Methods: A workshop was held bringing together experts in epilepsy and epileptogenesis and neurocysticercosis.

Results: Human neurocysticercosis and parallel animal models offer a unique opportunity to understand basic mechanisms of seizures. Inflammatory responses to degenerating forms and later-stage calcified parasite granulomas are associated with seizures and epilepsy. Other mechanisms may also be involved in epileptogenesis.

Significance: Naturally occurring brain infections with neurocysticercosis offer a unique opportunity to develop treatments for one of the world's most common causes of epilepsy and for the development of more general antiepileptogenic treatments. Key advantages stem from the time course in which an acute seizure heralds a start of the epileptogenic process, and radiographic changes of calcification and perilesional edema provide biomarkers of a chronic epileptic state.

Keywords: Epilepsy; Helminth; Seizure; Taenia solium.

Figure 1

One proposed mechanism of development of chronic epilepsy from acute seizures due to a degenerating cyst (left panel) to a calcification (right panel, left image) associated with perilesional edema (right panel, right image) as one cause of epilepsy in these patients. Epilepsy can also occur without the presence of perilesional edema or without obvious association to observable abnormalities. Left panel shows the same lesion with enhancement (left) and edema (right) in a patient who presented with seizures and right-sided signs. The right panel has three images of another patient presenting with seizures. A CT demonstrating a single calcifications (left) with enhancement (middle) and perilesional edema (right) by MRI imaging (Images from T.E.N.).