Sofía S. Sánchez Boluarte, MD, MSc, MSc
Nominated From: University of Washington
Research Site: Peru-Instituto Nacional de Ciencias Neurologicas
Research Area: Epilepsy
Primary Mentors: Dr. Joseph Zunt, Dr. Behnaz Esmaeili
Research Project
Risk factors for breakthrough seizures in patients with neurocysticercosis.
Neurocysticercosis (NCC) is caused by infection of the central nervous system (CNS) by the larval stage of the zoonotic tapeworm Taenia solium, and remains a major challenge in public health due to associated secondary epilepsy(1,2). It has been consistently demonstrated that NCC is one of the leading causes of acquired epilepsy in endemic countries(3–6) and likely worldwide; in fact, approximately 80% of the disease burden caused by epilepsy is located in developing countries(7,8).
T. solium larvae lodge in the brain parenchyma as viable cysts. At the end of their natural life cycle or subsequent to antiparasitic treatment, these cysts degenerate and a portion of these lesions progress to a residual parenchymal calcified lesion. Cerebral calcifications persist in the host brain permanently, and in endemic areas calcifications have been consistently associated with seizures in population and hospital-based studies(3–6).
There is consensus in the literature that an individualized approach to the discontinuation of antiseizure medication (ASM ) in people with epilepsy (PWE) is needed considering the main risk factors for recurrent seizures(9,10); older age at seizure onset, longer duration of epilepsy disease, abnormal neurological examination or psychiatric findings, abnormal EEG findings, increased number of seizures during ASM therapy or history of status epilepticus, greater number of ASM used during treatment, failure in previous withdrawal attempts, presence of an organic lesion(11,12). Additionally, gradual ASM withdrawal is also recommended (10,13,14).
Recommendations for ASM withdrawal in patients with epilepsy and NCC have never been systematically assessed and are mostly based on expert opinion(15). Most studies in NCC that report risk factors for seizure relapse after AED withdrawal have been done in NCC patients with mixed NCC (viable, degenerating, and/or calcified)(16) and in patients with a single enhancing lesion(17–20). Risk factors in these studies, besides the presence of residual calcifications, are having had recurrent or multiple seizures, abnormal interictal EEG, and seizure events that occurred under ASM treatment(21).
Research Significance
Because of the morbidity and mortality attributed to epilepsy, a higher percentage epilepsy is due to NCC in endemic countries such as Perú, and the paucity of information about this topic, we aim to determine the risk of breakthrough seizures in this group and their frequency. This will give us information about the factors that we must target to decrease the risk of seizures in this population. We begin from the unique opportunity of having access to four existing cohorts of well-defined patients with parenchymal NCC who were treated in randomized clinical trials of antiparasitic and steroid treatment for NCC.