Arturo Carpio

Epileptic Seizures and Epilepsy: Definitions Proposed by the International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE)

The International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE) have come to consensus definitions for the terms epileptic seizure and epilepsy. An epileptic seizure is a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Epilepsy is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures and by the neurobiologic, cognitive, psychological, and social consequences of this condition. The definition of epilepsy requires the occurrence of at least one epileptic seizure.

Recommendation for a definition of acute symptomatic seizure.

Purpose:  To consider the definition of acute symptomatic seizures for epidemiological studies, and to refine the criteria used to distinguish these seizures from unprovoked seizures for specific etiologies.

Cysticercosis and epilepsy: a critical review.

Summary: Neurocysticercosis (NC) remains a major public health problem in developing and some developed countries. Currently, the best procedures for diagnosing NC are neuroimaging studies. Immunoserologic assays, such as enzyme‐linked immunoelectrotransfer blot assay (EITB) or enzyme‐linked immunosorbent assay (ELISA), detect antibodies against Taenia solium, or cysticercus. Consequently, they are useful in identifying a population at risk of contact with the parasite but do not necessarily indicate a systemic active infection. Most seropositive individuals are asymptomatic. No data from prospective studies concern the proportion of these individuals that will develop seizures or other neurologic symptoms. There is a discrepancy between the results of serologic assays and neuroimaging studies: >50% of those individuals with NC diagnosed by computed tomography (CT) scan test EITB negative.

Neurocysticercosis: an update

Taeniosis and cysticercosis, diseases caused by the parasitic tapeworm Taenia solium, are distributed worldwide where pigs are eaten and sanitation is poor, and also in the more developed countries as a result of increasing migration. Neurocysticercosis is the commonest parasitic disease of the human nervous system. Immunological assays detect positivity for human cysticercosis in 8-12% of people in some endemic regions, which indicates the presence of antibodies against the parasite but not necessarily active or central-nervous-system infection. The only reliable tool for diagnosis of neurocysticercosis is imaging by CT or MRI. The presence of viable cysts with a mural nodule, associated with degenerative cysts and calcifications, is typical. Classification of neurocysticercosis into active, transitional, and inactive forms gives a good clinical-imaging correlation and facilitates medical and surgical treatment. The main clinical manifestations of neurocysticercosis are seizures, headache, and focal neurological deficits, and it can have such sequelae as epilepsy, hydrocephalus, and dementia. Treatment should be individually fitted for each patient, with antiepileptic drugs, analgesics, corticosteroids, or a combination of these. Anthelmintic drugs (praziquantel and albendazole) are used routinely, but so far no controlled clinical trial has established specific indications or definitive doses of treatment. Parenchymal forms of neurocysticercosis have a good prognosis in terms of clinical remission. The most effective approach to taeniosis and cysticercosis is prevention, which should be a primary public-health focus for less developed countries.

Prognosis for seizure recurrence in patients with newly diagnosed neurocysticercosis.

Objective: To determine the risk of seizure recurrence after a first seizure due to neurocysticercosis (NC) and to evaluate risk factors for seizure recurrence, including the influence of antihelminthic treatment. Methods: The authors prospectively followed 77 patients with a first seizure and active or transitional NC for >7 years (median 24 months). Results: Thirty-one patients (40.3%) experienced seizure recurrence. Kaplan–Meier estimated recurrence was 22% at 6 months, 32% at 12 months, 39% at 24 months, and 49% at 48 and 84 months. Treatment with an antihelminthic (albendazole) did not influence recurrence. On multivariable analysis, none of the following predicted recurrence: sex, presenting seizure type, classification of NC, localization of cysts, Todd paralysis, neurologic deficits at presentation, EEG abnormalities. Only change in CT predicted recurrence: 22% in patients in whom cysts disappeared and 56% in patients with persistent cysts (p < 0.05). In this latter group, recurrence was associated with persistence of an active lesion. Of those with two seizures, estimated risk of a third seizure was 68% by 6 years after the second seizure. Conclusions: Seizure recurrence is high after a first acute symptomatic seizure due to NC, but this seems related to persistence of active brain lesions. Recurrence risk is low and in keeping with seizure risk following other brain insults leading to a static encephalopathy in those in whom the NC lesion clears. Patients with NC should receive antiseizure medications until the acute lesion clears on CT. There is no correlation between treatment with antihelminthic agents and seizure recurrence.

Effects of albendazole treatment on neurocysticercosis: a randomised controlled trial

Aim: The aim of this trial was to evaluate the effects of albendazole (ALB) on cyst disappearance, reduction of the number of cysts and seizure recurrence. Methods: 178 patients with new onset symptoms due to active or transitional neurocysticercosis were randomly assigned to receive either 800 mg of ALB daily or placebo for 8 days. All patients also received prednisone. Imaging studies were done at baseline and at months 1, 6 and 12 of follow-up. Results: Active cysts were identified in 59 of 88 people randomised to ALB and 57 of the 90 in the placebo arm. By 1 month, 31% were free of active cysts in the treatment group compared with 7% in the placebo group (p = 0.001). In addition, the ALB group had a greater reduction in the number of active cysts compared with the placebo group (p = 0.001). After 1 month following treatment there was no additional gain by treatment group in the disappearance or reduction in the number of active cysts. ALB treatment had little effect on cysts in the transitional or calcification stage. We found no difference between the ALB and placebo groups in symptoms during treatment or in seizure recurrence during the 12 months after treatment. Conclusion: Albendazole plus symptomatic treatment leads to the disappearance of active cysts in 31% of patients compared with 7% of those with symptomatic treatment alone. This treatment effect occurs within the first 30 days after treatment. Trial registration number: NCT00283699.

A proposal for classification of neurocysticercosis.

The complicated pathophysiological and immunological changes in the central nervous system of patients with neurocysticercosis produce a variety of signs and symptoms, which complicate the clinical and surgical management of this disease. A complete and objective classification is needed, to improve the medical approach as a whole. We studied 336 patients, in whom we classified neurocysticerosis according to criteria of viability and location of the parasite in the CNS: active form (37.2%) when the cysticercus is alive, transitional form (32.8%) when it is in the degenerative phase, and inactive form (30%) when the parasite is dead. This classification establishes the correlation between the different forms of neurocysticerosis and its clinical manifestations, and can be used for planning therapeutic strategies.

Mortality of Epilepsy in Developing Countries

Summary:  During the last two decades, there has been a renewed interest in studying epidemiology of epilepsy in developing countries. While there are data on prevalence of epilepsy from many developing countries, there is very little information on the mortality of epilepsy in these same populations. This is because incidence studies of epilepsy are difficult to perform, death certificates are unreliable and often unavailable, and the cause of death is difficult to determine. We report on several studies of mortality in epilepsy in developing countries: Ecuador; the Parsi community of Bombay; a semiurban community in Vasai, India; Mali; Martinique; and Africa. Overall, these studies in general illustrate excess mortality among people with epilepsy when compared with the general population.

New diagnostic criteria for neurocysticercosis: Reliability and validity

The diagnosis of neurocysticercosis (NCC) remains problematic because of the heterogeneity of its clinical, immunological, and imaging characteristics. Our aim was to develop and assess a new set of diagnostic criteria for NCC, which might allow for the accurate detection of, and differentiation between, parenchymal and extraparenchymal disease.

The relationship between neurocysticercosis and epilepsy: an endless debate

Neurocysticercosis (NC), or cerebral infection with Taenia solium, is an important public health problem worldwide. Among the neurological sequelae of NC, seizures have been described as the most common symptom. Acute symptomatic seizures often result from degeneration of a viable cyst; however, not all of these patients with acute or provoked seizures will develop epilepsy (i.e., recurrent unprovoked seizures). Because of the high prevalence of epilepsy and NC, a causal, as well as incidental relationship between the two may exist. The epileptogenicity of calcified cysts as well as the potential association between NC and hippocampal sclerosis necessitates future research. Antihelminthic treatment of NC results in disappearance of viable cysts in about one-third of patients with parenchymal disease, but a reduction in seizure recurrence has not been demonstrated in randomized controlled trials. Prevention is critical to reduce the burden of seizure and epilepsy related to NC.