Browsing by Author "Hauser, W. Allen"

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Comment on epileptic seizures and epilepsy: definitions proposed by the International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE)
(2005-10) Beghi, Ettore; Carpio, Arturo; Berg, Anne; Forsgren, Lars; Hesdorffer, Dale C.; Hauser, W. Allen; Malmgren, Kristina; Shinnar, Shlomo; Temkin, Nancy; Thurman, David; Tomson, Torbjörn
Cysticercosis and epilepsy: a critical review
(1998-10) Escobar, Alfonso; Hauser, W. Allen; Carpio, Arturo
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: >SO% of those individuals with NC diagnosed by computed tomography (CT) scan test EITB negative. Pathophysiologic classification of NC into active, transitional, and inactive forms permits a good correlation between clinical manifestations and neuroimaging procedures and facilitates medical and surgical management and research. The most frequent clinical manifestations of NC are seizures. We assume that NC is the main cause of symptomatic epilepsy in developing countries; however, no case-control or cohort studies demonstrate this association. Most patients with NC with seizures have a good prognosis; nevertheless, further studies analyzing factors related to recurrence of seizures and possibilities of discontinuation of antiepileptic medications (AEDs) are needed. Regarding treatment of NC with antihelminthic drugs, no controlled clinical trials exist that establish specific indications, definitive doses, and duration of treatment. The most effective approach to taeniasis/cysticercosis infection is prevention. This should be a primary public health focus for developing countries. We critically review the available information regarding the epidemiology and diagnosis of human cysticercosis, the physiopathology and imaging correlation of the parasite in the central nervous system (CNS) of the host, the relation between seizures or epilepsy and NC, and the issues surrounding the treatment and prognosis of NC, including the use of antihelminthic therapy.
Effects of albendazole treatment on neurocysticercosis: A randomised controlled trial
(2008-06) Kelvin, Elizabeth A.; Carpio, Arturo; Bagiella, Emilia; Leslie, Denise; León, Pedro; Howard, Andrews; Hauser, W. Allen; Lisanti, Noemí; Aguirre, R.; Serrano, M.; Pesántes, J.; Moncayo, J.; Roman, M.
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.
Epilepsy in the developing world
(2009-07-09) Carpio, Arturo; Hauser, W. Allen
Developing countries (DCs) and developed countries have geographic, economic, and social differences. The prevalence and incidence of epilepsy are higher in DCs than in developed countries. However, within DCs, given the high incidence of epilepsy, the prevalence is relatively low, which may be due to high mortality for people with epilepsy (PWE). Neurocysticercosis is one of the main causes of symptomatic epilepsy in many DCs. Prognosis in DCs seems similar to that in developed countries. Because phenobarbital and phenytoin are available and inexpensive, they are the drugs most often used in DCs. The cost of newer antiepileptic drugs and the limited availability of resources for epilepsy care in DCs mean that care for PWE in DCs is marginalized and that many people receive no pharmacologic treatment. The most cost-effective way to decrease the treatment gap in DCs would be to deliver the epilepsy services through primary health care.
Investigation of familial aggregation of seizures in neurocysticercosis patients
(2009-03) Kelvin, Elizabeth A.; Carpio, Arturo; Bagiella, Emilia; Leslie, Denise; León, Pedro; Howard, Andrews; Hauser, W. Allen; Hesdorffer, Dale C.
Regional differences in the clinical manifestations of human neurocysticercosis (NCC) may indicate a role of host genetics. We examined whether there is familial aggregation of seizures in first-degree relatives of NCC patients with seizure versus NCC patients without seizure as presenting symptom in a group of patients in Ecuador. The results of our analyses were null, and there was no trend toward familial aggregation of seizures in NCC patients.
Is the course of neurocysticercosis modified by treatment with antihelminthic agents?
(1997-01-13) Carpio, Arturo; Santillán, Franklin; León, Pedro; Flores, Carlos; Hauser, W. Allen
Del Brutto should not be surprised by the results of our clinical trial of treatment of neurocysticercosis (NC).1 A series of articles were published in JAMA to "help physicians translate the results of medical research into clinical practice."2 In one of them, the authors state that "to the surprise of many and the indignation of a few," well-conducted randomized clinical trials have contradicted the results of less rigorous studies supporting therapies previously considered "standard" practice.3 To address comments related to the sequence of our studies, we must provide a brief background for the current report. In January 1984, we received support from the Consejo Nacional de Universidades y Escuelas Politécnicas del Ecuador (CONUEP), the institution responsible for scientific research in our country, for a project titled "Clinical Aspects of Neurocysticercosis in Ecuador." In this project, we performed a retrospective review of cases treated for NC between 1984
Prognosis for seizure recurrence in patients with newly diagnosed neurocysticercosis
(2002-12-10) Carpio, Arturo; Hauser, W. Allen
bjective: 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
Recommendation for a definition of acute symptomatic seizure
(2010-04) Beghi, Ettore; Carpio, Arturo; Forsgren, Lars; Hesdorffer, Dale C.; Malmgren, Kristina; Sander, Josemir W. A. S.; Tomson, Torbjörn; Hauser, W. Allen
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. METHODS: Systematic review of the literature and of epidemiologic studies. RESULTS: An acute symptomatic seizure is defined as a clinical seizure occurring at the time of a systemic insult or in close temporal association with a documented brain insult. Suggestions are made to define acute symptomatic seizures as those events occurring within 1 week of stroke, traumatic brain injury, anoxic encephalopathy, or intracranial surgery; at first identification of subdural hematoma; at the presence of an active central nervous system (CNS) infection; or during an active phase of multiple sclerosis or other autoimmune diseases. In addition, a diagnosis of acute symptomatic seizure should be made in the presence of severe metabolic derangements (documented within 24 h by specific biochemical or hematologic abnormalities), drug or alcohol intoxication and withdrawal, or exposure to well-defined epileptogenic drugs. DISCUSSION: Acute symptomatic seizures must be distinguished from unprovoked seizures and separately categorized for epidemiologic purposes. These recommendations are based upon the best available data at the time of this report. Systematic studies should be undertaken to better define the associations in question, with special reference to metabolic and toxic insults, for which the time window for the occurrence of an acute symptomatic seizure and the absolute values for toxic and metabolic dysfunction still require a clear identification.
Seizure in people with newly diagnosed active or transitional neurocysticercosis
(2011-03) Kelvin, Elizabeth A.; Carpio, Arturo; Bagiella, Emilia; Leslie, Denise; León, Pedro; Howard, Andrews; Hauser, W. Allen
Purpose: The aim of this study is to describe seizure as a presenting symptom in individuals with recently diagnosed neurocysticercosis (NCC). Methods: Using logistic regression, we examined the probability of having seizures as a presenting symptom among those with active or transitional NCC by host age and gender, and by number of cysts, location of the cysts in the brain, and phase of evolution of the encysted parasite. Results: We found that the odds of having seizures as presenting symptom for those in the youngest age group (3–24 years old) were 12.9 times that of the oldest participants (age 55–82 years) (p = 0.006). People with cysts in parenchymal locations had a significantly higher odds of seizures compared to those with all their cysts elsewhere (ventricles or subarachnoid) (OR = 6.2, p = 0.028); and the number of cysts was significantly associated with having seizures (OR = 1.1, p = 0.026). Host gender and cyst phase were not significantly associated with having seizures after adjusting for confounders and covariates. Conclusion: Children, those with cysts in parenchymal locations, and those with a higher number of cysts appear to be more likely to experience seizure when they have NCC cysts in the active or transitional stage.
The association of host age and gender with inflammation around neurocysticercosis cysts
(2009-09-01) Kelvin, Elizabeth A.; Carpio, Arturo; Bagiella, Emilia; Leslie, Denise; León, Pedro; Howard, Andrews; Hauser, W. Allen; Lisanti, Noemí; Aguirre, R.; Serrano, M.; Pesántes, J.; Moncayo, J.; Roman, M.
The results of previous investigations indicate that age and gender may influence the strength of the human host's immune response to infection of the central nervous system with the larvae of Taenia solium. Most of the relevant research on such neurocysticercosis (NCC) has, however, been conducted on hospital-based samples in developing countries, where differential access to healthcare may bias the study results. Using data from 171 NCC patients participating in a treatment trial, the associations of patient age and gender with the presence of inflammation around NCC cysts (i.e. cysts in the transitional phase) have recently been explored, after controlling for measures of economic and geographical access to healthcare. Data on cysts were collected from computed-tomography or magnetic-resonance images taken at four time-points, from baseline to 12-months post-treatment. The odds of having transitional cysts were evaluated by logistic regression whereas Poisson regression was used to explore the numbers of transitional cysts, with generalised estimating equations (GEE) used to account for the multiple observations over time. After controlling for healthcare access, the odds of having transitional cysts were found to be 1.5-fold higher for the female patients than for the male, although this association was not statistically significant (P = 0.136). In the Poisson model, however, the number of transitional cysts was found to be 1.8-fold higher in the female patients than in the male, and this gender effect was not only statistically significant (P = 0.002) but also constant over time. The association of host age with transitional cysts was more complicated, with significant interaction between age and time. It therefore appears that there are significant gender and age differences in the local immune response to NCC, even after adjusting for differences in healthcare access.