Epilepsy and Neurocysticercosis in Latin America: A Systematic Review and Meta-analysis (original) (raw)
A systematic review of the frequency of neurocyticercosis with a focus on people with epilepsy
2010
Background: The objective of this study is to conduct a systematic review of studies reporting the frequency of neurocysticercosis (NCC) worldwide. Methods/Principal Findings: PubMed, Commonwealth Agricultural Bureau (CAB) abstracts and 23 international databases were systematically searched for articles published from January 1, 1990 to June 1, 2008. Articles were evaluated for inclusion by at least two researchers focusing on study design and methods. Data were extracted independently using standardized forms. A random-effects binomial model was used to estimate the proportion of NCC among people with epilepsy (PWE). Overall, 565 articles were retrieved and 290 (51%) selected for further analysis. After a second analytic phase, only 4.5% of articles, all of which used neuroimaging for the diagnosis of NCC, were reviewed. Only two studies, both from the US, estimated an incidence rate of NCC using hospital discharge data. The prevalence of NCC in a random sample of village residents was reported from one study where 9.1% of the population harboured brain lesions of NCC. The proportion of NCC among different study populations varied widely. However, the proportion of NCC in PWE was a lot more consistent. The pooled estimate for this population was 29.0% (95%CI: 22.9%-35.5%). These results were not sensitive to the inclusion or exclusion of any particular study. Conclusion/Significance: Only one study has estimated the prevalence of NCC in a random sample of all residents. Hence, the prevalence of NCC worldwide remains unknown. However, the pooled estimate for the proportion of NCC among PWE was very robust and could be used, in conjunction with estimates of the prevalence and incidence of epilepsy, to estimate this component of the burden of NCC in endemic areas. The previously recommended guidelines for the diagnostic process and for declaring NCC an international reportable disease would improve the knowledge on the global frequency of NCC.
PLoS Neglected Tropical Diseases, 2011
Neurocysticercosis (NCC) is a major cause of epilepsy in regions where pigs are free-ranging and hygiene is poor. Pork production is expected to increase in the next decade in sub-Saharan Africa, hence NCC will likely become more prevalent. In this study, people with epilepsy (PWE, n = 212) were followed up 28.6 months after diagnosis of epilepsy. CT scans were performed, and serum and cerebrospinal fluid (CSF) of selected PWE were analysed. We compared the demographic data, clinical characteristics, and associated risk factors of PWE with and without NCC. PWE with NCC (n = 35) were more likely to be older at first seizure (24.3 vs. 16.3 years, p = 0.097), consumed more pork (97.1% vs. 73.6%, p = 0.001), and were more often a member of the Iraqw tribe (94.3% vs. 67.8%, p = 0.005) than PWE without NCC (n = 177). PWE and NCC who were compliant with anti-epileptic medications had a significantly higher reduction of seizures (98.6% vs. 89.2%, p = 0.046). Other characteristics such as gender, seizure frequency, compliance, past medical history, close contact with pigs, use of latrines and family history of seizures did not differ significantly between the two groups. The number of NCC lesions and active NCC lesions were significantly associated with a positive antibody result. The electroimmunotransfer blot, developed by the Centers for Disease Control and Prevention, was more sensitive than a commercial western blot, especially in PWE and cerebral calcifications. This is the first study to systematically compare the clinical characteristics of PWE due to NCC or other causes and to explore the utility of two different antibody tests for diagnosis of NCC in sub-Saharan Africa.
Seizure, 2020
We analyzed studies on neurocysticercosis (NCC) and epilepsy across Sub-Saharan Africa (SSA) to determine the prevalence of NCC in people with epilepsy (PWE) and the strength of association of NCC with epilepsy in the region. Methods: We conducted a systematic review of the existing literature on NCC and epilepsy in SSA. Diagnostic methods for NCC in the studies selected for our analysis included one or more of the following: positive brain CT, serum ELISA and serum EITB. A common prevalence and overall odds-ratio were then estimated using metaanalysis. Results: A total of 25 (overall) and 20 (case-control) studies met the inclusion criteria for the prevalence and strength of association estimation, respectively. The overall prevalence estimate of NCC in PWE was 22 % [95 % confidence interval [CI]: 17-27.0 %). The figures were higher in the Southern and Eastern Africa sub-region (45 % and 25 % respectively) but lower in the Central and Western Africa sub-region (6 % and 15 % respectively). The prevalence of NCC estimate in PWE varied with method of diagnosis; with 29 % 18 % and 15 % in studies that used a minimum of Brain CT, ELISA and EITB respectively. The overall odds ratio was 2.4 (95 % CI 2.1-2.8), p < 0.0001. Conclusion: The overall prevalence of NCC in PWE in SSA was 22 %. The prevalence figure varied with the subregion of SSA. The odd of NCC in PWE in SSA was 2.4. In spite of the sub-regional variation in NCC prevalence, this meta-analysis suggests that neurocysticercosis contributes significantly to epilepsy in SSA.
…, 2011
Purpose: Epilepsy is highly prevalent in developing countries like Honduras, with few studies evaluating this finding. This population-based study evaluated the impact of an 8-year public health and educational intervention program in reducing symptomatic epilepsies in rural Salamá, Honduras.Methods: We used the capture and recapture method including review of charts, previous databases, key informants from the community, and a second house-to-house survey for epilepsy. Epilepsy incidence and prevalence day after the interventions was May 5, 2005. Residents with active epilepsy with onset after May 1997 were offered neurologic evaluation, electroencephalography, and brain tomography. New data over 8 years were compared to preintervention data from the initial baseline 1997 study utilizing prevalence ratios and confidence intervals. Other calculations utilized chi square or Fisher’s exact tests.Key Findings: Thirty-three of 36 patients with onset of active epilepsy after 1997 accepted evaluations to determine etiology. Symptomatic etiology was found in 58.3%. Neurocysticercosis (NCC) was again the most frequent cause (13.9%), followed by perinatal insults (11.1%). Epilepsy secondary to NCC was significantly reduced from 36.9% in 1997 (p = 0.02). The incidence (35.7/100,000) and prevalence (11.8/1,000) of active epilepsy were not significantly reduced when compared to the incidence (92.7/100,000) and prevalence (15.4/1,000) of active epilepsy in 1997.Significance: Our cohort appears to indicate that health and educational community interventions can reduce preventable epilepsy from NCC in a hyperendemic population in a low-resource, developing country. Plans are underway for the Honduran Government to institute this rural model countrywide.
The Lancet Neurology, 2019
Background Seizures and their consequences contribute to the burden of epilepsy because they can cause health loss (premature mortality and residual disability). Data on the burden of epilepsy are needed for health-care planning and resource allocation. The aim of this study was to quantify health loss due to epilepsy by age, sex, year, and location using data from the Global Burden of Diseases, Injuries, and Risk Factors Study. Methods We assessed the burden of epilepsy in 195 countries and territories from 1990 to 2016. Burden was measured as deaths, prevalence, and disability-adjusted life-years (DALYs; a summary measure of health loss defined by the sum of years of life lost [YLLs] for premature mortality and years lived with disability), by age, sex, year, location, and Socio-demographic Index (SDI; a compound measure of income per capita, education, and fertility). Vital registrations and verbal autopsies provided information about deaths, and data on the prevalence and severity of epilepsy largely came from population representative surveys. All estimates were calculated with 95% uncertainty intervals (UIs). Findings In 2016, there were 45•9 million (95% UI 39•9-54•6) patients with all-active epilepsy (both idiopathic and secondary epilepsy globally; age-standardised prevalence 621•5 per 100 000 population; 540•1-737•0). Of these patients, 24•0 million (20•4-27•7) had active idiopathic epilepsy (prevalence 326•7 per 100 000 population; 278•4-378•1). Prevalence of active epilepsy increased with age, with peaks at 5-9 years (374•8 [280•1-490•0]) and at older than 80 years of age (545•1 [444•2-652•0]). Age-standardised prevalence of active idiopathic epilepsy was 329•3 per 100 000 population (280•3-381•2) in men and 318•9 per 100 000 population (271•1-369•4) in women, and was similar among SDI quintiles. Global age-standardised mortality rates of idiopathic epilepsy were 1•74 per 100 000 population (1•64-1•87; 1•40 per 100 000 population [1•23-1•54] for women and 2•09 per 100 000 population [1•96-2•25] for men). Age-standardised DALYs were 182•6 per 100 000 population (149•0-223•5; 163•6 per 100 000 population [130•6-204•3] for women and 201•2 per 100 000 population [166•9-241•4] for men). The higher DALY rates in men were due to higher YLL rates compared with women. Between 1990 and 2016, there was a non-significant 6•0% (-4•0 to 16•7) change in the age-standardised prevalence of idiopathic epilepsy, but a significant decrease in age-standardised mortality rates (24•5% [10•8 to 31•8]) and age-standardised DALY rates (19•4% [9•0 to 27•6]). A third of the difference in age-standardised DALY rates between low and high SDI quintile countries was due to the greater severity of epilepsy in low-income settings, and two-thirds were due to a higher YLL rate in low SDI countries. Interpretation Despite the decrease in the disease burden from 1990 to 2016, epilepsy is still an important cause of disability and mortality. Standardised collection of data on epilepsy in population representative surveys will strengthen the estimates, particularly in countries for which we currently have no or sparse data and if additional data is collected on severity, causes, and treatment. Sizeable gains in reducing the burden of epilepsy might be expected from improved access to existing treatments in low-income countries and from the development of new effective drugs worldwide. Funding Bill & Melinda Gates Foundation.
Future directions for epidemiology in epilepsy
Epilepsy & Behavior, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Epilepsia, 2017
Objective: Using a large-scale population-based study, we aimed to assess prevalence and patterns of presentation of neurocysticercosis (NCC) and its relationship with epilepsy in community-dwellers aged ≥20 years living in Atahualpa (rural Ecuador). Methods: In a three-phase epidemiological study, individuals with suspected seizures were identified during a door-to-door survey and an interview (phase I). Then, neurologists evaluated suspected cases and randomly selected negative persons to estimate epilepsy prevalence (phase II). In phase III, all participants were offered noncontrast computed tomography (CT) for identifying NCC cases. The independent association between NCC (exposure) and epilepsy (outcome) was assessed by the use of multivariate logistic regression models adjusted for age, sex, level of education, and alcohol intake. CT findings were subsequently compared to archived brain magnetic resonance imaging in a sizable subgroup of participants. Results: Of 1,604 villagers aged ≥20 years, 1,462 (91%) were enrolled. Forty-one persons with epilepsy (PWE) were identified, for a crude prevalence of epilepsy of 28 per 1,000 population (95% confidence interval [CI] = 20.7-38.2). A head CT was performed in 1,228 (84%) of 1,462 participants, including 39 of 41 PWE. CT showed lesions consistent with calcified parenchymal brain cysticerci in 118 (9.6%) cases (95% CI = 8.1-11.4%). No patient had other forms of NCC. Nine of 39 PWE, as opposed to 109 of 1,189 participants without epilepsy, had NCC (23.1% vs. 9.2%, p = 0.004). This difference persisted in the adjusted logistic regression model (odds ratio = 3.04, 95% CI = 1.35-6.81, p = 0.007). Significance: This large CT-based study demonstrates that PWE had three times the odds of having NCC than those without epilepsy, providing robust epidemiological evidence favoring the relationship between NCC and epilepsy.