Risk Factors for Epilepsy in a Rural Area in Tanzania

Abstract

Background and Methods: The high prevalence of epilepsy detected in rural Tanzania by Dr. Jilek-Aall since 1960, was verified by the World Health Organization (WHO) survey on neurological and seizure disorders. Neurologists and psychiatrists further interviewed both patients and controls using standard methods. The presence of possible risk factors was complemented by corroborative evidence through interviewing close relatives and scrutinizing medical records. Seizures were classified based on clinical symptoms and the use of EEG. Results: A family history of epilepsy in first-degree relatives was found in 46.6% of patients, but in only 19.6% of controls. The odds ratio for family history with epilepsy was 3.52 (95% confidence interval, CI 2.4–5.74, p < 0.001). A past history of febrile convulsion was found in 44% of patients in comparison to 23% of the control group which was significant (odds ratio 2.4, 95% CI 1.5–3.8; p < 0.001). A history of intrapartum complications was found in 12.1% of patients and 1.8% of controls (odds ratio 7.3, 95% CI 2.5–25.2; p < 0.002). Head injury was not a significant risk factor for epilepsy in this rural community. Conclusion: The results indicated a strongly independent association between four factors and the risk of developing epilepsy. It would seem more likely that previous brain insults/diseases play a significant major role in the cause of epilepsy in the Mahenge area. However, a genetic predisposition to low threshold for convulsions cannot be excluded.

Consanguinity and epilepsy in Oran, Algeria: A case–control study

“…These data are consistent with the strong association we found with family history of epilepsy and further supported by previous research conducted in Iran (Asadi-Pooya and Hojabri, 2005), Jordan (Daoud et al, 2003), Tanzania (Matuja et al, 2001), Kenya (Mung'ala-Odera et al, 2008) and India (Nair and Thomas, 2004;Kannoth et al, 2009) which also highlighted this association. However, it is well known that epilepsy is a multifactorial disease, and we recognize that members of the same family may also share other non-genetic factors such as socio-economic status, (Birbeck et al, 2007;Noronha et al, 2007).…”

Clinical and epidemiologic characteristics of nodding syndrome in Mundri County, southern Sudan

“…These episodes would occur several times each day, often during meals, and in some cases the illness progressed to generalized tonicclonic seizures, and to physical and mental deterioration. Similar head-nodding episodes, associated with physical and mental retardation and seizures, have been previously described in children in Uganda [1][2] , Tanzania [3][4] and Liberia 5 , and an association with onchocercias infection has been suggested. Our studies were the first to characterize Nodding Syndrome in southern Sudan.…”

“…The case-control study assessed a limited panel of parasites; the strongest association with Nodding Syndrome was the presence of parasitic infestation with Onchocerca volvulus, a combination that has been noted on previous occasions 1, 2,4 . There was no evidence to indicate the operation of an environmental pollutant, chemical agent, or other toxic factor.…”

Community-based prevalence and clinical characteristics of febrile seizures in Tanzania

“…As complex attributes seem to repeat in children with recurrent FS episodes (25) and recurrences, amongst others, may conceivably implicate subsequent epilepsy (8,26), the need of preventing these recurrent FSs becomes apparent. Since complex features, especially the prolonged types, seem to be associated with the development of epilepsy (7)(8)(9)27), this high percentage of complex features may be related to the reported higher prevalence of epilepsy in sub-Saharan Africa (10,11) in comparison to high-income nations (28). Beside complex attributes, the number of FS episodes, a positive family history of unprovoked seizures and neurological abnormality represent, inter alia, risk factors for subsequent epilepsy (3,8,29).…”