“Poor sanitation may be the single most important social factor underlying the increased prevalence of epilepsy in tropical and developing countries
Brain injuries, neurodevelopmental problems, and genetic predispositions that cause epilepsy in developed settings certainly result in epilepsy in developing countries as well. Traumatic brain injuries, due to poor transport infrastructure, are common, and head injury in regions of conflict are frequent. In addition, unique causes for epilepsy in developing and tropical settings must be considered. In some tropical settings, parasitic infestations are a common cause of epilepsy. details parasites that may result in epilepsy. Not included are HIV-related infections, as there is very limited data available regarding the natural history and long-term seizure risk among HIV/AIDS survivors of CNS opportunistic infections. An excellent Internet resource for further reading on CNS parasitosis is available at: http://www.dpd.cdc.gov/dpdx/HTML/Para_Health.htm
Parasitic Infestations Causing Epilepsy
While Part II will review treatment, evaluating what type of care is needed is also an essential part of effectively treating patients in developing countries. Evaluating a person with epilepsy or who may potentially have epilepsy in these countries requires an approach that is much the same as in developed settings. A good history of the suspicious event(s), as described by the patient as well as a family member or other person who has witnessed it, is critical. When working with a translator, it is important to learn the local terminology for seizures and epilepsy and make special efforts to avoid the use of locally pejorative terms. For instance, rather than labeling the events, solicit descriptions of them. Given the relative dearth of neurodiagnostics (e.g., EEG, neuroimaging) in developing countries, a full history and physical may be the sole data available to determine seizure semiology or epilepsy syndrome and thus, should be used to its maximum potential.
Efforts to investigate the underlying etiology of epilepsy in resource-limited settings may be frustrating. In extreme situations, blood tests for monitoring electrolytes, liver function, and AED levels may not be routinely accessible, and neuroimaging and EEG or both may not be available at all. Where EEG is available, the value of the EEG must be considered in the context of its technical quality. Poor quality recordings may offer little information of significance, especially in the nonacute outpatient setting. EEG interpretations by inexperienced or untrained readers tend to be biased toward overinterpretation. Inaccurate readings are especially problematic in EEGs of pediatric patients in whom the wide range of normal variants can be misinterpreted as epileptiform, leading to misdiagnosis as epilepsy and years of unnecessary and potentially harmful treatment (19
). When determining what diagnostic evaluation is warranted in a given situation, the physician must consider what is feasible as well as how the findings of the investigation will affect management when treatment options are few.
Knowledge of local diseases and toxins is critical for the optimal provision of clinical care. Isoniazid toxicity, either through attempted suicide or iatrogenic overdose, will present acutely as status epilepticus, and epilepsy develops frequently among survivors of isoniazid toxicity. Annual epidemics of Japanese encephalitis affect some regions of Asia, and long-term neurologic sequelae, including epilepsy, unfortunately are common (21
). Despite the reality that most children in very low-income countries are exposed, at least periodically, to malnutrition, the impact of malnutrition on brain development and any associated increased risk of epilepsy is almost entirely unstudied.