Parasites and Seizures

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1 88 NEUROl;OGICAL, PSYCHIA TRIC, AND DEVELOPMENTAL DISORDERS ischemia,

atrophy, and subsequent gliosis of these structures (mesial sclerosis). These

conditions in turn predispose to epilepsy and can now easily be visualized by

magnetic resonance ofthe brain in individuals thus affected.[l 1,86,87] In many

developing countries, most deliveries in rural areas are performed by

traditional

birth attendants. Complications with delivery are common, and the incidence

of preterm deliveries is at least twice that in developed countries.~89]

Mothers in developing countries are frequently malnourished, anemic, and exposed

to

a variety of infections that could affect the baby in utero or at delivery and

increase the risk for epilepsy.[l 9,86] Parasitic Infections

Neurocysticercosis is caused by Taenia holism (more commonly known as tapeworm).

This disease

may account for up to two-thirds of late-onset epilepsy (epilepsy starting

above age 20) in geographic regions in Africa, Asia, and Latin America in which

this infection is endemic.~90-98] Rapid control of transmis- sion of T. soli?vm

taeniosis from animal to human may be attained through a vac- cine that

renders pigs immune to cysticercosis.~99] (Additional information on

neurocysticercosis as a risk factor for epilepsy and the implications for

prevention and

treatment can be found in Annex 6-1.) Paragonomiasis, caused by the parasite

Paragonim?~s westermani, is endemic to Asia, particularly Korea, Japan, the

Philippines, and China, as well as some parts of Africa and South America.

Epileptic

seizures, usually focal motor, are a common manifestation of this

condition.[11,100,101 ~ Schistosomiasis can also induce seizures. This is the

case

particularly with S. japonicum infections, and less commonly with S. mansoni and

S.

haematobium infections. Acute schistosomiasis may produce a serious

encephalopathy with coma, papilledema, and partial or generalized seizures.

Chronic

forms of cerebral schistosomiasis, caused by embolized schistosoma eggs, are

commonly manifested in epileptic attacks.~102] Congenital toxoplasmosis,

acquired

during pregnancy, induces seizures in 40~0 percent of affected children, who

may display mental retardation and blindness as well.~103-104] Toxoplasmosis is

also a frequent opportunistic infection in patients with acquired

immunodeficiency syndrome (AIDS), inducing seizures in about 25 percent of

affected

individuals.~105] African trypanosomiasis, or sleeping sickness, is caused by T.

brucei, and is widely distributed through sub-Saharan Africa. The chronic stage

of the disease is characterized by progressive neurological involvement,

including partial and generalized seizures.tl06] Chagas disease, caused by T.

cruzi,

is a public health problem in rural areas of Central and South America.

Cerebral involvement is secondary to embolization of the parasite and manifests

itself as a late-onset epilepsy, involving mainly partial seizures. t 107]