Parasitic disorders.

Parasites infect the central nervous system of children, particularly in resource-poor areas and tropical countries. However, these infections are increasingly seen in the West with the increase in children travelling to these areas and immigrant populations. These conditions are important in the differential diagnosis of common neurological syndromes. Falciparum malaria is a common cause of seizures and coma in endemic areas. Neurocysticercosis is a common cause of acquired epilepsy in some areas. Schistosomiasis is an important cause of spinal cord disease. Toxocara is ubiquitous and may cause encephalitis and retinal changes, and may be associated with epilepsy. Other parasitic conditions tend to be localized to specific regions of the world. Parasitic diseases are often associated with eosinophilia, and some cause an eosinophilic meningoencephalitis, although there are many nonparasitic causes of this syndrome. Most parasitic conditions can be treated, but in some diseases it is unclear whether the treatment influences outcome.