Amebae can invade the central nervous system (CNS), causing rare but fatal infections. Seizures can complicate any of the ameba-caused clinical syndromes. Epidemiologic data are inadequate to comment on seizure incidence.

A few principal amebic parasites can cause CNS infection:

Amebic parasite	Entamoeba histolytica	Naegleria fowleri	Acanthamoeba or Hartmannella
Geographic distribution	Widespread distribution, tropics more virulent	Southeastern United States	Widespread
Host factors	Nonspecific	Freshwater swimming	Chronic illness, immunosuppression
Clinical syndrome	Entamoeba brain abscess (resembles brain abscess, tumor, chronic meningitis, or a combination of these)	Primary amebic meningoencephalitis (acute meningoencephalitis)	Granulomatous amebic encephalitis (resembles brain abscess, tumor, chronic meningitis, or a combination of these)
Signs/symptoms	Meningitic symptoms Focal signs Seizures	Acute meningitic symptoms Seizures Stupor/coma	Subacute-chronic meningitic symptoms Seizures Focal deficits Stupor/coma
CSF findings	increased protein decreased glucose	increased protein decreased glucose WBC (N) Wet mount: motile trophozoites	increase protein decreased glucose WBC (N,L) Wet mount: sluggish organisms

CSF = cerebrospinal fluid; N = neutrophils; L = lymphocytes; WBC = white blood cell.

Table adapted from MJ Aminoff, DA Greenberg, RP Simon. Clinical Neurology. Stamford, CT: Appleton & Lange, 1996;37; and DT Durack. Amebic infections. In WM Scheld, RJ Whitley, DT Durack (eds), Infections of the Central Nervous System. Philadelphia: Lippincott–Raven, 1997;831–844.
Adapted from: Goldstein MA and Harden CL. Infectious states. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;83-133.
With permission from Elsevier (www.elsevier.com).