Cysticercosis is a parasitic infection that results from ingestion of eggs from the adult tapeworm, Taenia solium.
When cysticercosis involves the central nervous system, it is called neurocysticercosis. Neurocysticercosis is the most common parasitic infection of the brain and a leading cause of epilepsy in the developing world.
Neurocysticercosis is acquired through consumption of food contaminated with feces of a T. solium tapeworm carrier. Eggs of the tapeworm are shed in stool and contaminate food through poor hygiene. When these eggs are ingested and exposed to gastric acid in the human stomach, they lose their protective capsule and turn into larval cysts, called oncospheres. Oncospheres cross the gastrointestinal tract and migrate via the vascular system to the brain, muscle, eyes, and other structures. Once in the brain, the larval cysts (cysticerci) initially generate a minimal immune response and may remain in the brain as viable cysts for years
The viable larval cyst is known as a vesicular cyst. At this stage, the scolex usually is identified as an eccentric nodule within the cyst.
Neurocysticercosis typically is first seen either with seizures (70% to 90% of acutely symptomatic patients) or headache
Headache usually indicates the presence of hydrocephalus, meningitis, or increased intracranial pressure.
When hydrocephalus is present, the use of antiparasitic drugs is relatively contraindicated, unless a shunt is placed before administration.
The mortality rate of patients with hydrocephalus or increased intracranial pressure is higher than the mortality rate of patients with seizures.
Albendazole and praziquantel are the principal antiparasitic drugs used to treat neurocysticercosis
Albendazole appears to be superior to PZQ and seems to be more effective in giant cysts and subarachnoid, intraventricular, or spinal neurocysticercosis.
Use of these medications may result in further increases in intracranial pressure in patients with cysticercal encephalitis and hydrocephalus. Hence, they should be used only after a ventricular shunt has been placed in these forms of neurocysticercosis.