Neurocysticercosis

Neurocysticercosis is cysticercosis of the nervous system. Cysticercosis is a disease caused by the larval stage of a parasite by name Taenia solium (pork tapeworm).

This disease is spread by poor hygienic conditions when people accidentally ingest the eggs of the pork tapeworm with the water and food. So it is common in developing countries. Eating contaminated under-boiled pork meat does not produce cysticercosis rather it causes the intestinal infection with the adult T solium.

The ingested eggs of this parasite reach the intestine and the larval forms are hatched. These larvae penetrate the intestinal wall and reach various organs and tissues like brain, muscle, eyes, skin, meninges (coverings of the brain and spinal cod) and cause irritation/inflammation, swelling etc.

If cysts occur inside the ventricles or the narrow tubes connecting them then obstructive hydrocephalus can result. Chronic meningitis, arachnoidtis etc can occur too.

When cysticercosis affects the nervous system it is the brain which most frequently involved. Seizures are one of the most common manifestations. These are partial seizures (simple partial or complex partial) with or without secondary generalization.

Other manifestations include headache, nausea vomiting, focal extremity weakness, sensory manifestations etc. Headache, nausea/vomiting also occur when hydrocephalus develops.

When muscles are affected muscle pain, weakness can occur. Blurring of vision, loss of vision can occur if eyes are involved.

Cysticercosis of the brain is diagnosed with a CT and/or MRI of the brain. Both tests have their own plus and minus. These imaging tests may show the characteristic scolex of the larval stage of the parasite. A cysticercal antibody test is usually done on the blood & spinal fluid.

There is some controversy regarding whether all cysticercosis needs to be treated or not, also with what drug, how long etc.

If treatment is considered then albendazole or praziquantel are used most often. A course of steroids is given too, especially if the brain lesions are associated with edema (swelling) etc.

Seizures can occur during the acute or chronic stage. Anti convulsants are given for this purpose.

Incidence of TB (tuberculosis) is high in many places where cysticercosis is prevalent and it has to be ruled out by relevant investigations.

A neurologist is frequently involved in the care of patients with Neurocysticercosis.