Section 6. Brain, Spinal Cord, and Nerve Disorders

Chapter 89. Infections of the Brain and Spinal Cord

Topics: Introduction | Acute Bacterial Meningitis | Chronic Meningitis | Viral Infections | Brain Abscess | Subdural Empyema | Parasitic Infections

Parasitic Infections

In some parts of the world, brain infections due to worms or other parasites may occur.

Cysticercosis, an infection of pork tapeworm larvae, is the most common parasitic infection in the Western Hemisphere (see Section 17, Chapter 196). After a person eats food contaminated with Cysticercus eggs, secretions in the stomach cause the eggs to hatch into larvae. The larvae enter the bloodstream and are distributed to all parts of the body, including the brain. The larvae form cysts that can cause headaches and seizures. The cysts degenerate and the larvae die, triggering inflammation, swelling, and neurologic symptoms, such as headaches, seizures, and sometimes weakness in certain muscles or pins-and-needles sensations in certain areas. The infection is treated with albendazole or praziquantel. Corticosteroids are given to reduce the inflammation that occurs as the larvae die.

Echinococcosis (hydatid disease) and coenurosis are infections with other types of tapeworm larvae. Echinococcosis can produce large cysts in the brain. Coenurosis produces cysts, which can block the flow of fluid around the brain. Schistosomiasis is an infection with blood flukes (see Section 17, Chapter 196). Echinococcosis, coenurosis, and schistosomiasis can cause neurologic symptoms similar to those of cysticercosis. These three infections can usually be controlled with drugs, such as albendazole, mebendazole, praziquantel, and pyrantel pamoate, but sometimes cysts must be removed surgically.