Neurocysticercosis: Causes, Symptoms, and Prevention

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026

Quick Answer: What is Neurocysticercosis?

Neurocysticercosis is a condition in which larvae of the pork tapeworm, Taenia solium, infect the brain and spinal cord and form cysts in brain tissue. The cysts cause pressure and inflammation, leading to seizures, severe headaches and cognitive problems. It is mainly spread by swallowing food or water contaminated with the parasite's eggs, often because of poor sanitation. [1]

What the research says

• Cysticercosis is a major contributor to late-onset epilepsy in tropical regions. A meta-analysis of 37 studies from 23 countries (24,646 people, 14,934 of them with epilepsy) found that people with cysticercosis had about 2.7 times the odds of epilepsy (odds ratio 2.7, 95% CI 2.1–3.6), with an estimated etiologic fraction of 63% in the exposed group (Debacq et al., PLoS Negl Trop Dis, 2017). [3]

• Antiparasitic treatment helps some people, and the benefit depends on the type of cysts. In a Cochrane review of 16 trials, albendazole reduced seizure recurrence in people with a single non-viable brain cyst (risk ratio 0.61, 95% CI 0.4–0.91; 5 trials, 396 participants) and probably improved complete clearance of lesions on scans (risk ratio 1.22; 13 trials, 1,324 participants). The evidence was uncertain for people with multiple cysts. Headache, abdominal pain, and nausea or vomiting were the most common side effects (Monk et al., Cochrane Database Syst Rev, 2021). [2]

Key Takeaways: Neurocysticercosis at a Glance

What is the life cycle of neurocysticercosis infection?

Understanding neurocysticercosis requires distinguishing it from a standard intestinal tapeworm infection. A person develops an adult tapeworm in their intestines by eating undercooked, contaminated pork. However, neurocysticercosis occurs when a person ingests the eggs shed by a human carrier.

Once ingested, these eggs hatch in the intestines into larvae. These larvae penetrate the intestinal wall and enter the bloodstream, eventually lodging in the brain, spinal cord, muscles, or eyes. In these locations, they form fluid-filled sacs known as cysts. These cysts can remain dormant for months or even years before symptoms appear, often triggered when the parasite begins to die and the body's immune system reacts to it.

What are the symptoms of neurocysticercosis?

The clinical presentation of neurocysticercosis depends heavily on the number of cysts present and their specific location within the brain. Some individuals may remain asymptomatic for years, while others experience severe neurological distress.

Neurological Manifestations

Seizures are the most common symptom, occurring in the majority of symptomatic cases. Patients also frequently report persistent, long-lasting headaches and dizziness. In some instances, the infection leads to cognitive impairments, such as trouble with memory, concentration, or thinking clearly. [1]

Physical and Emergency Signs

Other physical symptoms include muscle weakness and difficulty speaking. A particularly dangerous complication is intracranial hypertension, where pressure builds up inside the skull. This is a medical emergency characterized by sudden vision changes, severe nausea, vomiting, and excruciating headaches. [1]

What are the risk factors for neurocysticercosis, and how common is it?

Neurocysticercosis is most prevalent in rural areas of Asia, Africa, and Latin America, particularly where pigs are raised in close proximity to human living areas and can access human waste. [1]

The risk of infection is significantly higher for individuals who lack access to clean water or reliable sanitation systems. Living in a household with a tapeworm carrier is also a major risk factor, as the parasite's eggs can be easily transferred to shared surfaces or food if proper hand hygiene is not maintained. Interestingly, eating pork itself does not directly cause brain cysts; rather, it is the ingestion of eggs from human waste that leads to the condition. [1]

How is neurocysticercosis diagnosed?

Healthcare providers use a combination of clinical evaluation and advanced technology to diagnose neurocysticercosis. The process typically begins with a physical exam to assess neurological function.

Imaging tests are the primary method for confirmation. A CT scan or MRI allows doctors to visualize the cysts, determine their quantity, and see if they are active or calcified. While blood tests can provide supporting evidence of a parasitic infection, they are rarely used as the sole diagnostic tool. In complex or atypical cases, a lumbar puncture or even a brain biopsy may be required to rule out other conditions.

How is neurocysticercosis treated and managed?

Treatment for neurocysticercosis is highly individualized, focusing on killing the parasite while managing the inflammation and symptoms it causes. [1]

Medical Interventions

Antiparasitic medications are used to destroy the larvae. However, as the parasites die, they often cause increased swelling in the brain. To counteract this, doctors typically prescribe corticosteroids (anti-inflammatory drugs) alongside the antiparasitic treatment. For patients experiencing seizures, long-term antiseizure medication may be necessary, especially if calcified scars remain in the brain after the infection has cleared. [1]

Surgical Options

In severe cases where a cyst is blocking the flow of cerebrospinal fluid or causing life-threatening pressure, surgery may be required. This can involve removing the cyst or placing a shunt to relieve pressure. In some mild cases where the parasites have already died, no active treatment beyond symptom management may be needed.

How can you prevent neurocysticercosis?

The most effective way to eliminate neurocysticercosis is through rigorous hygiene and improved sanitation infrastructure. Consistent handwashing with soap after using the toilet and before handling food is the single most important preventive measure. [1]

On a broader scale, treating human tapeworm carriers and improving pig management—such as deworming and vaccinating livestock—can break the cycle of transmission. Ensuring that animals do not have access to human waste is critical for long-term control of the parasite in endemic regions. [1]

Conclusion

Neurocysticercosis is a challenging condition that highlights the intersection of biology and public health. While the idea of a brain parasite is distressing, the combination of modern imaging and effective medical treatments offers a clear path to recovery for most patients. Through education and improved hygiene, the global burden of this infection can be significantly reduced.

For more visual health guides and information on managing parasitic risks, explore our infographic templates.

Frequently Asked Questions

Can you get neurocysticercosis from eating bacon?

No, eating undercooked pork causes an intestinal tapeworm. You get neurocysticercosis by ingesting eggs from human waste.

Is neurocysticercosis contagious?

It is not spread through casual contact, but a carrier can spread eggs to others via contaminated food or surfaces.

What is the most common symptom of this infection?

Seizures are the most frequent symptom reported by patients.

How long can the parasite live in the brain?

Cysts can remain in the brain for months or even years before they are detected.

Can neurocysticercosis be cured?

Yes, with proper antiparasitic treatment and symptom management, most cases can be resolved.

What happens if the cysts are not treated?

Untreated cysts can cause chronic seizures, brain swelling, and potentially fatal pressure in the skull.

Are there vaccines for neurocysticercosis?

There are no vaccines for humans, but vaccines exist for pigs to prevent them from carrying the larvae.

What is the difference between cysticercosis and neurocysticercosis?

Cysticercosis refers to the infection in the body (muscles, eyes); neurocysticercosis specifically refers to the brain infection.

Can a CT scan see the parasites?

Yes, CT scans and MRIs are the primary tools used to see the cysts in the brain.

Do the parasites move around in the brain?

No, once the larvae lodge in the brain and form a cyst, they stay in that location.

Why do doctors use steroids during treatment?

Steroids reduce the inflammation caused when the parasites die from antiparasitic drugs.

Can you have neurocysticercosis without knowing it?

Yes, many people are asymptomatic until the cysts begin to die or grow.

Is this infection common in the United States?

It is rare in the US but is often seen in people who have traveled to or lived in endemic rural areas.

What is a calcified cyst?

It is a “scar” left behind after a parasite dies; these can still trigger seizures.

Can hand sanitizer prevent the infection?

Washing with soap and water is much more effective at removing tapeworm eggs than hand sanitizer.

How does the parasite get to the brain?

After hatching in the gut, the larvae enter the bloodstream and are carried to the brain.

Can children get neurocysticercosis?

Yes, anyone who ingests the eggs can develop the infection, regardless of age.

What is intracranial hypertension?

It is a dangerous increase in pressure inside the skull, often caused by brain swelling.

Can the infection affect the eyes?

Yes, the larvae can sometimes lodge in the eyes, which may require surgery to remove.

Is the treatment painful?

The treatment itself isn't painful, but the inflammation it causes can lead to temporary headaches or symptoms.

How long does treatment take?

The course of antiparasitic medication usually lasts a few weeks, but monitoring can continue for months.

Can a person have more than one tapeworm?

Yes, it is possible to have multiple adult tapeworms in the gut or many cysts in the brain.

What is the scientific name of the pork tapeworm?

It is called Taenia solium.

Does freezing pork kill the eggs?

Freezing pork can kill the larvae that cause intestinal tapeworms, but neurocysticercosis comes from human waste, not the pork itself.

Can the parasite be passed through breast milk?

No, there is no evidence that the infection can be passed through breastfeeding.

What is a lumbar puncture?

A procedure where fluid is taken from the spine to check for signs of infection.

Are seizures from neurocysticercosis permanent?

In some cases, calcified spots remain and can cause long-term epilepsy.

Can the infection be seen on a regular X-ray?

Usually no; CT scans and MRIs are needed for the brain, though calcified cysts in muscles might show on X-rays.

What is an endemic area?

A region where a specific disease or parasite is regularly found.

How many people are affected globally?

It is estimated that millions of people worldwide are affected, mostly in developing nations.

Can you get it from drinking tap water?

In areas with poor sanitation, tap water can be contaminated with parasite eggs.

Does cooking vegetables prevent the infection?

Yes, heat kills the eggs, and washing raw vegetables thoroughly also reduces risk.

Can the body's immune system kill the parasite?

Yes, parasites eventually die on their own, but the resulting immune response causes symptoms.

What is a “carrier”?

A person who has an adult tapeworm in their gut and sheds eggs in their stool.

Can you get it from a dog or cat?

No, Taenia solium specifically cycles between humans and pigs.

Is neurocysticercosis a form of cancer?

No, it is a parasitic infection, though the cysts can sometimes be mistaken for tumors on scans.

What is the most dangerous location for a cyst?

Cysts in the ventricles (fluid-filled spaces) of the brain are particularly dangerous as they can block fluid flow.

Can the infection cause a stroke?

While rare, the inflammation can sometimes affect blood vessels in the brain, leading to a stroke.

How do I know if my food is safe?

Practice good hygiene, eat at reputable places, and ensure food is prepared in a clean environment.

Can the parasite live in the heart?

It is very rare, but larvae can occasionally lodge in the heart muscle.

What is a brain biopsy?

The surgical removal of a small piece of brain tissue for testing.

Does the infection affect memory?

Yes, depending on the location of the cysts, it can cause significant memory problems.

Is the surgery for this dangerous?

Any brain surgery carries risks, but it is often necessary to save a patient's life in severe cases.

Can you have both an intestinal tapeworm and brain cysts?

Yes, a person can infect themselves (autoinfection) if they have an adult tapeworm and poor hygiene.

What are the signs of a tapeworm in the gut?

Often there are no symptoms, but some people notice weight loss or segments of the worm in their stool.

How large are the cysts?

They are typically about 1 to 2 centimeters in diameter.

Can the infection cause personality changes?

Yes, brain inflammation and cyst location can affect behavior and personality.

Is neurocysticercosis related to “mad cow disease”?

No, they are completely different; one is a parasite and the other is caused by prions.

Where can I find more information?

Consult a travel medicine specialist or a neurologist if you have concerns about exposure.

Related Reading

Epilepsy: Seizures, Symptoms, Causes, and Treatment explains seizures and epilepsy, the main symptom of neurocysticercosis.

Hydrocephalus: Symptoms, Causes & Treatment — What You Need to Know explains fluid buildup in the brain that cysts can cause.

Intestinal Parasites: Symptoms, Causes, and Effective Treatments covers intestinal parasites, including tapeworms, and how they are treated.

Antiseizure Medications: A Comprehensive Guide to Anticonvulsants describes the medicines used to control seizures.

References

1. Cleveland Clinic. Neurocysticercosis: What It Is, Symptoms & Treatment. Cleveland Clinic. Last updated September 30, 2025. https://my.clevelandclinic.org/health/diseases/neurocysticercosis

2. Monk EJM, Abba K, Ranganathan LN. Anthelmintics for people with neurocysticercosis. Cochrane Database Syst Rev. 2021;6:CD000215. PMID 34060667. https://doi.org/10.1002/14651858.CD000215.pub5

3. Debacq G, Moyano LM, Garcia HH, et al. Systematic review and meta-analysis estimating association of cysticercosis and neurocysticercosis with epilepsy. PLoS Negl Trop Dis. 2017;11(3):e0005153. PMID 28267746. https://doi.org/10.1371/journal.pntd.0005153

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always seek the counsel of a qualified healthcare professional regarding any medical condition or emergency. If you are experiencing a life-threatening emergency, call 911 or your local emergency services immediately.