Parasites, Brain Lesions, and the Question Neurologists Aren’t Asking

Parasites have been documented in peer-reviewed research to invade the brain and spinal chord, produce white matter lesions on MRI, and trigger a relapsing-remitting pattern of symptoms. One of these parasites is estimated to infect one-third of the global population. Another is found in North American backyards.

Parasites are not required to be tested for before a diagnosis of MS is made.

If you or someone you love has MS or another chronic disease, here is what the published research shows and what current diagnostic criteria are not asking for.

 

What Most People Are Never Told About MRI Lesions

Standard MRI cannot tell you what caused a lesion.

The same white spot on your MRI could represent:

• Active infection
• A resolved old infection
• An immune response
• Scar tissue
• Axonal loss

The imaging looks the same regardless of cause. A 2017 review in Frontiers in Neurology confirmed that T2 MRI lacks the ability to identify the underlying process. The image alone cannot tell you what is actually happening.

There is also a well-known problem in MS research called the clinico-radiological paradox: the number of lesions on MRI does not consistently predict disability. Some people have many lesions but few symptoms. Others have few lesions but severe disability.

A 2017 meta-analysis of 50 studies and more than 2,000 MS patients found only a moderate correlation between lesion burden and function.

If lesions were purely the result of an autoimmune attack, that connection should be much stronger.

 

The Autoimmune Theory Has a Missing Piece

The standard MS explanation: the immune system mistakenly attacks myelin.

The problem: after decades of research, scientists have not identified the specific target of that attack.

If the immune system is attacking a protein in your own body, researchers should be able to find it. Multiple reviews in Lancet Neurology acknowledge they have not.

This leaves room for another explanation: that the immune activity in MS lesions is not an error. It may be the immune system responding to an infectious invader in the CNS, doing exactly what it was designed to do.

 

Parasites That Cause Brain Lesions

Multiple parasites are documented in peer-reviewed literature to invade the brain, produce lesions similar or identical to MS lesions on MRI, and create relapsing-remitting symptom patterns. The following are the most studied.

 

Pork Tapeworm Larvae (Neurocysticercosis)

How you get it: Contact with tapeworm eggs in contaminated food, water, or surfaces. You do not need to eat pork.

What it does: Larvae travel through the bloodstream to the brain and form fluid-filled cysts. As cysts degenerate, the surrounding immune response intensifies and then subsides. New cysts in new locations create new inflammation.

Why it matters for MS: This natural pattern produces lesions that appear and resolve in multiple locations over time. That is exactly what the McDonald Criteria for MS are designed to detect. Published case reports document patients evaluated for MS who were ultimately found to have tapeworm larvae in the brain.

 

Dog and Cat Roundworm (Toxocara)

How you get it: Contact with soil or surfaces contaminated with dog or cat feces. This is a common exposure for pet owners, gardeners, or anyone who visits parks.

What it does: Larvae migrate into the brain and trigger white matter inflammation.

Why it matters for MS: A published radiology study documented multiple enhancing white matter lesions that improved on follow-up MRI after antiparasitic treatment. This is direct published evidence that parasite-caused brain lesions can be treated and can improve.

 

Raccoon Roundworm (Baylisascaris)

How you get it: Contact with contaminated soil in areas frequented by raccoons, including backyards, parks, and hiking trails across North America.

What it does: Larvae migrate through brain tissue, producing diffuse deep white matter changes documented on MRI by both published research and the CDC.

Why it matters for MS: This is not an exotic tropical parasite. It is in North American backyards.

 

Toxoplasma gondii

How you get it: Contact with cat feces, contaminated soil, or undercooked meat. Estimated to infect approximately one-third of the global population.

What it does: In healthy people, it usually causes no symptoms. But it forms cysts in brain tissue that persist indefinitely. In people with suppressed immune systems, it is the leading cause of intracerebral mass lesions. These appear as multiple ring-enhancing spots in the brain, often in the same areas where MS lesions characteristically appear.

Why it matters for MS: The CDC confirms that immunosuppressive therapy can trigger reactivation of a latent Toxoplasma infection. This means MS drugs that suppress the immune system may allow a pre-existing Toxoplasma infection to reactivate, producing new brain lesions that could easily be attributed to MS disease activity rather than the actual cause.

 

Lyme Disease (Borrelia burgdorferi)

How you get it: Biting insects.

What it does: CNS Lyme infection can produce white matter lesions, encephalopathy, myelitis, and vasculitis. A 2009 study in AJNR noted that the MRI white matter appearance of treated Lyme neuroborreliosis and MS display sufficient similarity to suggest a common pathogenesis. Published case series document multifocal white matter lesions in Lyme patients that resolved after antibiotic treatment.

Important note: Standard Lyme testing misses infection in some patients. A negative test does not rule it out.

 

What Was Found Directly in MS Patients’ Spinal Fluid

This may be the most significant and least-discussed finding in this entire area of research.

Pathologist Dr. Alan MacDonald, a Fellow of the College of American Pathologists, published research examining cerebrospinal fluid (CSF) directly from MS patients, looking specifically for parasitic organisms.

What he found:

In a 2021 paper in EC Microbiology, MacDonald examined frozen CSF from 10 MS autopsy patients collected between 1984 and 2014. He found microscopic tapeworm larvae in all 10 patients. Multiple stages of larval development were present. The larvae were not all the same. Each patient appeared to have a different tapeworm species, most likely picked up through everyday contaminated food.

In separate research, MacDonald reported finding nematode worms and filarial worm larvae in the CNS of every MS subject examined. He also found Borrelia burgdorferi inside those worms.

These findings have not been independently replicated but they represent a significant published observation. And they were only found because someone looked.

MacDonald noted that the expert panel governing MS clinical practice had declared spinal fluid microscopy in MS was “always without value.” That declaration has likely discouraged doctors and researchers from studying this.

A Serious Question About Immunosuppression

If MS lesions reflect immune activity against an infectious agent, suppressing the immune system raises a real concern.

Immunosuppressive drugs may dampen the immune response. But they do not treat the underlying parasite. In the presence of an active or latent parasitic infection, reducing immune surveillance may allow that infection to advance.

This is documented, not theoretical. The CDC and peer-reviewed literature confirm long-term immunosuppression is a risk factor for acquiring or reactivating multiple central nervous system (CNS) parasitic infections.

This is not a recommendation to stop any prescribed medication. That decision should be discussed with a physician. But it is a reason to ask whether a thorough infectious workup has been completed before diagnosis.

 

What Current MS Diagnosis Does Not Require

The McDonald Criteria require lesions in multiple locations over time and exclusion of some alternative diagnoses. But they do not require testing for any of the following organisms, all of which are documented to produce MS-like CNS lesions:

• Toxoplasma
• Toxocara (dog and cat roundworm)
• Taenia solium (tapeworm)
• Baylisascaris (raccoon roundworm)
• Schistosoma
• Borrelia (Lyme)

No spinal fluid microscopy for parasites. No systematic food, travel, or animal contact history.

A comprehensive parasitic screen before an MS diagnosis is not standard of care. Given the evidence, that is a gap worth taking seriously.

 

What This Means for Recovery

Several lines of published evidence show that treating an underlying infection can produce real improvement, including on MRI:

• Toxocara: Lesions improved on follow-up MRI after antiparasitic treatment (Matsuo et al., AJNR, 2003)
• Lyme: White matter lesions resolved after antibiotic treatment in published case series
• Neurocysticercosis: Tapeworm larvae (Neurocysticercosis): Brain lesions resolve and symptoms improved after antiparasitic treatment, according to IDSA guidelines.

Identifying and treating the infectious cause of CNS lesions, can produce recovery that immunosuppression cannot achieve.

Note: antiparasitic treatment can temporarily increase inflammation as the dying organism releases material into surrounding tissue. This requires preparation and proper support.

 

The Bottom Line

The argument is straightforward:

• Parasites are documented causes of CNS lesions
• Those lesions can be radiologically identical to MS lesions
• Parasites have been found in MS patient spinal fluid in published research
• Current MS diagnostic criteria require none of this to be investigated before diagnosis.

Whether an individual patient’s lesions are caused by parasites cannot currently be answered, because the question is not being asked.

It should be.

 

There are real solutions to recover from parasites today!

To restore health, we must focus on treating the cause of inflammation, which are parasites. First, identify the enemy (parasites), then support the body and treat the parasites while following a holistic approach. When parasitic infections are treated effectively, we can overcome inflammation or disease.

If you’re frustrated with the fact that our standard of care STILL doesn’t offer a real solution for treating MS and other diseases, then click on the link below to watch Pam Bartha’s free masterclass training and discover REAL solutions that have allowed Pam and many others to live free from MS and other diseases.

CLICK Here to watch Pam’s masterclass training

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