Case guesses:

Evan  writes:

Good evening. The weather here in Farmington Hills, Michigan after a beautiful Memorial Day weekend is a pleasant 78 degrees (25.6 C, 298.7 Kelvin).

The gentleman in this case is suffering from chronic calcific neurocysticerosis from the larval cystericus Taenia solium (pork tapeworm). TB would however remain in my differential diagnosis. Taenia solium is typically acquired by eating undercooked (or raw) pork infected with the cysticerci Taenia solium. They migrate to the brain and develop into mature cysts in 2-3 months.  These eventually degenerate and leave a granuloma host inflammatory cells and parasite remnants. This inflammation may cause seizures, but in this case, with a 20 year history of seizures, it is most likely from local vasculitis and thrombosis. Perilesional edema may be present on MRI around seizure episodes. EEG may show changes, but not necessarily. Serology tests are inconsistent, but enzyme linked immunoelectrotransfer blot assays of serum or CSF have shown significant specificity and sensitivity.

As this patient likely no longer has live Taenia solium after 20 years, cysticidal drugs are unlikely to be beneficial. Treatment should consist of ongoing seizure prophylaxis.



Karen writes:

First off, I have to confess I giggled when Dr. Griffin said “do do” which I interpreted as the noun “doo doo” 💩

I think the patient has ingested pork tapeworm eggs. He or a food-preparer probably ate undercooked pork containing tapeworms at one point. The worm then produced eggs, and these eggs followed a fecal-oral route of infection. The larvae then encysted in the brain causing seizures.

Twip it, twip it good,

Karen in Santa Barbara, CA

Sean writes:

Hi All,

Long time listener first time caller, here is my guess for the 42 year old patient with a history of seizures. 

I believe he is suffering from neurocysticercosis, due to the calcified lesion in his parietal lobe. He likely aquire this infection 20 some years ago when he began having seizures by ingesting the eggs of T. Solium. MRI of the rest of the patient would likely reveal many more extraneural lesions throughout the patients body. 

It is surprising that none of his previous doctors ever thought to have any brain imaging done to investigate the cause of his seizures as my guess is this would have lead to a much earlier diagnosis for him. 

Treatment with Albendazole and possible surgical removal of the brain lesion.

Thank you all for the work you do in educating us all about the wide world of parasites. As a biology undergrad I thoroughly enjoy procrastinating while working on my assignments by listening to TWIP and TWIV.


Sean from Vancouver

Alexander writes:

Dear Professors,

the patient here is not suffering from an ongoing parasitic infection. the single calcified lesion is probable evidence of a prior infection with the larvae of T. solium, also referred to as cysticercosis. Calcification indicates that the larva is dead and MRI did not show any additional lesions, therefore there is no indication for antiparasitic treatment at the moment. Looking for eggs in the stool might be worth considering, as he could also be infected with an adult T. solium, causing taeniasis, which would make him infectious to others.

His real problem is his structural epilepsy, which is most likely caused by the calcified lesion, and his stopping his antiepileptic medication. What this patient needs, in my opinion, is a thorough investigation into his reasons for that; did he have trouble remembering to take his dose? Did he experience side effects? Does he have barriers to acquiring his medications? Did he simply think he might not need it anymore? Most of these issues could be solved in one way or another and the goal should be to get him on antiepileptic therapy, as this seems to have worked very well in the past. Alternatively, referral for evaluation of antiepileptic surgery could be considered.

Lastly, since Vincent asked about raw or undercooked pork: Cysticercosis is acquired from foods contaminated with the stool of an infected animal (human or otherwise). Eating undercooked pork can cause taeniasis, which doesn’t cause epilepsy.

All the best,

Alexander from Vienna, Austria 

Owain writes:

Dear TWIP,

Oops, I sent my guess in too late to be read out on the last episode! Serves me right for putting it off. That’s ensured that I send this one in plenty of time..!

I’m thrilled to hear I won a book! Thanks very much for your generosity.

My guess this week is that this gentleman has neurocysticercosis, but I don’t know how common a single brain lesion is (as opposed to multiple). I suppose it varies with the intensity of infection, but the mention of the whole-body scan makes me think he has cysticerci elsewhere, so I’ll stick with that.

I also have a special request – I recently visited a close friend who has a new 11-week old baby, and coincidentally found out that his father listens to TWIP and TWIV! So I was wondering if you could give a shout out to Dermot Walsh and his adorable granddaughter Olive. If you need justification, an uncharitable soul might say new babies are pretty parasitic on their parents’ sleep? 

Thanks for all the cases!

All the best,


Alice writes:
Dear TWIP,

It’s currently 12 degrees and thunderstormy here in Cambridge.

Thanks for another interesting case! I believe the patient is suffering from neurocysticercosis caused by Taenia solium (pork tapeworm). The non-specific coarse calcification described is likely calcified cysticerci (larvae), but the CDC recommends confirmation using an immunoblot assay if available. In active infections, albendazole is the recommended course of treatment, with a corticosteroid such as dexamethasone prescribed at the same time to reduce the symptoms caused by the inflammatory response resulting from larval death. However, it is unlikely this patient has active infection, so anthelmintic therapy is not recommended. Instead, he should resume taking carbamazepine to manage his seizures, and other drugs to manage symptoms as and when they develop.

Best wishes,


Sara writes:

Dear Drs. Racaniello, Despommier, Griffin and Naula, 

Hello from a sunny and windy 22 C day in Montreal!  I had never heard of podoconiosis before last episode — so interesting!

A 42-year-old immunocompetent patient with a solitary, epileptogenic, intracerebral calcification present for >20 years produces a very broad differential. Luckily, we can narrow the differential based on the fact that this patient consumes . . . food. 😉 

Generally, a solitary intraparenchymal calcification in a patient with two decades of seizures would prompt me to produce a list of possible metabolic, endocrine, ischemic, neoplastic, toxic, and infectious causes. (I’d leave out the congenital causes like Tuberous sclerosis and Sturge Weber syndrome etc because of the adult onset of his epilepsy.) 

However, this case would not make it on the show if it weren’t caused by a parasite, still, here’s my narrowed list: 

Neurocysticercosis, (much more likely than any of the following:)

cerebral toxoplasmosis (likely the “serological testing” Dr. Griffin referred to)

remote ischemic cerebrovascular event,

septic embolic event from bloodstream infection


Likely diagnosis: My guess is that this patient has neurocysticercosis secondary to Tinea solium, acquired via fecal-oral-route from ingesting Tinea solium eggs from someone with taeniasis. 

Mechanism of infection: A beloved attending once “pimped” me with the question, “Can a lifelong vegetarian develop cysticercosis?” The answer is, “Yes.” You must consume meat to develop taeniasis, but no meat consumption is required to develop cysticercosis. (This is why I suspect Dr. Despommier asked, “do his family members eat pork?)

People develop adult tapeworm infection, taeniasis, by eating raw or undercooked meat containing cysticerci that then develop into adult worms within the intestines. Those adult worms lay eggs which are released with the stool. When that same person or another person consumes the eggs, those can hatch, and migrate out of the intestinal walls as larva and climb along vascular or nerve tracks to form cysts throughout the body (often muscle and brain). Taenia solium eggs can be eaten on a salad, fruit, cilantro etc. 

Treatment: This patient’s lesion is calcified (the worm is dead) and no one mentioned a “fluid-filled cyst” or a “ring enhancing cyst with a central scolex” which would indicate a viable cyst that would require treatment with praziquantel. Unless this patient has concurrent taeniasis or has viable cysts elsewhere (including in the muscles, heart, and eyes), the treatment for him is antiepileptic medications to prevent seizures. I would test members of his household for taeniasis to prevent reinfection for him or autoinfection for them. The “body scan” Dr. Despommier asked about that elicited a vague response from Dr. Griffin would reveal any other cysts for this patient. I’d want to do a careful eye exam. 

Thank you again for the incredible educational material! I’m two weeks away from starting my intern year and am trying to learn all that I can!!!! TWiP, TWiV and Infectious Disease Pusscast make learning so fun!! 



Daniel writes:

Hello again, Twip team,

It is 16 degrees C outside and we’ve had just about everything today, sun, clouds, wind and a little rain. The weather keeps you guessing this time of year. And now it is time to take a guess at what ails this man who is originally from Central America. The symptoms seem to match closely with neurocysticercosis caused by the pork tapeworm Taenia solium. People who are infected with the adult pork tapeworm excrete the eggs produced by the tapeworm in their feces. In unhygienic conditions, people can ingest these eggs from contaminated water, food or unwashed vegetables. Because our digestive system is similar to pigs, the eggs hatch and the larvae invade many tissues including the brain. And then they wait. But they can’t wait forever, eventually, they die and form calcified cysts. Trichinella spiralis and Toxocara canis/cati can also cause neurological issues if their larvae migrate through the brain. However, Trichinella prefers striated muscle where it modifies a sarcomere to its liking and I think someone would have to be aware that they are eating a bunch of uncooked meat before one wound up in the brain. An infection with Toxocara would be associated with inflammation, redness, ocular lavara migrans (OLM) or visceral larva migrans (VLM) and they only stay alive for 6-8 months. 

Cheers everyone,

Daniel from BC Canada

The Parasitology Club of the University of Central Lancashire writes:

Dear TWIP Professors: 

Greetings from Parasitology club at University of Central Lancashire located in the beautiful Northwest of England. Exams are done, the summer is coming, and we are planning for our summer school and the imminent arrival of PD7 books. Colleagues at our veterinary school have promised samples teaming with interesting parasites and something exotic from a nearby zoo, so we are looking forward to that.

Regarding the case of the 42-year-old Spanish speaking male originally from Tegucigalpa, Honduras who currently resides in the New York City area who was admitted to hospital after a seizure. He grew up in Honduras and has had a twenty-year history of seizures, but a physical examination revealed no other abnormal health conditions aside from coarse non-specific calcification in the cranium.

Our considered opinion is that the condition is neurocysticercosis caused by the tapeworm Taenia solium. T. solium, is a zoonotic parasite that infects both humans and pigs and when ingested it can spread from the small intestine to the central nervous system and any organs connected to it including the brain (Braae et al., 2017). It can be transmitted to humans by eating raw or undercooked pork that contains the cystercerci of T. solium, which attach to the epithelium of the small intestine and develop into adult tapeworms (CDC, 2022). Ingestion of Taenia ova or gravid proglottids from faecally contaminated material or a household contact with the tapeworm results in the hatching of the oncospheres which can spread from the intestines to the central nervous system via the bloodstream (Jain et al., 2010). 

Neurocysticercosis is a disease caused by the appearance of the cysts of T. solium in the brain, where they eventually clear or calcify. The calcification of the cysts can cause multiple deposits in the brain and are responsible for neurological conditions such as seizures and hypertension due to the inflammatory response in the brain (Bustos, 2021). The appearance of cysts outside of the brain is known as cysticercosis, and in rare cases it can be clinically presented in the cardiovascular system (Jain, 2010).

T. solium is endemic to Central America including Honduras in areas where humans and pigs are in close contact (zoonosis) and where sanitation is lacking (Beyersdorf, 2018). The presence of T. solium is rarer when pigs do not have contact with human faeces (CDC, 2020), but can still occur if there is a human carrier present and if poor hygiene practices are observed. Neurocysticercosis one of the most frequent causes of preventable epilepsy worldwide and has been estimated to be responsible for 30% of cases in countries where T. solium is endemic, with some communities potentially having a rate of up to 70% (WHO, 2022). 

Neurocysticercosis is diagnosed primarily by MRI or CT scans of the brain (CDC, 2020), serologic testing for patients with central nervous system symptoms, (William and Chelsea, 2021) with criteria including the presence of cysts in the sub retina, presence of the scolex of a parasite in a cyst, lesions that are <20mm in diameter, and movement of lesions on subsequent scans if more than one is carried out (Del Brutto, 2017).  

The recommended treatment for neurocysticercosis is the administration of anti-inflammatory drugs such as corticosteroids, with anthelmintic drugs in addition to corticosteroids and AEDs for cases with viable cysts. Certain cases may require surgical intervention (Abela, 2021, p.6-10)..

Thank you for providing us with another challenging case.


On behalf of the Parasitology Club of the University of Central Lancashire.

Reference List

Abela, B. (2021). WHO guidelines on management of Taenia solium neurocysticercosis. World Health Organization – Control of Neglected Tropical Diseases 

Beyersdorf, F. and Rylski, B. (2018) ‘Cysticercosis—rare but important’. The Journal of Thoracic and Cardiovascular Surgery. The Journal of Thoracic and Cardiovascular Surgery, 155(5) p. e159.

Braae, U. C., Devleesschauwer, B., Sithole, F., Wang, Z. and Willingham, A. L. (2017) ‘Mapping occurrence of Taenia solium taeniosis/cysticercosis and areas at risk of porcine cysticercosis in Central America and the Caribbean basin’. Parasites & Vectors. Parasites & Vectors, 10(1).

Bustos, J. A., Arroyo, G., Gilman, R. H., Soto-Becerra, P., Gonzales, I., Saavedra, H., Pretell, E. J., Nash, T. E., O’Neal, S. E., Del Brutto, O. H., Gonzalez, A. E. and Garcia, H. H. (2021) ‘Frequency and Determinant Factors for Calcification in Neurocysticercosis’. Clinical Infectious Diseases. Clinical Infectious Diseases, 73(9) pp. e2592–e2600. 

Centre of Diseases and Prevention (2020). Parasites – Cysticercosis [online]. Available from: [Accessed: 06/06/2022] 

Del Brutto, O. H., Nash, T. E., White, A. C., Rajshekhar, V., Wilkins, P. P., Singh, G., Vasquez, C. M., Salgado, P., Gilman, R. H. and Garcia, H. H. (2017) ‘Revised diagnostic criteria for neurocysticercosis’. Journal of the Neurological Sciences. Journal of the Neurological Sciences, 372 pp. 202–210. 

Gezercan, Y., Acik, V., Çavuş, G., Ökten, A.I., Bilgin, E., Millet, H. and Olmaz, B. (2016). Six different extremely calcified lesions of the brain: brain stones. SpringerPlus, [online] 5(1). doi:10.1186/s40064-016-3621-3.

2022 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved., William, A.P., Jr and Chelsea, M. (2021). Taenia Solium (Pork Tapeworm) Infection and Cysticercosis. MSD Manuals professional. Available at: [Accessed 14 Jun. 2022].

Jain, B. K., Sankhe, S. S., Agrawal, M. D. and Naphade, P. S. (2010) ‘Disseminated cysticercosis with pulmonary and cardiac involvement’. Indian Journal of Radiology and Imaging. Indian Journal of Radiology and Imaging, 20(04) pp. 310–313.

World Health Organization (2022). Taeniasis/cysticercosis [online]. Available from: [Accessed: 06/06/2022]

Martha writes:

Greetings. Keeping it brief since I’m typing on the phone.

Re. The 40ish man with the 20+Year hx of seizures & imaging showing calcified brain lesion. I’m guessing cysticercosis from ingesting embryonated Taenia solium eggs as a young person. 

Serological testing could support this dx. Since the parasite is dead and calcified he won’t benefit from antihelmenthic agents. A neurosurgeon could give an opinion re. removal and if anti seizure meds will be needed after removal.

Best wishes to you all


Kimono writes:
Dear TWiP Team!

Firstly, Dr. Daniel, I am so thankful that this 42 y/o Honduran gentleman with seizure disorder presented to your hospital! We rarely do further work-ups in a person with a pre-existing seizure disorder and a likely explanation for the breakthrough event – medication non-compliance.

My leading diagnosis is T. solium as the evil parasite, and neurocysticercosis as the cause of his seizures. My thoughts also went to T. gondii and a few other ‘neuroinvasive’ parasites, but the specific seizure history and solitary lesion made T. solium more likely.

His CT and MRI showed a solitary calcified lesion, which can represent invasive disease following the ingestion of T. solium eggs. Larva (oncosphere) hatch from the embryonated egg and can penetrate the wall of the small intestine, thus gaining entry into the bloodstream and then onward to many tissues, including the CNS. Here it encysts, differentiates, and develops into a space-filling lesion. In the CNS, oncospheres seem to have a suppressive hold on the host immune response until the parasites start to die, releasing this hold, and triggering inflammation and edema, which may be responsible for eliciting seizures.

PD-7 mentions that up to 15% of patients with cysticercosis also harbor an intestinal adult T. solium tapeworm and that they can even auto-infect with the eggs of their own tapeworm (yuck!). So, I would venture to guess that we may see more calcified lesions within muscle tissues, if he undergoes further ‘body imaging’ – as Prof. Dickson inquired about.

Diagnosis can be made by stool microscopy (if harbouring an intestinal tapeworm) – identifying Taenia eggs, analysis of the proglottids, or even the scolex. ELISA on fecal extracts, immunoblot assays, and serological assays seem to be more sensitive? And CT and MRI are used to help in diagnosing neurocysticercosis.

Treatment – Praziquantel is noted as effective against the adult T. solium, but it’s use can trigger CNS manifestations in the presence of neurocysticercosis. In these cases, PD7 mentions using a corticosteroid first (to help reduce inflammation and swelling) and then albendazole, possibly in combination with praziquantel.

I hope I got it right – but my simple mind is still grappling with why these seizures continue indefinitely…..would they not abate once the inflammation and edema have subsided, a while after calcification of the parasite? Or is it the mere presence of the calcified lesion in the CNS that is the culprit? Since his seizures started over 20 years ago, I would presume that this lesion calcified at about that time, and present imaging is now not showing any ring-enhancement.

Many thanks for providing such captivating topics through stimulating conversation!

Kimona (now in Vermont where it today is a bit overcast and a crisp 18 degrees celsius)

Eyal writes:

Dear heralds of knowledge and common sense.

G’Day from Sydney Australia where all has settled into a nice and mild Australian “winter”.

Tangent warning, since my last email, we have had our federal elections on Saturday May 21st, where the previous government has handed their dismissal letters, and on Monday morning the new government was sworn in, and everyone went on their merry way to have a beer in the pub. I was just thinking about the massive difference between our 2 democracies in light of the current January 6th hearings.

As to the 42-year-old gentleman who stopped taking his anti-seizure medication and has now relapsed.

Based on the case description there wasn’t too much to go by so I decided to try and see if any parasite typically causes adult epilepsy.

Not surprisingly, it looks like Neurocysticercosis which is caused by the larval cysts of the pork tapeworm (Taenia solium), is a leading cause of adult epilepsy and cases of it are growing in the US.

according to the NIH, treatment includes anti-parasitic drugs such as praziquantel and albendazole together with corticosteroids and antiepileptic drugs. Typically between the second and fifth days of anti-parasitic therapy, there is usually an exacerbation of neurological symptoms, attributed to local inflammation due to the death of the larvae.

Thank you for another opportunity to read about a new disease I have never (luckily) encountered before.


Chelsea writes:
Greetings from a sunny and comfortable 79 degree morning in Bat Cave, North Carolina.

My guess for episode 207 is neurocysticercosis based on the calcified lesion and seizure activity, alongside the unremarkable physical exam/labs and the patient’s upbringing in Honduras where Taenia solium is endemic.

Neurocysticercosis is caused by eggs of Taenia solium, or pork tapeworm, usually ingested via fecal-oral route from another person or animal who has an intestinal pork tapeworm. After the eggs are ingested, they hatch, become larvae, travel throughout the body and encyst themselves into surrounding tissue. If these larvae travel to the brain and encyst in cerebral tissue, as is the case for our patient, this will lead to neurocysticercosis.1

Though typically asymptomatic, once T. solium cysts start to degenerate, the body’s immune system begins to respond, causing inflammation, headaches, altered mental state and most commonly, epilepsy.2

Neurocysticercosis treatment for this patient would not include antihelminthic drugs, since the cyst is calcified.  Treatment would focus on controlling seizures and management of any existing edema, intracranial hypertension, or hydrocephalus that may occur.3

On a side note, I learned about T. solium for the first time in high school biology class my senior year in 2003. I’ve been a vegetarian since that very day (shout-out to Mrs. Beckerink!).




1.     Centers for Disease Control.

2.     This Podcast Will Kill You, Episode 96: We encyst you listen. May 17, 2022.

3.     Centers for Disease Control. Parasites-Cysticercosis. Resources for Health Professionals.

Andrew writes:

Kia ora from Pongaroa

Weather – today is the winter solstice. Need I say more? But we also are celebrating the Māori new year, Matariki (ma-ta-ree-kee), so that will keep our spirits up on these gloomy days.

Considering the city where our patient comes from has pork as one of its staple meats, I feel fairly confident in guessing he has Neurocysticercosis caused by the migration of an infestation of larval Taenia solium via the blood stream to the brain. Here the unfortunate creature died and calcified to produce, posthumously, the man’s seizures. As the TikTok generation keep telling each other, keep hydrated and take your meds.

This cause of the “falling sickness,” as it was known in ancient times, makes me wonder if this is what caused Julius Caesar’s epilepsy as he developed it later in life according to Plutarch. It is probably too late for an autopsy but it is fun to speculate.


Jennifer writes:

Good afternoon TWIP hosts Vincent, Christina, Dickson, and Daniel,

I’m a middle school science teacher, writing from my air-conditioned boudoir in Arlington, Virginia, on this sunny 85 degree Fahrenheit day. This is my first ever attempt to diagnose a case after listening for over 2 years. I am in love with Parasites without Borders, and would make a financial donation if I were able, but alas, my teacher salary won’t permit it. 

After hearing of the circumstances surrounding the gentleman from Honduras experiencing chronic seizures, it is my humble non-medical opinion that he is afflicted with neurocysticercosis caused by the larval cysts of Taenia solium, aka, the pork tapeworm. 

I base my diagnosis on the hints provided by Daniel and on the evidence corroborated by the CDC webpage:

My research started with a standard Google search of the terms “cranial coarse calcification” which led me to the following NCBI paper:

This, in course, led me to the acquired infection section found in Table 2, which provided the answer: “neurocysticercosis.” 

I do hope I have written this in time, but if not, I will try again! 

Kindly yours,


Elise writes:
Dear TWiP Collective,

How are you? I hope this finds you well. After a wave of excellent weather, we are now in the Hot and Murky phase of summer, which is very uncomfortable but matches my mood in the wake of upsetting and enraging Supreme Court Decisions. It is 75-ish degrees F ( 24 C) in Lower Manhattan and raining intermittently.

I do have a diagnostic guess for TWiP 206. I believe the gentleman is suffering from neurocysticercosis (and I make this guess not just because I had some inside scoop because I was sitting next to Vincent at the last recording— I did  detective work on my own).

The patient has had a history of epilepsy and while there are many iterations of this syndrome, one of its causes, particularly in certain Latin American countries (Honduras, where the patient is from, being one of them) is a tapeworm (Tania solium) infection. In this infection, a host ingests the tapeworm eggs and the larvae find their ways to different parts of the body including to the brain, where they can calcify and can create a host of problems including epilepsy, encephalitis, meningitis and neurological problems such as cognitive or personality changes and vision problems.

One detail I found that was particularly interesting is the suggestion that the helminth infection is a more likely candidate for this diagnosis than other parasites because these infections can produce a substantial immune response in the host where the autoantibodies that the body generates can actually induce epilepsy. I include this because it was really fascinating to me but since I discovered it in  a NOT AT ALL RECENT  National Library of Medicine article, it is possible that it has been disproved by now.

What is to be done for this patient who has been dealing with this infection for two decades? Will he need surgery to address the calcifications in his brain and relieve his symptoms? Is the solution to have him return to his medication and take it more faithfully?

As always I am so grateful to you all for everything you do and for keeping me interested and engaged especially at times when the world threatens to be overwhelming.

Best best wishes,

Elise (Mac Adam) in Lower Manhattan