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A Medical Guide to House

Sunday, October 15, 2006

Episode 101: Pilot

Chief Complaint: New-onset seizure.

History of Present Illness: Ms. Rebecca Adler is a 29 year old woman who had her first seizure one month ago during which she became dysarthric followed by tonic-clonic motor activity. Protein markers for the 3 most prevalent brain cancers at an outside hospital were negative. The patient's symptoms have not responding to radiation.

Past Medical History: None.

Medications: None.

No known allergies.

Social History:
She is a schoolteacher at an elementary school in Trenton, New Jersey. She is Dr. Wilson's cousin.

Family History:

1) Myocardial infarction: mother died of this
2) Cancer: none

Physical Exam:
Not performed.

Normal thiamine.

Medical Decision Making:
A head CT with IV contrast (to rule out a mass lesion and/or hematoma) was performed, which revealed no abnormalities. Aneurysm, stroke, ischemic disease, Creutzfeld-Jacobs disease, and Wernicke's encephalopathy were considered as possible diagnoses. A normal thiamine level from an outside hospital record precludes a diagnosis of Wernicke's encephalopathy. Repeat thiamine level conducted here was also normal. A contrast MRI was scheduled to be performed but had to be stopped because of unauthorization by Dr. Cuddy. On repeat contrast MRI, patient had an anaphylactic reaction to the gadolinium contrast and had to be treated with epinephrine 0.5 mg subcutaneously. Emergency tracheostomy performed, and an endotracheal tube was placed and promptly removed the next day. A diagnosis of cerebral vasculitis was considered, which would be consistent with the elevated erythrocyte sedimentation rate (despite the fact that the elevation was only mild). Steroids were given, to which the patient responded well. Environmental exposure to mold at the patient's school was considered, but none was found, The patient's elementary school students did reveal the presence of a parrot at the school, which led to the consideration of psittacosis. However, the fact that none of the schoolchildren were ill meant that this was likely not the cause of the patient's symptoms. The following day, the patient experienced temporary blindness followed by a generalized tonic-clonic seizure with supraventricular tachycardia up to 211 progressing to asystole, saturating 96% on room air. The patient was resuscitated with external defibrillation and experienced postictal confusion for 5 minutes, after which her mental status returned to baseline. Differential diagnoses under consideration included tumor, infectious processes, and vascular processes. In order to differentiate the 3 processes, all treatment was stopped to see how fast the patient declined. Decline over 1-2 months would point towards a tumor, decline over a few weeks would suggest an infection, and decline over a week would suggest a vascular process. The patient's home was also analyzed for environmental exposures. It was discovered that the patient's dog likely has fleas. Ham and eggs were discovered in the refrigerator. In terms of the patient's progress, she was unable to stand up at this point. It was found out that Ms. Adler was not in fact Dr. Wilson's cousin. Because ham is derived from pigs, a diagnosis of neurocystercosis was considered. The patient refused further treatment, and so an x-ray of her leg was performed to visualize worm larvae. A single lesion in the muscle was demonstrated, which confirmed the diagnosis. The patient was started on albendazole 400 mg bid x 4 weeks and discharged.

Differential Diagnoses:
Dr. Cameron: Creutzfeldt-Jacobs disease
Dr. Chase: Aneurysm, stroke, and ischemic disease
Dr. Foreman: Wernicke's encephalopathy, psittacosis
Dr. House: Cerebral vasculitis, neurocysticercosis

Commentary: Ms. Rebecca Adler is a 29-year-old woman with a new-onset seizure. Seizures aren't great things, and it makes sense to rule out dangerous causes of seizure before jumping to prescribing an anti-convulsant medication. In fact, one seizure doesn't generally even need to be treated with an anti-convulsant because approximately 50% of adults who have one seizure never have a second one. It is unclear whether Ms. Adler had more seizures, but given that she returned to this hospital after being ruled out for a tumor at an outside hospital, it is likely that Ms. Adler has had repeat episodes of seizure. Generally, a person needs to abstain from driving for 6 months following a seizure, so it's also curious as to how Ms. Adler was able to make it to the Princeton-Plainsboro Teaching Hospital (Maybe she got a ride from Dr. Wilson?). Anyways, here's the official work-up of a seizure as published in the American Family Physician journal in 1998 [1] (There's also a New England Journal of Medicine article in 2001 regarding diagnosis of seizures, but I'm going to try to stick to journals that are publicly available when possible).
  • Complete blood count, a basic metabolic panel, calcium, magnesium, and phosphorus.
  • Toxicology screen and evaluating hepatic function with synthetic and enzyme studies
  • Lumbar puncture is essential in patients in whom meningitis or encephalitis is suspected, as well as in immunocompromised patients, since occult meningitis is a common finding in this group.
  • Magnetic resonance imaging (MRI) when a machine is available, which is more sensitive than computed tomography (CT) in identifying these lesions. If the patient presesents with new focal deficits, persistent altered mental status, fever, recent trauma, persistent headache, cancer, treatment with anticoagulation or immunocompromised state, an emergent CT scan is often performed, given its widespread availability and speed and its superior ability in the detection of acute hemorrhage, compared with MRI.
  • Electroencephalography (EEG) for detection of epileptiform activity, strengthening the putative diagnosis; identification of focal electrocerebral abnormalities suggesting a focal structural brain lesion; and documentation of specific epileptiform patterns associated with particular epilepsy syndromes (for example, generalized spike-and-wave discharges associated with a generalized epilepsy, or focal discharges associated with a localization-related epilepsy).
During the course of Ms. Adler's evaluation, all of the above are presumably performed with the exception of a lumbar puncture, a tox screen, and an EEG. The CT shows no lesion, and an MRI (the best test for diagnosis of neurocystercercosis) couldn't be performed because of the patient's allergy to gadolinium contrast (which happens in 0.01% of patients [2]). Except for a case report here and there about diagnosing neurocystercosis with a lumbar puncture [3], the usual route of detection of neurocystercosis is via CT and MRI. At one point when Dr. Chase suggests using an x-ray to diagnose the disease, Dr. House remarks that it must be muscle that is x-rayed because the CSF (cerebrospinal fluid) has the same consistency as the cysticercosis (implying that this is the reason it wasn't seen on the CT scan of the head). This just seems to be entirely untrue. What you see in the brain (and muscle) is calcified cysts. A calcification has the same consistency as bone, so it should light up on a head CT, just like it did on the thigh muscle x-ray!

Conclusions: This is a ridiculous diagnosis. Yes, the thigh x-ray confirmed the presence of a lesion which is suggestive of cysticercosis, but there's no good reason that the same type of lesion should be completely absent from a head CT! Furthermore, why not check the stool for Taenia solium eggs (the organism responsible for cysticercosis)? If it's in the brain and in the muscle, it should be in the intestine where it all started, no? Ms. Adler admitted she was wearing a diaper at that point. I'm sure they could've just changed her diaper and taken the stool from the old one for sampling. The other thing that bothers me is that Dr. House dismisses the diagnosis of psittacosis (which comes from bird feces) on the basis of the kindergarten students not getting sick but was gung-ho about considering cysticercosis based on having ham in the fridge. It's not like each pig only goes into one packet of ham. If Ms. Adler got sick from a pig, then every other person who ate portions of that pig should be sick. This should've been picked up at a national level like episodes of mad cow disease from infected beef. Then again, Dr. Chase does tell Ms. Adler that this has been "in her system" for years, so maybe all her co-pig-eaters are dying while she's alive because of Dr. House. Just a thought.

1) Marks WJ Jr, Garcia PA. Management of seizures and epilepsy. Am Fam Physician. 1998 Apr 1;57(7):1589-600, 1603-4.

2) Murphy KJ, Brunberg JA, Cohan RH. Adverse reactions to gadolinium contrast media: a review of 36 cases. AJR Am J Roentgenol. 1996 Oct;167(4):847-9.

3) Katz B. Central American mesencephalopathy. Surv Ophthalmol. 1994 Nov-Dec;39(3):253-9.


Anonymous Anonymous said...

To the best of my knowledge, there would only be a finding on stool for o/p (proglottids - not eggs) if she was the definitive host. This would be the case if she ate infected pork, and had Taeniasis (often asymptomatic).

You don't get NCC from infected pork - its oral fecal. She must have eaten something that had the feces of a person infected w/ Taeniasis on it (gross yes, but it happens, and could happen anywhere). Then she would have ingested larvae- which travels to her tissue and encysts. The cysts cause disease by their location (brain) or with inflammation when they die (lifespan is a few years).

It would have been nice if they had given her some corticosteriods to decrease the inflammation and brain tissue destruction that happens when the albendizole kills the cysts.


8:16 PM  
Anonymous John Brown, MD said...

This is exceptional. Although you have probably graduated by now, and are in residency somewhere, hopefully you (or someone equally as bright and interesting) will be able to continue. One doc to a future doc -- great, great job.

6:16 PM  
Anonymous Ellen said...

Hey, this really helped me out. One of my grade 12 science projects is to watch a tv show/movie and write a report about how accurate or inaccurate the science was, and I happened to choose this episode of House. Thanks for doing this! It made a great guide for what I should be looking for.

7:26 PM  
Anonymous Anonymous said...

Don't forget the infection
can also be caused by moving the eggs and proglottids to the stomach
via retroperistalsis movement

10:40 AM  

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