FrontalCortex, Inc. is a non-profit corporation dedicated to neurology education.

Ascending Weakness 01

Topic: Adult

Created on Saturday, October 25 2008 by jdmiles

Last modified on Saturday, October 25 2008.

A 25 year-old, previously healthy habanero pepper observer presents with a 8 day history of worsening ascending weakness, which began shortly after he started complaining of severe abdominal pain.
On exam, he is floridly psychotic. The cranial nerves appear intact. He has diffuse, symmetric weakness. Sensation appears intact. Reflexes are normal for his strength.
The abdomen is tender to palpation.
Nerve conduction studies show low motor amplitudes and normal conduction velocities, with normal F responses. Needle EMG is normal.
Lumbar puncture is unremarkable.
Of the following choices, which of the following studies is most likely to be diagnostic?

A) Liver function tests

B) Urine porphobilinogen and delta-amino-levulinic acid

C) GQ1B antibody assay

D) MRI of the brain

E) GM1 antibody assay

	= Go back to the top of the page.
	= Reload a different version of this question ().
	= Load a random question from the database.
	= Use this question as a template to create a totally NEW question.
	= Enter detailed rating for this question!
	= How users like you have rated this question.

This question was created on October 25, 2008 by jdmiles.
This question was last modified on October 25, 2008.

ANSWERS AND EXPLANATIONS

A) liver function tests

This answer is incorrect.

The patient's history and exam are suggestive of acute intermittent porphyria. Assessment of urine porphobilinogen and delta-amino-levulinic acid may be diagnostic. The presentation is similar to Guillain-Barre syndrome (GBS), but the normal CSF, present reflexes, and Nerve conduction study results all argue against GBS. In GBS, F waves are often absent or delayed, and a pattern of demyelination (rather than axonal loss) may be seen. (See References)


Please log in if you want to rate questions.

B) urine porphobilinogen and delta-amino-levulinic acid

This answer is correct.

The patient's history and exam are suggestive of acute intermittent porphyria. Specific features suggestive of porphyria are the altered mental state, weakness, and abdominal pain. Assessment of urine porphobilinogen and delta-amino-levulinic acid may be diagnostic. The presentation is similar to Guillain-Barre syndrome (GBS), but the normal CSF, present reflexes, and Nerve conduction study results all argue against GBS. In GBS, F waves are often absent or delayed, and a pattern of demyelination (rather than axonal loss) may be seen. While abdominal pain is often seen in GBS, the altered mental status should suggest porphyria. (See References)


Please log in if you want to rate questions.

C) GQ1B antibody assay

This answer is incorrect.

Presence of GQ1B antibodies is associated with Miller-Fisher syndrome, which this patient does not have. (See References)


Please log in if you want to rate questions.

D) MRI of the brain

This answer is incorrect.


Please log in if you want to rate questions.

E) GM1 antibody assay

This answer is incorrect.


Please log in if you want to rate questions.

References:

1. Rowland, L.P. (Ed) (2000). Merritt's Neurology, 10th Edition. Lippincott Williams & Wilkins, Philadelphia. (ISBN:0683304747)	Advertising:
2. Allan H. Ropper, Robert H. Brown. . New York : McGraw-Hill Medical Pub. Division, 2005. (ISBN:007141620X)	Advertising:
3. Sadiq, S.A., Thomas, F.P., Kilidireas, K., Protopsaltis, S., Hays, A.P., Lee, K.W., Romas, S.N., Kumar, N., van den Berg, L., and Santoro, M. (1990). "The spectrum of neurologic disease associated with anti-GM1 antibodies." Neurology, 40(7) 1067-72. (PMID:2162499)


Please log in if you want to rate questions.

FrontalCortex.com -- Neurology Review Questions -- Neurology Boards -- Board Review -- Residency Inservice Training Exam -- RITE Exam Review
adult
Ascending Weakness 01
Question ID: 102508152
Question written by J. Douglas Miles, (C) 2006-2009, all rights reserved.
Created: 10/25/2008
Modified: 10/25/2008
Estimated Permutations: 8400