Floppy Infant 01
Topic: Pediatric
Created on Tuesday, September 4 2007 by jdmiles
Last modified on Tuesday, September 4 2007.
A term infant is notably weak and hypotonic at birth. The child is a product of an unremarkable pregnancy and a normal vaginal delivery with no other complications. The mother, a 32-year old female, had regular prenatal visits. Her past medical history is remarkable for occasional of diplopia, which is worse at night, and rarely accompanied by dysphagia. She has never been diagnosed or treated for these complaints. Physical exam of the mother reveals ptosis which worsens with prolonged upgaze. Physical exam of the infant shows diffuse weakness and hypotonia, with normal muscle bulk and intact sensation and reflexes.
Which of the following is the most likely prognosis?
This question was created on September 04, 2007 by jdmiles.
This question was last modified on September 04, 2007.
ANSWERS AND EXPLANATIONS
A) This infant will most likley have repeated bouts of weakness throughout childhood, but these will resolve by adolesence
This answer is incorrect.
Based on the history and physical exam, the mother most likely suffers from undiagnosed myasthenia gravis. The symptoms of myasthenia are caused by an antibody to the acetylcholine receptor in muscles. This antibody can cross the placenta, and cause weakness in the infant which can be more profound than the weakness of the mother. About 15% of infants born to myasthenic mothers are thought to develop neonatal myasthenia. After delivery, symptoms usually resolve without any specific intervention.
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B) This infant's weakness will worsen unless treated
This answer is incorrect.
Based on the history and physical exam, the mother most likely suffers from undiagnosed myasthenia gravis. The symptoms of myasthenia are caused by an antibody to the acetylcholine receptor in muscles. This antibody can cross the placenta, and cause weakness in the infant which can be more profound than the weakness of the mother. About 15% of infants born to myasthenic mothers are thought to develop neonatal myasthenia. After delivery, symptoms usually resolve without any specific intervention.
(
See References)
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C) This infant will be come progressively weaker regardless of treatment
This answer is incorrect.
Based on the history and physical exam, the mother most likely suffers from undiagnosed myasthenia gravis. The symptoms of myasthenia are caused by an antibody to the acetylcholine receptor in muscles. This antibody can cross the placenta, and cause weakness in the infant which can be more profound than the weakness of the mother. About 15% of infants born to myasthenic mothers are thought to develop neonatal myasthenia. After delivery, symptoms usually resolve without any specific intervention.
(
See References)
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| | |
| | |
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D) This infant will most likely develop improved strength distally, with chronic proximal weakness
This answer is incorrect.
Based on the history and physical exam, the mother most likely suffers from undiagnosed myasthenia gravis. The symptoms of myasthenia are caused by an antibody to the acetylcholine receptor in muscles. This antibody can cross the placenta, and cause weakness in the infant which can be more profound than the weakness of the mother. About 15% of infants born to myasthenic mothers are thought to develop neonatal myasthenia. After delivery, symptoms usually resolve without any specific intervention.
(
See References)
|
| | |
| | |
| Please log in if you want to rate questions. |
E) This infant will recover rapidly with supportive treatment
This answer is correct.
Based on the history and physical exam, the mother most likely suffers from undiagnosed myasthenia gravis. The symptoms of myasthenia are caused by an antibody to the acetylcholine receptor in muscles. This antibody can cross the placenta, and cause weakness in the infant which can be more profound than the weakness of the mother. About 15% of infants born to myasthenic mothers are thought to develop neonatal myasthenia. After delivery, symptoms usually resolve without any specific intervention.
(
See References)
|
| | |
| | |
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References:
| 1. Crawford, T.O. (1992). "Clinical evaluation of the floppy infant." Pediatr Ann, 21(6) 348-54. (PMID:1620559) |  |
| 2. Crawford, T.O. (2004). The floppy infant. In Bradley, W.G., Daroff, R.B., Fenichel, G.M., and Jankovic, J. (Eds.). Neurology in Clinical Practice, Fourth Edition. Butterworth Heinemann, Philadelphia, pp. 393-406. | |
| 3. (2003). "Myasthenia gravis: consequences for pregnancy, delivery, and the newborn." , 61(10) 1362-6. (PMID:14638956) | |
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pediatric
Floppy Infant 01
Question ID: 090407086
Question written by J. Douglas Miles, (C) 2006-2009, all rights reserved.
Created: 09/04/2007
Modified: 09/04/2007
Estimated Permutations: 4200
