WBR0631

Revision as of 23:46, 21 October 2013 by Rim Halaby (talk | contribs)
Jump to navigation Jump to search
 
Author [[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Microbiology, MainCategory::Pathology
Sub Category SubCategory::Gastrointestinal, SubCategory::Neurology
Prompt [[Prompt::A 2 year old boy is brought by his mother to the emergency department (ED) for altered level of consciousness. Upon further questioning, the mother reports that the child had a viral infection with fever and rash a few days ago and is being given aspirin to relive his symptoms. Rapid assessment in the ED is performed and blood is withdrawn and shows hyperammonemia, hypoglycemia, and lactic acidemia. Computed tomography (CT) scan of the brain shows diffuse edema. Which of the following molecular dysfunctions is most likely associated this patient's condition?]]
Answer A AnswerA::Absence of Golgi bodies in hepatocytes
Answer A Explanation AnswerAExp::Reye's syndrome is not associated with Absence of Golgi bodies in hepatocytes.
Answer B AnswerB::Presence of pleomorphic mitochondria in the liver and brain
Answer B Explanation AnswerBExp::Reye's syndrome is believed to be caused by the presence of pleomorphic mitochondria in the liver and brain. It is associated with aspirin ingestion in children.
Answer C AnswerC::Collagen defect with abnormal mitotic activity in the liver
Answer C Explanation AnswerCExp::Reye's syndrome is not associated with collagen defects or abnormal mitotic activity in the liver.
Answer D AnswerD::Absence of enzymes within the lysosomal complex
Answer D Explanation AnswerDExp::Reye's syndrome is not associated with the absence of enzymes within the lysosomal complex.
Answer E AnswerE::Presence of viral RNA molecules inhibiting protein degradation by the ubiquitin-proteosome pathway
Answer E Explanation AnswerEExp::Reye's syndrome is not associated with the dysregulation of the ubiquitin-proteosome pathway.
Right Answer RightAnswer::B
Explanation [[Explanation::The patient presents with Reye's syndrome, a form of acute encephelopathy characterized by the altered level of consciousness and typical findings on lab work-up, such as hyperammonenia, hypoglycemia, and lactic acidemia. Diffuse edema on neurological imaging is also characteristic of Reye's syndrome. In children, it is associated with the intake of aspirin that is usually ingested for its antipyretic properties during viral infections, such as VZV.

Reye's syndrome is believed to be caused by mitochondrial abnormalities with the presence of non-uniform loss of enzymatic activity in the mitochondria within cells of the liver and the brain, such as the loss of activity of pyruvate carboxylase. Exposure to chemical products that alter the intramitochondrial matrix and the low ATP:ADP ratio lead to inhibition of the proper formation of proteins required by the mitochondria and thus low enzymatic activity.

Educational Objective: Reye's syndrome is an acute encephalopathy typically seen in children following ingestion of aspirin. It is characterized by altered level of consciousness and altered metabolic blood panel. Reye's syndrome is due to a mitochondrial dysfunction with the presence of pleomorphic mitochondria in the liver and the brain that have a reduced enzymatic activity.


Reference: Van Coster RN, De Vivo DC, Blake D, et al. Adult Reye's syndrome: a review with new evidence for a generalized defect in intramitochondrial enzyme processing. Neurology. 1991; 41(11):1815-21.

Davies NW, Sharief MK, Howard RS. Infection-associated encephalopathies - their investigation, diagnosis, and treatment. J Neurol. 2006; 253:833-45.

Glasgow JF. Reye's syndrome: the case for a causal link with aspirin. Drug Saf. 2006; 29(12):1111-21.
Educational Objective:
References: ]]

Approved Approved::No
Keyword WBRKeyword::Reye, WBRKeyword::reye's, WBRKeyword::síndrome, WBRKeyword::aspirin, WBRKeyword::intake, WBRKeyword::ingestion, WBRKeyword::encephalopathy, WBRKeyword::altered, WBRKeyword::consciousness, WBRKeyword::viral, WBRKeyword::infection, WBRKeyword::VZV, WBRKeyword::rash, WBRKeyword::fever, WBRKeyword::hypoglycemia, WBRKeyword::hyperammonemia, WBRKeyword::lactic, WBRKeyword::acidemia, WBRKeyword::mitochondria, WBRKeyword::mitochondrial, WBRKeyword::dysfunction, WBRKeyword::pleomorphic, WBRKeyword::liver, WBRKeyword::brain
Linked Question Linked::
Order in Linked Questions LinkedOrder::