Answer for Metabolic Monday case on 9/17/18: Vitamin K Embryopathy

  • Causes:
    • Genetic (many)
    • Non-genetic: Hyperemesis gravidarium, eating disorders, warfarin use, GI malabsorption (IBD, celiac disease, bariatric surgery)
  • Imaging:
    • Midface hypoplasia (Binder-phenotype)
    • Chondrodysplasia punctata (CDP)
    • Punctate calcifications within cartilaginous structures
    • Cervical stenosis

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Answer for Metabolic Monday case on 9/10/18: Alexander Disease

  • MACROCEPHALY
  • Mutations in the GFAP gene (glial fibrillary acidic protein)
  • Need 4 of the 5 for the diagnosis:
  • 1.FRONTAL PREDOMINANCE but extensive cerebral WM change
  • 2.Periventricular rim bright on T1 and low on T2
  • 3.Basal ganglia (symmetric T2 HI caudate heads>putamen>thalami)
  • 4.Brainstem involvement (may lead to aqueduct obstruction)
  • 5.ENHANCEMENT where Rosenthal fibers greatest
  • Infantile form most common
  • Laboratory investigations NOT helpful

 

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Answer for Metabolic Monday case on 8/27/18: Metachromatic Leukodystrophy

  • Lysosomal disease (Arylsulfatase A deficiency)
  • Affects sphingolipids
  • butterfly” appearance with stripes
  • No contrast enhancement
  • Initially no subcortical U-fiber involvement
  • Usually presents second year of life (Late-infantile type)
  • Tigroid and leopard appearance of the white matter

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Answer for Toxic/Metabolic Monday case on 8/20/18: Carbon Monoxide Toxicity

  • Most neuroimaging studies reveal basal ganglia involvement (globus pallidus) with hypoattenuation on CT scans and T2 hyperintensity/restricted diffusion on MRI scans.
  • Globus pallidus involvement indicates a severe, acute event of hypoxia caused by cellular asphyxia
  • Delayed post-hypoxic leukoencephalopathy in approximately 3% of patients
  • White matter insult related to a post-hypoxic effect, sparing the cerebellum and brainstem

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Answer for Toxic/Metabolic Monday case on 8/13/18: Methanol Toxicity

  • Note the classic involvement of the caudate and putamen with hematoma in putamen on the left
  • Secondary injury from anoxia and acidosis
  • Toxin in windshield wiper fluid, antifreeze, photocopying fluid
  • Neurotoxicity related to its metabolite formic acid
  • Solvent for extraction of ephedrine from pharmaceutical tablets to make methamphetamine
  • Children very susceptible to the gas
  • Ingestion, inhalation, or dermal exposure
  • Can mimic Wilson and Leigh Disease
  • Ethylene glycol has imaging features similar to methanol toxicity.
  • Like methanol, there is an affinity for the basal ganglia with putaminal necrosis
  • MRI may also reveal symmetric T2-hyperintensity involving the basal ganglia, thalami, amygdala, hippocampi, and brainstem. Restricted diffusion related to cytotoxic edema can be seen within the corona radiata bilaterally
  • Ethylene glycol is an organic solvent found in antifreeze among other products
  • Due to its sweet taste, children are apt to consume large quantities of it
  • There are a variety of toxic metabolites that affect multiple organ systems, with the greatest damage to the central nervous, GI, cardiopulmonary, and renal systems
  • Putaminal hemorrhagic necrosis
  • Can involve white matter

Answer for Metabolic Monday case on 7/30/18: Thiamine Deficiency.

  • Thiamine (Vitamin B1) is required for glucose metabolism.
  • Wernicke’s encephalopathy brain injury is confined to selective regions particularly sensitive to thiamine deficiency because of their high oxidative metabolism such as the periventricular regions of the third ventricle, the dorsomedial nucleus of thalami, the hypothalamus, the mammillary bodies, the periaqueductal region, and the floor of the fourth ventricle.
  • The classical clinical triad of Wernicke’s encephalopathy is mental status changes, ophthalmoplegia, and ataxia, although atypical presentations are common in children. The condition can be fatal if left untreated.
  • It should be considered in any child with cancer and rapid neurological decline.

 

Answer for Toxic/Metabolic Monday case on 7/16/18: Opiate Overdose.  There is marked involvement of the cerebellum that produces effacement of the fourth ventricle and hydrocephalus within 24 hours.  Important to get short term follow up imaging in children with cerebellitis from opiate toxicity.

Answer for Metabolic Monday case on 7/9/18: Glutaric Aciduria Type I, a mitochondrial disorder.