NS76: Central Nervous System Malformations and Perinatal Brain Injury

  1. How much does the brain weigh?
    @ 5 months
    @ 9 months
    @ 20 years
    • 50 g
    • 500 g
    • 1500 g
    • Image Upload 2
  2. When does the cerebellum develop?
    • in the first 2 years of life, very small for infants
    • Image Upload 4
  3. What are three primary neural tube closure defects?
    • Anencephaly
    • craniorachischisis
    • Myelomeningocele
  4. What are 3 primary axialmesodermal defects?
    • encephalocele (herniation of neural tissue)
    • Meningocele (herniation of neural tissue)
    • Split cord (closed defect)
  5. What are 3 tail bud defects?
    • spina bifida occulta
    • split cord (low)
    • hydromyelia
  6. Anencephaly
    time period
    risk factors
    • Definition/Characteristics: failure of closure of the anterior neural tube which causes area cerebrovasculosa which is frog-like facies, underdeveloped hypothalamus, and adrenal cortical hyperplasia
    • Time period: 28 days of gestation
    • Indicators: high alpha-fetoprotein in amniotic fluid and maternal blood
    • Risk Factors: low folate in diet
  7. Occipital Encephalocele
    • Characteristics: Malformed brain tissue extending through a defect in the cranium (occipital and/or posterior fossa)
    • "Brain in a Bag"
  8. Spina Bifida
    • Spina Bifida Occulta: missing part of vertebral arch and accompanied with a tuft of hair
    • Meningocele: the leptomeniges extends out but not the spinal cord
    • Myelomenigocele: spinal cord extends out, can be open (more common) or closed, and usually associated with Chiari malformation and hydrocephalus, lumbar level most common
  9. Chiari II Malformation
    • Cerebellar tonsillar herniation
    • small posterior fossa
    • extension of medulla below foramen magnum
    • kinking of medulla
    • Hydrocephalus is associated with it due to stenosis/atresia of the cerebral aqueduct
    • Myelomeningoceles are associated with it
    • Beaked collicular plate
  10. Dandy-Walker Malformation
    • Agenesis of cerebellar vermis causing cystic dilation of 4th ventricle and enlargement of posterior fossa
    • Have arrestment of cerebellar development prior to 3rd month of gestation
  11. Holoprosencephaly
    • Characterized by failure of cerebral hemispheres to separate, cyclopia, proboscis, agnathia (jaw development problems), cleft lip/palate
    • Caused by defects in SHG (Sonic Hedgehog Gene) syndromic or trisomsy 13 non-syndromic
    • Classifications: Alobar, Semilobar, Lobar, Arrhinencephaly
  12. Agenesis of Corpus Callosum
    • Characterized by:
    • abnormal cingulate gyrus with radiating gyral pattern
    • Bat wing shaped lateral ventricles
    • Bundle of Probst
    • Can be clinically silent
    • Categories include:
    • Total or partial: Partial usually affects posterior splenium
    • Sporadic or syndromic: Aicardi (infantile spasms, polymicrogyria) Andermann (sensorimotor neuropathy, dysmorphic features), Meckel-Gruber (occipital encephalocele, liver/kidney abnormalities)
  13. Cavum Septi Pellucidi
    • Unfused leaflets of septum pellucidum
    • recall septum pellucidum is first grey matter
    • increased incidence in boxers (cause or effect though?)
  14. Cortical Dysplasia: Polymicrogyria
    • Multiple small cerebral gyri
    • fusion of molecular layer
    • four or fewer cortical layers
  15. Cortical Dysplasia: Lissencephaly
    • Smooth brain surface with fe cerebral gyri (Aguria or pachygyria)
    • Miller-Dieker syndrome due to LIS1 gene deletion
    • caused by contiguous gene deletion
  16. Hydranencephaly
    • Intrauterine bilateral coratid artery region infarct after 20 weeks gestation
    • Resorption of infarcted brain; replacement by fluid filled sac
    • Head Transilluminates (remember North Dakota story)
  17. Kernicterus
    Clinical Symptoms
    • Characterized by deposition (gross yellow staining) in BG, thalamus, hippocampus, inferior olivary nuclei, subthalamic nuclei, dentate nuclei, and most cranial nerve nuclei producing neuronal death and reactive glial scarring
    • Caused by bilirubin deposition due to passsage of unconjugated bilirubin through immature BBB compromised by hypoxia and acidosis
    • Clinical Symptoms: if survived then deafness and choreoathetoid cerebral palsy
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NS76: Central Nervous System Malformations and Perinatal Brain Injury
Neuroscience Week 7