Malformations

Question 1

What is the most common cause of neural tube defects?

Answer 1

Folate Deficiency

Question 2

Where is the most common location of a neural tube defect?

Answer 2

Lumbosacral Region

Question 3

What is the typical manifestation of spina bifida occulta?

Answer 3

• • Usually asymptomatic

- - Non-closure of vertebral arches, identified on X-ray

Question 4

What is the difference between Meningocele and Myelomeningocele?

Answer 4

Meningocele - lumbosacral protrusion with meninges and dura WITHOUT spinal cord involvement
Myelomeningocele - herniation of the spinal cord through the skin exposing it to the amniotic fluid – degrading and disorganizing neurons

Question 5

What are the clinical risk factors for Myelomeningocele?

Answer 5

– Folate Antagonists (Valproic Acid)

Question 6

What are the manifestations of Myelomeningocele?

Answer 6

• • Neuro deficits from the exposed area and down, including compromised control of sphincters.
• • Should be regularly catheterized to prevent infections
• • Seizure Disorder

Question 7

If an US exam of an unborn baby discovers a pedunculated protrusion in the occipital region, what might be it?

Answer 7

Encephalocele - cranial defect with protrusion of cerebrum/dura. Most commonly occipital, but can be anterior too.

Question 8

If Alpha-Feto Protein is discovered in the amniotic fluid, then what might be the defect occuring?

Answer 8

Neural Tube Defect

Anencephaly – defect of the calvarium

Question 9

If an infant is found to have Polymicrogyria, what might have occurred during pregnancy?

Answer 9

– Intrauterine Ischemia

Question 10

What are the two types of Polymicrogyria?

Answer 10

• • Focal – small area of increased gyri and folding in the creases
• • Diffuse – global throughout increased folds and gyri

Question 11

What is the most common cause of abnormal migration of cells in the CNS?

Answer 11

Deletion of LIS1 Gene

Question 12

If a patient is diagnosed with Miller-Dicker Syndrome, what might be the clinical manifestation?

Answer 12

• • Seizures
• • MR
• • Deletion of Lissencephy I gene
• • prominent forehead
• • bitemporal hallowing

Question 13

LIS1 Gene Deletion is most common associated with what?

Answer 13

• • Agyria

- - Pachygyria

Question 14

If MRI finds clefts within the cerebral hemispheres and the patient has marked MR, what might be the diagnosis?

Answer 14

– Schizencephaly

Question 15

If there is a mutation in the Sonic Hedge Hog gene, what might be a result?

Answer 15

– Arrhinencephaly – abnormal cleavage of the forebrain
Absence of Olfactory Bulbs
Holoprosencephaly

Question 16

In general terms, the more deformed the face, what does that mean?

Answer 16

The more deformed facial features, the more missing/abnormal internal things.

Question 17

What is Holoprosencephaly?

Answer 17

– Incomplete Seperation of the Lobes

Question 18

What are the three types of Holoprosencephaly?

Answer 18

• • Alobar – small brain and fused
• • Semi-lobar
• • Lobar – most normal, but still craniofacial abnormals

Question 19

If a patient has holoprosencephaly, what might you find clinically?

Answer 19

• • Olfactory Aplasia
• • Missing or deformed facial bones
• • Hydrocephalus
• • MR + Seizure disorders

Question 20

What generally is associated with Corpus Callosum agenesis?

Answer 20

• • Missing Singulate Gyri

- - Probst Bundles, fibers going back-front, instead of side to side to connect the hemispheres

Question 21

If a patient has not singulate gyri or corpus callosum, what might also be occuring?

Answer 21

– Migratory Defect

Question 22

If a female is born with corpus callosum agenesis with severe MR and intractible seizures, what might be cause?

Answer 22

Aicardi Syndrome – X-linked

Question 23

If a patient has an accidental finding of a cerebellar tonsillar herniation, what else might be present?

Answer 23

• • Syringomyelia, cyst in the spinal cord

- - loss of pain and temperature from those levels

Question 24

What is the different between Chiari Type 1 and Type 2?

Answer 24

Both have a cerebellar tonsillar herniation, but Type two also involves impingement of the medulla of brain stem, which is much more deadly.

Question 25

What might be present in Arnold-Chiari malformation?

Answer 25

• • Myelomeninocele
• • Vit A Deficiency
• • Lower Cranial Nerve Defects
• • Compromised automatic functions

Question 26

You notice a patient is missing his vermis of cerebellum, but still has both hemispheres, what do you diagnose him with?

Answer 26

Dandy Walker Malformation

Question 27

A transverse fluid filled cyst is found within the spinal cord – causing the patient to not have pain or temperature sensations from those levels, what is the etiology?

Answer 27

– Syringomyelia

Question 28

Cerebral Palsy is caused by?

Answer 28

• • Multi-ischemic insults occuring during the fetal / perinatal periods (strokes)
• • Nonprogressive neurologic defects

Question 29

If a premature infant is born and the lungs were not fully developed causing a period of hypoxia, what might the infant be at risk of?

Answer 29

Periventricular Leukomalacia

• • white matter necrosis from hypoxia
• • destroying of oligodendrocytes (myelinate axons)

Question 30

If a mother who is pregnant has history of asthma and has a very bad attack that requires her to be intubated due to prolonged hypoxia, what is here child at risk of?

Answer 30

Porencephaly – destruction of grey and white matter in the 3rd trimester due to extensive hypoxia
– Multicystic Encephalopathy

Question 31

What is the cause of a germinal matrix hemorrhage?

Answer 31

Typically a premature infant who undergoes significant stress during the birthing process has elevated blood pressure which causes hemorrhage in the caudate/thalamus region of the brain (due to not being fully developed yet)