Development Disorders

Question 1

What is a neurulation defect?

Answer 1

• The neural tube does not close during neurulation (the stage of embryogenesis that includes the formation and closure of the neural tube)

Question 2

What is a myeloschisis?

Answer 2

• Developmental anomaly characterized by a cleft spinal cord due to a failure of the neuroplate to form a complete tube

Question 3

What is the most common type of spina bifida?

Answer 3

• Spina bifida occulta

Question 4

What is spina bifida occulta?

Answer 4

• The neural arches fail to fuse dorsally

Question 5

Where does spinal bifida occulta typically occur on along the cord?

Answer 5

• Cadually

Question 6

What are the effects of spina bifida occulta?

Answer 6

• Cosmetic
• A dimple in the back of the bertebrae where the spinous process should be
• A tuff of hair

Question 7

What is a meningocele?

Answer 7

• Subarachnoid space bulges through unfused neural arches (mesodermal arch doesn’t completely close at all)

Question 8

What 2 protective layers of the the spinal cord bulge out in a meningocele?

Answer 8

• Dura and arachnoid

Question 9

How is the spinal cord affected in meningocele?

Answer 9

• The spinal cord remains in tact

Question 10

What is a meningomyelocele?

Answer 10

• Spinal cord and nerve root bulge through neural arches

Question 11

What is the difference between a meningocele, and a meningomyelocele?

Answer 11

• The spinal cord grows into the cyst

Question 12

What is the surgical procedure for a meningomyelocele?

Answer 12

• The cord may be pushed back into the vertebral column

Question 13

What is a syringomyelocele?

Answer 13

• The spinal cord bulges through the neural arches, and develops abnormally

Question 14

What is a myelocele?

Answer 14

• There is a gap in the neural arch, but there is no fluid filled cyst, so the cord is completely exposed to the environment.

Question 15

Which types of spina bifida are incompatible with life?

Answer 15

• Myelocele

- Syringomyelocele

Question 16

What is Arnold-Chiari syndrome?

Answer 16

• Congenital anomaly in which the cerebellum and medulla protrude down into the spinal cord through the foramen magnum

Question 17

What is anencephaly?

Answer 17

• The congenital absence of the cranial vault, with a failure of the cerebral hemispheres to develop as a result of a defect in the dvelopment of the rostral neural tube

Question 18

What is a meningoencephalocele?

Answer 18

• Protrusion of part of the cerebellum that is covered by meninges and skin

Question 19

How is a meningoencephalocele named?

Answer 19

By the partion of the skull through which it protrudes.

ex) Occipital, frontal, etc..

Question 20

What is a meningohydroencephalocele?

Answer 20

• Protrusion of part of the occipital lobe that contains a portion of the psoterior horn of a lateral ventricle