Developmental Disorders

Question 1

neurulation defects

Answer 1

the stage of embryogenesis that includes the formation and closure of the neural tube

at birth, NS stops growing. As you grow in size, the NS doesn’t keep growing

Question 2

Myeloschisis

Answer 2

a developmental anomaly characterized by a cleft spinal cord, owing to failure of the neuroplate to form a complete tube

spina bifida
meningocele
meningomyelocele
syringomyelocele
myelocele
arnold-chiari syndrome
anencephaly

Question 3

spina bifida occulta

Answer 3

failure of the neural arches of the vertebrae to fuse dorsally

Question 4

meningocele

Answer 4

subarachnoid space bulges through unfused neural arches (dura and arachnoid layer bulge out)

hole in posterior aspect of vertebrae- the only thing passing through is a cyst made of dura and arachnoid matter, filled with fluid

can be surgically removed

consists of a protrusion of the cranial meninges that is filled with CSF

Question 5

Meningomyelocele

Answer 5

spinal cord and nerve root bulge through arches

meningeal layers and caudal cord are in cyst

cord is completely developed by grows into the cyst

can sometimes be surgically repaired

Question 6

syringomyelocele

Answer 6

dorsal half of SC bulges out

spinal cord is not correctly formed and the neural tube doesn’t close; everything dorsal to the lumen is in the cyst (spinal cord is split in half)

**incompatible with life

Question 7

myelocele

Answer 7

entire cord bulges out
spinal cord is completely developed

**incompatible with life

Question 8

Arnold-Chiari syndrome

Answer 8

congenital anomaly in which the cerebellum and medulla protrude down into the SC through the foramen magnum

*can have different levels of this: some are functional, some are not

Question 9

Anencephaly

Answer 9

congenital absence of the cranial fault with failure of the cerebral hemispheres to develop as a result of a defect in the development of the rostral neural tube

person never develops a cerebrum

*incompatible with life

Question 10

meningocephalocele

Answer 10

consists of a protrusion of part of the cerebellum that is covered by meninges and skin

Question 11

meningohydroencephalocele

Answer 11

consists of a protrusion of part of the occipital lobe that contains part of the posterior horn of a lateral ventricle