CNS Pathology

Question 0

Dandy Walker malformation.

Answer 0

Enlarged posterior fossa
Absent or rudimentary cerebellar vermis
Greatly dilated 4th ventricle represented as a cyst-like structure
Bulging of occipital bone

Question 1

Types of cerebral edema.

Answer 1

Vasogenic: increased vascular permeability

• BBB disruption
• localized or generalized

Cytotoxic: increased intracellular fluid

• generalized insults (hypoxia)
• neuronal, glial, or endothelial cell

Question 2

What is Arnold Chiari type II often associated with?

Answer 2

Hydrocephalus (90%)

Myelomeningocele

Question 3

What is lost and what is spared in syringomyeloma?

Answer 3

Lost: thermal and painful sensation
Spared: tactile, joint position, and vibration

Question 4

Mutations of tuberous sclerosis complex.

Answer 4

TSC1 encodes hamartin
TSC2 encodes tuberin
Both proteins bind forming a complex that blocks the kinase mTOR leading to negative control do cell proliferation and high protein synthesis (voluminous cytoplasm)

Question 5

Features of tuberous sclerosis complex including typical triad presentation.

Answer 5

Major:
-facial angiofinromas, hypomelanotic macules, shagreen patch, hamartomas, cardiac rhabdmyomas & multiple retinal nodular hamartomas

Minor: pits in enamel and hamartomatous rectal polyps

Triad: angiofibromas, epilepsy,a me developmental delay

Question 6

Genetics and immunology of multiple sclerosis.

Answer 6

HLA-DR2
Single nucleotide polymorphisms in IL2 and IL7 receptors
CD4+ TH1 activate macrophages
TH17 activate leukocytes causing demyelination
-reactive against self myelin antigens

Question 7

Morphology of MS.

Answer 7

Acute plaque:

• macrophages contain PAS and debris
• perivascular cuffing
• depletion of oligodentrocytes

Inactive plaque:

• little to no myelin left
• gliosis

Shadow plaque:
-border of normal and affected white matter is not sharply delineated

Question 8

Clinical features of MS.

Answer 8

Bladder dysfunction
Ataxia
IgG in CSF
Weakness, spasticity 
Visual disturbances
Pins and needles, numbness, pain

Question 9

Amyotrophic lateral sclerosis (ALS).

Answer 9

Muscle atrophy
Mutation in SOD1 which encodes copper zinc superoxide (adverse gain of function - misfolded)
Reduced capacity to detoxify free radicals
UMN and LMN defects
No oculomotor defects
Fasiculations
Spasticity of arms and legs