CNS Pathoma

Question 1

What vitamin is necessary to prevent neural tube defects?

Answer 1

Folate, levels must be high enough prior to coneception

Question 2

What is a common characteristic seen during pregnancy due to anencephaly?

Answer 2

polyhydramnios

Question 3

What is the most common cause of hydrocephalus in newborns?

Answer 3

cerebral aqueduct stenosis

Question 4

What clinical finding is seen in children with cerebral aqueduct stenosis?

Answer 4

enlarging head cirumference due to dilation of the ventricles

Question 5

What is degenerated in syringlomyelia?

Answer 5

C8-T1 degeneration of the anterior white commissure, sometimes with involvement of the anterior horns

Question 6

What sxs are seen in syringomyelia?

Answer 6

loss of pain and temp in upper extremities, sensation intact. If involves anterior horn, then LMN signs.

Question 7

What sxs will present if syringomyelia spreads to invole the lateral horn?

Answer 7

Horner syndrome, loss of hypothalamospinal tract which carries sympathetics to the face

Question 8

Poliomyelitis spreads to CNS via what manner?

Answer 8

spreads through the blood

Question 9

What is damaged in poliomyelitis? sxs?

Answer 9

anterior motor horn– LMN signs (flaccid paralysis, myscle atrophy, fasiculations, weakness with dec muscle tone, impaired reflexes, negative babinski downward toes)

Question 10

What is Wednig-Hoffman Disease?

Answer 10

inherited degeneration of anterior motor horn, presents as a “floppy baby”, death in a few years

Question 11

What gives rise to the LMN lesions in ALS?

Answer 11

degernation of anterio motor horn

Question 12

What gives rise to UMN lesions in ALS?

Answer 12

degeneration of lateral corticospinal tract

Question 13

How can you differentatie between syringomyelia and ALS?

Answer 13

ALS is only motor loss, sensation intact. Syringomyelia is loss of sensation (pain and temp)

Question 14

What mutated enzyme can lead to ALS?

Answer 14

zinc-copper superoxide dismutase mutation– leads to free radical injury in neurons.

Question 15

What is the frataxin gene in friedreich ataxia involved in?

Answer 15

mitochondrial iron regulation–loss or mutation of this gene results in iron buildup and free radical damage (fenton reaction)

Question 16

What heart condition is associated with Friedrich’s Ataxia?

Answer 16

hypertrophic cardiomyopathy

Question 17

How does N. meningitidis spread to the brain?

Answer 17

enters through the nasopharynx and enters the blood to access the meninges

Question 18

Where do you place the needle for a lumbar puncture?

Answer 18

@ L4-L5 (level of iliac crest). Spinal cord ends at L2, but subarachnoid space and cauda equina continue to S2

Question 19

What layers are transversed during a lumbar puncture?

Answer 19

skin, ligaments, epidural space, dura and arachnoid. Do not pierce the pia!

Question 20

What two major classes of cerebrovascular disease exist?

Answer 20

Can be ischemic or hemorrhagic.

Question 21

What two classes of ischemic cerebrovascular disease exist?

Answer 21

Focal and global

Question 22

What are the common causes of global cerebral ischemia?

Answer 22

Low perfusion (atherosclerosis), acute decrease in blood flow (cardiogenic shock), chronic hypoxia (anemia), and repeated episodes of hypoglycemia (insulinoma)

Question 23

What areas of the brain are most suspetible to moderate global ischemia?

Answer 23

Watershed areas, pyramidal neurons (layers 3, 5, 6) and purkinje layer of the cerebellum

Question 24

What type of necrosis can damage to the purkinje layers lead to?

Answer 24

laminar necrosis, creates a line of necrosis

Question 25

Definition of transient ischemic attack?

Answer 25

if symptoms of stoke last less than 24 hours

Question 26

What causes a thombotic stroke?

Answer 26

Atherosclerosis, which usually develops at branching points (MCA and internal carotid bifurcation in circle of wilils)

Question 27

What does a thrombotic stroke look like?

Answer 27

pale infarct in the periphery of the cortex

Question 28

What causes an embolic stroke?

Answer 28

a fib, clot from left heart that lodges in the MCA

Question 29

What will an embolic stroke look like grossly?

Answer 29

**hemorrhagic infarct** (thrombus lysed allowing reperfusion of the cortex)

Question 30

What causes a lacunar stroke?

Answer 30

**hyaline arteriolosclerosis**-- due to benign HTN, diabetes. Infarction of **lenticulostriate** **vessels** resulting in small cystic areas of the brain

Question 31

What causes a pure motor stroke?

Answer 31

infarction of internal capsule

Question 32

What causes a pure sensory stroke?

Answer 32

infarction of the thalamus

Question 33

What is the first sign of liquefactive necrosis in the brain

Answer 33

Red neurons, see at 12 hours

Question 34

What is the end result of a lacunar stroke after healing?

Answer 34

fluid filled cystic space that is surrounded by gliosis

Question 35

What is a common cause of a intracerebral hemorrhage?

Answer 35

Charcot-Bouchard microaneurysm of lenticulostriate vessels due to hypertention and hyaline arteriolosclerosis which weaksens the vessel wall

Question 36

What is the most common site of a intracerebral hemorrhage?

Answer 36

basal ganglia

Question 37

Why is the lumbar puncture yellow in subarachnoid hemorrhage?

Answer 37

xanthochromia--yellow hue due to bilirubin breakdown

Question 38

Where will a berry aneurysm most likely occur?

Answer 38

branch points of ACA in circle of willis, due to the **lack of a media layer at branching points**

Question 39

What is a complication of tonsillar herniation?

Answer 39

cardiopulmonary arrest--cerebellar tonsils into the foramen magnum

Question 40

Complication of uncal herniation?

Answer 40

Compress CNIII (down and out eye), compress PCA (contralateral homonymous hemianopsia), rupture of paramedian artery (brainstem hemorrhage)

Question 41

What causes progressive multifocal leukoencepharlopathy?

Answer 41

JC Virus of oligodendrocytes, in immunosuppressed patients

Question 42

What brain matter is affected in MS?

Answer 42

autoimmune destruction of myelin and oligodendrocytes.

Question 43

What eye issue is commonly associated with MS?

Answer 43

internuclear ophthalmoplegia- damage to the MLF

Question 44

What gene is associated with increased risk and decreased risk of Alzheimer's disease?

Answer 44

increased risk- ApoE4 decreased risk- ApoE2 (4\>2=inc risk in 4)

Question 45

What gene is associated with early onset alzheimers?

Answer 45

presenilin 1

Question 46

On what chromosome is APP located on, and what population is at increased risk for developing Alzheimer's because of this?

Answer 46

Chr 21-- Downs

Question 47

What is cerebral amyloid angiopathy?

Answer 47

Amyloid can also deposit around the vessels increasing the risk of hemorrhage

Question 48

What are neurofibrillary tangles made of?

Answer 48

hyperphosphorylated tau--Alzheimers

Question 49

What neurotransmitter is dec in Alzheimers and where is it normally located?

Answer 49

loss of ACh from the nucleus of meynert

Question 50

What are the histological findings of Alzheimers?

Answer 50

neurofibrillary tangles (tau) and neuritic plaques (extracellular AB amyloid with entangled neuritic processes)

Question 51

What part of the brain is affected by Pick's disease?

Answer 51

frontal and temporal lobe

Question 52

What is the histological finding in Pick's disease?

Answer 52

Pick bodies--round saggregates of tau protine in neurons of the cortex

Question 53

What disease is due to a loss of dopaminergic neurons in substantia nigra of basal ganglia?

Answer 53

Parkinson Disease

Question 54

What drug contaminant has been linked to Parkinson Disease?

Answer 54

MPTP contaiminant in illicit drugs

Question 55

What are the hisotlogical findings of Parkinson Disease?

Answer 55

eosinophilic inclusion of **alpha-synuclein Lewy bodies** found in the substantia nigra

Question 56

What disease is associated with degeneration of GABAergic neurons in the caudate nucleus?

Answer 56

Huntington Disease

Question 57

When are the extra trinucleotide repeats gained in Huntington Disease?

Answer 57

during spermatogenesis, leads to anticipation