Basic Reactions, Edema, Herniation

Question 1

Excess CSF within the cranial cavity due to decreased outflow of CSF, resulting in enlargement of one or more ventricles; further classified as either communicating or noncommunicating depending on where obstruction is

Answer 1

Hydrocephalus

Question 2

_________ hydrocephalus is due to obstruction within ventricles (cerebral aqueduct)

_________ hydrocephalus is due to obstruction in Subarachnoid space or villi

Answer 2

Non-communicating

Communicating

Question 3

Ventriculomegaly that results secondarily from a loss of brain tissue (brain atrophy)

Answer 3

Hydrocephalus ex vacuo

Question 4

Common causes of Hydrocephalus

Answer 4

Aqueduct Stenosis (congenitally or acquired stenosis of cerebral aqueduct)

Dandy-Walker malformation (a hindbrain malformation causing cystic dilatation of 4th ventricle)

Chiari II malformation (a hindbrain malformation)

Post-Inflammatory/Hemorrhagic (blockage due to inflammatory cells or hemorrhage)

Tumors

Question 5

Barrier that controls the extracellular environment of the brain by regulating the movement of molecules from blood; keeps out infectious agents and may impede drug delivery to brain and CSF; lipid-soluble molecules are not restricted

Answer 5

Blood-Brain Barrier

Question 6

How can the breakdown of the BBB occur

Answer 6

Inflammation; Tumors; infarcts; Trauma

Question 7

Breakdown of the BBB results in inc. vascular permeability, leading to an increase in __________ detectable by lumbar puncture (LP)

Answer 7

CSF protein

Question 8

An increase of brain volume due to increased fluid (not ventricles); can be either extra/intracellular fluid; can be due to trauma, infarcts, tumors, infections, water intoxication, etc.; can result in MASS EFFECT

Answer 8

Brain Edema

Question 9

Type of Brain Edema; EXTRACELLULAR edema due to inc. permeability of brain capillaries (BBB breakdown); mainly in WHITE matter

Answer 9

Vasogenic brain edema

Question 10

Vasogenic edema is typically in the (white/gray) matter

Answer 10

White

Question 11

Type of Brain Edema; INTRACELLULAR edema due to osmotic imbalance between the cell and extracellular fluid; mainly in the GRAY matter

Answer 11

Cytotoxic brain edema

Question 12

Cytotoxic edema is typically in the (white/gray) matter

Answer 12

Gray

Question 13

Type of Brain Edema; EXTRACELLULAR edema in the periventricular WHITE matter

Answer 13

Interstitial (hydrocephalic) brain edema

Question 14

Hypothesis that states that the skull is a closed system. Therefore, the CSF, blood, and brain tissue inside of it must remain at a relatively constant volume. Any increase in volume of one component means that other components must be reduced in volume to not increase pressure.

Answer 14

Monro-Kellie hypothesis

Question 15

Cerebral Perfusion Pressure (CPP) can be measured by what formula?

Answer 15

Mean Arterial Pressure - Mean ICP

• As ICP increases, the CPP decreases (which can lead to brain ischemia)

Question 16

Finding on fundoscopy for increased ICP

Answer 16

Papilledema (swelling of optic disc)

Question 17

What can cause increased ICP

Answer 17

Masses (tumor, abscess, hematoma, etc.)
Hydrocephalus
Brain Edema (trauma, meningitis, encephalopathy, etc.)
Obstruction (of dural venous sinuses)
Idiopathic Intracranial HTN

Question 18

herniation caused by horizontal (left-to-right) midline shift; may compress the Anterior cerebral artery

Answer 18

Subfalcine herniation

Question 19

the movement of brain tissue from one intracranial compartment to another; herniation of either uncal (medial temporal lobe) or central (diencephalon) compresses the upper brainstem; may compress the Posterior cerebral artery

Answer 19

Transtentorial Herniation

Question 20

Brain herniation through the foramen magnum compressing the medulla

Answer 20

Tonsilar Herniation

Question 21

A dilated ipsilateral pupil and contralateral hemiplegia (paralysis of one side of body) can be due to a _______ herniation

Answer 21

uncal

Question 22

Stain that can show myelin sheaths surrounding individual axons

Answer 22

Luxol Fast Blue stain

Question 23

How can an intracranial mass result in brain ischemia and death

Answer 23

Intracranial mass –> Inc. ICP –> dec. CPP –> ischemia

Intracranial mass –> brain herniation –> brainstem compression –> death