Cerebral Edema & Other Related Disorders

Front 1

Definition of cerebral edema

Back 1

Excess fluid in the brain.

Front 2

Definition of intracellular (cytotoxic) edema

Back 2

Excess fluid in the brain, where water moves into cells

Front 3

Pathogenesis of of intracellular (cytotoxic) edema.

Back 3

Causes include:
(1) Dysfunctional Na+/K+ ATPase Pump
(2) Hyponatremia causing osmotic shift.

Front 4

Examples of intracellular (cytotoxic) edema

Back 4

(1) Generalized Hypoxic Injury (Dysfunctional Na+/K+ ATPase Pump)
(2) Inappropriate ADH syndrome (Hyponatremia causing osmotic shift.)

Front 5

Definition of Extracellular (vasogenic) edema

Back 5

Excess fluid in the brain due to increased vessel permeability

Front 6

Pathogenesis (cause) of extracellular (vasogenic) edema

Back 6

1. Acute inflammation
2. Metastasis,
3. trauma,
4. lead poisoning,
5. Respiratory acidosis, &
6. hypoxemia

Front 7

What do respiratory acidosis & hypoxemia do to cerebral edema?

Back 7

Increase vessel permeability thereby enhancing cerebral edema and causing damage to tight junctions of endothelial cells

Front 8

What is the purpose of hyperventilating patients with head trauma?

Back 8

A patient with head trauma is purposedly hyperventilated to produce respiratory alkalosis, which causes cerebral vessel constriction. This decreases the risk of increased vessel permeability and cerebral edema. Respiratory acidosis and hypoxemia cause vasodilation of cerebral vessels and damage to tight junctions of endothelial cells, which increases cerebral vessel permeability resulting in cerebral edema.

Front 9

What are the signs of increased intracranial pressure (intracranial hypertension)?

Back 9

1. Papilledema
2. Headache &
3. projectile vomiting without nausea.
4. Sinus bradycardia &
5. hypertension

Front 10

What is a consequence of increased intracranial pressure (intracranial hypertension?

Back 10

A potential consequence of increased intracranial pressure (intracranial hypertension) is cerebral herniation.

Front 11

What is papilledema?

Back 11

Swelling of the optic disk.

Front 12

What is the significance of observing papilledema in a patient?

Back 12

It is a sign of cerebral edema

Front 13

Definition of pseudotumor cerebi.

Back 13

Benign intracranial hypertension with the absence of tumor or obstruction to cerebrospinal fluid (CSF) flow.

Front 14

What is the pathogenesis of pseudotumor cerebri?

Back 14

Pathogenesis of pseudotumor cerebri is
(1) Decreased CSF absorption
(2) Other causes such as vitamin A toxicity (treatment of acne with isoretanonic acid or Eskimos eating polar bear liver) or tetracycline

Front 15

What is the epidemiology of pseudotumor cerebri?

Back 15

Pseudotumor cerebri commonly occurs in young obese females.

Front 16

What are the clinical findings of pseudotumor cerebri?

Back 16

The signs of increased intracranial pressure which are:
1. Papilledema
2. Headache and projectile vomiting without nausea.
3. Sinus bradycardia & hypertension

Front 17

What is the pathogenesis (cause) of cerebral herniation?

Back 17

It is a complication of increased intracranial pressure where portions of the brain become displaced through either openings of dural partitions or openings of the skull.

Front 18

Definition of subfalcine herniation.

Back 18

In subfalcine herniation, the cingulate gyrus herniates under the falx cerebri.

Front 19

What vessel is compressed by a subfalcine herniation?

Back 19

The anterior cerebral artery (ACA) is compressed by a subfalcine herniation.

Front 20

Definition of uncal herniation.

Back 20

Uncal herniation is where the medial portion of the temporal lobe herniates through the tentorium cerebelli.

Front 21

Clinical findings associated with uncal herniation.

Back 21

-eye deviated down & out
-pupil is mydriatic (dilated)
-ptosis of eyelid
-Hemorrhagic infarction of the occipital lobe.
-contralateral hemianopia with macular sparing.

Front 22

Complications from a uncal herniation include

Back 22

1. Compression of the midbrain -results in Duret's hemorrhages
2. Compression of the oculomotor nerve (CN III).
a. Eye deviated down & out
b. Pupil is mydriatic (dilated)
- Compression of parasympathetic postganglionic fibers.
c. Ptosis of eyelid due to weakening of levator palpebri innervated by CN III.
3. Compression of posterior cerebral artery
a. causes hemorhagic infarction of occipital lobe
b. Damage of visual cortex produces contralateral hemianopia with macular sparing.

Front 23

What should you associate with uncal herniation?

Back 23

-Midbrain hemorrhage
-oculomotor palsy
-mydriasis

Front 24

Definition of tonsillar herniation.

Back 24

Cerebellar tonsils herniate into the foramen magnum.

Front 25

Gross findings in tonsillar herniation

Back 25

-"Coning" of the cerebellar tonsils
-Cardiorespiratory Arrest.