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Neuro Block 1 - KJ > Cerebral Edema > Flashcards

Cerebral Edema Flashcards

1
Q

What things can make the brain swell?

A

Edema, Extra CSF and tumors - It doesn’t take much increase in pressure to cause symptoms in patients

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2
Q

What are the two kinds of edema?

A
  1. Vasogenic

2. Cytotoxic

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3
Q

What is vasogenic cerebral edema?

A

It is caused by increased vascular permeability. Fluid shifts into intercellular spaces in brain. It can be localized (tumor, access) or generalized (hypoxia, insult to brain)

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4
Q

What is cytotoxic cerebral edema?

A

It is caused by cell membrane injury. It is seen in hypoxia or with metabolic damage to cells. It involves increased intracellular fluid.

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5
Q

What happens with vasogenic edema?

A

Something happens that damages or changes the permeability of the vessels and this causes fluid to leak out (more space between cells)

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6
Q

What happens in cytotoxic edema?

A

There is no damage to intracellular junctions, but there is something missing up the transport to from the cells (metabolic, etc.) Endothelial cells look swollen.

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7
Q

What can cause unilateral cerebral edema?

A

Brain tumor

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8
Q

How do you treat cytotoxic cerebral edema?

A

Can’t. Resistant to any known medical treatment.

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9
Q

How do you treat vasogenic cerebral edema?

A
  • Vasogenic responds to steroids and osmotherapy (mannitol). It is usually not very responsive to diuretics or carbonic anhydrase inhibitors (agents that suppress cerebrospinal fluid production).
    1. Steroids
    2. Mannitol
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10
Q

How do steroids help vasogenic edema?

A

Steroids (dexamethasone) reduces water permeability of tight junctions.

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11
Q

How does mannitol help vasogenic edema?

A
  • Osmotic diuretic
  • 1-2 g/kg, typically lasts 4-6 hours
  • Small sugar that doesn’t cross BBB
  • So number of particles in blood > number of particles in cells or CSF
  • Osmotic force pulls water across membranes
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12
Q

How else do steroids function?

A
  • They reduce WBC numbers and keep them away from inflammation sites.
  • They are transcriptional regulators that turn proteins on and off.
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13
Q

What is Hydrocephalus?

A

It is the accumulation of excessive CSF within the ventricular system.

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14
Q

What happens if hydrocephalus happens in infancy vs. adulthood?

A

Infancy - sutures will enlarge and head enlarges

Adult - Ventricles expand, crushing brain and increasing cranial pressure

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15
Q

What are the 5 kinds of hydrocephalus?

A
  • Communicating
  • Non-communicating
  • Ex vacuo
  • Increased CSF production
  • Normal pressure
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16
Q

What are two other ways to get a hydrocephalus?

A
  1. Blocked ventricle pathway (ex: tumor)
  2. Blocking CSF exit through arachnoid granulations - can occur after bad meningitis heals and the tissue thickens/blocks pathway
17
Q

What is a noncommunicating hydrocephalus?

A
  • Block in ventricular system
  • Only part of the ventricular system is enlarged
  • Causes:
  • -Congenital malformation
  • -Tumor
  • -Abscess
  • -Hematoma
18
Q

What is a communicating hydrocephalus?

A
  • Block in subarachnoid space
  • Entire ventricular system is enlarged
  • Causes:
  • -Resolving meningitis
  • -Subarachnoid hemorrhage
  • -Dural sinus thrombosis (blood clot)
19
Q

What is hydrocephalus Ex Vacuo?

A
  • No block in ventricular system
  • Ventricular system is dilated due to brain atrophy (with compensatory increase in CSF volume)
  • Causes:
  • -Alzheimer’s disease
  • -Pick disease
  • Brain itself shrinks
20
Q

What is Hydrocephalus due to increased CSF?

A
  • An uncommon type

- Cause: choroid plexus papilloma

21
Q

What is normal pressure hydrocephalus?

A

-Elderly patient with
–Gait disturbance (slow, unsteady, wide-based)
–Unrinary incontinence
–Dementia
-Large ventricles, no cortical atrophy
-Maybe a form of communicating hydrocephalus
-Symptoms may be reversible!
Theory: Something happened that initially blocked the flow of CSF through the ventricles - then, as ventricles enlarged the pressure normalized on its own
-Often misdiagnosed as alzheimer’s disease

22
Q

How do you treat hydrocephalus?

A
  • Reduce fluid volume and pressure
  • Get fluid out:
  • -Surgery to remove tumor or blockage
  • -Shunt to redirect CSF drainage
  • Decrease CSF production using drugs:
  • -Acetazolamide
  • -Furosemide
23
Q

What does Acetazolamide do?

A

It’s a carbonic anhydrase inhibitor. CA is a major enzyme at the blood-brain barrier that acts as a buffer in the blood.

24
Q

What does furosemide do?

A

It blocks NKCC pump (Na, K, 2Cl pump) and this will produce the driving osmotic force for CSF production.

25
Q

What causes increased intracranial pressure?

A

Mass effect (edema, tumor, hematoma)

  • Increased intracranial pressure compromises blood flow to brain
  • Symptoms: headache, papilledema (optic disc swelling), decreased level of consciousness
  • If severe, may lead to herniation
26
Q

What is herniation of the brain?

A
  • One part of the brain gets pushed into another compartment
  • Symptoms:
  • -Focal neurologic symptoms
  • -“Brainstem” symptoms (resp. and cardiac arrest, coma)
  • -Often fatal
27
Q

What can cause herniation?

A
  1. Unilateral space-occupying lesions
    - Tumor
    - Abscess
    - Hematoma
  2. Diffuse lesions
    - Edema
    - Encephalitis
    - Subarachnoid hemorrhage
28
Q 
Subfalcine herniation (upper)
Transtentorial herniation (mid)
Tonsillar herniation (near cerebellum)
A

Examples of Herniation

29
Q

What is subfalcine (cingulate) herniation?

A
  • Expansion of one hemisphere displaces cingulate gyrus under the fall.
  • Can cause compression of branches of anterior cerebral artery
  • . . .leading to weakness of limbs, aphasia, etc. . .
30
Q

Temporal lobe compressed against tentorium, affecting:

  • Third cranial nerve
  • -fixed, dilated pupil
  • -imparied ocular movements
  • Brainstem
  • -Duret hemorrhages
  • -Imparied consciousness
  • Posterior cerebral artery
  • -Ischemia in primary visual cortex
  • Contralateral cerebral peduncle
  • -Hemiparesis
A

Things that can happen during a Transtentorial (Uncinate) Herniation:

31
Q

What is tonsillar herniation?

A
  • Displacement of the cerebellar tonsils through the foramen magnum
  • Compresses medulla, compromising vital respiratory and cardiac centers
  • Life-threatening!

Neuro Block 1 - KJ (23 decks)

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