Block 1 Edema- Hydrocephalous Flashcards
What is the treatment of Vasogenic edema?
Steroids and osmotherapy
Steroids like dexamethasone reduce the water permeability of tight junctions
Mannitol
- an osmotic diuretic, last 4-6 hours
- small sugar that doesn’t cross the BBB so increases particles in the blood
What are the two types of cerebral edema?
Vasogenic - caused by increased vascular permeability, fluids shift to intracrllular spaces in the brain, localized or general
Cytotoxic - caused by cell membrane injury, increased intracellular fluid, seen in hypoxia or metabolic damage
What is mannitol?
A osmotic diuretic
Small sugar that doesn’t cross the BBB
What is hydrocephalus?
Accumulation of CSF in the ventricles
Head enlarges if during infancy
What is communicating hydrocephalus?
Block in the subarachnoid space
Entire ventricular system is enlarged
Caused by: meningitis, subarachnoid hemmorhage, dural sinus thrombosis
What is noncommunicating hydrocephalus?
Block in ventricular system, only one ventricle is blocked
Caused by: congenital malformation, tumor, abscess, hematoma
What is hydrocephalus Ex Vacuo?
No block in ventricular system
Ventricular system is dilated due to brain atrophy
Caused by: Alzheimer’s and pick disease
Is hydrocephalus due to increased CSF common?
Nope
But caused by choroid plexus papilloma
What is normal pressure hydrocephalus?
Large ventricles, no atrophy.
May be a form of communicating hydrocephalus
May be reversible
In elderly Px
Gait disturbance, urinary incintinence, dementia
Often misdiagnosed as Alzheimer’s
What is the treatment of hydrocephalus?
Get fluid out by surgery or shunt
Decrease production with
Acetazolamide (carbonic acid Inhibitor)
Furosemide (Na, K, 2Cl pump inhibitor)
What are symptoms of brain herniation?
Focal neurological problems
Brainstem symptoms
Often fatal
Increase cranial pressure
What are causes of herniation?
Tumor, abscess, hematoma
Diffuse lesions: edema, encephalitis, subarachnoid hemmorhage.
What is a subfalcine (cingulate) herniation?
Expansion of one hemisphere displaces cingulate gyrus under the falx.
Can compress branches of anterior cerebral artery leads to weakness of limbs, aphasia
What is a transtentorial (uncinate) herniation?
Temporal lobe compression (herniation) against Tentorium/brainstem.
Get CN III compression (dilated pupil, decreased eye movements)
Ischemia in visual cortex
Get duret hemmorhages
Impaired consciousness
What is a tonsillar herniation?
Displacement of the cerebellar tonsils through the foramen magnum
Compress medulla, compressing vital respiratory and cardiac centers
Life-threatening!
