Edema, Hydrocephalus and Increased Intracranial Pressure

Question 1

Cerebral edema: vasogenic or cytotoxic

Treatment

Answer 1

Increased vascular permeability
Rye’s syndrome, vessels around tumor
Fluid shifts into intercellular spaces in brain
Localized or generalized

OR

Cell membrane injury
Increased intracellular fluid
Typically seen in hypoxia or with metabolic damage

Mannitol

Question 2

Types of hydrocephalus: Communicating, non-communicating, Hydrocephalus Ex Vacuo, Hydrocephalus Due to Increased CSF, or Normal Pressure Hydrocephalus

Answer 2

Non-communicating Hydrocephalus -
Block in ventricular system
Only part of the ventricular system is enlarged
Causes: Congenital malformation, Neoplasms, Inflammatory processes (abscess), Hemorrhage.

Communicating Hydrocephalus -
Block in subarachnoid space
Entire ventricular system is enlarged
Causes: Resolving meningitis, Subarachnoid hemorrhage, Dural sinus thrombosis

Hydrocephalus Ex Vacuo -
No block in ventricular system
Ventricular system is dilated due to brain atrophy (with compensatory increase in CSF volume)
Causes: Alzheimer disease, Pick disease, Massive hypoxic episode

Hydrocephalus Due to Increased CSF -
An uncommon type of hydrocephalus
Cause: choroid plexus papilloma

Normal Pressure Hydrocephalus
Elderly patient with: Gait disturbance (slow, unsteady, wide-based) Urinary incontinence, Dementia, Large ventricles.
No cortical atrophy
Maybe a form of communicating hydrocephalus
Symptoms may be reversible!

Question 3

High CSF treatment

Answer 3

Mannitol
Shunt to reabsorb CSF
Carbonic anhydrase inhibitor, acetazolamide (Diamox)
Furosemide (Na, K 2 Cl pump inhibitor)

Question 4

Subfalcine (Cingulate) Herniation

Answer 4

Expansion of one hemisphere displaces cingulate gyrus under the falx.
Can cause compression of branches of anterior cerebral artery
…leading to weakness of limbs, aphasia, etc.

Question 5

Transtentorial (Uncinate) Herniation

Answer 5

Temporal lobe compressed against tentorium, affecting:
Third cranial nerve
Fixed, dilated pupil – part of the brain is herniating, one pupil will be dilated
Impaired ocular movement
Posterior cerebral artery
Ischemia in primary visual cortex
Brainstem
Duret hemorrhages – pinpoint hemorrhages
Impaired consciousness
Contralateral cerebral peduncle
Hemiparesis

Question 6

Tonsillar Herniation

Answer 6

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