Chapter 28: The CNS - Intro Flashcards
What is Vasogenic edema and is often seen following what?
- Increased EXTRAcellular fluid due to BBB disruption and increased vascular permeability
- Fluid shifts from INTRAvascular compartments to INTERcellular spaces
- Can be either localized (i.e., adjacent to neoplasms or inflammation) or generalied often follows ischemic injury
What is Cytotoxic edema and when is it seen?
- Increase in INTRAcellular fluid secondary to neuronal, glial, or endothelial cell membrane injury
- Generalized hypoxic/ischemic insult or w/ metabolic derangment
In practice, will oftens see elements of which type of edema(s)?
What morphological characteristics of the brain will be seen and this can lead to?
- Both vasogenic and cytotoxic edema
- Gyri flattened, sulci narrowed, and ventricles compressed —> Herniation!
What type of injury is associated with localized vs. generalized vasogenic edema?
- Localized: adjacent to inflammation or neoplasms
- Generazlied: follow ischemic injury
What is the most common cause of noncommunicating (obstructive) hydrocephalus in the neonate/infant?
Aqueductal stenosis

Enlargement of the entire ventricular system (“symmetric dilation”) due to accumulation of CSF not being properly absorbed at the dural sinus level is known as?
Communicating (“non-obstructive”) hydrocephalus
What 2 congenital conditions cause ventricular system obstruction?
1) Acqueductal stenosis
2) Dandy-Walker malformation
What is Hydrocephalus Ex-Vacuo?
Whom is it seen in?
What is the CSF pressure?
- Compensatory increase in ventricular volume secondary to loss of brain parenchyma
- Atrophy with increasing age, stroke or other injury, chronic neurodegenerative disease
- CSF pressure is NORMAL!!!

Herniation is displacement of brain tissue due to _____ or ______
Mass effect or Increased intracranial pressure
What is diffuse vs. focal mass effect that is associated with herniation?
- Diffuse: generalzied brain edema
- Focal: tumors, abscesses, or hemorrhages
Subfalcine herniation involves displacement of the _______ under the _______
Cingulate gyrus under the falx cerebri
A subfalcine herniation may lead to compression of the ________ artery leading to infarction
Anterior Cerebral artery (ACA)
What symptoms would result from Subfalcine herniation with compression of the ACA?
Contralateral lower extremity weakness
Transtentorial (uncinate, mesial temporal) herniation occurs when?
Which specific part and of which lobe?
MEDIAL aspect of the TEMPORAL lobe is compressed against the free margin of the tentorium

What are 3 possible consequences of progression of transtentorial herniations?
1) Compression of CN III —> pupillary dilation; eye is “down and out” (ipsilateral to lesion)
2) Compression of PCA —> ischemia of primary visual cortex
3) Large herniation may compress contralateral cerebral peduncle —> hemiparesis ipsilateral to side of herniation = Kernohan notch = “false localizing sign”
What are Duret hemorrhages and are a result of what?
- Progression of transtentorial herniation producing secondary hemorrhagic lesions in the midbrain and pon

- “Flame-shaped” lesions
Why is it crucial to exam the eyes of a patient you expect to be suffering from increased intracranial pressure?
Look for papilledema
What are congenital causes of hydrocephalus?
- Intrauterine infections (TORCH)
- Agenesis/atresia/stenosis
- Arnold chiari malformations
- Dandy walker syndrome
- Cranial defects: Achondroplasia and Craniostenosis
Which rare type of brain tumor leads to increased CSF production, thus causing increased ICP and hydrocephalus?
Choroid Plexus Papilloma/Carcinoma

What is the most common parasitic nervous system disease in the world and can lead to hydrocephalus?
- Cysticercosis
- Taenia Solium (pork tapeworm)

What are the characteristic of normal pressure hydrocephalus and who is it seen in?
- Symmetric type usually occuring in adults >60
- Develops slowly over time; drainage of CSF is blocked gradually
- Enlarged ventricles still exert pressure on brain and can become symptomatic w/ pt’s exhibiting dementia-like manifestatons
- Dementia may be similar to Alzheimers and gait abnormalities may suggest Parkinson disease
- NPH is often misdiagnoses as one of these diseases
What is the classic triad of clinical findings exhibited by patients with normal pressure hydrocephalus?
- “Wet, wacky, and wobbly”
- Often exhibit a magnetic gait
- Dementia-like sx’s; impaired recognition (often not severe)
- Urinary incontinence; appears late in illness and is generally of the spastic hyperreflexic, increased-urgency type
A right hemisphere trans-tentorial herniation, causes a Kernohan’s notch in the _____ cerebellar peduncle, which results in ________ motor impairment.
A right hemisphere trans-tentorial herniation, causes a Kernohan’s notch in the left cerebellar peduncle, which results in right-sided motor impairment.
What is a tonsillar herniation and why is it life threatening?
- Displacement of the cerebellar tonsils through the foramen magnum
- Can can brainstem compression and compromises vital respiratory and cardiac centers in the medulla




