Abnormalities with CSF Flashcards
What is cerebral perfusion pressure?
Defined as mean arterial pressure - intracranial pressure
Determines blood flow into the brain
What are three ways increased ICP can damage the brain?
Brain tissue damage via compression
Blood flow can be compromised causing a stroke or compression hemorrhage
Brain can herniate
What is a subfalcine herniation?
Herniation into the interval between the falx cerebri and corpus callosum
Seldom causes specific symptoms
What is an uncal herniation?
Uncus of the temporal lobe is displaced through the tentorial notch
Compression of ipsilateral crus cerebri - contralateral motor weakness
Compression of contralateral crus - ipsilateral motor weakness
Decreased consciousness, ipsilateral pupillary dilation
What is pressure coning?
A cone of cerebellar tissue may descend into the foramen magnum, squeezing the medulla
Severely decreased consciousness, change in vitals (medulla)
What is the most common cause of subarachnoid hemorrhage?
Rupture of aneurysm - berry in CoW
May also occur from leakage of arteriovenous malformations or angiomas
What are the cardinal symptoms of subarachnoid hemorrhage?
Sudden onset of a severe headache
Stiff neck (nuchal rigidity)
Altered level of consciousness
How can a hemorrhage involving meninges/sinuses be caused in infants?
Breech, excessive molding of head
Tearing of bridging veins or rupture of a venous sinus
Shearing force that tears the attachments of the falx cerebri from the tentorium cerebelli
What indicates the presence of a basal fracture?
Leakage of CSF or bleeding from the auditory canal
Should always be viewed as a serious clinical sign
Why do fractures of the skull increase the risk of meningeal bleeding?
Meningeal vessels are also distributed to bone
Describe and epidural hematoma.
Dura is separated from the bone, causes a lens shaped hematoma
Can result in brain herniation
Can be followed by a period of normalcy, before a subsequent decompensation
Describe a subdural hemorrhage
Bleeding into the dubdural space between the dura and arachnoid membranes
Crescent-shaped hematoma
Most commonly occur from anterior-posterior displacement of the brain, more common in the elderly
What is a concussion?
transient disruption of brain funnction; can involve a temporary alteration of consciousness
referred to as a mil traumatic brain injury
produces damage in the white matter underlying the prefrontal cortex
What is chronic traumatic encephalopathy?
Caused by repeated head trauma or repeated TBIs
Charachterized by memory loss, paranoia, depression and ataxia
What are the two general types of hydrocephalus?
Non-communicating - obstructive
Communicating - non obstructive
Describe Non-communicating hydrocephalus
Fluid flow out of one or more of the ventricles is blocked
Occurs from blockage or stenosis anywhere in the system
Usually a complication of another disorder (brain tumor)
If possible, shunt from the lateral ventricle to the peritoneal cavity (under the skin)
What can cause aqueductal stenosis/hydrocephalus in infants?
IF their mothers were infected with mumps or rubella virus
What happens to the head in newborns with non-communicating hydrocephalus?
Head enlarges
Describe Communicating hydrocephalus.
CSF is freely communicating, but either too much CSF produced, or not enough removed
All ventricles will be enlarged and the head will swell enormously
In adults, associated with increased ICP and damage to the brain
Treatment - medications to reduce production or surgically destroying some of the choroid plexus
What is idiopathic intracranial hypertension (pseudotumor cerebri)?
Increased ICP with no apparent cause on imaging
Causes severe daily pulsatile headaches
Visual distrubances
What are the risk factors for IIH?
Females
Tetracycline antibiotics
Obesity
Vitamin A excess
Estrogen birth control
What is the treatment for IIH?
Initial: Lumbar Puncture, Drugs to reduce CSF production
Chronic: Lose weight
What is Normal Pressure hydrocephalus?
Communicating hydrocephalus without an associated increase in ICP
Occurs in elderly adults
Treatment is to place a shunt in ventricles
What are the three cardinal features of NPH?
Gait difficulty
Cognitive disturbance
Urinary incontinence
