Block 1 Unit 5 Neurological System Flashcards
What is the function of gray matter?
Receive, integrate, store and transmit information
What is the outmost layer of cell bodies of neurons within the cerebral cortex?
Grey matter
What is the inner most layer composed of myelinated nerve fibers calledaxons?
White matter
What is the function of white matter?
The framework and support of the neurologic system which provides support, protection, and nourishment to the neurons
What is the Blood Brain Barrier and it’s purpose?
A highly selective, semipermeable border of endothelial cells that maintain the delicate metabolic balance in the CNS.
It regulates the transport of nutrients, ions, water, and waste products through selective permeability
What is the Vestibulo-Ocular reflex test?
A test that stimulates the acoustic nerve by delivering cold water into the ear canal
What should happen during the Vestibulo-Ocular reflex test?
When cold water enters the ear and the inner ear hanged temperature, it should cause fast, side to side eye movement (nystagmus)
What is the Vestibulo-Ocular reflex testing for?
To see if there’s damage to the acoustic nerve
What is a abnormal Vestibulo-Ocular reflex test result?
No nystagmus, may point to acoustic nerve damage to the ears balance sensors and or brain damage
What causes pinpoint/ nonreactive pupils in patients?
Pontine lesion, or medication such as opiates
What causes midsize/ nonreactive pupils in patients?
Could be a midbrain lesion
What causes unilateral large >6mm and or a blown pupil and is nonreactive in patients?
Pressure on the theoculomotor nerve on the same side as the eye
What causes bilateral large/ nonreactive pupils in patients?
Brain stem lesion or herniation
What causes oval shape pupils in patients?
Increased ICP (18-35mmhg)
What causes irregular shaped pupils in patients?
Cataracts or trauma
What is a intracranial pressure monitor fiber optic bolt?
A bolt with a Fiber optic wire is placed in the brain to measure ICP.
Where can a intracranial pressure monitor fiber optic bolt be placed?
-subdural
-epidural
-intraparenchymal
-subarachnoid
What are the disadvantages of a intracranial pressure monitor fiber optic bolt?
-only measures pressure
- not ttherapeutic, unable to drain CSF
What are the advantages of a intracranial pressure monitor fiber optic bolt?
-no clotting or bubbles dampening waveform
-less infection risk
-only have to zero once
-less artifact
What is CPP?
Central perfusion pressure, a calculation of the approximate pressure on the cerebral blood flow in the brain
How is the CPP calculated?
MAP-ICP= CPP
Use to determine average pressure on the perfusion within the brain
What is a normal ICP?
5-15
What is associated with CPP < 50mmhg?
Impaired neuronal function
What is associated with CPP > 150mmhg?
Brain edema and HTN encephalopathy
What is it called when you have dripping of clear fluid from the nose with a patient with a basal skull fracture?
CSF rhinorrhea
What is it called when you have dripping of clear fluid from the ears with a patient with a basal skull fracture?
Otorrhea
What are the additional sx if specifically bacterial meningitis?
-Altered metal status
-Fever and malaise
Who’s most at risk for bacterial meningitis?
-Infants
-people living in a group setting
-lower immune response
-travelers going into countries that have it spreading
-individuals working with meningitis pathogens such as microbiologist
You have a pt who came into the ED with a Cheif complaint of being lethargic, nausea, vomiting, photophobia, HA, and neck stiffness. What could possibly be the Dx?
Meningitis
Who’s at great risk for fungal meningitis?
People with weakened immune systems
Who’s at great risk for viral meningitis?
Children <5 and those with weakened immune systems
What increase cerebral blood flow?
-Hypercapnia
-Hypoxemia
-Hyperthermia
What decreases cerebral blood flow?
-Hypocapnia
-Hyperoxemia
-Increased blood viscosity Hypothermia
-ICPHTN Vasopressors
-Cerebral vasospasm
What does AVPU stand for?
A-Alert
V-Verbal response
P-Pain response
U-Unresponsive
What does decorticate posturing indicates?
There is a lesion or brain injury in the cerebral cortex, thalamus, or midbrain
Describe a patient that has positive decorticate posturing ?
The arms are turned inwards
“towards the core”
Describe a patient that has positive decerebrate posturing ?
The arms are rotated outward,
“wings to heaven”
What does it mean if you have a pt with a positive decerebrate posturing ?
Lesion of the brainstem
What happens to the optic nerve sheath if you have increased ICP?
It expands
An ONSD >5mm is suggestive of what?
Elevated ICP
