Flashcards in Neuro Deck (59)
Describe the relationship between CBF and PaCO2
Low CO2 means decreased CBF (In fact, they are directly proportional!) So 1 mmHg less of CO2 means a 1-2 decrease in CBF
What is the structure in the carotid artery that contains baroreceptors? What happens when it is stretched? what surgery might you see this in? What contains chemoreceptors?
1. Carotid sinus
2. hypotension, bradycardia
4. Carotid body
Describe Charcot Marie Tooth disease
1. demyelinating disease of the peripheral nerves
2. leads to sensory and motor loss of the distal extremities
3. autosomal dominant
What part of the brain controls inspiration and expiration?
1. ventral: expiration
2. dorsal: inspiration
The lower pontine apneustic center stimulates the dorsal respiratory group while the upper pontine pneumotaxic center inhibits it.
What are the afferent and efferent limbs of the corneal reflex?
What defect is most commonly associated with a Myelomeningocele?
Chiari II malformation
What fibers run through the grey rami communicates?
post ganglionic sympathetic nerve fibers. The pre- ganglionic fibers run through the white rami communicates
What can you give as a pre-med to help with succinylcholine myalgias?
2. calcium gluconate
3. vitamin C
When is a vasospasm following SAH most likely to occur? When is re-bleeding most likely to occur?
1. 48-72 hrs
2. Within the first 48 hours
What are the most accurate sites to measure core temperature?
2. distal esophagus
3. pulmonary artery
What artery does trans cranial doppler (TCD) use to detect flow velocities during a CEA?
When is it common for women to develop a relapse from MS?
What electrolyte abnormality is associated with GBS? And why?
SIADH --> hyponatremia
Name two ways that you can decrease CPP
1. directly drain CSF from drain
2. Increase MAP
Which nerves have PS pre- gangiolinc neurons? Where do they reside?
1. III, VII, IX, X
2. III: edinger westfall nucleus
3. VII, IX, X: medulla oblongata
What drug interferes with microelectrode recordings?
Midazolam, most other IV agents are OK to use
True or False: Hyperthermia is brain protective after a neurologic insult
FALSE: HYPOthermia is neuroprotective
What tool can be used to help ensure no limb nerve injury occurs during spinal surgery?
SSEPs. These can alert of spinal cord damage or peripheral nerve damage
Which position puts you most at risk for post operative vision loss
Horseshoe head rest
Explain hyperkalemic periodic paralysis
What receptor is involved in hypokalemic periodic paralysis?
There is a mutation in the Na voltage gated channel that leads to prolonged depolarization, myotonia, and paralysis. Therefore, the patients are dependent on K efflux to start depolarization. If K is HIGH, then K efflux is slowed and the patient remains paralyzed. Can affect the tongue and eyelids
Factors that worsen this are 1) rest after exercise, 2) metabolic ACIDOSIS, 3) hypoglycemia, 4) extremes of temperature 5) depolarizing muscle blockers
What is a common complication of AVM embolization procedures? How do you treat it?
1. cerebral edema
2. hypotension, hypocapnia, hypothermia, and propofol
Describe Autonomic hyperreflexia
1. Happens when damage above T12 occurs
2. Any sort of stimulation to the skin, bladder, uterus, viscera leads to activation of the the sympathetic pre-ganglionic fibers, which then affects the splanchnic outflow tract. However, the inhibitory fibers are damaged: SO below the injury you get uninhibited sympathetic stimuli (vasospasm), while vasodilation and sweating occur ABOVE the lesion
Describe some anesthetic considerations in kids with muscular dystrophy. What is an appropriate anesthetic plan?
1. Cardiac defects: many of these kids can get CHF and dysrhythmia
2. Respiratory issues: weak respiratory muscles and poor clearance of mucus leads to increased risk for pulmonary infections and therefore possible prolonged intubation following surgery
3. GI dysmotility and gastroparesis: increased risk for aspiration
4. Avoidance of succinylcholine due to up-regulated Ach receptors
5. Avoidance of volatile anesthetics due to increased risk for rhabdomyolysis
6. Induction with IV propofol and rocuronium
Which site on the NMJ post junctional nAchR does the Ach bind?
Alpha 1 subunit
Describe what a MEP is? When is it most commonly used? What is the pathway that the neurons follow?
1. MEP: motor evoked potential, this is when electrodes are placed transcrianially (over the scalp) or directly on the brain to stimulate the descending motor pathway
2. This is used in surgeries where the artery of adamkiewicz is at risk (the anterior blood supply to the spinal cord)
3. Lower limb cortex --> inter capsule --> brainstem --> corticospinal tract --> peripheral nerve
Describe the role of the carotid body vs. the carotid sinus. What CN do each of these utilize to send messages to the brain to increase ventilation? What surgery puts the carotid body at risk?
1. Carotid body is at the branch of the common carotid artery. It is a group of cells that transmits signals to the brain when PaO2 decreases below 100 and then below 50.
2. The carotid sinus is in the proximal internal carotid artery and it detects PaCO2 levels
3. Both use CN IX (glossopharyngeal) to send signals to the brain
4. CEA: if this nerve gets knocked out, the the body is only relying on hypercarbic drive to increase ventilation and this is often times attenuated (or decreased) by narcotics and anesthetic gas
What vertebrae differentiates Quad vs. paraplegic?
Describe neurogenic pulmonary edema
Following TBI and increased ICP, there is a massive discharge of sympathetic activity that causes pulmonary vasoconstriction. This can happen w/in a few hours
Compare tetanus and botulism
1. Tetanus inhibits GABA and Glycine release from at the pre-synaptic channels in the brain, which inhibits the inhibitory neurons --> tetany
2. Botulism inhibits Ach release in the spinal cord, so the alpha motor neurons are not activated --> flaccid paralysis