Module 6 Evoked Potentials And Pain Paths/CNS Flashcards
What tract is monitored by SSEPs
Dorsal Leminiscal is all sensory system: cuneatus and Gracillus tracts
Cuneatus and gracilis tracts of dorsal leminiscal system are located where in SC
What information do they carry
Posterior cord
Sensation of touch, pressure, and vibration
Pathway for dorsal leminiscal sensory system
Ascend on ipsilateral side and crossover in brainstem to thalamus and primary sensory cortex
General anesthetics produce sedation and hypnosis by
Depressing the RAS
What nerves are stimulated in SSEPs
Tibial, median, or ulnar nerves
SSEPs are recorded from the scalp
CN IX supplies
Glossopharyngeal nerve
Posterior 1/3 tongue
Vallecula
Anterior surface of epiglottis
Motor for deglutition (swallowing)
Cranial nerve controlling equilibrium
Vestibular branch of CN VIII
Motor innervation of tongue supplied by
CN XIII hypoglossal
What structure provides collateral blood flow to the brain if major blood vessel carrying blood to the brain becomes obstructed
Circle of Willis
Formula for CBF
CPP/CVR
CPP formula
MAP-ICP
Single most important determinant of CBF
PaCO2 when between 20-80mmHg
Effect of hypercarbia on CBF
CBF increased by hypercarbia
How does CBF change for each mmHg decrease in PaCO2
1 ml/100g/min
Cerebral metabolic rate decreases by how much for each degree Celsius drop in temperature
6-7% for each degree Celsius temperature drops
CBF is autoregulated over what MAP range
50-150 mmHg
What is normal ICP
15 mmHg
CSF volume
Total daily production/absorption
150ml
500-750 ml/day
What 2 areas of the brain have no BBB
Chemoreceptor trigger zone
Capillaries of choroid plexus
Autonomic hyperreflexia symptoms
Paroxysmal HTN
Bradycardia
Vasoconstriction below the lesion
Vasodilation above the lesion
4 Anesthetic concerns for MS patient
Neuraxial can exacerbate symptoms
Symptoms worsened by increased temperature
Corticosteroids may be needed
Succinylcholine can cause hyperkalemia
4 neurodegenerative diseases with high risk of aspiration pneumonitis
ALS
Huntinton’s chorea
Creutzfeldt-Jakob
Parkinson’s
Frequency for 4 brain waves
Delta 0-4 Hz
Theta 4-7 Hz
Alpha 8-12 Hz
Beta >12Hz
What happens to EEG waveforms when anesthetic depth increases
Increased amplitude and synchrony