neuro Flashcards
autoregulation fails when? x2
MAP
under 60
greater than 150
(cerebral flow depends on SBP)
cerebral perfusion pressure equation
CPP = MAP - ICP
circle of willis
compensates for decreased bloodflow in order to maintain perfusion
- posterior cerebral arteries
- posterior communicating arteries
- internal carotid arteries
- anterior cerebral arteries
- anterior communicating artery
subarachnoid hemorrhage is
caused by bleeding in arachnoid space, between pia & arachnoid membrane
- blood mixes w CSF around brain/spinal cord
- results:
↑ ICP
↓CPP
meningeal irritation
↓ CSF reabs into venous sys
SAH causes
traumatic
non-traumatic: ruptured aneurysm (85%), ruptured AVM, tumor
“worst headache of my life”
think SAH!
SAH: s/s
- “worst hHA of my life”
- n/v/projectile
- seizure/LOC
- unilateral pupil dilation
- photophobia, visual ∆s
- nuchal rigidity (4-6 hrs later)
- CN III, IV, VI deficits (eyes do tricks)
Hunt Hess Score for?
SAH mortality
SAH imaging
non-con head CT + head CTA /OR/ LP
- usually CTA esp if higher susp SAH vs meningitis
blood in LP classic for
SAH
SAH tx: SBP goal, htn, hypotn (rx x4)
SBP goal 120 - 130
htn: IV labetalol, nicardipine
hypo: levophed (↑MAP), dopamine works too
SAH tx traumatic vs aneurysmal tx
traumatic: neurosurg intervention
aneurysmal: coiling, clipping
why are vasospasms + SAH bad?
decreases perfusion
SAH tx total
- SBP 120 - 130 (maintain perfusion)
- intervention: neurosurg, coil, clip
- avoid hyperthermia (38+C) & hypoglycemia (BG 60+)
- monitor
- rebleed (ICU 2-3 wk for monitor)
- aseptic fever r/t central reg of hypothalamus
- SIADH r/t pituitary malfxn
- vasospasm, ↑ ICP, cerebral ischemia
aseptic fever + SAH
r/t central regulation of hypothalamus
SIADH + SAH
r/t pituitary malfxn
cushing reflex
aka vasopressor response aka cushing effect aka phenomenon etc
physiological nervous system response to increased ICP that results in cushing’s triad
cushing’s triad
indicative of increased ICP - late stages, brain herniation imminent
- ↑ BP
- cheyne stokes breathing
- ↓ HR
CTA vs head CT with contrast
angiogram: specific type of CT w contrast - timed so it will highlight arteries or veins of interest
CT will be timed to show capillary beds of soft tissues
arteriovenous malformation
congenital defect of circulatory system, tangled arteries & veins bypass capillary beds
AVM s/s
progressive neuro sx: seizure, vertigo, HA, dysarthria, memory deficits, risk for rupture
AVM tx
endovascular embolization, surgical resection, radiosurgery, combo
linear skull fracture
no bone depression
depressed skull fracture
outer table of skull depressed below inner table
basilar skull fracture types x3 + 1 associated
anterior fossa: raccoon eyes + rhinorhea
middle fossa: battle sign + CSF (tympanic membrane)
posterior fossa
associated dural tear results in rhinorrhea, otorrhea, increased risk infection1
raccoon eyes sign of
anterior fossa basilar skull fracture
battle sign indicative of
middle fossa basilar skull fracture
supratentorial (uncal) herniation
Shifting of lateral temporal lobe (uncas) → tentorial notch = compression of lateral midbrain, third cranial nerve, & posterior cerebral artery
supratentorial (uncal) herniation: s/s
Sluggish to dilated pupils
Contralateral hemiparesis/hemiplegia
Restlessness deteriorating to loss of consciousness
Respiratory changes: Cheyne-stokes, ataxic pressure
Decorticate & decerebrate posturing
Dilated fixed pupils, flaccidity, & respiratory arrest
concussion
Diffuse brain injury assoc w general or widespread neurological dysfxn
Temporary LOC (seconds to minutes to hrs)
Retrograde amnesia/Anterograde amnesia
Cognitive abilities impaired s/t neuronal injury: twisted/ stretched
contusion
Bruising of brain @ site of impact or distal (contra coup forces)
Freq: frontal/temporal lobes, or brain stem involved
Assoc w prolonged LOC
Implications: monitor closely for edema, ↑ ICP, possible herniation
types of cerebral hematoma
epidural - arterial
– rapid deterioration/LOC + herniation
subdural - venous
– most common
intracranial - into parenchyma d/t direct trauma or shearing forces
– poor prognosis d/t assoc injuries
epidural hematoma
Bleeding btw inner table & dura mater
Freq occurs w linear skull fracture
ARTERIAL BLEED: middle meningeal art, assoc w temporal/parietal injury
Rapid deterioration w LOC & herniation
subdural hematoma
Bleed btw dura mater & arachnoid meninges
MOST COMMON - venous bleed
Assoc w other injuries (contusions)
sx r/t area of injury, degree ↑ ICP
intracranial hematoma
Bleeding into brain parenchyma from direct injury or shearing of small vessels
MOI: trauma, GSW
Poor prog d/t assoc injuries (↑ mortality)
migraine headache s/s
premonitory sx (aura), photophobia, N, V
cluster headache s/s
ipsilateral lacrimation, rhinorrhea, ptosis, 30 - 180 min long
migraine tx x3
sumatriptan (Imitrex)
midrin (non-opioid analgesic, has APAP in it, sympathomimetic)
rizatriptan (Maxalt)
cluster headache tx
indomethacin (NSAID)
nifedipine, nimodipine
ergots & triptans: nota bene!!
do not use these drug types within 24 hours of each other - serotonin syndrome risk!
(class: abortive migraine meds)
visceral pain
organs, body cavities
C fibers
somatic pain
alpha & delta fibers
body tissue injury: skin, SQ tissue, bones, blood vessels, muscles
neuropathic pain
d/t primary lesion in nervous system sustained by aberrant somatosensory processing in PNS or CNS - not related to nociceptor stimulation
central (ex: phantom limb) vs peripheral (ex: neuralgia)
cancer pain treatment steps x3
- mild: non-opioid analgesics
- moderate pain or no relief from #1 - opioids (codeine or hydrocodone), hydrocodone w APAP, or lortab adjuvant
- severe or no relief from #2:
- morphine, hydromorphone, methadone, fentanyl, oxycodone
- combo w non-opioid or h
short acting opioids WHO Step 1 or 2
codeine
hydrocodone
oxycodone
short acting opioids WHO Step 2 or 3
morphine (IR)
hydromorphone (Dilaudid)
oxycodone
long acting opioids
MS Contin
Fentanyl
Methadone
no ceiling dosage for?
MS
