neuro disorders exam 3 Flashcards
cerebral blood flow is modulated by
CMR
-CPP
PaCO2
PaO2
drugs and pathologies
cerebral blood flow is _____/_____
50ml/100g of brain tissue
brain tissue, csf, and blood have a combined volume of ________
1200-1500ml
ICP should be
5-15mmHg
monroe kelly hypothesis
Monro-Kellie hypothesis: any increase in one component of intracranial volume must be offset by a decrease in another component to prevent an elevated ICP
- initially once the room runs out youl have an increase in ICP
when ICP increased the ___ will increase to keep CPP adequate
MAP
the cranial vault is compartmentalized why?
protective mechanism
flax cerebri
the falx cerebri: a reflection (fold) of dura that separates the two cerebral hemispheres
WHat type of herniation are these symptoms describing?
pupillary dilatation, ptosis, and lateral deviation of the affected eye, brainstem compression and death
Uncal herniation
tentorium cerebri
the tentorium cerebelli: a reflection of dura that lies rostral to the cerebellum and marks the border btw the supratentorial and infratentorial spaces
Subfalcine herniation
pushes right to left or left to right
How do tumors increase intracranial pressure? 3 way
cerebral edema
size
obstructing CSF flow (around the third ventricle)
What things increase ICP? 4 things
tumors
hematomas
blood in the CSF
infections
How can we decrease ICP?
elevate head of bed
hyperventilation (decrease CO2 and cause vasoconstriction)
CSF drainage (EVD, ventric)
hyper-osmotic drugs
diuretics
corticosteroids (increase integrity of BBB and decrease swelling)
cerebral vasoconstriction (propofol)
surgical decompression
Subfalcine Herniation: Herniation of hemispheric contents under the_______; typically, compressing branches of the __________, creating a midline shift
falx cerebri
anterior cerebral artery
Transtentorial Herniation is a Herniation of the _______ contents past the ________ ______, causing brainstem compression in a rostral to caudal direction. This leads to AMS, defects in gaze and ocular reflexes, hemodynamic and respiratory compromise, and death
supratentorial
tentorium cerebelli
Uncal Herniation is a subtype of _____ _____, where the uncus (medial portion of temporal lobe) herniates over the tentorium cerebelli. This results in ipsilateral oculomotor nerve dysfunction
transtentorial herniation
Herniation of the cerebellar tonsils can occur due to elevated infratentorial pressure, causing the cerebellar structures to herniate through the _______
Sx: medullary dysfunction, cardiorespiratory instability and subsequently death
foramen magnum
What is included in the neurological assessment?
- look at history
- what treatments have they had
- review imaging
- look at trends
- drugs they are taking
- risk and benefits of anesthetic options
- are they up to date on seizure meds? steroids?
- clear preop documentation and why you are chosing the anesthetic plan you are choosing
What is the onset of MS?
20-40
What is MS?
autoimmune demylination of central nerves
what are symptoms of MS?
weakness, sensory disorders, visual impairment, autonomic instability
there is an extreme range of symptoms
How is MS managed?
managed with corticosteroids, immune modulators, targeted antibodies
Why do we get a liver function test for MS patients?
LFT if on Dantrolene & Azathioprine (bone marrow suppression, liver function impairment)
very tough on the liver
same for MG
MS patients will be on steroids. WHat labs do you want?
glucose and electrolytes
you will need a stress dose steroid
What small thing in the OR can cause an exasterbation of MS?
temp, keep them warm
Why do you avoid Sux in MS?
their body will increase in immature N-ach receptors and this will spike the K level
In MS the cranial nerves are susceptible and this will cause what symptoms?
diplopia, ptosis
bulbar involvment
Bulbar involvement → laryngeal/pharyngeal weakness→ respiratory insufficiency, aspiration rx
Thymic-hyperplasia is common in what neuro disorder
MG
What is the treatment for MG
IVIG (risk for infection) , and plasmapheresis
pyridostigmine (6hr half life, must take morning before surgery)
What is MG
Autoimmune; Antibodies generated against N-Ach-R’s at skeletal motor endplate
Effects skeletal muscle, not smooth or cardiac muscle
what does pyridostigmine do to sux?
prolongs sux and esters LA
What is Eaton-Lambert syndrome?
Disorder causing the development of autoantibodies against VG Calcium chnls presynaptic
Reduce Ca++ influx into the presynaptic Ca++ channels→↓Ach release @ the NMJ
What is eaton lambert associated with?
small cell lung carcinoma
what is the treatment for EL syndrome?
Tx: Selective K+ chnl blocker “3-4 diaminopyridine”
Ach-E inhibitors, immunologics (Azathioprine), steroids, plasmapheresis, IVIG
ELS and very sensitive to what drugs?
ND-NMB and D-NMB
mainly ND-NMB
what is the preferred anesthesia for ELS?
regional because of the lack of respiratory support
What is muscular dystrophy?
Hereditary disorder of muscle fiber degeneration c/b breakdown of the dystrophin-glycoprotein complex, leads to myonecrosis, fibrosis, and skeletal muscle mbrn permeability. 6 types of MD.
What is the most common MD?
Duchenne MD
2-5yr boys
What labs will be increased in MD?
elevated creatine kinase because of the breakdown of muscle tissue
What are anesthesia considerations with MD?
CBC, BMP, PFTs, consider CK
Pre-op EKG, echocardiogram. Evaluate for cardiomyopathy
Caution with ND-NMB’s, careful monitoring throughout
“Hypermetabolic Syndrome” similar to MH seen with Succs & volatile anesthetics
Hypermetabolic syndrome can lead to: rhabdomyolysis, hyperkalemia, Vfib, cardiac arrest
Avoid Succs & VA as they exacerbate instability of muscle membrane
Consider low dose rocuronium and TIVA for GA
Have MH cart with Dantrolene available
RA preferred over GA to avoid triggers and cardiopulmonary complications
Why do you avoid Sux and volatiles in MD?
can cause hypermetabolic syndrome which causes rhabdo, high K, Vfibb, death
TX dantrolene
What is the preferred anesthetic in MD?
TIVA and low dose rocc
What is myotonic distrophy?
Myotonic Dystrophy: most common myotonia. Onset 20-30’s
Sx: muscle wasting in face, masseter, hand, pre-tibial muscles
may also affect pharyngeal, laryngeal, diaphragmatic muscles
cardiac conduction may be affected; 20% have MVP
What is myotonia congenita?
Myotonia Congenita: Milder form, involving the skeletal muscles
smooth & cardiac muscles are spared
What is central core disease?
Central Core disease: Rare. Core muscle cells lack mitochondrial enzymes
Sx: Proximal muscle weakness & scoliosis
Myotonias are triggered by ___ and _____
stress and cold temp
What are the Tx for myotonias?
Tx: No cure. Sx managed w/Quinine, Procainamide, Steroids
Anesthetic considerations for myotonias
Assess the extent of cardiac and pulmonary abnormalities
Assess breath and heart sounds for abnormalities
GI hypomotility-↑aspiration risk
High rx of endocrine abnormalities. Look at thyroid & glucose levels
Keep patients warm to avoid flare-ups
Avoid Succinylcholine b/c fasciculations trigger myotonia
Optimize preop respiratory status
Caution with opioids to avoid post-op respiratory depression
Pts are increased risk for post-op resp weakness
in myotonias avoid _____
SUX
Avoid Succinylcholine b/c fasciculations trigger myotonia
What are the three major dementias?
Alzheimer’s (70%), Vascular dementia (25%), Parkinsons (5%)
What is parkinsons disease?
Degeneration of dopaminergic fibers of basal ganglia
Dopamine regulates (inhibits excess stimulation) the extrapyramidal motor system, which is stimulated by Ach
In Parkinsons, these motor neurons are over stimulated
What are the triad of symptoms and treatment of parkinsons?
Triad of sx: skeletal muscle tremor, rigidity, akinesia
Rhythmic “pill rolling,” facial rigidity, slurred speech, difficulty swallowing, respiratory difficulty, depression & dementia
Tx: Levodopa (crosses BBB), anticholinergics, MAOIs (inhibit dopamine degradation), Deep brain stimulator
What do you want to avoid in dementia?
versed, opioids, TIVA is preferred
Whats the biggest risk factor for parkinsons?
Unknown cause; Advanced age is biggest risk factor
What medications do you avoid in parkinsons?
Avoid Reglan, Phenothiazines, Butyrophenones
Avoid Demerol if on MAOI
Describe the assessment of parkinsons pts
Assess severity, with special attn to degree of pulmonary compromise
Review home meds, as many may interact with our drugs (ex. MAOIs)
Review basic labs along w/PFT if respiratory sx
May need EKG, Echo if indicated
↑aspiration risk (dysphagia, possible dementia)
PO Levodopa must be continued to avoid unstable extreme extrapyramidal effects s/a chest wall rigidity
Avoid Reglan, Phenothiazines, Butyrophenones
Avoid Demerol if on MAOI
Deep brain stimulators may need to be disabled to avoid interaction w/cautery
If cautery used, bipolar recommended as it reduces scattering of electro-currant
Do you continue levodopa before surgery?
PO Levodopa must be continued to avoid unstable extreme extrapyramidal effects s/a chest wall rigidity
Common symptoms of brain tumors are
Common sx:
↑ICP
Papilledema
Headache
AMS
Mobility impairment
Vomiting
Autonomic dysfunction
Seizures
Describe Gliomas
Gliomas: Primary tumors. Least aggressive astrocytomas
Often found in young adults w/new onset seizures
Describe Pilocyctic astrocytomas
Pilocyctic astrocytomas: Children & young adults
Mostly benign, good outcomes if resectable
describe Anaplastic astrocytomas:
Anaplastic astrocytomas: Poorly differentiated
Usually evolve into Glioblastoma Multiforme
describe Glioblastoma Multiforme
Glioblastoma Multiforme: Carry a high mortality
Usually requires surgical debulking & chemo
Life expectance is usually within weeks, even w/treatment
describe Meningiomas
Meningiomas: Usually benign. Arise from dura or arachnoid tissue
Good prognosis w/surgical resection
describe Pituitary Adenomas
Pituitary Adenomas: Noncancerous, varying subtypes
Transsphenoidal or open craniotomy for removal is usually curative
describe Acoustic Neuromas:
Acoustic Neuromas: Usually benign schwannomas involving the vestibular component of CN VIII within the auditory canal
Good prognosis w/resection +/- radiation
Brain Tumors: Pre-anesthesia
Review history & physical
Inquire about previous therapies, presenting symptoms & neurological deficits
Radiation damage may lead to lethargy and AMS
Chemotherapy may also have neurological effects
Pts are often on steroids to minimize cerebral edema
Will need to continue steroids, monitoring glucose levels
Anticonvulsants common (supratentorial lesions, closer to motor cortex)
Autonomic dysfunction may manifest on EKG, labile HR & BP’s
CBC, BMP (glucose), EKG
CT/MRI
Pre-op steroids & antiseizure meds per surgeon
Mannitol often used to reduce intracranial volume & pressure
What is the most common type of stroke?
ischemic
_______ is the leading cause of death and disability
stroke
Causes of Ischemic stroke are categorized according to the TOAST classification into 5 groups:
1class. Large artery atherosclerosis (e.g., carotid stenosis)
2class. Small vessel occlusion (e.g., lacunar stroke)
3class. Cardioaortic embolic (e.g., emboli from atrial fibrillation)
4class. Other etiology (e.g., stroke due to hypercoagulable states or vasculopathies)
5class. Undetermined etiology
Transient ischemic attack: sudden focal vascular neurologic deficit that resolves within ______ hrs
24
What medications will you give for acute ischemic stroke
aspirin and tPA
tPa is 3-4 hours past onset
hemorrhagic strokes are more ____ than ischemic
deadly
blood is supplied to the brain by
internal carotid arteries
vertebral arteries
know all this stupid shit
______ pts who experience a TIA will subsequently suffer a stroke
1/3
a CT will distinguish what?
ischemic vs hemorrhagic
revascularization allows for thrombectomy or thrombolytics
this leads to the best outcome
patients with ischemic stroke usually have what other health problems?
Patients w/ischemic stroke frequently have CV risk factors, including HTN, DM, CAD, Afib, and valvular disease, that could impact vasoactive drug choices and hemodynamic goal
The 2 most reliable predictors of outcome for hem stroke are: ______ & ______
estimated blood volume & change in LOC
hemorrhagic CVA tx
anticonvulsants
evacuation of blood
bp management
ICP control
go to ICU after
the pt is on anticoags for CVA prevention. WHat do you do
consult prescriber
the pt is on a new anticoag for thrombus. WHat do you do
no elective cases for 3 months
Pre-op assessments for CVA
Careful review of history, deficits, imaging, treatments, and co-existing diseases
Assess orientation, pupils, bilateral grip strength, LE strength
Ask about headaches, tinnitus, vision/memory loss, bathroom issues
Look at route cause of CVA: Vascular disease, embolic (a-fib, prosthetic valve, right to left shunt/PFO)
Imaging: Carotid U/S, CT/MRI head & neck, echocardiogram
Preop EKG
CBC, BMP, possible T & C
Cerebral oximetry if possible
Aline, 2 IVs and/or CVC
High risk pts for CVA that pause LA anticoags (Warfarin) will need SA anticoags (LMWH, IV unfractionated heparin) to bridge the gap
yup
cerebral aneurysms
sx
rx
dx
surgical tx within ____
Majority aneurysms not diagnosed before rupture
Only 1/3 aneurysm pts have sx before rupture
Sx: Headache, photophobia, confusion, hemiparesis, coma
Rx: HTN, smoking, female, oral contraceptives, cocaine use
Dx: CT/angio, MRI, Lumbar puncture w/CSF analysis if rupture suspected
Intervention should be performed within 72h of rupture for best outcomes
Pt may be on steroids, glucose monitoring important
Pre-anesthesia: CT/MRI, EKG, Echo, CBC, BMP, T&C w/blood available
BP control, mannitol? *aim is to avoid rupture
seizure prophylaxis
Surgical tx: coiling, stenting, trapping/bypass (very large aneurysms)
Neurosurgeon may be on standby in case of intra-op rupture/SAH
Post SAH Vasospasm
Risk for vasospasm 3-15 days post SAH
Free hgb triggers inflammatory mediators, which reduce nitric oxide availability and increase endothelin 1, leading to vasoconstriction
Triple H therapy (Hypertension, Hypervolemia, Hemodilution)
To avoid complications of hypervolemia, HTN is the initial main treatment
Interventional treatments s/a balloon dilation and direct injection of vasodilators relieve the spasm
Pre-anesthesia interventions: Same as with aneurysm, although normally less-invasive
aneurysm grading (hunt & hess and BCS)
she said just know that there are grading systems
H&H scores mortality
WFNS is based on GCS
Whats an AVM
Arterial to venous connection w/o intervening capillaries
high flow, low resistance shunting
Spetzler martin grading system grades what
AVM severity
most avms are
supratentorial
Whats the tx for AVMs and the pre-anesthesia managment
Dx: Angiogram, MRI
Tx: radiation, angio-guided embolization, surgical resection (higher mortality)
Pre-anesthesia: H&P, review meds, imaging, CBC, BMP, T&C, EKG, Echo
BP control, mannitol?, seizure prophylaxis, CVC or 2 Lg bore IV’s, Aline
What is a Chiari malformation and the types
Congenital displacement of the cerebellum
Type 1: downward displacement of cerebellum
Type 2 (Arnold Chiari): downward displacement of cerebellar vermis, often assoc w/myelomeningocele
Type 3: Rare; occipital encephalocele w/downward cerebellar displacement
Type 4: cerebellar hypoplasia w/o displacement of posterior fossa contents
*Not compatible with life
What are the sx, tx, and pre anesthesia implications of chiari malformation
Sx: headache, extending to shoulders/arms, visual disturbances, ataxia
Tx: Surgical decompression
Pre-anesthesia: Review H&P, deficits, imaging, CBC, BMP, T&C
May hyperventilate to ↓ICP, Lg bore IV x 2 or CVC, Aline
tubular sclerosis
AKA “Bourneville Disease”
Autosomal dominant disease causing benign hemartomas, angiofibromas, and other malformations that can occur anywhere in the body
Lesions of the brain include: cortical tumors & giant-cell astrocytomas
Often involves co-existing tumors of face, oropharnyx, heart, lungs, liver & kidneys
Presentation likely includes mental retardation and seizure disorders
Anesthesia consideration must take into account airway compromise, as well as cardiac and/or kidney involvement
Von Hippel-Lindau Disease is associated with _____
phenochromocytoma
Benign tumors of the CNS, eyes, adrenals, pancreas and kidneys
Neurofibromatosis anesthesia considerations
Anesthesia considerations account for increased ICP, airway issues, scoliosis, possibility of pheochromocytoma
avoid what anesthesia with neurofibromatosis
spinal
Hydrocephalus is treated with what
lasix and acetoazolamide
VP shunt or ETV
Malfunctions of VP shunt will usually occur with in the _____ ____ of having it
first year
Main goal of TBI is
preventing secondary injury
Secondary injuries: neuroinflammation, cerebral edema,
hypoxia, anemia, electrolyte imbalances, and neurogenic shock
do you insert an NG or OG tube for TBI?
hell no, may have basilar sf and you will put that shit in their brain
How do you intubate a seizure patient?
*May be called to intubate post-seizure→ RSI w/cricoid pressure
what drugs are you worried about with a patient with seizure disorders?
Phenytoin, Tegretol, Barbiturates are enzyme-inducers
Likely require higher doses of hepatically-cleared medications
