Spring 2024 (Exam III) Neurological Diseases Flashcards
Cerebral Blood flow is modulated by?
Cerebral metabolic rate
CPP (MAP-ICP)
Aterial blood CO2
Aterial blood O2
Various drugs and intracranial pathologies
With autoregulation CBF is approx (blank) brain tissue per minute.
Which is _____ ml/min
this is how much of CO?
50 mL/ 100g
750 mls/ min
15%
The vault is enclosed by the?
dura mater and bone
Brain tissue, intracranial CSF and Intracranial blood have a combined volume of?
what is the normal ICP at this volume?
1200 - 1500 mls
5-15 mmHg
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
This diagram describes what?
monroe-kellie hypothesis
the incracranial vault is considered what?
compartmentalized
this is reflection of the dura that seperates the 2 cerebral hemispheres?
falx cerebri
a reflection of dura that lies rostral to the cerebellum and marks the border btw the supratentorial and infratentorial spaces
tentorium cerebelli
______ = Herniation of hemispheric contents under _____ ; typically, compressing branches of the anterior cerebral artery , creating a _____
Subflacine Herniation
falx cerebri
midline shift
Transtentorial Herniation is herniation of the supratentorial contents past what?
tentorium cerebelli
Transtentorial herniation causes?
causes brainstem compression in the rostral to caudal direction
This leads to
- AMS
- defects in gaze and ocular reflexes
- hemodynamic
- respiratory compromise
- death
Uncas is located where?
medial portion of temporal lobe
a subtype of transtentorial herniation, where the uncus herniates over the tentorium cerebelli
uncal herniation
what are the S&S of uncal herniation
- Ipsilateral oculomotor nerve dysfunction
- pupillary dilatation
- ptosis
- lateral deviation of the affected eye
- brainstem compression
- death
can occur due to elevated infratentorial pressure, causing the cerebellar structures to herniate through the foramen magnum
herniation of the cerebellar tonsils
S&S of cerebellar tonsils herniation
medullary dysfunction, cardiorespiratory instability and subsequently death
label the numbers
- Subfalcine → midline shift
- Transtentorial -> pushing down caudally
- Cerebellar contents through foramen magnum -> towards the medulla
- Traumatic event → cause herniation out of cranial cavity
Tumors can increase ICP in 3 ways
1) directly d/t size
2) indirectly by causing edema in surrounding brain tissue
3) by obstructing CSF flow (like with tumors involving the 3rd ventricle)
Intracranial hematomas cause increased ICP similar to mass lesions
Blood in the CSF, as is seen in subarachnoid hemorrhage, may lead to?
obstruction of CSF reabsorption, and granulations can further exacerbate increased ICP
Infections s/a meningitis or encephalitis can lead to?
edema or obstruction of CSF reabsorption
how does Hyperosmotic drugs decrease ICP?
increase osmolarity, drawing fluid across BBB
how do corticosteroids decrease ICP?
decrease swelling and enhance the integrity of the BBB
how does cerebral vasoconstricting anesthetics like propofol decrease ICP?
decrease CMRO2 and CBF
this is a progressive, autoimmune demyelination of central nerve fibers?
onset?
characterized?
multiple sclerosis (MS)
- onset is 20-40
- characterized by periods of exacerbations and remissions
Risk factors for MS
Rx factors: Female, 1st deg relative w/ MS, EBV (epstein barr virus), other AI disorders, smoking
what triggers MS?
Triggers: stress, elevated temps, postpartum period
S&S of MS
progressive motor weakness
sensory disorders
visual impairment
autonomic instability.
Sx vary b/o site of demyelination
is there a cure for MS?
No, managed with corticosteroids, immune modulators and targeted antibodies
For MS if respiratory compromise, consider?
Pulmonary function test
LFT’s are drawn on MS only if?
what are some considerations with steroid use?
LFT if on Dantrolene & Azathioprine (bone marrow suppression, liver function impairment)
Close attn to glucose and electrolytes as steroids may impact levels
Considerations for patients with MS on long term steroids are?
Consider giving pre-op steroids in anyone with long-term steroid use
LT steroids cause adrenal suppression, so a stress-dose of steroids may be necessary for surgery
what are some anesthetic considerations for patients with MS?
Any increase in body temp can precipitate an exacerbation of MS sx
general and regional anesthesia, PNB’s are acceptable options
Avoid Succinylcholine as it may induce hyperkalemia
(Upregulated N-ach receptors)
Autoimmune; Antibodies generated against N-Ach-R’s at skeletal motor endplate
myasthenia Gravis (MG)
MG effects what kind of muslce?
Effects skeletal muscle, not smooth or cardiac muscle
Muscle weakness is worsened by what in MG?
S&S are exacerbated by what?
Muscle weakness, exacerbated w/exercise
Sx exacerbated by: pain, insomnia, infection, surgery
Cranial symptoms associated with MG
Ocular sx common-diplopia, ptosis
Bulbar involvement → laryngeal/pharyngeal weakness→ respiratory insufficiency, aspiration rx
This is common in 10% of MG cases
Thymic hyperplasia
(90% pts improve after thymectomy)
what is the treatment for MG?
Tx: Ach-E inhibitors (Pyridostigmine), immunosuppressive agents, steroids, plasmapheresis, IVIG
Preanesthetic Considerations with MG are?
Reduce paralytic dosage to avoid prolonged muscle weakness
If respiratory compromise -> do pulmonary function tests
Optimize respiratory function
Consider pre-op steroids in anyone with long-term steroid use
Counsel patients on the increased risk of needing post-op resp support/ventilation until fully recovered from anesthesia
Why are opioids used with caution in MG?
avoid resp compromise
In MG, Ach -E inhibitors may prolong what?
Succ’s and Ester LA’s
Labs for MG include?
Labs: CBC, BMP, +/-LFT (LFT if on Azathioprine)
Close attn to glucose and electrolytes as steroids may impact levels
Disorder causing the development of autoantibodies against VG Calcium Channels
Eaton Lambert Syndrome
what is the specific MOA of the Eaton Lambert Syndrome?
Reduce Ca++ influx into the presynaptic Ca++ channels→↓Ach release @ the NMJ
S&S of Eaton Lambert Syndrome
Sx similar to MG
Sx: progressive limb-girdle weakness, dysautonomia, oculobulbar palsy
>60% cases assoc w/ small cell lung carcinoma
Treatment for Eaton Lambert syndrome invovles what?
Selective K+ chnl blocker “3-4 diaminopyridine”
Ach-E inhibitors
immunologics (Azathioprine)
steroids
plasmapheresis
IVIG
This represents what?
Lambert-Eaton syndrome
Pre-anesthetic Considerations for Eaton Lambert Syndrome
Assess existing deficits
If respiratory compromise, consider pulmonary function tests
Eaton Lambert Syndrome is very sensative to what?
VERY sensitive to ND-NMB & D-NMB
more sensitive to ND-NMB than MG patients
Extreme caution with paralytic and opioid dosing
Counsel on risks for needing post-op resp support until fully recovered from anesthesia
Describe Muscular Dystrophy (MD)
Hereditary disorder of muscle fiber degeneration c/b breakdown of the dystrophin-glycoprotein complex
leads to myonecrosis, fibrosis, and skeletal muscle mbrn permeability.
how many types of MD
6
Most common and severe form of MD
Duchenne MD
occurs only in boys
onset is 2-5 yrs
wheel chair bound by 8-10 years
avg lifespan is 20-25 years d/t cardiopulmonary complications
S&S of MD
progressive muscle wasting without motor/sensory abnormalities
kyphoscoliosis
long bone fragility
respiratory weakness
frequent pneumonia
EKG changes
what labs specifically are elevated in MD?
Elevated serum creatine kinase c/b muscle wasting
Preanesthetic considerations for MD
CBC, BMP, PFTs, consider CK
Pre-op EKG, echocardiogram. Evaluate for cardiomyopathy
Caution with ND-NMB’s, careful monitoring throughout
Can happen when succs and volatiles are given with MD?
Hypermetabolic Syndrome
Avoid Succs & VA as they exacerbate instability of muscle membrane
Hypermetabolic Syndrome Can lead to: rhabdomyolysis, hyperkalemia, Vfib, cardiac arrest
Alternative anesthetic for MD
Consider low dose rocuronium and TIVA for GA
Have MH cart with Dantrolene available
RA preferred over GA to avoid triggers and cardiopulmonary complications
what are the myotonic dystrophies mentioned in class?
myotonic dystrophy
myotonia congenita
central core disease
prolonged contraction after muscle stimulation
seen in several muscle disorders
myotonia
most common myotonia. Onset 20-30’s
Myotonic Dystrophy
Myotonic Dystrophy s/s
muscle wasting in face, masseter, hand, pre-tibial muscles
may also affect pharyngeal, laryngeal, diaphragmatic muscles
cardiac conduction may be affected; 20% have MVP
Myotonia Congenita: s/s
Milder form, involving theskeletal muscles
smooth & cardiac muscles are spared
describe Central Core disease
Rare. Core muscle cells lack mitochondrial enzymes
Sx:Proximal muscle weakness & scoliosis
Myotonias are triggered by_____
Tx?
Myotonias are triggered by stress & cold temps
Tx: No cure. Sx managed w/Quinine, Procainamide, Steroids
pre-anesthetic considerations for mytonic dystrophies
- GI hypomotility-↑aspiration risk
- High rx of endocrine abnormalities.
- Keep patients warm to avoid flare-ups
- Avoid Succinylcholine b/c fasciculations trigger myotonia
- Pts are increased risk for post-op resp weakness
3 Major Dementia Syndromes:
Alzheimer’s (70%),
Vascular dementia (25%),
Parkinsons (5%)
Degeneration of dopaminergic fibers of basal ganglia
Parkinsons disease
_______ regulates (inhibits excess stimulation) the extrapyramidal motor system, which is stimulated by____
Dopamine regulates (inhibits excess stimulation) the extrapyramidal motor system, which is stimulated by Ach
Triad of sx in parkinsons
tx:
Triad of sx: skeletal muscle tremor, rigidity, akinesia (inability to voluntarily move one’s muscles and limbs)
: Levodopa (crosses BBB), anticholinergics, MAOIs (inhibit dopamine degradation), Deep brain stimulator
avoid which drugs with parkinsons as pre-anesthetic considerations
Avoid Reglan, Phenothiazines, Butyrophenones
Avoid Demerol if on MAOI
_____ must be continued to avoid unstable extreme extrapyramidal effects s/a chest wall rigidity
_______may need to be disabled to avoid interaction w/cautery
PO Levodopa must be continued to avoid unstable extreme extrapyramidal effects s/a chest wall rigidity
DBS may need to be disabled to avoid interaction w/cautery
Primary tumors. Least aggressive astrocytomas
Often found in young adults w/new onset seizures
gliomas
Children & young adults
Mostly benign, good outcomes if resectable
pilocytic astrocytoma
Poorly differentiated
Usually evolve into Glioblastoma Multiforme
anaplastic astrocytomas
Carry a high mortality
Usually requires surgical debulking & chemo
Life expectance is usually within weeks, even w/treatment
Glioblastoma Multiforme
Usually benign. Arise from dura or arachnoid tissue
Good prognosis w/surgical resection
meningiomas
Noncancerous, varying subtypes
Transsphenoidalor open craniotomy for removal is usually curative
Pituitary Adenomas
occlusion of ACA
contralateral leg weakness
occlusion of MCA
contralateral hemiparesis and hemisensory deficit (face and arm more than leg)
aphasia
contralateral visual field defect
occlusion of PCA
contralateral visual field defect
contralateral hemiparesis
occlusion of penetrating arteries
contralateral hemiparesis
contralateral hemisensory deficits
basilar artery occlusion
oculomotor deficits and/or ataxia w/ crossed sensory and motor deficits
vertebral artery occlusion
lower cranial nerve deficits and/or ataxia w/ crossed sensory deficits
Hemorrhagic stroke is 4x more likely to cause death than
ischemic
The 2 most reliable predictors of outcome are:
Estimated blood volume & Change in LOC
Bloodwithin the brainis called
An intraparenchymal hemorrhage
Blood in the epidural, subdural, or subarachnoid spaces are referred to as
Blood in the epidural, subdural, or subarachnoid spaces are referred to as epidural hematoma, subdural hematoma, and subarachnoid hemorrhages, respectively
Blood located in the ventricular system
Blood located in the ventricular system is an intraventricular hemorrhage, and usually occurs in conjunction with other types of hemorrhagic stroke
New anticoagulant for thrombus=
New anticoagulant for thrombus=No elective cases within 3 months
High rx pts for CVA that pause LA anticoags (Warfarin) will need ____ to bridge the gap
If RA planned, ____for sufficient time to safely perform block
High rx pts for CVA that pause LA anticoags (Warfarin) will need SA anticoags (LMWH, IV unfractionated heparin) to bridge the gap
If RA planned, d/c anticoagulants for sufficient time to safely perform block
s/s of cerebral aneurysms
r/x?
dx?
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 ___rupture for best outcomes
72 hr
Risk for vasospasm post SAH
Risk for vasospasm 3-15 days post SAH
Triple H therapy for post SAH vasospasms
Triple H therapy (Hypertension, Hypervolemia, Hemodilution)
moa of post SAH vasospasms
Freehgbtriggers inflammatory mediators, which reduce nitric oxide availability and increase endothelin 1, leading to vasoconstriction
To avoid complications of hypervolemia, _____
To avoid complications of hypervolemia, HTN is the initial main treatment, and then do volemia
2 grading scales for aneurysms
Hunt and Hess
GCS
Arterial to venous connection w/o intervening capillaries
Creates an area of high flow, low resistance shunting
Believed to be congenital
AVM
s/s, dx, tx of AVM
Sx: range from mass-effects to hemorrhage
Majority are supratentorial
Dx: Angiogram, MRI
Tx: radiation, angio-guided embolization, surgical resection (higher mortality)
Type 1 chiari malformation
Type 1: downwarddisplacement ofcerebellum
Type 2 chiari malformation
Arnold Chiari):downwarddisplacementofcerebellar vermis, often assoc w/myelomeningocele
Type 3 chiari malformation
Rare; occipital encephalocele w/downward cerebellar displacement
Type 4 chiari malformation
cerebellar hypoplasia w/o displacement of posterior fossa contents
*Not compatible with life
chiari malformation s/s, tx
Sx: headache, extending to shoulders/arms,visual disturbances, ataxia
Tx: Surgical decompression
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
Tuberous sclerosis
Tuberous sclerosis
Often involves co-existing tumors of ____
Presentation likely includes ___
Often involves co-existing tumors of face,oropharnyx, heart, lungs, liver &kidneys
Presentation likely includes mental retardation and seizure disorders
Autosomal dominant
Benign tumors of the CNS, eyes, adrenals, pancreas and kidneys
May present w/ pheochromocytoma
Von Hippel-Lindau Disease
TBI
Categorized: “penetrating” or “non-penetrating,” d/o breech of dura
Severity categorized by Glasco-Coma Scale
Primary injury: occurs at time of insult
Secondary injuries: neuroinflammation, cerebral edema,
hypoxia, anemia, electrolyte imbalances, and neurogenic shock
Intubation required in severe TBI (GCS <9, AW trauma, resp distress)
Mild hyperventilation to control ICP
CT of head/neck ASAP
Neurofibromatosis
Autosomal dominant
3 types:
Type 1 (most common)
Type 2
Schwannomatosis (rare)
Numerous disease presentations
Anesthesia considerations account for increased ICP, airway issues, scoliosis, possibility of pheochromocytoma
Avoid NA d/t high likelihood of spinal tumors
hydrocephalus tx:
- mainly consists of diuretics (furosemide & acetazolamide decrease CSF production) although this remains controversial in children
- Serial lumbar punctures have also been tried but only as a temporizing measure
- The majority of cases require surgical treatment
- VP shunt: drain placed in ventricle of the brain andempties into peritoneum
- ETV: catheter placed into the lateral ventricle that drains into the peritoneal space, right atrium, or more rarely the pleural space
- Shunt malfunction occurs most frequently in the first year of placement (high failure rate)
: transient, paroxysmal, synchronous discharge of neurons in the brain
Can be c/b transient abnormalities: hypoglycemia, hyponatremia, hyperthermia, intoxication
In these cases, treating the underlying cause is curative
Epilepsy: recurrent seizures d/t congenital or acquired factors
Antiepileptic drugs decrease neuronal excitability/enhance inhibition
seizure disorders
disorder of CSF accumulation, causing increased ICP, that results in ventricular dilatation
hydrocephalus
can vary widely in origin &symptoms
Outcomes are generally less favorable
Metastatic Carcinomas:
Usually benign schwannomas involving the vestibular component of CN VIII within the auditory canal
Good prognosis w/resection +/- radiation
Acoustic Neuromas:
Astrocytoma tumor types:
Gliomas
pilocytic astrocytomas
anaplastic astrocytomas
glioblastoma multiforme
