Neurologic Diseases (Exam III) Flashcards
What vessels provide the blood flow to the brain?
- 80% via the carotid arteries
- 20% via the vertebral arteries
Name the pertinent vasculature of the circle of Willis.
This card is just to look at the picture on the other side.
5 factors
How is cerebral blood flow modulated?
- CMR (cerebral metabolic rate)
- CPP (cerebral perfusion pressure) MAP-ICP
- ICP
- PaCO₂
- PaO₂
How much O₂ is required by the brain per minute?
3 mlO₂ / 100g / min
What is the average cerebral blood blow?
50ml/100g/min
~750ml/min
15% of CO
What drugs and/or metabolic states will decrease CMR?
- Hypothermia
- Anesthetic drugs (VAA, prop, etomidate, etc)
What drugs and/or metabolic states will increase CMR?
- Hyperthermia
- Seizures
- Ketamine
- N₂O
What temperature range do we generally want to keep our patients in?
36 - 38° C
This card previously said 42 which is 107.6F lol
How is Cerebral Perfusion Pressure (CPP) calculated?
CPP = MAP - ICP
Name the three components of the brain that form the Monroe-Kellie Doctrine.
- Brain 80%
- Blood 12%
- CSF 8%
What is the Monroe Kellie Doctrine?
Any increase in one component of the intracranial space (blood, brain tissue, CSF) must be met with an equivalent decrease in another to prevent increased ICP.
What is the normal CPP range?
80 - 100 mmHg
An ICP > ____ mmHg will compromise CPP.
30
What pathologic processes or disease states are known to cause an increase in ICP?
- Tumors
- Hematomas
- Blood in CSF
- Infection
- Aqueductal Stenosis
Tx? Shunts? Shunt malfunction happens when?
Hydrocephalus
- CSF accumulation causing high ICP
- Tx w/ lasix and acetazolamide
- VP shunt or
- endoscopic third ventriculostomy (ETV)
-catheter placed into lateral ventricle –> drains into peritoneal space, r. atrium, or pleural space - Shunt malfunction occurs most frequently in first year
What range is normal for ICP?
5 - 15 mmHg
What symptoms are seen with abnormally high ICP?
- Headache
- N/V
- Papilledema
- ↓LOC
What does Cushing’s Triad indicate?
What is the triad?
↑ICP
- ↑sBP
- ↓HR
- ↓RR (Cheyne-Stokes)
Uncal Herniation
- Subtype of transtentorial herniation
- Medial portion of temporal lobe (uncus) herniates over the tentorium cerebelli
- Sx: Pupillary dilation, ptosis, lateral deviation of affected eye, brain stem compression
What is CN I?
Olfactory - smells
What is CN II?
Optic - vision
What is CN III?
Oculomotor - vision (convergence, pupillary accomodation)
What is CN IV?
Trochlear - vision (convergence, pupillary accommodation)
What is CN V?
Trigeminal - Face
What is CN VI?
Abducens - vision (convergence, pupillary accommodation)
What is CN VII?
Facial -symmetry, smile, anterior tastes
What is CN VIII?
Acoustic - hearing
What is CN IX?
Glossopharyngeal - Gag; posterior taste
What is CN X?
Vagus
What is CN XI?
Spinal accessory - shrugging shoulders
What is CN XII?
Hypoglossal - Tongue protrusion
Injury to this cranial nerve results in bell’s palsy.
CN 7
Eye movement in controlled by what cranial nerves?
3, 4, 6
What level of the spinal cord is affected with diaphragmatic paralysis?
Above C5
What is spinal shock?
Loss of vascular tone w/ flaccid paralysis below site of injury.
Are more strokes ischemic or hemmorrhagic?
- Ischemic (88%)
- Hemmorrhagic (12%)
Which type of stroke is more likely to cause death?
Hemmorrhagic (4x more likely)
What are specific risk factors for hemmorrhagic stroke?
- HTN
- Cigarettes
- Cocaine
- Female
5 listed
What are specific risk factors for ischemic stroke?
- HTN
- Cigarettes
- HLD
- DM
- EtOH
Where is bleeding located with an epidural hematoma?
Inbetween the dura and the skull
What intracranial bleed is characterized by:
lucidity → unconscious → conscious → unconscious
Epidural hematoma
Where is bleeding in subdural hematomas located?
Between the dura mater and the arachnoid mater.
What intracranial bleed is often characterized as the “worst headache of one’s life”?
Subarachnoid hemorrhage
What location is often the site of bleeding in subarachnoid hemmorhaging?
Circle of Willis (usually aneurysmal rupture)
Cerebral _______ is one of the complications often caused by subarachnoid hemorrhage.
vasospasm
Often occurs 3rd day post bleed and peaks 5-7 days in.
How is cerebral vasospasm treated?
Triple “H” Therapy
- HTN
- Hypervolemia
- Hemodilution
Intraarterial CCB injection
What type of hemorrhage occurs within the brain tissue itself?
Intracerebral (intra-parenchymal) hemorrhage.
What anti-cholinergic is best for Alzheimer’s patients?
Why is this?
Glycopyrrolate (doesn’t cross the BBB)
5
What factors possibly increase the risk of developing Parkinson’s?
- Welding
- Herbicides
- Pesticide
- Genetics
- Advanced age
What drugs will counteract levodopa and are contraindicated in Parkinson’s patients?
- Metoclopramide
- Haloperidol
- Droperidol
- Promethazine
Onset age? Risk factors? Triggers? S/s? Tx?
What is MS?
- Progressive, autoimmune demyelination of central nerve fibers
- Onset: 20-40
- Risk factors: Female, 1st degree relative hx of, Epstein-Barre Virus, smoking, other autoimmune dx
- Triggers: Stress, high temperature, post-partum
- Sx: Motor weakness, sensory disorders, visual impairment, autonomic instability
- No cure; manage symptoms w/ steroids, immune modulating drugs (azathioprine), IVIG
Respiratory concerns? Labs? Give steroids? Types of anesthesia?
Anesthesia Considerations for MS
What is critical in maintaining? Which NMB do we avoid?
- PFT if respiratory compromise
- Labs: CBC, BMP, LFT (depending on drugs taken)
- Consider pre-op steroids
- Temperature management is critical
- General, regional, and peripheral nerve blocks are acceptable
- Avoid succs
What induction agent is a good first-line agent for treatment of acute seizures?
Propofol
What are the s/s of seizures whilst under anesthesia?
- ↑HR
- HTN
- ↑ ETCO₂
Under normal conditions, what is the combined volume contained within the brain?
Brain tissue, intracranial CSF, intracranial blood have a combined volume of 1200-1500ml
Falx Cerebri
Dura that separates the two cerebral hemispheres
Tentorium Cerebelli
- Dura that lies rostral to the cerebellum
- Marks the border between supra & infratentorial spaces
Subfalcine Herniation
- Herniation of hemispheric contents under the falx cerebri
- Typically compresses branches of the anterior cerebral artery leading to a midline shift
Transtentorial Herniation
- Herniation of supratentorial contents past the tentorium cerebelli
- Causes brainstem compression —> leading to AMS, gaze & ocular reflex defects, hemodynamic & respiratory compromise
Cerebellar Tonsil Herniation
- Can occur due to elevated infratentorial pressure
- Causes cerebellar structures to herniate through the foramen magnum
- Cardiorespiratory instability & death
- Subfalcine
- Transtentorial
- Cerebellar contents through foramen magnum
- Traumatic event causing herniation out of cranial cavity
8 methods listed
Methods we can use to decrease ICP?
- Elevate HOB, keep head midline; promotes venous drainage
- Hyperventilation
- EVD
- Hyperosmotic drugs- mannitol, 3%, 23%
- Diuretics
- Corticosteroids
- Propofol
- Surgical decompression
Which nerves are susceptible? Triggers? Tx?
Myasthenia Gravis
Hyperplasia of which organ is common?
- Autoimmune; antibodies generated against n-AChr at neuromuscular junction
- Cranial nerves are susceptible-
-Ocular: Diplopia, ptosis
-Bulbar: Laryngeal/pharyngeal weakness –> aspiration risk - Thymic-hyperplasia is common
- Triggers: pain, insomnia, infection, surgery
- Tx: ACh-E inhibitors, immunosuppresive (azt), steroids, plasmapheresis, IVIG
Respiratory tests? Labs? Steroids? What prolongs succs?
Anesthesia Considerations for MG
May need post-op…?
- PFT if respiratory compromise
- Labs: CBC, BMP, LFT (depending on drugs taken)
- Consider pre-op steroids
- ACh-E inhibitors will prolong succs and ester LA’s
- May need post-op ventilation
Risk factor? Sx? Tx?
Eaton-Lambert Syndrome
- Autoimmune antibodies created against to voltage gated Ca++ channels
-Reduces Ca++ influx into cells –> decreases release of ACh into synapse @ NMJ - > 60% of cases are assoc. w/ small cell lung carcinoma
- Sx: Progressive limb-girdle weakness, dysautonomia, oculobulbar palsy
- Tx: K+ channel blocker (3-4 diaminopyridine), ACh-E inhibitors, AZT, steroids, plasmapheresis, IVIG
Senstive to what? May need post-op…?
Anesthesia Considerations ELS
- The most sensitive to non-depolarizing & depolarizing NMB
- Extreme caution w/ paralytics & opioids
- May need post-op ventilation
How many types? Most common type? Sx?
Muscular Dystrophy
- Hereditary disorder; breakdown of dystrophin-glycoprotein complex –> essentialy leads to skeletal muscle atrophy
- Duchenne is most common (boys, 2-5yrs)
-6 types total - Sx: Progressive muscle wasting without motor/sensory abnormalities, kyphoscoliosis, long bone fragility, resp. weakness, ekg changes, frequent pneumonia
- Elevated serum creat kinase due to muscle wasting
Pre-op exam needed? High risk for what? Avoid which drugs?
Anesthesia Considerations- Muscular Dystrophy
Anesthesia type preferred?
- Same as everything else w/
- Pre-op Ekg
- High risk for MH
- High risk for hypermetabolic syndrome (similar to MH, tx’ed same way)
- Have MH cart
- Avoid succs, VA
- RA preferred, TIVA for GA
Triggered by what? These conditions are managed with?
Myotonia
- Prolonged contraction after muscle stimulation
- Seen in several muscle disorders
- Triggered by stress & cold temp
- Managed w/ Quinine, Procainamide, Steroids
Myotonic Dystrophy
- Most common myotonia
- Onset 20’s-30’s
- Can affect pharyngeal, laryngeal, diaphragmatic muscles
- Cardiac conduction can be affected
Myotonia Congenita
- Most mild form of myotonic dystrophies
- Only involves skeletal muscles
Central Core Disease
- Rarest form of myotonic dystrophies
- Core muscle cells lack mitochondrial enzymes
- Progressive muscle weakness and scoliosis
Avoid what? Temp management?
Anesthesia Considerations for Myotonic Dystrophies
- Same as all other neuro disorders
- Avoid succs- triggers myotonia
- Keep them warm
Three types? Consent? High risk for what? Anesthesia preferred?
Dementia
- Alzheimers- 70%
- Vascular dementia- 25%
- Parkinsons- 5%
- Look for advanced directive; may not be able to consent
- Pre-op meds could affect anesthetics (AChE-I, MAOI’s, psych meds)
- High risk for post-op delirium (don’t give versed)
- Regional anesthesia preferred
Triad of sx? Tx?
Parkinson’s
- Degeneration of dopaminergic fibers in basal ganglia —-> lack of dopamine
- Causes dysregulation of extrapyramidal motor system –> overstimulated motor neurons
- Skeletal muscle tremor, rigidity, akinesia
- Tx: Levodopa, anticholingergics, MAOI, deep brain stimulator
Need to continue which med? Avoid what? Need to disable?
Parkinson’s Anesthesia Considerations
- Need to continue levodopa
- Avoid reglan, phenothiazines, butyrophenones
- Avoid demerol if taking an MAOI
- DBS needs to be disabled or use bipolar cautery
Astrocytomas
Can be primary or metastatic
Most common glial tumor
Glioma
* Primary tumor. Least aggressive. Often seen in young adults w/ new onset seizures
Pilocyctic astrocytoma
* Mostly benign. Seen often in children & young adults
Anaplastic astrocytoma
* Poorly differentiated –> evolve into glioblastoma
Glioblastoma Multiforme
* High mortality. Usually requires surgery & chemo
Meningioma
- Usually benign
- Arise from dura or arachnoid tissue
- Good prognosis
Pituitary Adenoma
- Noncancerous
- Transsphenoidal resection or open crani
Acoustic Neuromas
- Usually benign schwannoma involving the vestibular component of CN VIII in auditory canal
- Good prognosis
Metastatic Carcinoma
- Varies widely in origin & symptoms
- Prognosis not favorable
Pre-op meds will be dictated by? Imaging?
Brain Tumor Anesthesia Considerations
- Steroids to minimize cerebral edema
- Pre-op steroids and anticonvulsants per surgeon
- CT/MRI pre and post-op
- Mannitol
5 Classes
TOAST Classification for Ischemic Strokes
- Large artery atherosclerosis (carotid)
- Small vessel occlusion (lacunar)
- Cardioaortic embolic (a. fib)
- Other (hypercoagulable states)
- Undeterminded
Two most reliable predictors of outcome in a hemorrhagic stroke
- Estimated blood volume of hemorrhage
- Degree of change in LOC
If started on anticoags, when can they have elective surgery?
CVA, Anticoags, & Surgery
Bridge warfarin with? Regional anesthesia? CVA prophylaxis?
- No elective cases within 3 months if started on an anticoagulant for thrombus
- If taking anticoagulants for CVA prophylaxis, need to consult with prescribing provider
- If taking Warfarin, will need to bridge with Heparin or Lovenox
- Caution with regional- ensure anticoagulants are d/ced in an appropriate timeframe
Cerebral Aneurysms
- Only 1/3rd diagnosed prior to rupture
- Rx factors: HTN, smoking, female, oral contraceptives, cocaine
- Dx: CT/angio, MRI, lumbar puncture
- Need to intervene w/in 72hours of rupture
- Tx: Coiling, stenting, trapping/bypass
two systems
Aneurysm Grading for Prognosis
Two classification systems
Hunt & Hess
* 0-5
* 0 being unruptured, least mortality
* 5 being deep coma, highest mortality
World Federation of Neurosurgeons System
* 0-5. Uses GCS to classify
* 0 being unruptured
* 5 having a GCS of 3-6
What is the grading system?
AVM
- Arterial-venous connection
- Creates an area of high-flow
- Believed to be congenital
Spetzler-Martin AVM Grading System:
Predicts surgical outcome based on points assigned (based on size, pattern of venous drainage, eloquence of adjacent brain??)
Four types
Chiari Malformation
Congenital displacement of the cerebellum
- Type 1: Downward displacement
- Type 2: Arnold Chiari. Downward displacement of cerebellar vermis, often seen w/ myelomeningocele
- Type 3: Rare. Occiptal encephalocele w/ downward cerebellar displacement
- Type 4: Cerebellar hypoplasia. Not compatible w/ life
Tumors are often where?
Tuberous Sclerosis
- Bourneville Disease
- Autosomal dominant
- Disease causing benign hematomas, angiofibromas, other lesions
- Brain lesions can include: cortical tumors & giant cell astrocytomas
- Often involves tumors of face, oropharynx, heart, lungs, liver, kidneys
- Presents w/ mental retardation and seizure disorders
Von Hippel-Lindau Disease
- Autosomal dominant
- Benign tumors of CNS, eyes, adrenals, pancreas, kidneys
- May have pheochromocytoma
How many types? Will likely see what?
Neurofibromatosis
- Autosomal dominant
- Three types: 1 (most common), 2, Schwannomatosis
- Possibility of pheochromocytoma
- Likelihood of spinal tumors- avoid neuraxial
