Neuro Disease Assessment COPY Flashcards
What factors modulate cerebral blood flow (CBF)?
Cerebral metabolic rate
CPP (MAP-ICP)
PaCO2 and PaO2
drugs, pathologies
What is the approximate cerebral blood flow with autoregulation?
50 mL/100g brain tissue/min
~750mL/min
What does the intracranial and spinal vault contain?
Neural tissue
blood
CSF
What is the normal combined volume of brain tissue, intracranial CSF, and intracranial blood combined?
1200-1500mL
What is the normal intracranial pressure (ICP) range?
5-15 mmHg
What is the Monro-Kellie hypothesis?
Increase in one component must be offset by a decrease in another to prevent elevated ICP
How do homeostatic mechanisms compensate for increased ICP?
By increasing MAP to support CPP
What can happen if compensatory mechanisms for increased ICP fail?
Result in cerebral ischemia
What reflection of the dura separates the two cerebral hemispheres?
falx cerebri
What reflection of the dura lies rostral to the cerebellum and marks border between supratentorial and infratentorial spaces?
tentorium cerebelli
What is subfalcine herniation?
Hemispheric contents herniate under the falx cerebri.
What artery is compressed in subfalcine herniation?
Anterior cerebral artery
What is transtentorial herniation?
Supratentorial contents herniate past the tentorium cerebelli.
What is the consequence of transtentorial herniation?
Brainstem compression
What is the result of brainstem compression in transtentorial herniation?
AMS, gaze and ocular reflex defects, hemodynamic and respiratory compromise, and death
What is uncal herniation?
Subtype of transtentorial herniation where the uncus (medial temporal lobe) herniates over the tentorium cerebelli.
What are the manifestations of uncal herniation?
Pupillary dilatation, ptosis, lateral eye deviation, brainstem compression and death
What are the symptoms of herniation of the cerebellar tonsils?
Medullary dysfunction, cardiorespiratory instability
What are the types of brain herniation are indicated in 1-4?
- Subfalcine
- Transtentorial
- Cerebellar contents through foramen magnum
- traumatic hernation out of cranial cavity
How do tumors cause increased ICP?
- Directly due to size
- indirectly by causing edema in surrounding brain tissue
- obstructing CSF flow
How do intracranial hematomas cause increased ICP?
Similar to mass lesions
How can blood in the CSF lead to increased ICP?
Obstruct CSF reabsorption
What effect can infections like meningitis have on ICP?
Lead to edema or obstruction of CSF reabsorption
What positioning method encourages jugular venous outflow to decrease ICP?
Elevation of the head
How does hyperventilation help decrease ICP?
Lowers PaCO2 ⇒ vasoconstriction
How does using external ventricular drain (EVD) to decrease ICP?
CSF drainage
How do hyperosmotic drugs help decrease ICP?
Increase osmolarity, drawing fluid across BBB
What do diuretics do to help decrease ICP?
Induce systemic hypovolemia
How do corticosteroids help decrease ICP?
Decrease swelling and enhance BBB integrity
What is the role of cerebral vasoconstricting anesthetics like propofol in decreasing ICP?
Decrease CMRO₂ and CBF
What is a surgical intervention to decrease ICP?
Surgical decompression
What components are considered in a neurological assessment?
History, symptoms, baseline neuro-deficits
What should be included in pre-op documentation for a neurological assessment?
Factors considered and rationale for chosen plan
What is multiple sclerosis (MS)?
Progressive autoimmune demyelination of central nerve fibers
What are some risk factors for MS?
- Female
- Epstein-Barr Virus
- other AI disorders
- smoking
What are some exacerbation triggers for Multiple Sclerosis?
- Stress
- elevated temps
- postpartum period
What are the symptoms of Multiple Sclerosis?
- Motor weakness
- sensory disorders
- visual impairment
- autonomic instability
How is MS managed?
Corticosteroids
immune modulators
targeted antibodies
No cure
What is close temperature management critical for patients with Multiple Sclerosis?
increase in body temp can cause exacerbation of MS
Why might a stress-dose of steroids be necessary for an MS pt?
Long term steroids cause adrenal suppression
Why is it important to monitor glucose and electrolytes in MS patients?
Steroids impact levels
Why should Succinylcholine be avoided in MS patients?
May induce hyperkalemia from upregulated nAChRs
What is Myasthenia Gravis?
Autoimmune disorder characterized by production of antibodies that attack nAchR’s
Which muscle type is affected in Myasthenia Gravis?
Skeletal muscle
What exacerbates muscle weakness in Myasthenia Gravis?
Exercise
What are common symptoms of Myasthenia Gravis?
Diplopia
ptosis
Muscle weakness
respiratory insufficiency
risk of aspiration
What surgical procedure can improve 90% of patients with Myasthenia Gravis?
thymectomy
What can exacerbate symptoms of Myasthenia Gravis?
Pain
Insomnia
Infection
surgery
What are the treatment options for Myasthenia Gravis?
Ach-E inhibitors, immunosuppressive agents, steroids, plasmapheresis, IVIG
Preanesthetic Considerations for Myasthenia Gravis
Assess deficits, consider pulmonary function tests
MG Management During Anesthesia
Reduce paralytic dosage, caution with opioids
MG Labs
CBC, BMP, LFT (if on Azathioprine)
MG Steroid Considerations
Monitor glucose/electrolytes, consider pre-op steroids for long-term use
MG Post-Anesthesia respiratory considerations
Increased risk of resp support/ventilation until recovery
What is Eaton-Lambert Syndrome?
Autoantibodies against VG Calcium chnls ⇒ decreased release of ACh presynaptically
What is the most common associated cancer with Eaton-Lambert Syndrome?
Small cell lung carcinoma
What are the symptoms of Eaton-Lambert Syndrome?
- Progressive limb-girdle weakness that improves with repeated use
- dysautonomia
- oculobulbar palsy
What are treatment options for Eaton-Lambert Syndrome? (6)
- Selective K⁺ channel blocker (3-4 diaminopyridine)
- AChE inhibitors
- immunologics (azathioprine)
- steroids
- plasmapheresis
- IVIG
How consideration should be made with neuromuscular blocking agents and LEMS?
LEMS pts are VERY sensitive to ND-NMBs and D-NMBs
What should patients be counseled on regarding post-operative respiratory support?
Risks for needing it until fully recovered
What is Muscular Dystrophy?
Hereditary disorder of muscle fiber degeneration from dystrophin genetic abnormalities
What is the most common and severe form of Muscular Dystrophy?
Duchenne MD
What population is affect by Duchenne’s MD?
- Only in boys
- Onset 2-5yo
- avg lifespan ~20-25yr
What are symptoms of Duchenne Muscular Dystrophy? (5)
Progressive muscle wasting
long bone fragility
kyphoscoliosis
respiratory weakness
frequent Pneumonia
What is a key characteristic seen in Duchenne MD laboratory tests?
Elevated serum creatine kinase from muscle wasting
What cardiac evaluations should be performed pre-operatively?
Pre-op EKG, echocardiogram. Evaluate for cardiomyopathy
What syndrome is similar to MH and can be seen with Succinylcholine and volatile anesthetics with muscular dystrophy?
Hypermetabolic Syndrome
What complications can hypermetabolic syndrome lead to?
rhabdomyolysis
hyperkalemia
Vfib
cardiac arrest
What muscle relaxant and anesthesia approach is recommended for patients with MD?
low dose rocuronium and TIVA
Why is regional anesthesia preferred over general anesthesia in at-risk patients?
To avoid triggers and cardiopulmonary complications
What is myotonia?
Prolonged contraction after muscle stimulation
What are the symptoms of myotonic dystrophy?
Muscle wasting, may affect various muscles including face, airways and cardiac muscles
20% of individuals with myotonic dystrophy may have ___?
mitral valve prolapse (MVP)
How are myotonias triggered in these disorders?
By stress and cold temperatures
What is myotonia congenita?
milder form of myotonic dystrophy involving skeletal muscles but not smooth or cardiac muscles
What is central core disease?
disorder where core muscle cells lack mitochondria enzymes ⇒ proximal muscle weakness and scoliosis
What is the treatment approach for these myotonia disorders?
Symptom management with Quinine, Procainamide, Steroids
no cure
Why should Succinylcholine be avoided in myotonia disorders?
Fasciculations trigger myotonia
What should be assessed in pre-anesthetic considerations for myotonia disorders?
Cardiac and pulmonary abnormalities
endocrine abnormalities
What poses an increased risk of aspiration in myotonia?
GI hypomotility
What caution should be taken with opioids in these myotonia patients?
To avoid post-op respiratory depression
What are the 3 major dementia syndromes?
Alzheimer’s (70%)
Vascular dementia(25%)
Parkinson’s (5%)
What type of anesthesia should be considered to reduce the risk of post-op delirium?
Consider TIVA
Why should opioid use be minimized in dementia pts?
avoid exacerbating delirium
RA preferred to decrease opioid requirements
What is the cause of Parkinson’s Disease?
Degeneration of dopaminergic fibers of basal ganglia
Unknown cause; Advanced age is a risk factor
How does dopamine play a role in Parkinson’s Disease?
Regulates extrapyramidal motor system (inhibits excess stimulation)
What is the triad of symptoms of Parkinson’s Disease?
Tremor, rigidity, akinesia
TRAP
What are some signs of Parkinson’s Disease?
rhythmic Pill rolling
facial rigidity
slurred speech
dysphagia
dementia
respiratory difficulty
What are some treatment options for Parkinson’s Disease?
Levodopa
Anticholinergics
MAOIs
Deep brain stimulator
What should be assessed in patients with Parkinson’s disease before anesthesia?
Assess severity and degree of pulmonary compromise
Why is it important to review the patient’s home medications before anesthesia in Parkinson’s disease?
Many may interact with anesthetics (MAOIs)
Which medications should be avoided in patients with Parkinson’s disease before anesthesia?
Avoid: Reglan, Phenothiazines, Butyrophenones
Avoid Demerol if on MAOI
Why is PO Levodopa continued before anesthesia in Parkinson’s disease?
To avoid unstable extreme extrapyramidal effects
What type of cautery is recommended if used in patients with Parkinson’s disease? Why?
Bipolar cautery- reduces scattering of electrocurrent
if pt has deep brain stimulator
What are common symptoms of brain tumors?
↑ICP
Papilledema
Headache
AMS
Mobility impairment
Vomiting
Autonomic dysfunction
Seizures
What can the mass effects of a brain tumor cause?
Neurologic deficits
Which CNS glial cells are the most common?
Astrocytes
Which tumors are primary tumors, least aggressive astrocytomas?
Gliomas
Which tumors are usually found in young adults with new onset seizures?
gliomas
Which tumors are mostly benign, good outcomes if resectable?
Pilocytic astrocytomas
Which tumors usually evolve into glioblastoma multiforme?
Anaplastic astrocytomas
Which tumors carry a high mortality (weeks) and usually require surgical debulking and chemo?
Glioblastoma Multiforme
What is the general prognosis for meningiomas?
Usually benign, Good prognosis with surgical resection
What surgical methods are typically used for the removal of pituitary adenomas?
Transsphenoidal or open craniotomy usually curative
What is the typical prognosis for acoustic neuromas?
Good prognosis with resection +/- radiation
What are characterized by benign schwannomas involving the vestibular component of CN VIII within the auditory canal?
acoustic neuromas
Why are patients often on steroids before surgery for brain tumors? Should they be continued?
Minimize cerebral edema
will need to continue
What are common medications used for brain tumor patients closer to the motor cortex?
Anticonvulsants
What is often used to reduce intracranial volume and pressure in brain tumor patients?
Mannitol
How may autonomic dysfunction manifest in brain tumor patients?
manifest on EKG, labile HR & BP’s
What are strokes characterized by?
Sudden neurological deficits from Ischemia (88%) or hemorrhage (12%)
What is the leading cause of death and disability globally?
Stroke
Where is blood supplied to the brain from?
Internal carotid arteries & vertebral arteries
What are the joining vessels on inferior brain surface?
circle of willis
What does the circle of Willis provide during ideal circumstances?
Collateral circulation to multiple areas of the brain
What are the clinical features of an anterior cerebral artery occlusion?
Contralateral leg weakness
What are the clinical features of a middle cerebral artery occlusion?
- Contralateral hemiparesis and hemisensory deficit
- Aphasia
- contralateral visual field defect
What are the common clinical features of posterior cerebral artery occlusion?
- contralateral visual field defect
- contralateral hemiparesis
What are the common clinical features of penetrating artery occlusion?
- Contralateral hemiparesis
- contralateral hemisensory deficits
What are the clinical manifestations of vertebral artery occlusion?
lower cranial nerve deficits and/or ataxia
What deficits may occur with basilar artery occlusion?
Oculomotor deficits and/or ataxia with crossed sensory and motor deficits
What is an ischemic stroke?
Occlusion of a vessel in the brain causing cellular ischemia
What is a transient ischemic attack (TIA)?
Sudden neurologic deficit resolving in 24 hrs
Why is a non-contrast CT needed in suspected stroke cases?
To distinguish ischemic from hemorrhagic stroke
___ of pts who experience TIA will subsequently suffer a stroke
1/3
What is often the recommended initial treatment for acute ischemic stroke?
PO Aspirin
What is essential in the pre-anesthetic evaluation for revascularization in ischemic stroke treatment?
Baseline neuro assessment, ability to lay flat, cardiovascular function
What CV risk factors do patients with ischemic stroke frequently have?
HTN, DM, CAD, Afib, valvular disease
How is stroke revascularization usually performed?
performed in IR, and angiographic and radiographic guidance during administration of thrombolytics or thrombectomy
What is an acute hemorrhagic stroke and its effect?
Bleeding inside cranial vault impairing brain perfusion
What are the two most reliable predictors of outcome in hemorrhagic strokes?
Estimated blood volume & change in LOC
What are the subtypes of hemorrhagic stroke based on the location of blood?
Intraparenchymal
epidural hematoma
subdural hematoma
subarachnoid hemorrhages
intraventricular hemorrhage
What does conservative treatment for hemorrhagic CVA focus on?
Reduction of ICP, blood pressure control, seizure precautions
What is a key aspect of surgical treatment for hemorrhagic CVA?
Evacuation of the hematoma
New anticoagulant for thrombus=No elective cases within ____
3 months
What is required when there is a need to discontinue anticoagulants for regional anesthesia (RA)?
For RA planned, d/c anticoagulants for sufficient time to safely perform block
What assessments should be conducted for a patient with cerebrovascular disease pre-op?
(Mini neuro exam)
Orientation
pupils
grip strength
LE strength
What symptoms should be asked about in a patient with cerebrovascular disease pre-op?
Headaches, tinnitus, vision/memory loss, bathroom issues
What should be examined regarding the root cause of cerebrovascular accident?
Vascular disease, embolic causes
What imaging studies are recommended for a patient with cerebrovascular disease pre-op?
Carotid U/S, CT/MRI head & neck, echocardiogram
What tests should be performed preoperatively on a patient with cerebrovascular disease?
EKG, CBC, BMP, possible T & C
What vascular access measures should be considered pre-op?
A-line, 2 IVs and/or CVC
What is the recommended timeframe for intervention in cerebral aneurysms post-rupture?
Within 72 hours
What are some risk factors for cerebral aneurysms? (5)
HTN
smoking
female
oral contraceptives
cocaine use
What are the common symptoms of cerebral aneurysms? (5)
Headache
photophobia
confusion
hemiparesis
coma
What imaging techniques are used for diagnosing cerebral aneurysms?
CT/angio, MRI, Lumbar puncture with CSF analysis if rupture suspected
What are some pre-anesthesia assessments needed for a patient with a cerebral aneurysm?
CT/MRI, EKG, Echo, CBC, BMP, T&C with blood available
What are the surgical treatment options for cerebral aneurysms?
Coiling, stenting, trapping/bypass for very large aneurysms
What does anesthesia management generally entail?
Avoid rupture
BP control
Seizure prophylaxis
Why is glucose monitoring important in patients with cerebral aneurysms?
May be on Steroids, may lead to hyperglycemia
When does the risk for vasospasm typically occur post SAH?
3-15 days post SAH
What triggers inflammatory mediators in post-SAH vasospasms?
Free hgb
What does free hgb trigger that reduces nitric oxide availability and increases endothelin 1?
Inflammatory mediators
What does Triple H therapy stand for in managing post-SAH vasospasms?
Hypertension
Hypervolemia
Hemodilution
What is the initial main treatment to avoid complications of hypervolemia in managing post-SAH vasospasms?
HTN
What interventional treatments can relieve vasospasm in post-SAH cases?
Balloon dilation, direct injection of vasodilators
What is the main aneurysm grading scale used for prognosis?
Hunt and Hess Classification
ranges from
- 0: unruptured aneurysm: 0-2% mortality
- 5: deep coma, decerebrate: 40-50% mortality
What is an Arteriovenous Malformation (AVM)?
Arterial to venous connection without intervening capillaries
What symptoms can Arteriovenous Malformations present with?
Range from mass-effects to hemorrhage
AVM create an area of ___ flow, ___ resistance shunting
high flow
low resistance
How are Arteriovenous Malformations diagnosed?
Angiogram, MRI
What are the treatment options for Arteriovenous Malformations?
Radiation
angio-guided embolization
surgical resection
What interventions may be needed for patients with Arteriovenous Malformations before anesthesia?
BP control
seizure prophylaxis
CVC or 2 large bore IV’s
A-line
How is a Spetzler-martin arteriovenous malformation grading system scored?
What are congenital brain abnormalities?
Defects in development or structure of CNS, often hereditary
What is Chiari Malformation?
Congenital displacement of cerebellum
What are the different types of Chiari Malformation?
- Type 1: downward displacement of cerebellum
- Type 2: downward displacement of vermis
- Type 3: occipital encephalocele, downward cerebella displacement
- Type 4: cerebellar hypoplasia, w/o displacement (not compatible with life)
What are the symptoms of Chiari Malformation?
Headache
visual disturbances
ataxia
How is Chiari Malformation treated?
Surgical decompression
What pre-anesthesia considerations should be taken for Chiari Malformation?
may hyperventilate to ↓ICP
2 large bore IV or CVC
A-line
What is another name for Tuberous Sclerosis?
Bourneville Disease
What type of disease is Tuberous Sclerosis?
Autosomal dominant disease causing benign hemartomas, angiofibromas and other malformations
What are some brain lesions seen in Tuberous Sclerosis?
Cortical tumors, giant-cell astrocytomas
Which organs can be affected by Tuberous Sclerosis tumors?
Face
oropharynx
heart
lungs
liver
kidneys
What are common presentations associated with Tuberous Sclerosis?
Mental retardation and seizure disorders
What must be considered during anesthesia for Tuberous Sclerosis patients?
Airway compromise, cardiac/kidney involvement
What is Von Hippel-Lindau Disease characterized by?
Autosomal dominant disease causing tumors of the CNS, eyes, adrenals, pancreas, kidneys
What should be considered in anesthesia management for patients with Von Hippel-Lindau Disease and pheochromocytoma?
Exaggerated HTN
Why may neuraxial anesthesia be limited in Von Hippel-Lindau Disease patients?
Co-existing spinal cord tumor
What is neurofibromatosis characterized by?
genetic disorder of nervous system causing tumors to form on the nerves in the body
What are the three types of neurofibromatosis?
Type 1 (most common)
Type 2
Schwannomatosis (rare)
What are some anesthesia considerations for patients with neurofibromatosis?
Increased ICP
Airway issues
Scoliosis
Possible pheochromocytoma
Why should neuraxial blockade be avoided in patients with neurofibromatosis?
High likelihood of spinal tumors
What is hydrocephalus?
Disorder of CSF accumulation causing increased ICP and ventricular dilation
What causes the accumulation of CSF in hydrocephalus?
Imbalance between CSF production and absorption
What are some possible causes of hydrocephalus?
congenital or acquired: Meningitis, tumors, head injury, stroke
What are the main treatment options for hydrocephalus?
Diuretics
Serial LPs
Ventriculoperitoneal (VP) shunt
Endoscopic Third Ventriculostomy (ETV)
What is a VP shunt in the treatment of hydrocephalus?
Drain placed in ventricle draining into peritoneum
What is a ETV in the treatment of hydrocephalus?
Drain placed in lateral ventricle of brain and empties into peritoneal space, R atrium, or pleural space
When does VP shunt malfunction most frequently occur?
First year after placement
What are the two categories in which Traumatic Brain Injury (TBI) can be classified?
Penetrating or non-penetrating depending on breach of the dura
How is the severity of TBI categorized?
Glasco-Coma Scale
What are some examples of secondary injuries in TBI?
Neuroinflammation
cerebral edema
hypoxia
electrolyte imbalances
neurogenic shock
When is intubation required in severe TBI?
GCS <9
AW trauma
resp distress
Why might mild hyperventilation be recommended for TBI?
To control ICP
What imaging is recommended ASAP for TBI patients?
CT of head/neck
What should be done before emergent surgery?
C-spine stabilization
adequate IV access, CVC
a-line
Possible uncrossmatched blood
What labs and medications should be considered intra-op?
ISTAT labs, Pressors, Bicarb, Calcium, Blood products
Why should NGT/OGT be avoided?
Potential for basal skull fx
What is a seizure?
Transient, paroxysmal, synchronous discharge of neurons in the brain
What are some possible transient abnormality causes of seizures?
hypoglycemia
hyponatremia
hyperthermia
intoxication
What is epilepsy?
Recurrent seizures due to congenital or acquired factors
What is the action of antiepileptic drugs?
Decrease neuronal excitability/enhance inhibition
What are important pre-anesthesia considerations in regard to seizure history?
- Determine seizure source (if known) and how well controlled
- Have antiseizure drugs on board before incision
Which medications are enzyme-inducers for seizures?
Phenytoin, Tegretol, Barbiturates
What may be required for hepatically-cleared medications in patients actively taking seizure medications?
Likely higher doses required
What action may be needed post-seizure in some cases?
RSI intubation with cricoid pressure
