neurologic emergencies and surgical intervention Flashcards
normal intracranial pressure in adults
- <10-15 mmHg
intracranial components by volume percentage
- brain parenchyma: 80%
- CSF: 10%
- blood: 10%
following a significant increase in ICP, brain injury can result from
- brainstem compression (herniation)
- reduction in CBF (cerebral blood flow)
uncal herniation will present as
- CN III compression
- unilateral fixed, dilated pupil
- progressive deterioration in LOC
papilledema is a sign of
- increased intracranial pressure
Cushing’s triad is an ominous finding of elevated ICP. what does it involve?
- bradycardia
- respiratory depression
- hypertension
decorticate posturing. describe it? Reflects destructive lesion in the
- arms flexed: hands to the body core
- lesion in the corticospinal tract from cortex to upper midbrain
decerebrate posturing. describe it? Reflects destructive lesion in the
- arms extended
- corticospinal tract at level of pons or upper medulla
describe rating scale for motor function of extremities
- 1/5 minimal flicker
- 2/5 movement with gravity eliminated
- 3/5 movement against gravity
- 4/5 weakness
- 5/5 complete
managememt of elevated ICP
- referral to neurosurgery
- oxygenation: maintain O2 sat >90%
- control HTN/avoid hypotension: maintaine cerebral perfusion pressure > 60 mmHg
- elevate head of bed to 30 deg
- analgesia/sedation
- IV mannitol: osmotic diuresis
- mechanical ventilation to lower PaCO2
what are the three types of skull fractures
- linear
- depressed
- basilar
define linear skull fracture
-
single fracture that most often extends through the entire thickness of the calvarium
- majority have minimal or no clinical significance
define depressed skull fracture
- segment of skull is forced below the level of adjacent skull
- may be open or closed
depressed skull fractures often involve injury to the brain parenchyma and are associated with increased risk of
- infection
- seizure
- death
define Basilar skull fracture
- involves at least one of the bones that comprise the base of the skull
- temporal bone, occipital bone, sphenoid bone, and/or ethmoid bone.
Basilar skull fractures occur most commonly through which bone
- temporal bone
signs of Basilar skull fracture
- hemotypmanum
- “raccoon eyes”
- battle sign
- CSF otorrhea or rhinorrhea
imaging modality of choice for a suspected skull fracture
- noncontrast CT scan
a brain contusion - area of bruising on the brain- is associated with localized
- ischemia
- edema
- mass effect
what is a diffuse axonal injury (DAI)
- shearing of white matter tracts from traumatic sudden deceleration injury (blunt trauma) -> severe intracranial injury
CT scan of diffuse axonal injury will show
- blurring of gray to white matter margina
- cerebral hemorrhage
- cerebral edema
which type of intracranial hematoma is most associated with a skull fracture
-
epidural hematoma
- middle meningeal artery
which intracranial hematoma is characterized by a collection of venous blood between the dura matter and the arachnoid
- subdural hematoma
- tearing of bridging veins
clinical presentation
- brief LOC
- lucid interval
- rapid clinical deterioration
what will CT scan likely show
- epidural hemotoma
- lens-shaped
what will CT scan of subdural hematoma likely show
- crescent shape
differentiate betwen acute, subacute, and chronic subdural hematoma
- acute: symptoms within 24-48 hours after onset
- subacute: sx 3-14 days after onset
- chronic: sx > 2 weeks after onset
nontraumatic causes of subarachnoid hemorrhage
- aneurysm
- vascular malformation
clinical presentation
- “worst headache of my life”
- subarachnoid hemorrhage
evaluation of subarachnoid hemorrhage
- CT scan noncontrast
- LP
- RBC and xanthochromia
what is the gold standard for detecting intracranial aneurysms
- digitial subtraction angiography
most common cause of hemorrhagic stroke
- hypertension
management of hemorrhagic stroke
- neurosurgical consult
- BP control, avoid hyperglycemia
- sz prophylaxis
- hemostatic therapy
- reversal of anticoagulation
intraventricular hemorrhage puts a person at risk for
- hydrocephalus
causes of intraventricular hemorrhage
- primary uncommon
- more commonly extension of intracerebral hemorrhage or SAH
target BP for patient with an ischemic stroke who is not a candidate for IV thrombolysis
- no intervention unless BP
- > 220 systolic or > 120 diastolic
target BP for patient with an ischemic stroke who is a candidate for IV thrombolysis
- SBP < 185
- DBP < 110
inclusion criteria for thrombolytics
- clinical diagnosis of ischemic stroke
- onset of symptoms < 4.5 hours before tx
- age > or = 18 yo
treatment of status epilepticus (sz lasting 5 minutes)
- Iv lorazepam (or diazepam) + IV phenytoin
what is indicated for all patients with a new seizure
- CT or MRI
patients with a new onset seizure can be discharged with outpatient f/u if
- returned to baseline
- normal CT scan
- normal lab evaluation
what is a jefferson fracture? cause
- most common fracture of C1 atlas
- caused by axial compression
is jefferson fracture usually associated with spinal cord damage?
- no
- because canal diameter is not compromised
C2 (axis) fractures, fractures of dens are usually associated with what type of injury
- forcefull flexion or extension
C2 (axis) fractures, fractures of dens are broken down into what types? which are stable?
- Type 1: stable
- Type 2, 3: unstable
What is the hangman’s fracture?
- C2 fracture involving both pedicles
hangman’s fracture. type of injury associated with it?
- hyperextension with compression
- if death occurs: usually instantaneous due to spinal cord transection
What is a burst fracture
- direct axial load -> fragments displacing in all directions
- spinal cord may be injured if fragments enters spinal canal
disk herniation diagnosed with what imaging modality
MRI
clinical presentation
- urinary retention
- radiculopathy
- bilateral lower extremity muscle weakness
- saddle anesthesia
- decreased anal spincter tone
cauda equina syndrome
evaluation of cauda equina syndrome
- emergent MRI or CT myelography
neurogenic shock occurs most commonly after
- cervical spine injury
anterior cord syndrome will present with
- complete motor paralysis below level of lesion
- loss of pain and temperature sensation below level of lesion
- retained proprioception and vibratory sensation
central cord syndrome will present with
- hyperextension injury of cervical spine
- motor impairment, greatest in upper extremities
brown sequard syndrome presents wtih
- spinal cord hemisection
- ipsilateral loss of motor function, proprioception and vibration sensation
- contralateral loss of pain and temperature
near total ventilatory muscle paralysis will occur with injury to spinal cord at what level
- above C3
what is the most common demyelination neuropathy
- guillain-barre syndrome
clinical presentation
- previous mild URI or gastroenteritis, influenza immunization or surgery
- acute onset of ascending paralysis starting distally
- weakness symmetric
- guillain-barre syndrome
LP in guillain-barre syndrome will show
- elevated CSF protein without pleocytosis (increase in white blood cell)
which type of meningitis is a neurologic emergency
- bacterial
patients with meningitis should be given early IV
dexamethasone
definitive diagnosis of brain abscess
- stereotactic (open) brain biopsy
