Flashcards in Head Trauma Deck (22):
An epidural hematoma is a blood accumulation between what?
skull and dura mater
What is the usual cause of an epidural?
trauma to the temporal bone leading to laceration of the middle mengineal artery
less frequently, laceration of the middle meningeal vein or a dural venous sinus
What is the classic presentation of an epidural?
a lucid interval immediately after the precipitating event, followed by a decline in the level of consciousness with rapid progression to coma
uncal herniation can develop as the result of hematoma expansion
What will be seen on head CT in an epidural?
a lens-shaped hyperdense lesion between the skull and the dura
What is the management for an epidural?
surgical evacuation is required
What is the cause of a subdural?
tearing of the bridging veins that connect the surface of the brain and the dural sinuses
Subdurals can be either acute after a trauma or chronic. Do they always need evacuation?
No - they may require evacuation depending on the severity of the neurological symptoms, but can often resolve on their own
What will a subdural look like on head CT and how does this differ from an epidural?
they'll look like a crescent-shaped hyperdensity overlying the brain surface and underlying the skull. They differ from epidurals in their ability to cross suture lines
What are the recommendations for how long athletes should sit out after concussion?
No LOC and symptoms lasting less than 15 min: can return to play right away, but should sit out a week if a second such event occurs that same day
No LOC and symptoms lasting over 15 min: be evaluated frequently by a trainer and sit out for a week
LOC: be evaluated at a hospital and take 1-2 weeks off
What will diffuse axonal injury look like on CT?
multiple areas of punctate hemorrhage in the deep white matter and corpus callosum
25% of patients with acute severe head injury will have a posttraumatic seizure within one week. What percentage of these patients will go on to develop epilepsy?
(note: AEDs will reduce the incidence of early seizures, but will not change the overall risk for the later development of epilepsy)
Central herniation occurs with downward herniation of the diencephalon through the tentorial notch. How does this present clinically?
decreased in the level of alertness
small, reactive pupils due to disruption of sympathetic pathways from the hypothalamus
as it proceeds, the pt may assume a decorticate posture upon stimulation
eventually fixed midposition pupils and decerebrate posturing
final stages - motionless and unresponsive to stimulation
Uncal herniation is most often produced by what?
expansion of a mass located laterally within the brain
What is the first deficit seen with an uncal herniation?
an ipsilateral IIIrd nerve palsy, bollowed by impairment of consciousness
Continued uncal herniation will cause compression of the contralateral cerebral peduncle against the free edge of the tentorium with a resulting hemiplegia that is ipsilateral or contralateral to the herniating uncus? What is this called?
This is Kernohan's notch phenomenon
Expansile frontal lobe masses will produce herniation of what?
the cingulate gyrus beneath the falx cerebri
Often a cingulate gyrus herniation does not change the clinical picture much beyond that of the frontal mass, but what might you see if it's severe?
leg weakness through compression of the ACA
What is the normal ICP in an adult?
less than 15 mm Hg
Cerebral perfusion pressure is defined as what? What is the goal?
the difference between the mean arterial pressure and the ICP
goal is a CPP between 60 and 75 mmHg
When should you consider monitoring the ICP with an intraventricular pressure monitor?
in any head injury patient with a GCS less than 9 and abnormalities on the head CT
What are some management options for elevated ICP?
elevate the head of the bed to 30 degrees
hyperventilate to a PCO2 between 25 and 30 mmHg
Mannitol or hypertonic saline
IV barbiturates to reduce cerebral metabolism
CSF drainage with a ventricular drain
hemicraniectomy if severe