neuro 17 Flashcards
cause of epidural hematoma
severe head injury with a temporal bone fracture and resultng laceration go the middle meningeal artery (less commonly laceration of middle meningeal vein or a dural venous sinus)
classic presentation of epidural hematoma
lucid interval, followed by rapid decline in consciousness as hematoma enlarges
complication of epidural hematoma
brain herniation
characteristic CT for epidural hematoma
lens shaped hyperdense region between the skull and the dura mater
cause of subdural hematoma
tearing of bridging veins that connect the surface of the brain to the dural sinuses
symptoms of subdural hematoma
headache is most common; contalateral hemiparesis, seizures, and cortical dysfunction
CT for subdural hematoma
crescent-shaped hyperdensity overlying the brain surface and underlying the skull
how to distinguish epidural from subdural hematoma on CT
subdural crosses suture lines, whereas epidural does not
central (transtentorial) herniation
decreae in alertness, shortly followed by small reactive pupils due to disruption of sympathetic pway from the hypothal
what happens as central herniation proceeds
decorticate posturing, hten midbrain compression with fixed midposiiton pupils and decerebrate posturing; then death
what causes uncal herniation
expnsion of a mass lterally in the brain which leads to a medial shift of the uncus of the temporal lobe
first clinical deficit in uncal herniateion
ipsilateral third nerve palsy, accompanied or shortly followed by an impairment of consciousness