Intracranial Bleeding B&B Flashcards
what are 5 possible causes of raised intracranial pressure (ICP)?
- mass lesions (tumors)
- cerebral edema (large stroke, severe trauma)
- hydrocephalus
- obstruction of venous outflow (thrombosis)
- idiopathic intracranial HTN (aka pseudotumor cerebri)
what are the general symptoms of increased ICP (intracranial pressure)? (3)
- headache (due to pain fibers of CN V in dura mater)
- depressed consciousness (due to pressure on midbrain reticular formation)
- vomiting
what is the cause of papilledema? (2)
aka optic disc swelling - due to increased ICP (intracranial pressure)
also seen in severe HTN
usually bilateral, shows blurred margins of the optic disc on fundoscopy
patients with very high intracranial pressure (ICP) can present with _____ triad:
Cushing’s Triad: HTN + bradycardia + irregular respiration
unconscious patients with severely high intracranial pressure (ICP) may present with 1 of 2 “postures”… what are they, and what is the differentiating factor?
unconscious patients with severely high ICP may exhibit posturing, which comes in 2 varieties:
- decorticate = arms flexed, due to cerebral hemisphere damage
- decerebrate = arms extended (at sides), due to brainstem damage
it is believed the key difference is the red nucleus (controls a lot of flexors - if spared, pt exhibits decorticate; if lesion is below, pt exhibits decerebrate)
Unconscious pt is brought to the ED and is found to have severely high ICP. They are lying with their arms flexed onto their abdomen. What kind of damage occurred?
unconscious patients with severely high ICP may exhibit posturing, which comes in 2 varieties:
- decorticate = arms flexed, due to cerebral hemisphere damage
- decerebrate = arms extended (at sides), due to brainstem damage
it is believed the key difference is the red nucleus (controls a lot of flexors - if spared, pt exhibits decorticate; if lesion is below, pt exhibits decerebrate)
Unconscious pt is brought to the ED and is found to have severely high ICP. They are lying with their arms extended at their sides. What kind of damage occurred?
unconscious patients with severely high ICP may exhibit posturing, which comes in 2 varieties:
- decorticate = arms flexed, due to cerebral hemisphere damage
- decerebrate = arms extended (at sides), due to brainstem damage
it is believed the key difference is the red nucleus (controls a lot of flexors - if spared, pt exhibits decorticate; if lesion is below, pt exhibits decerebrate)
how is the Glasgow Coma Scale scored?
GSC score is 3 (bad) to 15 (good)
- eye (1-4 points): does not open, opens to painful stimuli, opens to voice, opens spontaneously
- verbal (1-5 points): no sound, incomprehensible, inappropriate words, confused, oriented
- motor (1-6 points): no movements, decerebrate posturing (arms extended), decorticate posturing (arms flexed), withdrawal to pain, localizes to pain, obeys commands
what are the 4 types of brain herniation syndromes?
expanding volume (blood, tumor) forces brain through weakest points - most patients do not survive
- subfalcine: side to side (cingulate gyrus under falx cerebri)
- uncal: side to bottom, transtentorial (uncus into brainstem)
- central: diencephalon downward towards midbrain
- tonsillar: cerebellum through the “hole” (compress midbrain)
what occurs in a subfalcine hernation?
cingulate gyrus (brain tissue right next to corpus collosum) herniates under the falx cerebri (dura mater separating hemispheres)
this drags the anterior cerebral artery (ACA) with it!! gets compressed —> contralateral leg paresis (supplies motor neurons of lower leg)
which type of brain herniation presents with leg paresis due to compression of the ACA?
subfalcine herniation: cingulate gyrus (brain tissue right next to corpus collosum) herniates under the falx cerebri (dura mater separating hemispheres)
this drags the anterior cerebral artery (ACA) with it!! gets compressed —> contralateral leg paresis (supplies motor neurons of lower leg)
what occurs in an uncal herniation?
uncal = medial temporal lobe
uncus herniates across the tentorium (dura mater above cerebellum) —> compresses midbrain
presents with dilated pupil (ipsilateral) + visual loss + hemiparesis or quadriparesis
what are the symptoms of an uncal herniation? (4)
uncus (medial temporal lobe) herniates across the tentorium (dura mater above cerebellum), compressing midbrain
- ipsilateral CNIII compression —> loss of PNS innervation causes dilated “blown” pupil
- collapse of ipsilateral posterior cerebral artery (PCA) —> cortical blindness + homonymous hemianopsia
- cerebral peduncle compression —> contralateral w/wo ipsilateral (Kernohan’s notch) paresis
- duret hemorrhage of pons and midbrain (perforating branches of basilar artery draining veins)
which type of brain herniation presents with blown (dilated) pupil + visual loss + hemiparesis OR quadriparesis?
uncus (medial temporal lobe) herniates across the tentorium (dura mater above cerebellum), compressing the midbrain
- ipsilateral CNIII compression —> loss of PNS innervation causes dilated “blown” pupil
- collapse of ipsilateral posterior cerebral artery (PCA) —> cortical blindness + homonymous hemianopsia
- cerebral peduncle compression —> contralateral (hemi) w/wo ipsilateral (quad) (Kernohan’s notch) paresis
- duret hemorrhage of pons and midbrain (perforating branches of basilar artery draining veins)
what occurs in a transtentorial herniation?
transtentorium = dura matter separating cerebrum from cerebellum
thalamus/ hypothalamus/ medial parts of both temporal lobes are forced through tentorium cerebellum (downwards)
—> somnolence, LOC, small/reactive pupils (early) to non-reactive (late), posturing, death
how does a transtentorial herniation present?
transtentorium = dura matter separating cerebrum from cerebellum
thalamus/ hypothalamus/ medial parts of both temporal lobes are forced through tentorium cerebellum (downwards)
—> somnolence, LOC, small/reactive pupils (early) to non-reactive (late), posturing, death
An unconscious pt is brought to the ED. Upon initial assessment, the pupils are small and reactive. However, within a few hours they become non-reactive, and the patient exhibits posturing. What has likely occurred?
transtentorium = dura matter separating cerebrum from cerebellum
thalamus/ hypothalamus/ medial parts of both temporal lobes are forced through tentorium cerebellum (downwards)
—> somnolence, LOC, small/reactive pupils (early) to non-reactive (late), posturing, death
what occurs in a tonsillar herniation?
cerebellar tonsils (bottom portions) herniate downward through foramen magnum
most commonly caused by posterior fossa mass lesion
compression of medulla —> depressed respiratory/cardiac centers —> cardio-respiratory failure