Neuro - Anat & Phys (Intracranial hemorrhage & Strokes) Flashcards
Pg. 462-463 in First Aid 2014 Sections include: -Intracranial hemorrhage -Ischemic brain disease/stroke
Name 4 kinds of intracranial hemorrhage.
(1) Epidural hematoma (2) Subdural hematoma (3) Subarachnoid hematoma (4) Intraparenchymal (hypertensive) hemorrhage
What causes an epidural hematoma? To what is it often secondary?
Rupture of middle meningeal artery (branch of maxillary artery), often secondary to fracture of temporal bone
What clinical phenomenon is characteristic of epidural hematoma patients?
Lucid interval
What are 2 kinds of damage that can result from epidural hematoma? What is the pathogenesis leading to this damage?
Rapid expansion under systemic arterial pressure –> (1) transtentorial herniation, (2) CN III palsy
Describe the CT findings characteristic of an epidural hematoma. Of these, which is the most significant characteristic?
CT shows biconvex (lentiform), hyperdense (light) blood collection NOT CROSSING SUTURE LINES. CAN CROSS FALX, TENTORIUM.
What causes a subdural hematoma?
Rupture of bridging veins
What kind of bleeding occurs with a subdural hematoma? Explain the consequence of this.
Slow venous bleeding (less pressure = hematoma develops over time)
What are 4 patient populations in which subdural hematomas are seen? What are 3 predisposing factors to subdural hematomas?
Seen in (1) elderly individuals, (2) alcoholics, (3) blunt trauma, (4) shaken baby (Predisposing factors: brain atrophy, shaking, whiplash)
Describe the CT findings characteristic of a subdural hematoma. Of these, which is the most significant characteristic?
Crescent-shaped hemorrhage that CROSSES SUTURE LINES. Midline shift. CANNOT CROSS FALX, TENTORIUM.
What are 2 causes of a subarachnoid hemorrhage?
(1) Rupture of an aneurysm (such as berry [saccular] aneurysm, as seen in Marfan, Ehlers-Danlos, ADPKD) or (2) an AVM (Atriovenous malformation).
What is an example of aneursym that could rupture and lead to subarachnoid hemorrhage? What are 3 examples of conditions associated with such an aneurysm?
Rupture of an aneurysm (such as berry [saccular] aneurysm, as seen in Marfan, Ehlers-Danlos, ADPKD)
What are 2 significant findings in the history of present illness that may suggest subarachnoid hemorrhage?
(1) Rapid time course (2) Patients complain of “worst headache of my life (WHOML)”
What is the spinal tap finding associated with subarachnoid hemorrhage?
Bloody or yellow (xanthochromic) spinal tap
What are 2 risks following subarachnoid hemorrhage? How soon after? Which of these is visible on CT?
2-3 days afterward, risk of (1) vasospasm due to blood breakdown (not visible on CT, treat with nimodipine) and (2) rebleed (visible on CT)
How is vasospasm secondary to subarachnoid hemorrhage treated?
Nimodipine
What is another name for intraparenchymal hemorrhage? What most commonly causes it?
Intraparenchymal (hypertensive) hemorrhage; Most commonly caused by systemic hypertension
Other than systemic hypertension, what are 3 other conditions in which intraparenchymal (hypertensive) hemorrhage is seen?
Also seen with amyloid angiopathy, vasculitis, and neoplasm
Where in the brain and/or in what fashion does intraparenchymal (hypertensive) hemorrhage typically occur?
Typically occurs in basal ganglia and internal capsule (Charcot-Bouchard aneurysm of lenticulostriate vessels), but can be lobar
Name an aneurysm that affects internal capsule and is associated with intraparenchymal (hypertensive) hemorrhage.
Charcot-Bouchard aneurysm of lenticulostriate vessels
In the setting of ischemic brain disease or stroke, when does irreversible damage begin?
Irreversible damage begins after 5 minutes of hypoxia
What 4 parts of the brain are most vulnerable to ischemic brain disease or stroke (i.e., hypoxia)?
Most vulnerable - (1) hippocampus, (2) neocortex, (3) cerebellum, (4) watershed areas.
How are neurons impacted by ischemic brain disease or stroke?
Irreversible neuronal injury
How is MRI used for imaging stroke? What is the most significant use of MRI in the setting of stroke?
Bright on diffusion-weighted MRI in 3-30 minutes (highest sensitivity for early ischemia)
How is CT used for imaging stroke? What is the most significant use of CT in the setting of stroke?
Dark abnormality on noncontrast CT in ~12-24 hours. Absence of bright areas on noncontrast CT highly accurate to exclude hemorrhage (contraindication for tPA).
