Path: CNS trauma Flashcards
Describe Cushing’s Reflex
Increased intracranial pressure (like from hemorrhage) leads to compression of the cerebral venous system and decreased blood flow to the brain. The medulla responds by releasing a sympathetic response leading to arterial constriction to raise blood pressure.
The baroceptors sense increased BP and decrease the heart rate with a parasympathetic response.
Overall: increased BP and bradycardia
What vessel is involved in an epidural hematoma and where does blood accumulate?
Middle Meningeal Artery
Accumulation between the calvaria and dura
What causes loss of consiousness during a concussion?
Sudden cessation of signals from the brain to the reticular formation in the brainstem.
What vessels are involved in a subdural hematoma and where does the blood accumulate?
Bridging cerebral veins
-blood accumulates between the dura and arachnoid mater
What is the major problem with subdural hematomas?
When the low pressure veins rupture, often the blood clots and forms a thrombus. The thrombus can detach causing rebleeding. Often this blood ends up in the CSF and can be detected in lumbar puncture.
What is a cerebral contusion?
Traumatic bruise on the brain’s surface usually caused by trauma that forces the brain to impact the skull.
Most common congenital vascular malformation.
Arteriovenous Malformation
-very common cause of stroke and very difficult to treat.
What is a berry aneurysm?
Saccular aneurysm usually resulting from a weakened arterial wall. Common sites are around the circle of willis.
What is an atherosclerotic aneurysm?
Fusiform aneurysm that involves an outpouching of both walls of a blood vessel. Bleed mainly into the putamen.
What is a Charcot-Brouchard aneurysm.
Aneurysm caused by thickened vascular walls and lipid deposits that result in hypertension.
What is the greatest hemorrhage risk in premature infants?
Hemorrhages into the ventricular system
Most common cause of watershed infarcts.
Global ischemia caused by myocardial infarction, hemorrhage, or some other type of impaired blood flow to the brain.
Most common cause of ischemia and cerebral infarct.
Occlusive disease such as emboli or atherosclerosis.
