Cerebrovascular Accidents 1 and 2

Question 1

Infarction

Answer 1

Disruption of blood flow to the brain.

Question 2

Infarct

Answer 2

Area of damage or dead tissue resulting fro an infarction.

Question 3

Ischemia

Answer 3

Insufficient or no blood flow to the brain as a result of a blockage.

Question 4

Thrombotic Stroke

Answer 4

Caused by a build up of plaque and other particles that block the blood vessel, resulting in loss of blood flow.

Question 5

Embolic Stroke

Answer 5

Thrombotic material breaks off a vessel wall and blocks a smaller vessel. Usually originate in the peripheral and migrate to the brain.

Question 6

Effects of Obstructive Strokes

Answer 6

Depends on the location of the blockage, but typically results in lateralised limb weakness and/or sensory changes. If stroke occurs in the left hemisphere, speech/language deficits and depression arise. If the stroke occurs in the right hemisphere, perceptual deficits and apathy result.

Question 7

Transient Ischemic Attack

Answer 7

Episode of temporary obstruction of vessels lasting less that 24 hours. Warning sign for a full blown stroke.

Question 8

CNS Control of Blood Flow

Answer 8

3 mechanisms. Autoregulation (vessels relax and constrict in response to blood pressure changes), metabolic (increased CO2causes dilation of vessels, decreased CO2 results in vessel constriction) and innervation (vessels are fully innervated with ANS neurons).

Question 9

Haemorrhagic Stroke

Answer 9

Results from a blood vessel in the brain breaking and leaking blood into surrounding tissue.

Question 10

Aneurysm

Answer 10

Most common form of haemorrhagic stroke. Blood vessel balloons and bursts. Most likely if aneurysm is more than 10mm. Results in dramatic symptoms (migraine, vomiting), focal neurological pain, stiff neck and can be instantly fatal.
41% occur in anterior communicating or anterior cerebral artery. 34% occur in middle cerebral artery.

Question 11

Hypertensive Haemorrhage

Answer 11

Associated with weakened vessel walls and high blood pressure. Typically involves vessels at the base of the cerebral hemisphere (basal ganglia, thalamus and brainstem). High mortality but survivors range from vegetative to near normal.

Question 12

Arteriovenous Malformations

Answer 12

Tangled mass of blood vessels that gradually grow. Very rare (congenital condition). AVM and high blood pressure increases risk of haemorrhagic stroke. Minimal cognitive deficits if remain intact. Deficits may be lateralised or contralateral

Question 13

Silemt Stroke

Answer 13

Strokes that occur with no symptoms. Detected on later brain scans as crescent shaped infarcts.