Stroke

Question 1

Define Stroke

Answer 1

Is a sudden loss of blood supply to the brain leading to permanent tissue damage caused by thrombotic, embolitic or heamorrhagic events

Question 2

What type of herniation if brain compressed under the Falx Cerebri

Answer 2

Subfalcine or Cingulate

Question 3

What type of herniation if brain compressed under the Tentorium Cerebelli

Answer 3

Transtentorial or Uncal

Question 4

What type of herniation if brain compressed through the foramen Magnum

Answer 4

Tonsilar

Question 5

What are the typical symptoms of a Uncal or transtentorial herniation

Answer 5

• CNIII compression resulting in no pupil reflex and no occulomotor function
• Corticospinal tract compression resulting in postural symptoms
• Occipital lobe compression of the primary visual cortex (V1) resulting in homonymous hemianopia

Question 6

What are the most common causes of Stroke

Answer 6

Infarction due to occlusion (80%), haemorrhage (15%) and sub-arachnoid haemorrhage (5%)

Question 7

What happens to Neurons after infarction

Answer 7

Loss of oxygen input, cannot produce ATP, loss of ion pumps, cells swell, can have increased ICP and then herniation

Question 8

What causes majority of deaths?

Answer 8

Secondary effects such as pneumonia, CVD(share commone risk factors) or PE

Question 9

Primary features of Stroke that lead to death

Answer 9

Death of neurons in control centres or Raised ICP

Question 10

Causes of Ischemic Stroke

Answer 10

Small vessel disease from Hypertension, thrombosis, emboli from athero-emboli + ulceration, pump failure, DVT (hole in heart to bypass lungs)

Question 11

Causes of hemorrhagic Stroke

Answer 11

Hyaline Artherosclerosis, Aneurysms (saccular or Berry), Amyloid angiopathy, bleeding disorders, atherosclerosis, tumour, surgery, congenital problems (no capillaries and venous rupture) or drugs

Question 12

Common Sites of Thrombus generation in the circle of Willis

Answer 12

Vertebral Arteries, Basilar arteries, MCA and internal carotid

Question 13

Common sites of Aneurysms

Answer 13

ICA junction, MCA bifurcation, Posterior and Anterior Communicating Arteries, most likely will affect the anterior region of circulation

Question 14

Risk Factors of Stroke

Answer 14

- CVD factors
	○ Such as aging, hyperlipideamia
- Hypercoagulable states
	○ Bleeding or thrombus formation
- Cardiac disease (AF)
- Diabetes

Question 15

What are lucunar infarcts

Answer 15

infarcts that occur to deep structures

Question 16

Consequences of hyaline arteriolosclereosis

Answer 16

Protein deposition in response to hypertension leading to vessel occlusion and infarct. However can also lead to wall weakening and the vessel can form aneurysms and the lead to haemorrhage

Question 17

Causes of cardiac mediated strokes

Answer 17

Anuerysms of left ventricle, valve vegetation, AF, DVT (septal defects)

Question 18

Pathogenesis of Strokes

Answer 18

Ischemia, cells die, cells swell, raised ICP, compensation, if prolonged and severe leads to hearniation and death. if resolved, the cells can swell, pycnotic nucleus, liquefaction necrosis and macrophage infilatration. Days to weeks for macrophages to remove dead tissue and therefore around 1-2 months will form a cystic cavity filled with CSF like fluid

Question 19

What is re-perfusion injury

Answer 19

Thrombi/emboli occlude vessel, leads to vascular death, resolution of thrombi and then heamorrhage as the blood vessels not able to withstand pressure.

Question 20

What is a duret’s haemorrhage

Answer 20

Is bleeding in the brainstem due to raised ICP

Question 21

Where are Congophillic/Amyloid angiopathy commonly localised

Answer 21

Small/recurrent peripheral hemorrhages of the cerebrum and is associated with Alzheimer’s disease

Question 22

Risks of Cerebellar haemorrhage

Answer 22

May not lead to cerebellum defects yet has the potenital to block the 4th ventricle and hence pressure must be releived

Question 23

What are the most likely vessels that result in intracerebral heamorrhages

Answer 23

Deep vessels due to hyaline arteriolosclerosis, can be the lenticulostriate vessels to the basal ganglia

Question 24

What is the most likely cause of mutlifocal haemorrhages

Answer 24

Coaggulopathy problems from clotting factor disorders, thrombocytopenia or leukemia

Question 25

Causes of Sub-arachnoid haemorrhages

Answer 25

Ruptures of Succulent Aneurysms (Berry are congenital)

Question 26

Risk Factors of Saccular Aneuryms

Answer 26

Sex and Age (Female and young), Polycystic kidney disease, collagen disorders, hypertension, congenital coartation of aorta, smoking and alcohol

Question 27

Most common regions

Answer 27

Anterior blood supply (90%) and posterior blood supply (10%) at the MCA bifurcation, ICA trifurcation and the communicating arteries. There are risks too of ventricular haemorrhage

Question 28

treatment of Aneurysms and why?

Answer 28

Clip the neck of aneurysms, remove blood to prevent raised ICP,cerebral odema, hydrocephalus and vasospasm