Stroke

Question 1

Hemorrhagic Stroke (+ causes)

Answer 1

• (15%) - caused by vascular rupture into actual brain parenchyma (intracerebral hemorrhage)
  
  • Bad b/c direct exposure of neurons to blood/toxic blood products
• Causes -
  - Trauma
  - Hypertension —> micro-aneurysms
  - Hemorrhagic conversion of ischemic stroke (ischemic stroke then leads to bleed)
  - Cerebral Amyloid Angiopathy - amyloid deposits —> micro damage
  - Vascular formations that cause high pressure -fistula OR congenital arteriovenous malformation (artery connected to vein at birth)
  - Cerebral aneurysms- Berry at bifurcation (usually congenital) “sudden worst headache of life”

Question 2

Ischemic Stroke (+ causes)

Answer 2

• (85%) - caused by vascular occlusion —> infarction
• Causes -
  - Thrombus - on mechanical heart valve, due to atrial fib, DVT —> patent foramen oval —> through heart, vegetation from endocarditis embolism
  - Atherosclerosis - ruptured plaque is thrombogenic OR flow failure OR cholesterol embolism
  - Arterial Dissection - high velocity movements can tear arteries
  - Inflammation of small arteries due to drugs, infection, autoimmunity

Question 3

TIA

Answer 3

-Transient Ischemic Attack

• “mini stroke”- vascular occlusion that RESOLVES very quickly (<24 hr)
  
  • Then treat risk factors to prevent re-occurence (hypertension, Diabetes, smoking)

Question 4

3 Types of Hemorrhages Not Considered Stroke

Answer 4

• Subdural Hematoma - tearing of veins; usually benign and not treated unless mass effect
• Epidural Hematoma - emergency; usually bleed of middle meningeal artery outside suture lines which can press down on brain —> herniation
• Subarachnoid Hemorrhage - usually due to trauma or berry aneurysm (at bifurcation); blood accumulates in subarachnoid space & any areas w/ CSF

Question 5

6 Diff Diagnosis of Acute Neural Deficit

Answer 5

• Stroke
• Seizure (paralysis in post-ictal state)
• Migraine (aura may include hemiparesis)
• Psychogenic (fake)
• Delirium - too high or too low glucose
• Radiculopathy/ Bell’s Palsy

Question 6

Ischemic Stroke Management (Decision & 2 Tx)

Answer 6

• TIME MATTERS (find out how long they have been symptomatic)
• Head CT (is is hemorrhagic or ischemic?) - FAST
  
  • Must decide if opening occluded artery is feasible and worth it
    
    • If core (area of impaired function that is irreversible) is small & large penumbra (area impaired but reversible b/c just hypo perfusion)
• If ischemic…
  
  • IV tPA (IV tissue plasminogen activator)
    
    • Check glucose, control BP, ask if on anti-coagulants
    • Must be w/in 4.5 hrs BUT earlier = more effective
    • Tx of choice for small arteries/lacunar strokes
  • IA treatment (intra-arterial - remove clot)
    
    • Should be done w/in 6 hrs
    • Used mainly for larger arteries
    • Use catheter

Question 7

Dominant Hemisphere Stroke

Answer 7

(L MCA for most ppl)

- Both expressive & receptive aphasia
- Ipsilateral gaze preference - b/c damage to LGN
- Contralateral hemiparesis and loss of sensation in arms/face (+ sometimes leg if internal capsule)
- If subcortical… legs definitely involved

Question 8

Non-Dominant Stroke

Answer 8

(R MCA for most ppl)

- Same as dominant BUT no language problems …instead contralateral hemi-neglect

Question 9

PCA Stroke

Answer 9

Contralateral hemianopsia due to occipital lobe injury

Question 10

Lateral Medullary Syndrome

Answer 10

• Contralateral loss of pain & temp of body
• Ipsilateral loss of pain & temp of face
• Horner’s
• Nystagmus, vertigo, nausea, diplopia
• Dysphagia
• Nucleus ambiguus damage —> ipsilateral vocal cord, and palate weakness

Question 11

Classic Lacunar Syndromes

Answer 11

• More specific deficits (pure motor, pure sensory or combined) & no cortical signs (no language or vision problems; no neglect)
• Posterior Limb = pure motor
• VP thalamus = pure sensory