Stroke

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Stroke its consequences

• Patient WW
• Medical history
• History of high blood pressure (hypertension)
• Massive Stroke in Right Hemisphere
• Behavioral changes
• Partially paralyzed on left side.
• Poor emotional control and judgment.
• Unaware of his illness (anosognosia).

• WW was Woodrow Wilson, 28th US President of USA

Special thanks to Chris Rorden, U. South Carolina
2

• Similar cases exist today
• Sen Tim Johnson (D-South Dakota)
• An hemorrhagic stroke (arteriovenous malformation)

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Stroke

• Stroke is a leading cause of disability. In
  western world
• Heart Disease
• Stroke (10 of deaths worldwide)
• Cancer
• In USA alone
• 500,000 people suffer stroke per year
• 150,000 people die of stroke per year
• 4 million living with stroke
• 30 billion in health care costs
• 2/3 of strokes in people gt 65 y-old

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types of stroke
Ischemic (80) the brain artery is clogged (aka
obstructive)
Haemorrhagic (20) the brain artery ruptures
bleeding
emobolic
thrombotic
- Some are transitory ischemic attacks (TIA).
- Infarct Dead tissue following stroke
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• Lesions look different depending on
• How old the lesion is acute vs. 3 days old
• Type of scan (CT, MRI)
• Example of Stroke

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newer MRI protocols

• Diffusion-weighted imaging
• Strokes show up immediately.
• Shows permanent white-matter damage.

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Imaging Infarcts

• MRA (Magnetic Resonance Angiography)

Xray
MRI
MRA
stroke MRA
8
Obstructive strokes treatment

• Treatment
• Counterindicated for
• haemorrhagic strokes
• Prevention of all strokes
• Control blood pressure
• No smoking
• Reduce cholesterol
• stent

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Neuronal death in stroke

• Obstruction
• Reduction of O2 glucose
• Na/K pump stops working
• Increase in action potentials
• Release of glutamate
• Open Na channels -gt Na rushes in -gt so does water
  -gt swelling
• open Ca channels -gt activate enzymes -gt lesion
  cell

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Stroke Consequences

• As always, it depends on which brain area is
  affected
• Example
• Haemorraghic Stroke It usually lesions
  orbitofrontal cortex

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Haemorrhagic strokes
aneurism a sac-like protrusion of an artery
caused by a weakened vessel wall

• aneurysm ruptures ? bleeding
• Symptoms
• Really bad headache .
• Throwing up
• Other neurological symptoms
• Treatment Surgery to clip aneurysm
• Consequences Orbitofrontal lesion (OFC)
• Symptoms
• Changes in personality
• This is true also of lesion of OFC lesion by
  other mechanisms (trauma, dementia)

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orbitofrontal lesion

• symptoms
• Social disinhibition
• Poor emotion regulation
• Denial of deficit
• Inability to navigate the social world
• Anatomy
• Orbitofrontal Cortex
• Amygdala

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Visual Areas for recognizing objects
Lesion
stimulus
Activation in fMRI in healthy adults
14
Visual brain area for Color perception
Cerebral Achromatopsia bilateral damage to V4

15
Area important for speech

• Left frontal cortex
• Non-productive aphasia (brocas aphasia)
• Also brought about by dementia that affects same
  area
• http//psych.rice.edu/mmtbn/

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Hippocampus

• Memory deficit
• But so does Alzheimers disease

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In sum

• Two types of stroke
• Ischemic
• Haemorraghic
• Behavioral consequences are determined by
  location of lesion!

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Spared slides

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Ischemic Strokes
Major Arteries ? Carotid ? Anterior Cerebral ?
Middle Cerebral ?Posterior Cerebral
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Occlusion of middle cerebral artery (MCA)

• embolism travels up carotid artery
• MCA supplies lateral bank of cortex (image from
  strokecenter.org)
• Damages regions near superior temporal sulcus
  (sylvian fissure) (figure shows regions damaged
  in 24 MCA patients, Mort et al. 2003)