Stroke and Company

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Stroke and Company

• Clinical Clerk Consolidation Rounds
• 2005-2006 Academic Year

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Outline

• Basic introduction
• Epidemiology
• Pathogenesis
• Examination
• Stroke syndromes
• TIA
• Cerebral infarcts
• Cerebellar infarcts
• Brain stem infarcts
• Lacunar strokes
• Hemorrhagic strokes (in brief)
• Management and treatment
• Cases

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This session will NOT cover

• Subarachnoid hemorrhage
• Spinal cord infarcts
• Stroke in the young
• Stroke genetics
• Cerebral vascular anatomy
• Advanced assessment modalities (NIH stroke scale,
  ASPECTS score, perfusion studies, intracranial
  doppler etc.)

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Introduction
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Key Concepts

• Strokes are sudden neurologic deficits that
  result from ischemia/infarction (80) or
  hemorrhage (20)
• Because of the fragile nature of the brain, the
  deficit quickly becomes irreversible
• This rule is broken via neuroplasticity, which
  occurs especially in young, robust brains
• Stroke is a disease of the old
• Regardless the etiology, treatment depends on
  prompt response, and an understanding of the
  neural substrate affected

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Some Definitions

• Stroke - deficits gt 24 hours
• TIA - deficits lt 24 hours
• RIND - deficits gt 24 hours but lt 3 weeks
• (the notion of RINDs is of little clinical value,
  but may be on your exam)
• Brain attack is a term used in attempt to
  galvanize public awareness against the
  counter-revolutionary threat of the stroke enemy

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Basic Pathogenesis

• Strokes arise from
• Emboli
• Lipo-hyalinosis
• Watershed/global hypoperfusion
• Metabolic failure

• Source of embolic fragments
• Heart
• Heart
• Heart
• Vessels
• Carotids
• Vetebrobasilar
• Circle of Willis and branches thereof
• Aortic arch (suspect this in vasculopaths)
• Shunting via a PFO

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Introduction (a. fib)

• A. fib ? stroke source (though it often does)
• CHADS

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Introduction (differential)

• Also consider
• Infection (sinus thrombosis, parasites)
• Inflammation (CNS vasculitis)
• Neoplasm (gliomas, mets, bleeding into either)
• Metabolic (hyper or hypoglycemia)
• Medication (narcotics, EtOH)
• Seizure
• Migraine

• You will often be asked to assess patients with
  decreased level of consciousness and be asked if
  this is a stroke ? ironically, decreased LOC, at
  least acutely, is rarely caused by stroke

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Examination
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Examination

• The goal is to chronicle the deficits
• In the case of acute strokes, the goal is also to
  determine eligibility for tPA
• Dont forget ABCs

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With all strokes

• Presentation depends on the area involved
• Area involved depends on
• the vessels involved
• the etiology of the stroke
• (see point 4 in your hand out)
• Where is the lesion, what is the lesion

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Stroke Syndromes
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TIAs

• Transient (ischemic) deficit lasting less than 24
  hours
• In practice, a deficit that persists for more
  than a few hours will end up being a stroke
• A harbinger
• Aggressive evaluation for treatable lesions
• Aggressive secondary prevention
• The urgency is greater in women

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Cerebral Strokes

• In general a cerebral stroke results in the loss
  of a function (rather than the loss of modulation
  of a function)
• Deficits are contralateral to the side of the
  lesion
• Deficits are generally multi-modal and
  devastating
• Cognitive alteration can often result
• An important distinction in the acute diagnosis
  of cerebral strokes is whether it was cortical or
  sub-cortical.

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Cerebellar Strokes

• In general a cerebral stroke results in an
  altered modulation of function
• Deficits are ispilateral to the side of the
  lesion
• Deficits are more subtle
• Cognitive alteration is rare
• However, because of the smallness of the
  posterior fossa, these strokes can be rapidly
  fatal if edema and herniation ensue.

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Brainstem Strokes

• In general these strokes are devastating
• The compact anatomy of the brainstem is very
  unforgiving to injury.
• Deficits will affect the cranial nerves.
• You can have crossed findings (e.g.
  Wallenbergs)
• You can have decreased level of consciousness.

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Lacunar Strokes

• Lacunar are small, strategically placed lesions
  resulting from
• Disease of small perforating vessels
• Lipohylainosis?
• Microatheromas?
• Do not usually respond well to anti-platelet/anti-
  coagulation and you do not tPA (generally) these
  patients)

• Lacunar stroke syndromes
• Pure motor hemiparesis
• Sensorimotor
• Ataxic hemiparesis
• Pure sensory
• Clumsy hand-dysarthria

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Hemorrhage

• In general Hemorrhagic strokes are accompanied
  by
• Pain
• Decreased level of consciousness
• Evident on CT

• Common causes include
• Hypertension
• Amyloidosis (if old)
• Angiopathy
• Aneurysm (if h/a)
• AVM
• Coagulopathy
• Trauma

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Intracranial Hemorrhages
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Stroke Management
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Management (secondary prevention)

• Anti-platelet
• ASA
• Clopidogrel (Plavix)
• Dipyridamole/ASA (Aggrenox)
• Anti-coagulation
• Anti-hypertensive
• ACE inhibitor
• Thiazide diuretic
• Statin

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Management (non-acute stroke)

• Blood pressure management
• Labetalol
• 180/110 ? 130/60
• Blood sugar management (6 ? 4)
• Frequent assessment
• Watch for deterioration (edema or bleed)
• Specialized issues
• Feeding
• Agitation

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Management (acute stroke)

• To tPA or not
• Intra-arterial
• Intra-venous
• Inclusion criteria
• Exclusion criteria

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End
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Stroke in the Young

• (Hyper) Coagulopathy
• Dissection
• Sinus thrombosis
• Infection
• Non-ischemic etiologies
• Seizure
• Tumour
• Genetic syndromes (mitochondrial disorders, blood
  dyscrasias, collagen diseases)

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NIH Stroke Scale

• Rapid neurologic examination designed to localize
  strokes
• Its utility in the general medical situation is
  limited, and you can easily miss many things with
  it
• It is, however
• Fast
• Doest not require any tools (not even a reflex
  hammer)

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1a Level of Consciousness

• A global assessment of response to stimulus
• Must be performed
• Language, ET tubes, and trauma/bandages may
  hinder but cannot preclude this item

• 0 alert
• 1 arousable by minor stimulation
• 2 requires repeated and sustained stimulation
• 3 responds only by reflex or does not respond

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1b LOC Questions

• Ask
• What month is it?
• How old are you?

• 0 Both answers correct
• 1 One answer correct
• 2 Neither answer correct

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1c LOC Commands

• Ask px to
• Open AND close their their eyes.
• Grip THEN release their hand.
• The key is to select a test where the px must
  perform a task, and then perform its antithesis.

• 0 performs both
• 1 performs one
• 2 performs neither

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2 Best Gaze

• Only test horizontal movements.
• Use eye contact, dolls or money as ways to
  stimulate pursuit.

• 0 normal
• 1 partial gaze palsy
• 2 force gaze deviation (cannot overcome gaze
  preference with oculocephalic)

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3 Visual Fields

• Test central quadrants
• Test either with confrontation finger counting,
  or with visual threat

• 0 normal
• 1 partial hemianopia (difficult to obtain only
  score if clear asymetry or quandrantanopia seen)
• 2 complete hemianopia
• 3 bilateral hemianopia (cortical blindness)

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4 Facial Palsy

• Use pantomime or commands.
• Remove bandages, tapes etc. as much as possible.

• 0 normal
• 1 minor paralysis (blunting of nasolabial fold)
• 2 partial paralysis (lower face involved)
• 3 complete paralysis (upper and lower face or
  bilateral involvement)

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5 and 6 Motor (Arms and Legs)

• Arms and legs are held at 45 degrees (if supine)
  or 90 degrees (if sitting) so as to maximize the
  effect of gravity.
• Arms should be held for 10 s.
• Legs should be held for 5.
• Each limb is scored separately.

• 0 no drift
• 1 drift, but does not hit bed/other supports
• 2 cannot maintain anti-gravity
• 3 no effort against gravity
• 4 no movement

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7 Ataxia

• The key here is unsteadiness OUT OF KEEPING with
  weakness.

• 0 no ataxia
• 1 ataxia in 1 limb
• 2 ataxia in 2 limbs
• Also note which limbs are involved.

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8 Sensory

• Err on the side of severity. If the px cannot
  respond, they get 2.
• Use noxious stimulus or a needle.

• 0 normal
• 1 mild to moderate (appreciates stimulus
  present, but not the quality of it)
• 2 total sensory loss

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9 Language

• Either bring along a standardized picture and ask
  the px to describe it, or ask a px to name
  objects readily available. A magazine or even
  instruction pages can be used if youre in a
  pinch.

• 0 normal
• 1 mild to moderate difficult to understand,
  but speechs main elements are intact
• 2 severe inference needed as communication
  limited fragments
• 3 mute, global aphasia

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10 Dysarthria

• Can defer if px intubated or some other
  impediment present

• 0 normal
• 1 mild to moderate slurs but ultimately
  understandable
• 2 severe unintelligible or mute

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11 Extinction and Inattention

• Based on previous maneuvers
• Visual extinction
• Somatic extinction
• Inattention to one side during the examination
• NEVER untestable

• 0 normal
• 1 extinction
• 2 profound inattention

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12 Distal Motor Function

• Support the arm and ask px to extend fingers. If
  they cannot, place fingers in full extension and
  observe for flexion movements over 5 s.
• Score each hand separately

• A full extension
• B some extension
• C no extension
• Note the non-numerical scoring

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What wasnt tested?

• Reflexes
• Tone
• Gait
• Swallowing or lower cranial nerves
• Pupils
• These should be tested after the initial rush of
  the acute stroke protocol, as they are important
  from a prognostic, monitoring, management and
  diagnostic point of view.