Stroke and Company Clinical Clerk Consolidation Rounds 2005-2006 Academic Year.
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Transcript of Stroke and Company Clinical Clerk Consolidation Rounds 2005-2006 Academic Year.
Stroke and Company
Clinical Clerk Consolidation Rounds
2005-2006 Academic Year
Outline
1. Basic introduction Epidemiology Pathogenesis
2. Examination3. Stroke syndromes
TIA Cerebral infarcts Cerebellar infarcts Brain stem infarcts Lacunar strokes Hemorrhagic strokes (in brief)
4. Management and treatment5. Cases
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….)
Introduction
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
Some Definitions
Stroke - deficits > 24 hoursTIA - deficits < 24 hoursRIND - deficits > 24 hours but < 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
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
Introduction (a. fib)
A. fib stroke source (though it often does)
CHADS:Item Points
Prior stroke 2
Age >75 1
DM 1
HTN 1
CHF 1
Score Annual Risk
0 1.9
1 2.8
2 4
3 5.9
4 8.5
5 12.5
6 18.2
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
Examination
Examination
The goal is to chronicle the deficits
In the case of acute strokes, the goal is also to determine eligibility for tPA
Don’t forget ABCs
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…
Stroke Syndromes
TIA’s
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
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.
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.
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. Wallenberg’s)
You can have decreased level of consciousness.
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:
1. Pure motor hemiparesis
2. Sensorimotor
3. Ataxic hemiparesis
4. Pure sensory
5. Clumsy hand-dysarthria
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
Intracranial
Hemorrhages
Stroke Management
Management (secondary prevention)
Anti-platelet ASA Clopidogrel (Plavix) Dipyridamole/ASA (Aggrenox)
Anti-coagulationAnti-hypertensive ACE inhibitor Thiazide diuretic
Statin
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
Management (acute stroke)
To tPA or not Intra-arterial Intra-venous
Inclusion criteria
Exclusion criteria
End
Stroke in the Young
(Hyper) CoagulopathyDissectionSinus thrombosisInfectionNon-ischemic etiologies: Seizure Tumour
Genetic syndromes (mitochondrial disorders, blood dyscrasias, collagen diseases)
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)
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 = alert1 = arousable by minor stimulation2 = requires repeated and sustained stimulation3 = responds only by reflex or does not respond
1b: LOC Questions
Ask: What month is it? How old are you?
0 = Both answers correct
1 = One answer correct
2 = Neither answer correct
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
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)
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)
4: Facial Palsy
Use pantomime or commands.
Remove bandages, tapes etc. as much as possible.
0 = normal1 = minor paralysis (blunting of nasolabial fold)2 = partial paralysis (lower face involved)3 = complete paralysis (upper and lower face or bilateral involvement)
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
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.
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
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 you’re in a pinch.
0 = normal
1 = mild to moderate: difficult to understand, but speech’s main elements are intact
2 = severe: inference needed as communication limited fragments
3 = mute, global aphasia
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
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
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
What wasn’t tested?
ReflexesToneGaitSwallowing or lower cranial nervesPupils
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.