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.