Ray Taylor Ray Taylor Valencia Community College Valencia Community College Department of Emergency Medical Services Department of Emergency Medical Services

Ray TaylorRay Taylor Valencia Community CollegeValencia Community College Department of Emergency Medical Services Department of Emergency Medical Services

Overview

Background Anatomy/Physiology Major Stroke Syndromes Assessment and Evaluation Diagnosis Prehospital Case Studies Summary

Questions

Question

Hemorrhagic stroke accounts for what percent of all strokes?A. Less than 5%B. 15% - 20%C. 50%D. 80%

Question

Which one of the following events causes the majority of ischemic strokes?A. Ventricular fibrillationB. ThromboembolismC. Atrial fibrillationD. Intracerebral hemorrhage

Question

In a patient suspected of having an acute brain attack, which one of the following is the best way to differentiate between an ischemic or hemorrhagic cause?A. The historyB. The physical examinationC. A CT scan of the brainD. An MRI scan of the brain

Question

A patient has sudden weakness of the left arm and leg. EMS is called and the patient’s blood pressure is found to be 250/150mmHg. The most appropriate action to be taken by EMS is to monitor and record the blood pressure and:A. Administer labetalol 15mg IVB. Administer nifedipine 10mg SLC. Administer NTG SLD. Do not administer any antihypertensive agent

Question

Which one of the following pairings is incorrect?A. Left brain dysfunction – right sided

weaknessB. Brainstem dysfunction – slurred speechC. Cerebellum dysfunction – dyscoordinationD. Subarachnoid hemorrhage – inappropriate

speech

Question

Which one of the following is true regarding the “ischemic penumbra”?A. It is brain tissue with irreversible ischemiaB. It is unaffected by the use of TPAC. It is worsened by hypotensionD. Can be seen on a CT scan of the brain

Question

All of the following are true statements regarding stroke, except:A. It is the leading cause of disability in the USB. It is a preventable conditionC. Death from stroke may be reduced by the

treatment with TPAD. Its incidence increases with age

Question

All of the following are signs of a brainstem stroke, except:A. AphasiaB. Hemisensory lossC. Nausea and vomitingD. Vertigo

Question

All of the following assessments are components of the initial on-site prehospital stroke examination, except:A. ReflexesB. SpeechC. Facial symmetryD. Arm strength

Background (USA)

#1 Disability #3 Killer

500,000/year 20% mortality

50 million dollars per year

Old therapy rehabilitation reduce risk of future

strokes

Current therapy acute interventions reduce brain area of

ischemia Blood sugar Blood pressure

Background

0

2

4

6

8

10

12

14

16

18

EMS arrival(A)

EMS-ED (B) Total EMS(A+B)

Car-ED

Median Hours to ED Arrival (EMS vs Car)

Goal

Kothari.(Cincinnati) Ann Emerg Med 1999; 33: 1.

2nd Goal

Background

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Prehospital thru EDtime

Goal

CTMD evalPrehospital

Median Time (Hours) Spent Evaluating Stroke Patients(Prehospital = time at home + EMS [small part])

Kothari (Cincinnati). Ann Emerg Med 1999; 33: 1.

Background - Who is Eligible

> 3 h47%

Resolved15%

Bleed11%

Minor10%

Too ill7%

BP2%

Seize4%

Other1%

Eligible3%

O’Connor RE. Ann Emerg Med 1999; 33: 9-14

Anatomy & Physiology

Anterior Cerebral Artery

leg > arm - opposite side of ischemia

sensory deficits = motor deficit sites

frontal lobe - impaired judgement/insight

Middle Cerebral Artery

face/arm > leg: ignore side/site of deficit

sensory = motor deficit sites aphasia = speech

Posterior cerebral vision/mentation

Vertebrobasilar

vertigo/gait/cranial nerves (face/eyes/tongue)

syncope***

Anatomy & Physiology Ischemic Stroke

low flow occluded blood vessel

(carotid) embolic - clot travels from

heart

80%

Hemorrhagic Stroke 20% bleed into brain - stop

TIA temporary deficit - < 30-60

minutes high risk of future stroke

Ischemic Stroke

Clot occluding arteryClot occluding artery

Most common cause: thromboembolism

Possible sources of clot:

Heart

Large artery (to brain)

Small artery (in brain)

CLOTCLOT

INFARCTINFARCT

Ischemic Stroke: Modifiable Risk Factors

Hypertension (systolic and diastolic)

Cigarette smoking Prior stroke/ TIA Heart disease Diabetes mellitus, hyperlipidemia Hypercoagulable states Carotid bruit Cocaine, excess alcohol

Ischemic Stroke: Nonmodifiable Risk Factors

Advanced age Male gender African-American heritage Family history of early stroke

or MI

Intracerebral Hemorrhage

Bleeding into brainBleeding into brain

Most common cause:chronic hypertension

Other causes:

Vessel malformation

Tumor, bleeding abnormalities

Subarachnoid Hemorrhage

Bleeding around brainBleeding around brain

Most common cause:aneurysm rupture

Other causes:

Vessel malformation

Tumor, bleeding

abnormalities

Transient Ischemic Attack (TIA)

Reversible focal dysfunction, usually lasts mins

Among TIA pts who go to ED: 5% have stroke in next 2 days

25% have recurrent event in next 3 months

Decrease stroke risk with proper therapy: artery source—antiplatelet (ASA), surgery

heart source—anticoagulation (warfarin)

Background

Risk Factors # factors 90 day stroke risk

Age > 60 yearsDiabetes MellitusDuration TIA > 10 minWeakness with TIASpeech impaired occurredwith TIA

012345

0%3%7%

11%15%34%

JAMA 2000; 284: 2901.

Risk of Stroke Following ATransient Ischemic Attack

Penumbra

Core

Time Is Brain: Save The PenumbraTime Is Brain: Save The Penumbra

Clot in Artery

Time is Brain: Save the Penumbra

In first few hours of ischemic stroke, brain tissue can still be saved

Zone of reversible ischemia (“penumbra”) surrounds core of irreversible infarction

Patient symptoms due to both infarcted core and ischemic penumbra

One cannot determine by exam how much brain can still be saved

Time is Brain: Save the Penumbra

Thrombolytic (fibrinolytic) agent t-PA can limit brain damage safely if given w/in 3 h—it reduces risk of disability due to ischemic stroke by 30%

Administer t-PA only if: clinical diagnosis confirmed by CT scan

within 3 hours of onset

age 18 or older

no other contraindications

Major Stroke Syndromes

LEFT HEMISPHERELEFT HEMISPHERE

RIGHT HEMISPHERERIGHT HEMISPHERE

BRAINSTEMBRAINSTEM

CEREBELLUMCEREBELLUM

HEMORRHAGEHEMORRHAGE

1

2

5

4

3

1

2

3

4

5

Left (Dominant) Hemisphere: Typical Signs (Right Side and Aphasia)

AphasiaAphasia

Left Gaze PreferenceLeft Gaze Preference

Right HemiparesisRight Hemiparesis

Right Hemisensory Right Hemisensory LossLoss

Right Visual Field Right Visual Field DeficitDeficit

Right (Nondominant) Hemisphere: Typical Signs (Left Side)

Right Gaze PreferenceRight Gaze Preference

Left HemiparesisLeft Hemiparesis

Left Hemisensory Left Hemisensory LossLoss

Left Hemi-inattentionLeft Hemi-inattention

Left Visual Field Left Visual Field DeficitDeficit

Brainstem: Typical Signs (Both Sides)

QuadriparesisQuadriparesis

Sensory Loss in Sensory Loss in

All 4 LimbsAll 4 Limbs

Crossed Signs Crossed Signs

(1 side of face and (1 side of face and

contralateral bodycontralateral body

Hemiparesis Hemiparesis

Hemisensory LossHemisensory Loss

Brainstem: Typical Signs (continued)

Oropharyngeal Oropharyngeal Weakness:Weakness:

Dysarthria, DysphagiaDysarthria, Dysphagia

Eye Movement Eye Movement Abnormalities:Abnormalities:

DiplopiaDiplopia

Dysconjugate GazeDysconjugate Gaze

Gaze PalsyGaze Palsy

Decreased LOCDecreased LOC

Nausea, VomitingNausea, Vomiting

Hiccups, Abnormal Hiccups, Abnormal RespirationsRespirations

Vertigo, TinnitusVertigo, Tinnitus

Cerebellum: Typical Signs (Coordination)

Ipsilateral Limb Ipsilateral Limb Ataxia Ataxia (dyscoordination)(dyscoordination)

Truncal or GaitTruncal or Gait

Ataxia (imbalance)Ataxia (imbalance)

Symptoms Suggestive of Hemorrhage

Subarachnoid Subarachnoid Hemorrhage:Hemorrhage:

Intolerance to LightIntolerance to Light

Neck Stiffness / PainNeck Stiffness / Pain

Intracerebral Intracerebral Hemorrhage:Hemorrhage:

Focal Signs Such Focal Signs Such as Hemiparesisas Hemiparesis

Both Subarachnoid Both Subarachnoid and Intracerebral and Intracerebral Hemorrhage:Hemorrhage:

HeadacheHeadache

Nausea, VomitingNausea, Vomiting

Decreased LOCDecreased LOC

The Focused NeurologicThe Focused Neurologic

Assessment and EvaluationAssessment and Evaluation

The Focused NeurologicThe Focused Neurologic

Assessment and EvaluationAssessment and Evaluation

Cincinnati and LA Prehospital Stroke Scales

Perform on scene during Primary Survey Perform on scene during Primary Survey

under “D” – Disability:under “D” – Disability:

Speech Facial Droop Arm Drift Grip

“Speech, Droop, Drift, Grip!”

Speech: Repeat Phrase

“You can’t teach an old dog new tricks.”

Abnormal:

Wrong or inappropriate words (aphasia)

Slurred words (dysarthria) or unable to

speak

(Aphasia = left hemisphereDysarthria = cranial nerves)

Facial Droop (Cranial Nerves):Show Teeth or Smile

Abnormal: One side of face does not move as well

as the other side

Right-sided droop ©© AHA 1997AHA 1997

Arm Drift (Motor):Close Eyes, Hold Out Arms

Abnormal: One arm does not move or drifts down

Right-sided drift ©© AHA 1997AHA 1997

Prehospital Stroke Scale

Grip Normal right and left Abnormal right or absent right Abnormal left or absent left Comparison of sides

Prehospital Stroke Identification

0%10%20%30%40%50%60%70%80%90%

100%

Sensitivity Specificity

No scale

LA scale

Cincinnati scale

Smith. Prehospital Emerg Care 1998; 2: 170.Kidwell (Los Angelos) Stroke 2000; 31: 71.Kothari (Cincinnati). Ann Emerg Med 1999; 33: 373.

Cincinnati Prehospital Stroke Scale Normal Patient

Click picture to play video

CRANIAL NERVESCRANIAL NERVES

MENTAL STATUSMENTAL STATUS

Miami Emergency Neurologic Deficit Exam Expanded Prehospital Stroke Exam

CHECK IF ABNORMAL

LIMBSLIMBS

Level of Consciousness (AVPU)Level of Consciousness (AVPU)

Speech “You can’t teach an old dog new tricks.” (repeat)Speech “You can’t teach an old dog new tricks.” (repeat)

Abnormal = wrong words, slurred speech, no speechAbnormal = wrong words, slurred speech, no speech

Questions (age, month)Questions (age, month)

Commands (close, open eyes) Commands (close, open eyes)

Facial Droop (show teeth or smile) Facial Droop (show teeth or smile) RT RT LTLT

Abnormal - one side does not move as well as otherAbnormal - one side does not move as well as other

Visual Fields (four quadrants)Visual Fields (four quadrants)

Horizontal Gaze (side to side)Horizontal Gaze (side to side)

Motor–Arm Drift (close eyes and hold out both arms)Motor–Arm Drift (close eyes and hold out both arms) RT LT RT LT

Abnormal–arm can’t move or drifts downAbnormal–arm can’t move or drifts down

Leg Drift (open eyes and lift each leg separately)Leg Drift (open eyes and lift each leg separately)

Sensory–Arm and Leg (close eyes and touch, pinch)Sensory–Arm and Leg (close eyes and touch, pinch)

Coordination–Arm and Leg (finger to nose, heel to shin)Coordination–Arm and Leg (finger to nose, heel to shin)

Miami Emergency Neurologic Deficit Exam Normal Patient


Cincinnati Prehospital Stroke Scale Left Hemispheric Stroke


Miami Emergency Neurologic Deficit Exam Left Hemispheric Stroke


Diagnosis and Management

Prehospital Exclude masqueraders

hypoglycemia/hyperglycemia drugs/toxins trauma hypoxia

Neurologic screen Cincinnati/LA prehospital stroke scale not meant to be 100% accurate

Management - Glucose

Lo Very Hi

Cellular pH 6.84 6.46

NADH (oxidativestress)

114% 173%

Infarct volume(total hemisphere)

14% 35%

Neurologic Effects of Lo glucose vs. Very Hi glucose on Infarcted Brain (Rabbit Model)

Thoralf. Stroke 1999; 30: 160-170.

Management - Glucose

Glucose < 120N = 35

Glucose > 120N = 72

Return towork

72% 43%

Death 0% 12%

Pulsinelli. Am J Med 1983; 74: 540.

Management - Blood Pressure

80%

85%

90%

95%

100%

105%

CNS flow (% of good side)

20 17 14 12

MAP drop

Relationship of CNS tissue perfusion (SPECT scan)to drop in BP after treatment

Lisk. Arch Neurol 1993; 50: 855.

Acute Stroke Patients: Indications for Antihypertensive Therapy

In general: Consider: absolute level of BP?

If BP: >185/>110 mm Hg = fibrinolytic therapy contraindicated Consider: other than BP, is patient candidate for fibrinolytics?

If patient is candidate for fibrinolytics: treat initial BP >185/>110 mm Hg

Consider: response to initial efforts to lower BP in ED? If treatment brings BP down to <185/110 mm Hg: give

fibrinolytics Consider: ischemic vs hemorrhagic stroke?

Treat BP in the 180-230/110-140 mm Hg range the sameThe obvious: no fibrinolytics for hemorrhagic stroke

Treatment of High BP in Acute Stroke Patients

BP Level

>185/>110 mm Hg

During/after fibrinolytic treatment BP may rise:

DBP >140 mm Hg

>230/121-140 mm Hg

180-230/105-120 mm Hg

Fibrinolytic Candidate

Nitropaste or labetalol IVif BP remains elevated:

no fibrinolytics

Nitroprusside infusion

Labetalol, then prn nitroprusside

Labetalol

Not a Fibrinolytic Candidate

No acute therapy indicated

Nitroprusside infusion

LabetalolAcute therapy only if hypertensive urgency

also present

Diagnosis and Management

ED Diagnosis

History and Physical in ED Supplemented with CT

normal in 1st 24-48 hours

Thrombolytic Therapy

Emergent CT Scan

Is necessary to rule out nonstroke cause of

symptoms

Is necessary to differentiate ischemic vs.

hemorrhagic stroke

Exam alone cannot distinguish stroke vs.

nonstroke or ischemia vs. hemorrhage

Noncontrast CT Scan: Ischemic Stroke (Left Hemisphere)

R R 4 Hours4 Hours L L

Subtle blurring and Subtle blurring and compression of sulcicompression of sulci

R R 4 Days4 Days L L

Obvious dark changes Obvious dark changes of infarctionof infarction

Noncontrast CT Scan: Hemorrhagic Strokes

““Ball” of whiteBall” of whiteblood in thalamusblood in thalamus

R LR LR R LL

White blood incisterns & 4th ventricle

Intracerebral Hemorrhage Subarachnoid Hemorrhage

What Pathology Does This Scan Show?

Scan A

Scan A


Hypodense area:

• Ischemic area with edema, swelling

• Indicates >3 hours old

• No fibrinolytics!

LeftRight


Scan B


Scan B

(White areas indicate hyperdensity = blood)

Large left frontal intracerebral hemorrhage.

Intraventricular bleeding is also present

No fibrinolytics!

LeftRight


Scan C


Scan C

Acute subarachnoid hemorrhage

Diffuse areas of white (hyperdense) images

Blood visible in ventricles

and multiple areas on surface of brain

Management - Thrombolytics

0%

10%

20%

30%

40%

50%

60%

BarthelIndex

modifiedRankin

Glasgowoutcome

NIHSS

t-PA

Placebo

Percent of Patients with Minimal/No deficit at 3 months

NINDS. New Engl J Med 1995; 333: 1581.

Fibrinolytic Therapy: Yes/No Checklist

Inclusion Criteria

(all “Yes” boxes must be checked before fibrinolytics are given)

Yes

Age 18 years or older

Clinical diagnosis of ischemic stroke causing a measurable neurologic deficit

Time of symptom onset well established to be <180 minutes before treatment would begin


Exclusion Criteria(all “No” boxes must be checked before fibrinolytics are given):

No

Evidence of intracranial hemorrhage on noncontrast head CT

Only minor or rapidly improving stroke symptoms

High suspicion of subarachnoid hemorrhage even if CT is normal

Active internal bleeding (eg, gastrointestinal bleeding or urinary bleeding within last 21 days)

Known bleeding diathesis, including but not limited to

— Platelet count <100 000 mm3

— Patients who received heparin in last 48 hours; have elevated PTT

— Recent anticoagulant use (eg, coumadin); have elevated PT


Exclusion Criteria (cont’d)(all “No” boxes must be checked before fibrinolytics are given):

No

<3 mo ago: intracranial surgery, head trauma, previous stroke

<14 days ago: major surgery or serious trauma

<7 days ago: lumbar puncture

Recent arterial puncture at noncompressible site

History of intracranial hemorrhage, AV malformation, or aneurysm

Witnessed seizure at start of stroke

Recent acute myocardial infarction

SBP >185 mm Hg/DBP >110 mm Hg; confirmed several times

BP must be treated aggressively to bring within these limits

Management - thrombolytics

Requirements - all within 3 hours Recognition/identification

potentially eligible patients

History Awaken with weakness does NOT count) Exclusion criteria

Exam detailed NIH stroke scale

CT scan must be read by neuro-radiologist (subtle exclusions)

Consent

Management - other options

New neuroprotective agents Selective intra-arterial

thrombolytics angioplasty? Stents/coils? EXTENDS window to 4-6 hours

Immediate assessment: <10 minutes from arrival• Assess ABCs, vital signs• Provide oxygen by nasal cannula• Obtain IV access; obtain blood samples (CBC,

electolytes, coagulation studies)• Check blood sugar; treat if indicated• Obtain 12-lead ECG, check for arrhythmias• Perform general neurological screening assessment• Alert Stroke Team: neurologist, radiologist,

CT technician

Immediate neurological assessment: <25 minutes from arrival• Review patient history• Establish onset (<3 hours required for fibrinolytics)• Perform physical examination• Perform neurological examination:

Determine level of consciousness (Glasgow Coma Scale) Determine level of stroke severity (NIH Stroke Scale or

Hunt and Hess Scale)• Order urgent noncontrast CT scan

(door-to–CT scan performed: goal <25 minutes from arrival)• Read CT scan (door-to–CT read: goal <45 minutes from arrival)• Perform lateral cervical spine x-ray (if patient comatose/history

of trauma)

Acute Stroke Algorithm

EMS assessments and actions

Immediate assessments performed by EMSpersonnel include• Cincinnati Prehospital Stroke Scale

(includes difficulty speaking, arm weakness, facial droop)

• Los Angeles Prehospital Stroke Screen• Alert hospital to possible stroke patient• Rapid transport to hospital

Suspected Stroke

DetectionDispatchDelivery

Door

Case-Based

Prehospital Scenarios

Case-Based

Prehospital Scenarios

Case 1: On scene


Case 1:Transport (patient is 60 / month is December)


Case 1: Discussion

1. Is this more likely a stroke or stroke mimic?

2. What are the physical findings?

3. Where in the brain is the abnormality?

4. Is the radio report complete?

5. Is this patient a candidate for t-PA?

Case 2: On Scene


Case 2:Transport(patient is 45 / month is December)


Case 2: Radio Report


Case 2: Discussion






Case 3: On Scene


Case 3:Transport(patient is 48 / month is October)




Case 3: Discussion






Case 4: On Scene


Case 4:Transport(patient is 69 / month is December)




Case 4: Discussion






SummaryKey Evaluation Targets for Stroke Patient:

Potential Fibrinolytic Candidate?

Door-to–doctor first sees patient …….………… 10 min

Door-to–CT completed …….………………….. 25 min

Door-to–CT read ...…………..………………… 45 min

Door-to–fibrinolytic therapy starts …………….. 60 min

Neurologic expertise available* …..…………… 15 min

Neurosurgical expertise available* …………… 2 hours

Admitted to monitored bed ..……...…………… 3 hours

Maximum Intervals Recommended by NINDS

Thank You

I’M OUTTA HERE

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Ray Taylor Ray Taylor Valencia Community College Valencia Community College Department of Emergency Medical Services Department of Emergency Medical Services