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
Click picture to play video
Cincinnati Prehospital Stroke Scale Left Hemispheric Stroke
Click picture to play video
Miami Emergency Neurologic Deficit Exam Left Hemispheric Stroke
Click picture to play video
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
What Pathology Does This Scan Show?
Hypodense area:
• Ischemic area with edema, swelling
• Indicates >3 hours old
• No fibrinolytics!
LeftRight
What Pathology Does This Scan Show?
Scan B
What Pathology Does This Scan Show?
Scan B
(White areas indicate hyperdensity = blood)
Large left frontal intracerebral hemorrhage.
Intraventricular bleeding is also present
No fibrinolytics!
LeftRight
What Pathology Does This Scan Show?
Scan C
What Pathology Does This Scan Show?
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
Fibrinolytic Therapy: Yes/No Checklist
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
Fibrinolytic Therapy: Yes/No Checklist
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
Click picture to play video
Case 1:Transport (patient is 60 / month is December)
Click picture to play video
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
Click picture to play video
Case 2:Transport(patient is 45 / month is December)
Click picture to play video
Case 2: Radio Report
Click picture to play video
Case 2: 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 3: On Scene
Click picture to play video
Case 3:Transport(patient is 48 / month is October)
Click picture to play video
Case 3: Radio Report
Click picture to play video
Case 3: 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 4: On Scene
Click picture to play video
Case 4:Transport(patient is 69 / month is December)
Click picture to play video
Case 4: Radio Report
Click picture to play video
Case 4: 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?
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
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