Clinical Diagnosis of Stroke and Stroke Subtypes …Clinical Diagnosis of Stroke and Stroke Subtypes...
Transcript of Clinical Diagnosis of Stroke and Stroke Subtypes …Clinical Diagnosis of Stroke and Stroke Subtypes...
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 1
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Clinical Diagnosis of Stroke
and Stroke Subtypes
Louis R Caplan, MD
Professor Neurology Harvard Medical School
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1. Think
Don’t let cook -book guidelines and protocols change
your thoughtful systematic stepwise clinical approach
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2. Stroke - evaluation
The most important investigations are:
• A thorough history
• A physical examination emphasizing the heart
and blood vessels
• A competent neurological examination
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 2
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3. Clinical diagnosis- step 1
Begin to acquire information from the history
about what and where
• What
– Pathology
� Is it a stroke?
� What subtype?
•Where
– Location of the brain lesion
– Location of the vascular lesion
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History- the what diagnosis (1)
Ecology (a priori odds)
• Past and present medical ills and risk factors
– Hypertension
– Diabetes
– Coronary artery or other heart disease
– Obesity
– Claudication
– Smoking
– Illicit drugs
– Family history of vascular disease
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• Past strokes and TIAs (specific queries)
• Activ ity at onset
• Associated symptoms (headache, vomiting, loss
of consciousness)
• Temporal course
– Maximal at onset
– Gradual progressive
– Stepwise, fluctuating, stuttering
History- the what diagnosis (2)
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
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Neurological symptoms and their location
History- the where diagnosis
• For example:
– weakness of one side of the body → v isual sy mptoms?
� double v ision or striking v ertigo?
• Query the patient about specif ic symptoms
on which they may not spontaneously elaborate
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4. After the history, make hypotheses about the what and where diagnoses
Order the diagnoses according to probability
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Case example
• A 55 year old Chinese woman develops during hours
a right hemiparesis
• Her family says that her speech is abnormal
• She has had hypertension and diabetes controlled
with oral antihyperglycemic agents
• She is not known to have heart disease
• She has not reported headache before or during
her neurological symptoms
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
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What diagnoses
• Thrombosis- MCA 30%
• Thrombosis- lacunar 25%
• Thrombosis- intracranial ICA- 15%
• Thrombosis or dissection neck ICA 10%
• Intracerebral hemorrhage- 10%
• Brain embolism 10%
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Where diagnoses
• Left cerebral hemisphere
– Deep- basal ganglia, internal capsule- 35%
– Deep and cortical- 30%
– Cortical- 15%
• Left brainstem- 20%
– Pons, midbrain, or thalamus
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5. Plan the general and neurological
examinations to distinguish between
the various what and where hypotheses
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 5
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Queries to test during the exam
• BP- is it very high?
• Any cardiac abnormality? any neck or cranial bruit?
• Is the speech abnormality aphasia or dysarthria?
• Is the motor weakness equal in face, arm, hand,
thigh, and leg?
• Are there any sensory or v isual field abnormalities?
• Are there any abnormalities of eye movement?
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Case example- examination
• BP 140/75
• No heart abnormalities; no neck or cranial bruits
• Some paraphasic errors in speech
• Right face and hand weaker than right lower limb
• Difficulty localizing touch in the fingers
of the right hand
• No v isual field defect
• Slight asymetry of conjugate gaze with slower
saccadces to the right
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6. Revise the what and where diagnoses
after the history and examination have
been completed
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 6
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Modified what diagnoses
• Thrombosis- MCA 40%
• Thrombosis- intracranial ICA- 20%
• Thrombosis or dissection neck ICA 20%
• Intracerebral hemorrhage- 10%
• Brain embolism 10%
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Modified where diagnoses
Left cerebral hemisphere
• Deep- basal ganglia, internal capsule- 30%
• Deep and cortical- 30%
• Cortical- 25%
• Thalamus- 15%
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7. Plan the imaging and laboratory
investigations in relation to the what
and where hypotheses
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 7
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Could the patient have hypoglycemic hemiparesis
or a subdural hematoma, or have bled into a brain tumor?
8. Ask if the cause of the symptoms might
be other than stroke
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9. Routine blood tests
• Hematocrit, WBC, pla telet count
• Prothrombin time (INR)
• Blood sugar
• BUN, Creatinine
9. Routine blood tests
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10. Find out what is wrong with every patient as completely as you can
Precise detailed diagnosis has great intrinsic value even
when there is no presently accepted treatment
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 8
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Stroke is a cerebrovascular disease
• Patients with stro ke have disease of the vasculature
that supplies the brain
• We really need a vascular diagnosis
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Data needed to logically treat stroke patients
• The nature, location and severity of the causative
vascular-cardiac-hematological conditions
• The mechanism of ischemia- hypoperfusion
or embolism
• The cellular and serological components of the blood
• The state of the brain- normal, “stunned”, or infarcted
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11. Obtain brain and vascular imaging
• CT and CTA (or rapid sequence cranial CT after dye );
CT perfusion imaging
• MRI and MRA with diffusion & perfusion imaging
• CT or MRI with extracranial and transcranial ultrasound
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 9
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12. MRI can be performed as the sole brain imaging procedure if a T2*-weighted
sequence is performed
T2*-weighted MRI images show recent and old brain
and subarachnoid hemorrhages better than CT scans
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13. CT and MRI brain images can yield
data re vascular lesions
Examine the flow voids carefully
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 10
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In the Chinese woman described, CT scan showed a striato-capsular infarct
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Striato-capsular infarct
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 11
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14. Obtain vascular testing; This is critical for treatment decisions
• CTA (with CT perfusion if available)
• “Triphasic CT” after contrast
• MRA (with or without contrast)
• Neck ultrasound and TCD
14. Obtain vascular testing; This is critical for treatment decisions
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MRA-
same
patientMRA
CTA
Submitted by Walter Koroshetz MD
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Perfusion CT
Wintermark, Ann Neurol 2002
Infarct
Penumbra
IV rtPA Day 7
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 12
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Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 13
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TCD
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Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 14
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Triphasic CT perfusion
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Patient scan at 3 hours
rt-PA giv en rescanned
18 hours aft er infusion
MRA DWI T2 weighted
MRA DWI T2 weighted
Linfante/Linas/Schlaug BIDMC 1999
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
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1 hour post tPA infusion Perfusion weighted MRI
Diffusion weighted MRI
hypoperfusion
R MCA occlusion
tissue injury
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24 hours post tPA infusion
diffusion weighted MRI
Perfusion weighted MRI
reperfusion
R MCA open
tissue injury
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Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 16
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MRA and then cerebral angiography
in this Chinese woman showed an occlusion
of the left MCA at its origin;
The ICA and other arteries were normal
Was this occlusion due to intrinsic MCA
atherostenosis with occlusion or to embolism?
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MCA
occlusive
disease
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
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15. The heart and aorta are important to study
as potential sources of embolism
and for coexistent atherostenotic
coronary artery disease
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Trans-esophageal echocardiogram
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
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LV
LA
RV
Left atrial thrombusAortic plaquesLeft atrial thrombus
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LV
Left atrial thrombus
Left ventricle thrombus
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Patent foramen ovale
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
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In this Chinese woman, transesophageal
echocardiography with views of the heart
and aorta were completely normal;
I concluded that she most likely had intrinsic
MCA disease
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16. Sometimes reviewing the history
and/or the examination a second and even
third time can yield very useful
diagnostic information
• In this woman, on later questioning she recalled two
transient attacks- each very brief, of numbness in her
right hand and face that she had forgotten
• This made the likelihood of an intrinsic MCA
lesion highly likely
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17. Plan treatment depending on the anatomy,
pathology, and pathophysiology of the brain
and vascular lesions
Clinical Diagnosis of Stroke
and Stroke Subtypes
Prof. Louis R. Caplan
The screen versions of these slides have full details of copyright and acknowledgements 20
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18. Treatment considerations includes many items:
• Acute therapy especially to restore blood flow
• Prophylaxis to prevent the next stroke
• Management of risk factors
• Promoting recovery
• Education of patient and caregivers
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