Stroke Flashcards
Modified Rankin Score 0
No symptoms
Modified Rankin Score 1
Despite symptoms, able to perform all normal activities of daily living
Modified Rankin Score 2
Slight disability unable to perform all normal activities without assisitance
Modified Rankin Score 3
Moderate disability. Able to walk without assistance - however needs other considerable assistance
Modified Rankin Score 4
Moderately severe disability. Unable to attend to own bodily needs and needs assistance to walk
Modified Rankin Score 5
Severe disability. Bed ridden. Incontinent. Constant care
Modified Rankin Score 6
Death
Velocity criteria for carotid artery stenosis in doppler US
A specificity of 100 percent was found for PSV (peak systolic velocity) >440 cm/sec, EDV (end diastolic velocity) >155 cm/sec, or carotid index >10 (peak internal carotid artery [ICA] velocity ÷ common carotid artery [CCA] velocity). The sensitivity for these measures was 58 percent, 63 percent, and 30 percent, respectively. By combining these criteria, the sensitivity increased to 72 percent.
A sensitivity of 96 percent was found for PSV >200 cm/sec combined with either an EDV >140 cm/sec or a carotid index >4.5. The specificity for these combined measures was 61 percent.
Most sensitive measure on USS of stenosis
Carotid index >4 i.e peak internal carotid velocity/peak common carotid velocity
Two MRIs used for evaluating carotid stenosis
‘time of flight’ MRA (magnetic resonance angiography) or gadolinium enhance MRA/ contrast enhanced MRA (CEMRA)
Five Lacunar syndromes
- Pure motor hemiparesis - equal face, arm, leg - no sensory, visual or language deficit
- Pure sensory - face, arm, leg - sensory loss without weakness, visual or language deficit
- Dysarthria - slurred speech
- Clumsy hand - ataxic hand
- Ataxic hemiparesis - unilateral weakness and clumsiness
Lipohyalinotic occlusion of small penetrating arteries (<200mcm) that branch from larger intracerebral arteries - produce small infarcts call lacunes
TIA: risk of stroke in week
risk of stroke (untreated) is ~10% in first week
TIA therapy
All TIAs must go home in a CAB
o Cholesterol lowering agent - Commence a statin
o Anthithrombotic
• AF absent - antiplatelet
• 1st line – aspirin
• 2nd line – if already on aspirin and had a TIA – clopidogrel
• 3rd line – if on clopidogrel and had TIA - DAPT
• AF present anticoagulate
o Blood pressure lowering meds – commence an oral antihypertensives
• Calcium channel blockers are best, can also use ACE-I/ARB and thiazides
• Beta-blockers – may increase risk of stroke recurrence BUT are indicated with concurrent IHD
Evidence suggests that this approach reduces the RR of stroke by 80%
ABCD3-I score
Utility and meaning
TIA risk stratification score Age >60 BP >140/90 Clinical features - Speech without weakness = 1 - Unilateral weakness = 2 Duration - 10-59 mins = 1 - >1 hour = 2 Diabetes Dual presentatino (2nd pres. in a week) = 2 imaging: ipsilateral carotid stenosis >50% = 2 MRI DWI hyperintensity = 2 Points total 13
0-3 low risk 2-3 %
4-7 Intermediate risk <6%
8-13 High risk >18 %
Antihypertensive therapy for stroke
Labetalol 10mg over 1-2 minutes can use 20 mg
Can use labetalol ongoing to maintain BP <180 with infusion 2-8mg/hr
Or nicardipine 5mg/hr IV titrate up 2.5mg per hour every 5-15 minutes if not down trending. Max 15mg/hr
Hydralazine IV 10mg- direct vasodilator. Can give 20mg. Drop is sudden within 10-30 mins. May need concurrent beta blocker
Lasts 2-4 hours.
BP management of stroke patient NOT receiving thrombolysis
No management unless severe hypertension >220 or 120 diastolic. Or if patient has coronary artery disease, heart failure, dissection or other reason to lower.
Lowering of 15% during first 24 hours after stroke is recommended.
Inclusion and exclusion criteria for thrombolysis
Inclusion criteria
Clinical diagnosis of ischemic stroke causing measurable neurologic deficit
Onset of symptoms <4.5 hours before beginning treatment; if the exact time of stroke onset is not known, it is defined as the last time the patient was known to be normal or at neurologic baseline
Age ≥18 years
Exclusion criteria
–Patient history–
Ischemic stroke or severe head trauma in the previous three months
Previous intracranial hemorrhage
Intra-axial intracranial neoplasm
Gastrointestinal malignancy
Gastrointestinal hemorrhage in the previous 21 days
Intracranial or intraspinal surgery within the prior three months
–Clinical–
Symptoms suggestive of subarachnoid hemorrhage
Persistent blood pressure elevation (systolic ≥185 mmHg or diastolic ≥110 mmHg)
Active internal bleeding
Presentation consistent with infective endocarditis
Stroke known or suspected to be associated with aortic arch dissection
Acute bleeding diathesis, including but not limited to conditions defined under ‘Hematologic’
–Hematologic–
Platelet count <100,000/mm3*
Current anticoagulant use with an INR >1.7 or PT >15 seconds or aPTT >40 seconds or PT >15 seconds*
Therapeutic doses of low molecular weight heparin received within 24 hours (eg, to treat VTE and ACS); this exclusion does not apply to prophylactic doses (eg, to prevent VTE)
Current use (ie, last dose within 48 hours in a patient with normal renal function) of a direct thrombin inhibitor or direct factor Xa inhibitor with evidence of anticoagulant effect by laboratory tests such as aPTT, INR, ECT, TT, or appropriate factor Xa activity assays
–Head CT–
Evidence of hemorrhage
Extensive regions of obvious hypodensity consistent with irreversible injury
Timing for mechanical thombectomy
Thombectomy (clot retrieval) within 6 hours–> indicated in large vessel occlusion
Trial showing extension of time window for stroke management with mechanical thrombectomy
DAWN trial: Endovascular therapy within 24 hours of symptom onset NIHSS >10 ICA or M1 Failed or contraindicated thrombolysis Mismatch age related: mRS at baseline 1 or less Older than 80, NIHSS more than 10 and infarct volume <21 Or Younger than 80 10-19 NIHSS: less than 31 ml 20 or more NIHSS less than 51ml
Hemicraniotomy (When and NNT)
In young patients (younger than 60), before symptoms onset i.e. coma, NNT =2, saves lives but not disability
Define valvular AF
AF caused by low flow states or high thromboembolic risk: mechanical valve or mitral stenosis
When to anticoagulate post stroke?
1,3,6,12 Rule 1 Day post TIA 3 post minor stroke 6 post moderate stroke 12 post large stroke or haemorrhage
Indication for endarterectomy
Greater than 70% stenosis in a patient without already significant morbidity/disability
50-70% may be indicated if good QOL and life expectancy
Below this - Risk of stroke is minimal (0.5%) if medical management is observed (statin, antiplatelet and BP management)
Surgical intervention after TIA or stroke should be within 2 weeks. But greater than 48 hours.
Stenting is not routinely performed except for certain circumstances (radiation induced stenosis, stenosis of prev. endarterectomy)
Single most important risk factor for stroke
HTN
CCB have the best evidence - beta blockers only in the setting of IHD
PROGRESS and PROFESS trials with ACE and ARB
Demonstrated the degree of BP reduction is the key, not necessarily the drug. Telmesartan not shown to have benefit (only reduced BP by 4mmHg vs 2 of placebo
Most common causes of ICH
Hypertension, cerebral amyloid angiopathy, vascular malformations and anneurysms
Most common site of hypertensive bleeds
small penetrator arteries that branch of major intracerebral arteries, often at 90 degree angles – very susceptible to hypertension due to direct pressure of much larger arteries
Supply to :Pons and midbrain, thalamus, putamen, caudate and cerebellum
