TIA Flashcards
WHAT IS TIA?
ischaemic (usually embolic) neurological event with symptoms lasting <24h (often much shorter). Without intervention, more than 1 in 12 patients will go on to have a stroke within a week, so prompt management is imperative
results in reversible neurologic deficits without acute infarction (i.e., imaging findings show no signs of infarction)
(Previously, the definition of TIA required that the duration of symptoms be less than 24 hours. Since 2009, there has been less emphasis on symptom duration; the most important factor is now the absence of infarction.)
etiology of TIA ?
Atherothromboembolism from the carotid is the chief cause: listen for bruits (though not a sensitive test)
Cardioembolism: mural thrombus post-MI or in AF, valve disease, prosthetic valve
Hyperviscosity: eg poly- cythaemia, sickle-cell anaemia, myeloma.
Lacunar/small vessel disease (e.g., due to chronic hypertension)
what are the clinical manifestation of TIA?
Signs Specific to the arterial territory involved
Acute, transient focal neurologic symptoms
Typically, symptoms last < 1 hour (the majority of cases resolve in < 15 minutes).
sometimes Amaurosis fugax occurs when the retinal artery is occluded, causing unilateral progressive vision loss ‘like a curtain descending
Embolic: often a single, discrete episode lasting hours rather than minutes
Lacunar/small vessel disease: Symptoms usually resemble those seen in lacunar stroke.
Large vessel disease/low-flow state: often recurrent episodes lasting minutes
Global events (eg syncope, dizziness) are not typical of TIAs
diagnostics of TIA?
Start the workup as soon as possible following symptom onset and within 24 hours of patient presentation.
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Immediate: serum glucose
(Evaluate for hypoglycemia, HHS, or DKA, all of which have symptoms that may mimic TIA.)
within 24 hours of presentation:
CBC ( signs of an infection, bleeding, thrombocytosis, or polycythemia vera.)
BMP - Evaluate for electrolyte (e.g., hyponatremia) and metabolic (e.g., acidosis) disorders that can mimic TIA symptoms. Assess renal function for potential use of contrast with imaging
Coagulation panel
Serum troponin
Serum lipid panel
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neuroimaging
Neuroimaging is indicated for all patients with suspected TIA within 24 hours of presentation to rule out acute cerebral infarct (i.e., ischemic stroke).
CTA head and neck
MRI brain
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All patients: ECG to evaluate for atrial fibrillation or acute myocardial infarction.
All patients: ECG to evaluate for atrial fibrillation or acute myocardial infarction.
Patients with suspected embolic source or unknown etiology: Further cardiac evaluation is indicated. [14]
Echocardiography
TTE is preferred.
what is the risk stratification for TIA?
Score 6 to 7: high two-day stroke risk (8%)
Estimating the patient’s risk of a future stroke after a TIA helps guide management decisions
ABCD(2) risk assessment score is most frequently used to assess short-term stroke risk.
(However, validation studies have shown that it has poor accuracy.)
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Age
≥ 60 years
=1
Blood pressure
SBP ≥ 140 mm Hg
OR DBP ≥ 90 mm Hg
=1
Clinical features Speech impairment only =1 Unilateral weakness =2
Duration of symptoms 59 minutes or less =1 ≥ 60 minutes =2
Diabetes mellitus
=1
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Score 0 to 3: low two-day stroke risk (1%)
Score 4 to 5: moderate two-day stroke risk (4%)
must be assessed by a specialist within 24h.
Other factors that suggest increased risk are: • AF • >1 TIA in a week • TIA while anticoagulated
what is the management of TIA?
A-E
BP (cautiously lower; aim for <140/85mmHg, p140
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Perform immediate ECG and POC (point of care) glucose - bedside
Identify candidates for repercussion therapy immediately - thrombosis is should be imitated within 60 mins for optimum recovery
Rapid focused neurological assessment - Determine the time of symptom onset Risk factors for ischemia stroke GCS Pupillary examination Perform severity assessment-NIHSS
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Choice of antithromboric agent should take the following into consideration:
Preventative pharmacotherapy the patient was taking at the time of the TIA event
TIA severity (and risk of subsequent ischemic stroke)
Suspected etiology
Patient comorbidities
Timing: within 24 hours
give aspirin 300mg OD for 2wks, then switch to clopidogrel 75mg OD. If this is contraindicated or not tolerated, give aspirin 75mg
OD combined with slow-release dipyridamole
Perform immediate neuroimaging to rule out acute infarct and alternate diagnoses.
should be completed within 24 hours
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Stratify the risk of stroke and determine appropriate disposition.
Low risk: Schedule appropriate outpatient studies prior to discharge.
High risk: Admit to hospital under internal medicine or neurology service.
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Consider further cardiology studies.
what are the preventive stroke
excercise
hypertension - reduce salt intake - ace and arb , target less than 130/80
dm - glycemic control to less than 7 percent
hypercholestrolemia - No coronary artery disease or cardioembolic source and LDL cholesterol > 100 mg/dL: Start atorvastatin
Other ASVCD present: lipid-lowering therapy with statin ± ezetimibe to a target LDL cholesterol < 70 mg/d
stop smoking
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preventive stroke medication periodic to TIA
low risk TIA-
aspirin (clopidrogel alternative )
high risk TIA -
Dual antiplatelet therapy - aspirin and a platelet P2Y12 receptor blocker (e.g., clopidogrel) used to reduce the risk of thrombosis after arterial stenting (e.g., PCI)
for 21 days
and for secondary prevention of stroke
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what are the dd for TIA ?
Hypoglycaemia, migraine aura (p458), focal epilepsy (symptoms spread over seconds and often include twitching and jerking), hyperventilation, reti- nal bleeds.
Brain tumor
Brain abscess
if there is cardiac stenosis of 70-99 percent at first presentation of TIA what is performed
carotid endarterectomy is performed within 2 weeks
and if operative risk is acceptable
higher operative risk in females , over 75 , high systolic pressure , contralateral artery occluded
do not stop aspirin preoperatively
THIS SURGERY IS PREFERED TO end-vascular carotid artery angioplastyy with stenting - TO THOSE WHO CAN TOLERATE IT - DUE TO higher periprocedure stroke and mortality rates with stenting
what are the lifestyle managements for TIA ?
driving is prohibited for atleast 1 month
