ISCHEMIC STROKE
Transient ischemic attack (TIA)
Created 23/03/2021, last revision 25/10/2022
- a transient ischemic attack (TIA) is a medical emergency
- despite its seemingly mild course, TIA is a serious predictor of subsequent ischemic stroke and death
- following TIA, the risk of recurrent stroke is 8% in the first week, 11.5% at 1 month, and 17.3% at 3 months [Coull, 2004]
- following TIA, the risk of recurrent stroke is 8% in the first week, 11.5% at 1 month, and 17.3% at 3 months [Coull, 2004]
- true incidence and prevalence of TIA are challenging to determine because of inconsistent criteria
- the reported crude annual incidence rate for the TIA was 35.2 per 100 000 (95% CI, 30.6–40.3) and 28.6/100 000 (95% CI, 24.1–33.5) when standardized to the 2011 European population. TIAs are rare in young adults (<45 years) and relatively rare in subjects aged 45–64 years; after that, the incidence steeply increased, peaking in subjects aged ≥ 85 years, in all sexes [Degan, 2017]
- evaluation of TIA and initiation of multimodal therapeutic interventions should be urgent to decrease the risk of subsequent stroke
- especially TIAs within 24-48 h should be managed as a stroke
TIA definition
- the former definition of TIA (sudden focal neurological deficit lasting < 24h with presumed vascular origin) became obsolete
- about 30-50% of such defined TIA patients have infarct lesions on DWI [Oppenheim, 2004]
- the likelihood of a DWI lesion increases with symptom duration; DWI is positive in over 60% of TIA cases lasting > 30 min [Inatomi, 2004]
Transient episode of neurologic dysfunction due to the focal brain, spinal cord, or retinal ischemia, usually lasting < 1h, without acute infarction or tissue injury.
TIA or stroke?
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Etiology
- TIA subtypes, classified according to the pathophysiological mechanisms, are similar to ischemic stroke subtypes → TOAST classification of stroke
- the common vascular risk factors are the same as in stroke (e.g., diabetes, hypertension, age, smoking, unhealthy diet and obesity, alcoholism, stress, and lack of physical activity)
Clinical presentation
- TIA symptoms are sudden in onset
- TIAs usually last a few minutes with complete resolution of symptoms and signs
- the signs and symptoms of a TIA resemble those found in a stroke:
- hemiparesis, quadruparesis
- hemihypesthesia
- speech disturbances
- aphasia
- slurred speech (dysarthria)
- vision disturbances
- blindness in one or both eyes, visual field deficit
- double vision
- vestibular syndrome
- cerebellar syndrome (ataxia, dysmetria)
- global symptoms (lightheadedness, isolated delirium, syncope) and positive symptoms (scintillations) are not typical for a TIA
Diagnostic evaluation
- TIA very often occurs hours or days before a stroke; it can thus serve as both a warning of a future stroke and an opportunity to prevent it
- prompt evaluation and identification of potentially treatable conditions are essential
- specialist review of a patient within 24 h after the onset of symptoms is recommended (ESO guidelines 2021)
- review in a TIA clinic or hospitalization in a stroke unit are reasonable options (depending on locally available resources and the patient´s preferences)
- the main goals of a TIA evaluation:
- to prove the vascular origin of the symptoms and to exclude an alternative nonischemic origin
- because of the often already negative neurological finding, the history of symptoms must be carefully discussed (can help diagnose TIA or even its etiology)
- uniform repeated attacks indicate either pathology at the level of some peripheral branch or stroke mimic (migraine etc.) ⇒ differentiating TIA from the “stroke mimics“
- to determine the underlying vascular mechanism to select the optimal therapy
- it is most important to exclude significant carotid stenosis and major cardioembolic source
- palpitations, arrhythmias, and valve defects, together with symptoms and signs from various territories, point toward a cardiac etiology (TOAST 2)
- to prove the vascular origin of the symptoms and to exclude an alternative nonischemic origin
Who should be admitted to the hospital?
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- transient ischemic attack (TIA) is a medical emergency defined as a brief episode of neurological dysfunction due to focal brain, spinal cord, or retinal ischemia without acute infarction or tissue injury (negative imaging)
- TIA requires prompt evaluation and treatment to reduce the risk of subsequent stroke (about 1 in 3 people with TIA will eventually have a stroke)
- the ABCD2 score is a simple clinical prediction tool that helps to stratify patients presenting with a TIA according to their risk of stroke
- ≥ 4 points ⇒ high stroke risk; hospitalization is recommended (2-day stroke risk is > 4%, 7-day stroke risk: 5.9%!)
- always use this score together with clinical judgment and brain and vascular imaging findings!
ABCD2 score
(max. 7 points, high stroke risk ≥ 4 )
|
|
A Age ≥ 60 years
|
1
|
B BP ≥ 140/90 mmHg (either SBP ≥ 140 or DBP ≥ 90)
|
1
|
C Clinical features of the TIA
Unilateral weakness
Speech disturbance without weakness
|
2
1
|
D Duration of symptoms
<10 minutes 10-59 minutes
≥ 60 minutes |
0
1
2
|
D History of diabetes
|
1
|
0-3
|
low risk
2-Day Stroke Risk: 1.0% 7-Day Stroke Risk: 1.2% 90-Day Stroke Risk: 3.1% |
outpatient management |
4-5
|
medium risk
2-Day Stroke Risk: 4.1% 7-Day Stroke Risk: 5.9% 90-Day Stroke Risk: 9.8% |
hospitalization rather recommended |
6-7
|
high risk
2-Day Stroke Risk: 8.1%
7-Day Stroke Risk: 11.7% 90-Day Stroke Risk: 17.8% |
hospitalization recommended |
Acute evaluation of TIA patient
- focused history
- onset, duration, timing, symptoms specification, any aggravating or relieving factors
- risk factors, concomitant diseases (CAD or PAD, smoking, drug abuse, obesity, diabetes mellitus, dyslipidemia, and hypertension)
- clinical exam
- assess neurological deficits, including speech disturbances, visual field defects, etc.
- cardiac examination
- carotid auscultation for a carotid bruit detection
- brain imaging (preferred modality is DWI within 24h or CT+CTP if DWI cannot be performed) (ESO 2021) (AHA/ASA 2013 I/B)
- DWI has a greater sensitivity than CT for detecting small infarcts
- vessel examination – neurosonology or CTA/MRA (urgent in recent TIA) ( AHA/ASA guidelines 2013 I/A)
- ESO guidelines 2021 suggest using MRA or CTA for confirmation of large artery stenosis ≥ 50% detected by ultrasound in order to guide further management
- strength of MRA compared to ultrasound and CTA is its relative insensitivity to arterial calcifications
- blood tests
- complete blood count (CBC) + coagulation + ESR
- biochemistry panel
- lipid panel
- diabetes mellitus screening
- urine drug screen in selected cases
- complete blood count (CBC) + coagulation + ESR
- ECG
- standard ECG (AFib?)
- continue with Holter ECG or prolonged ECG monitoring for at least three weeks (with loop recorder)
- prolonged cardiac rhythm monitoring is reasonable, especially in patients with cortical infarcts with no clear source to exclude paroxysmal AFib
- standard ECG (AFib?)
- TTE (transthoracic echocardiogram) + TEE (transesophageal echocardiogram)
- search for PFO, valve, and other intracardial abnormities, aortic plaques
- EEG in DDx of stroke mimics
→ etiological diagnosis and classification of stroke see here
Differential diagnosis
- differentiate TIA from stroke mimics
Therapy and prevention
- immediately start multimodal therapeutic intervention
- treatment may substantially reduce the risk of a future stroke or recurrent TIA (by 80%) – EXPRESS trial
- the same-day assessment and initiation of standard risk-modification measures following TIA decreased the 90-day risk of stroke from 10.3 to 2.1% compared with delayed (or routine) outpatient evaluation and treatment
- early treatment did not increase the risk of intracerebral hemorrhage or another bleeding.
Antithrombotic therapy
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Surgery and endovascular procedures
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Vascular risk factors management and others
- start aggressive blood pressure treatment (⇒ BP < 135/85 mm Hg, ACE-I are preferred) → acute blood pressure management
- treat hyperlipidemia
- manage other vascular risk factors
- consider specific treatment of some particular underlying etiologies (vasculitis, etc.)
- even in TIA patients, post-traumatic stress disorder (PTSD) with depression or anxiety may develop (Kiphuth, 2014]
- train adaptive coping strategies and cautiously brief about the realistic stroke risk associated with TIA
- if needed, use anxiolytics or antidepressants