Transient Ischaemic Attack Flashcards
TIA and Statins
In addition to diet and exercise modifications, all patients who are diagnosed with stroke or TIA should be commenced on statin therapy irrespective of the cholesterol level.
TIA - ABCD2
NICE issued updated guidelines relating to stroke and transient ischaemic attack (TIA) in 2008. They advocated the use of the ABCD2 prognostic score for risk stratifying patients who’ve had a suspected TIA:
A Age >= 60 years 1
B Blood pressure >= 140/90 mmHg 1
C Clinical features
- Unilateral weakness 2
- Speech disturbance, no weakness 1
D Duration of symptoms
- > 60 minutes 2
- 10-59 minutes 1
Patient has diabetes 1
This gives a total score ranging from 0 to 7. People who have had a suspected TIA who are at a higher risk of stroke (that is, with an ABCD2 score of 4 or above) should have:
aspirin (300 mg daily) started immediately
specialist assessment and investigation within 24 hours of onset of symptoms
measures for secondary prevention introduced as soon as the diagnosis is confirmed, including discussion of individual risk factors
If the ABCD2 risk score is 3 or below:
specialist assessment within 1 week of symptom onset, including decision on brain imaging
if vascular territory or pathology is uncertain, refer for brain imaging
People with crescendo TIAs (two or more episodes in a week) should be treated as being at high risk of stroke, even though they may have an ABCD2 score of 3 or below.
TIA - Antithrombotic Therapy
Antithrombotic therapy
clopidogrel is recommended first-line (as for patients who’ve had a stroke)
aspirin + dipyridamole should be given to patients who cannot tolerate clopidogrel
these recommendations follow the 2012 Royal College of Physicians National clinical guideline for stroke. Please see the link for more details (section 5.5)
these guidelines may change following the CHANCE study (NEJM 2013;369:11). This study looked at giving high-risk TIA patients aspirin + clopidogrel for the first 90 days compared to aspirin alone. 11.7% of aspirin only patients had a stroke over 90 days compared to 8.2% of dual antiplatelet patients
TIA - Carotid Endarterectomy
With regards to carotid artery endarterectomy:
recommend if patient has suffered stroke or TIA in the carotid territory and are not severely disabled
should only be considered if carotid stenosis > 70% according ECST* criteria or > 50% according to NASCET** criteria
- European Carotid Surgery Trialists’ Collaborative Group
- *North American Symptomatic Carotid Endarterectomy Trial
When to image after a TIA?
The national institute of clinical excellence (NICE) state that patients with a suspected TIA who are at a high risk of stroke (ABCD2 score of 4 or above) where the pathology or vascular territory is uncertain require urgent brain imaging, preferably diffusion weighted MRI.
Example Question:
An 83-year-old female presents to the emergency department. The patient describes a vague history of arm and leg weakness and loss of vision though is unsure of a particular limb or visual field distribution. She states that these symptoms seemed to last around 6 hours. There are no abnormalities noted in the upper and lower neurological examination nor cranial nerve examination in the emergency department. The patient has a history of regular migraine of around 2 a week for the last 20 years, type two diabetes mellitus treated with metformin and hypertension which was diagnosed 8 years ago currently treated with amlodipine.
Her observations are.
Blood pressure - 145/90 mmHg
Heart rate - 83 beats per minute
Temperature - 37.5C
Respiratory rate - 15
Oxygen saturation - 98% on air
You suspect the patient may have had a transient ischaemic attack. Which radiological investigation is the most appropriate to aid diagnosis at this stage?
MRI head with fluid attenuation inversion recovery (FLAIR) CT head with contrast Carotid dopplers MRI head > MRI head with diffusion weighted imaging
This patient is an example of someone who has had a suspected transient ischaemic attack (TIA) who requires urgent brain imaging.
The patient in this question has an ABCD2 score of at least 5, the vague clinical history also make the vascular territory uncertain. Therefore diffusion weighted MRI is most suitable. She may require a Doppler ultrasound of her carotid arteries in the future, though this would preferably happen after the MRI.
TIA and Referral for Carotid Endarterectomy
Patients with a TIA or small ischaemic stroke with evidence of significant carotid artery stenosis (male patients with a carotid artery stenosis of 50-99% or female patients with a carotid artery stenosis of 70-99%) that corresponds to the same side as the stroke/TIA should be considered for an urgent carotid endarterectomy (CEA) within 14 days.
Indications for Carotid Endarterectomy - Example Question
A 70-year-old male is evaluated at the neurology outpatient department for an episode of left sided body weakness which lasted for around 30 minutes and resolved completely. He described the episode as an inability to move the left side of his body and an associated numbness and tingling sensation in the area involved. He remained conscious throughout and was able to communicate verbally with his family members during the episode.
He suffers from hypertension and has hypercholesterolaemia. He is also a smoker with a 40 pack year history and is known to be a heavy drinker.
He has also noted a tremor in both his hands which tends to improve after he has a drink. He also feels unsteady while walking and feels the need to grip something otherwise he may lose balance.
His medication includes amlodipine 5mg daily and atorvastatin 20mg daily.
On examination, his blood pressure is 150/95mmHg and his pulse is 86bpm regular. A carotid bruit is audible over both sides of the neck. Neurological examination reveals impaired sensations in a glove and stocking distribution. The remaining clinical examination is normal.
Investigations reveal:
ECG: deep S waves in lead V1-V3 and tall R waves in V4-V6
CXR: Enlarged cardiac silhouette with flecks of calcification around the aorta
Carotid artery Doppler studies reveal 85% occlusion in the right external carotid. 50% occlusion in the right internal carotid. Left internal carotid is 80% occluded while there is a 60% occlusion in the left external carotid artery.
Which of the following is the most suitable treatment option in this patient?
Left internal carotid endarterectomy > Optimizing medical management Right external carotid endarterectomy Percutaneous stenting of the right internal carotid artery Percutaneous stenting of the left internal carotid artery
In the aforementioned scenario, the patient has suffered from a right sided TIA and has recovered completely. The question aims to assess the candidates knowledge pertaining to intervention in patients with TIAs and carotid stenosis.
Carotid endarterectomy or endovascular stenting is recommended in patients with symptomatic stenosis of the affected vessel >70%. In the patient described above, the symptoms involve the left side of the body, hence the right carotid is involved. The degree of stenosis in the right internal carotid is 50 % and therefore the treatment of choice would be optimization of medical therapy with improved blood pressure control and antiplatelet agents rather than intervention.
The carotid stenosis in the left internal carotid is asymptomatic therefore not an indication for endarterectomy.
The external carotids do not form part of the circle of Willis and do not contribute to the blood supply of the brain.
The reference to his benign essential tremor is of no relevance to his clinical condition.
TIA - Crescendo TIAs: Example Question
A 63-year-old man presents to the emergency department with a 5-minute episode of slurred speech earlier in the day. His wife noticed that his face was drooping to one side as well. He had no arm weakness and is now completely back to normal. He is normally well and on no regular medication and is not allergic to any medication. He works as a plumber and smokes 10 cigarettes per day for the last 40 years and drinks alcohol socially. On further questioning he mentions that he had a similar episode also lasting 5 minutes four days ago whilst at work. On examination, his blood pressure is 135/70 mmHg and his heart rate is 58/min. He has no focal neurology and his cardiovascular and respiratory examinations are unremarkable. He has been given 300mg of Aspirin by the paramedics.
His blood tests are as follows:
Hb 138 g/l Platelets 283 * 109/l WBC 8.1 * 109/l INR 1.1 PT 13 seconds
Na+ 142 mmol/l K+ 4.4 mmol/l Urea 6.4 mmol/l Creatinine 89 µmol/l CRP 5 mg/l Total cholesterol 3.8 mmol/l HDL 1.3 mmol/l
His ECG shows normal sinus rhythm and rate of 65/min.
What is the most appropriate management for this patient?
Outpatient TIA clinic appointment Outpatient CT head and carotid dopplers within the next week > Admit for urgent (< 24 hours) CT head & carotid dopplers Thrombolysis Long term clopidogrel
This gentleman has had crescendo TIAs (2 in a 7 day period). This necessitates treatment as high risk i.e. admission and urgent (<24 hours) CT head and carotid dopplers. His ABCD score is 3 (1 for age and 2 for symptoms). This would normally put him in the low-risk category (see below) but the presence of crescendo episodes the ABCD score is irrelevant. Thrombolysis is not appropriate as the neurology has resolved. OP TIA clinic and imaging and dopplers within the week are not appropriate given the crescendo episodes.
Crescendo TIA - Diagnosis and Mx: Example Question
A 77-year-old female has two episodes of weakness affecting the left arm and leg each lasting ten minutes, both within the space of 2 days. She did not attend the emergency department after the first episode. Her only significant past medical history is hypertension, for which she takes amlodipine 5mg OD. She has experienced one similar episode to this one year ago but did not seek medical attention. Her daughter is present who informs you that the patient has lost a significant amount of weight in the last year. On further questioning, she reports some haemoptysis lately. Her blood pressure in the department was 170/90mmHg initially.
Her bloods reveal
Hb 11.5 g/dl
Platelets 149 * 109/l
WBC 13.1 * 109/l
Na+ 132 mmol/l
K+ 5.3 mmol/l
Creatinine 111 µmol/l
CRP 15 mg/l
ECG: Sinus tachycardia, rate 104/min
What is the most appropriate management for this lady?
Aspirin + transient ischaemic attack (TIA) clinic referral Aspirin and dipyridamole + TIA clinic referral Aspirin and clopidogrel + TIA clinic referral > Admit for CT head + aspirin Reassure and discharge
This question tests the candidate’s knowledge of TIA risk stratification. The patient fulfils the criteria of crescendo TIAs (two TIAs in a 7 day period). This warrants urgent assessment and urgent imaging. Any patient with an ABCD2 score greater than 4 or crescendo TIA should be admitted.
TIA - ABCD2 Calculation! Example Question
A 60-year-old man with a history of hypercholesterolaemia, hypertension and type 2 diabetes mellitus reports an episode of right sided facial weakness and dysphasia lasting thirty minutes earlier that same day. His symptoms have since resolved. His blood pressure is recorded at 130/85 mmHg and there is a carotid bruit present on the left side. What is his ABCD2 score?
3 4 > 5 6 7
His age (1), history of diabetes (1), facial weakness (2) and duration (1) give him a score of 5.
Crescendo TIAs
People with crescendo TIAs (two or more episodes in a week) should be treated as being at high risk of stroke, even though they may have an ABCD2 score of 3 or below.
