Aids to Diagnosis - TIA
The following information (from Stroke: a practical guide to management, Warlow et al) may help the non-specialist identify and manage TIA's. You can read more about TIAs on our Stroke pages.
What is a TIA?
A focal neurological or monocular event
- Weakness of one side
- Simultaneous bilateral weakness
- Difficulty understanding or expressing words
- Difficulty reading or writing
- Difficulty calculating
- Altered feeling on one side
- Loss of vision in one eye
- Loss of vision of half or quarter of the visual field (ie both eyes)
- Bilateral blindness
- Double vision
- Difficulty dressing
- Visual, spatial, perceptual dysfunction
Symptoms and signs are usually "negative" ie loss of function. They can be "positive" ie pins and needles, shaking, scintillations in vision, but this is rare.
The onset is abrupt, without intensification or spread. Maximal deficit usually occurs in a few seconds. The offset is usually within 1 hour. It is always, by definition, within 24 hours.
4. Associated Symptoms
TIA’s occur without warning. Headache may occur. Loss of consciousness is only rarely due to TIA.
5. Neurological signs
Neurological signs (eg reflex assymetry, upgoing plantar) may be present during the attack. There may also be signs or previous cerebrovascular disease.
6. Frequency of attacks
TIA’s recur but frequent stereotyped attacks raises the possibility of partial seizure or hypoglycaemic episodes.
7. Risk factors
Patients with TIA usually have risk factors for cardio and cerebro-vascular disease.
What is not a TIA?
The following are unlikely to be due to TIA:
- Generalised weakness or sensory disturbance
The following, if isolated, are also unusual: Vertigo, tinnitus, dysphagia, dysarthria, diplopia, ataxia
What if it is a TIA?
- Urinalysis, FBC, Viscosity, U&E, Lipids, Glucose, VDRL, ECG, CXR
- Carotid ultrasound (if carotid distribution TIA and patient would be surgical candidate)
- CT head scan
Advised secondary prevention and numbers needed to treat (to prevent one further event per year)
||Number needed to treat
|Warfarin, if patient in AF
|Antihypertensive agent (whatever the BP)
|Statin (whatever the lipids)
|Carotid endartectomy (if>70% stenosis in symptomatic carotid)
|Addition of clopidogrel to aspirin
TIA is now considered a medical emergency. The ABCD score below gives the risk of stroke in some clinical scenarios. Daily TIA clinics are held at both Gloucester Royal and Cheltenham General Hospitals. Referral is by referral form, fax (08454222092 -CGH, 08454226326 - GRH) or letter. These clinics give access to opinion, investigation and treatment. If the risk of stroke, as calculated below, is in the higher group emergency admission may be appropriate.
ABCD Scoring - giving risk of stroke within two days of TIA
|BP >/= 140/90
|Clinical features: Unilateral weakness
|Clinical features: Speech impaired without weakness
|Duration >/= 60 minutes
|Duration 10-59 minutes
|3 or below