The following images are helpful in reviewing the sensory and motor pathways.
In patients with TIAs there is a definite risk of ~10% in the next 90 days of having a stroke. Studies suggest that 1/2 of this risk happens in the first 3-7 days. Consequently, a TIA should be thought of as a medical emergency warranting risk factor modification and assessment for treatable cause (i.e. atrial fibrillation, >70% ipsilateral carotid stenosis). However, not all transient neurological symptoms are TIAs! We need some means of selecting which patients are most likely to actually have a stroke so we can focus our efforts on them.
Several attempts have been made to help determine which patients with TIA are most likely to have a stroke. The one I like is the ABCD2 score.
A - Age Greater than 60 == 1 point
B - BP >140 in ER == 1 point
C - Clinical Features: Weakness == 2 points, Speech problem == 1 point, other == 0
D - Duration: >1hr ==2 points, 15-60mins = 1 point, <15 mins = 0 points
D - Diabetes == 1 point
Low Risk = 0-3 points -- 1.0% had stroke in 2d, 1.2% in 7d, 3.1% in 90d
Medium Risk = 4-6 -- 4.1% in 2 d, 5.9 in 7d, 9.8% in 90d
High risk = Greater than 6 -- 8.1% in 2d, 12% in 7d, 18% in 90d
Consider that crescendo TIA is a different story and this model does not apply to patients with crescendo TIAs.
In general low risk patients can be treated as outpatients with risk factor modification and investigations.
Medium risk patients probably can be treated with expedited investigations and risk factor modification. This will depend on the clinical context. For example a 40 year-old patient with 3 hours of objective weakness would score 4, but probably should be more urgently investigated.
High risk patients should probably be admitted for urgent investigations and for monitoring for indications for acute thrombolysis should stroke occur.
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