Seby John, MD
Perry JJ, Sharma M, Sivilotti MLA, Sutherland J, Worster A, Émond M, et al. A Prospective Cohort Study of Patients With Transient Ischemic Attack to Identify High-Risk Clinical Characteristics. Stroke. 2013
In this article, Perry and colleagues identify clinical factors associated with the occurrence of stroke after a TIA, and propose a new stratification score. So after the California score, ABCD and ABCD2, we now have the Canadian TIA score. An ounce of prevention is worth a pound of cure certainly holds true for TIA management. Patients after TIA are at high short-term risk of stroke, and immediate medical/surgical interventions reduce this risk. Hence, the continuing efforts to refine TIA triage.
This was a prospective study done in 8 Canadian ERs where patients with TIA were enrolled. The WHO definition of TIA was used which did not require imaging to exclude infarction. Clinical features that strongly correlated with developing a stroke included: first ever TIA, language disturbance, duration > 10 minutes, unilateral weakness, gait disturbance, elevated BP, atrial fibrillation, infarction on CT, and elevated blood glucose. Vertigo, lightheadedness and visual loss were less associated with an impending stroke. Based on this, a 13 variable score was developed with score ranging from -3 to 23 to predict the probability of stroke within 7 days (range 0.01% to greater than 27.6%)
This study gives clinicians valuable information about which clinical features are worrisome and may be a harbinger of stroke. However, much like the previous TIA scores, I don’t feel the Canadian TIA score by itself should be used to make decisions. My bottom line is that all patients presenting with a TIA should be emergently evaluated at minimum with basic labs, neurovascular imaging and electrocardiogram +/- echocardiography, and institutions should devise mechanisms to best accomplish this. Subsequently, this score can be used to decide whether the patient should be admitted or observed. However, if resources are limited and screening is impossible, this score may help choose patients for selective specialist assessment and investigations. Validation studies are needed.