Abstract 2592: Weakness of ABCD2 Scoring In Transient Ischemic Attack
Introduction: The ABCD2 score is a screening tool used to determine the risk for stroke within the first two days following a TIA. The ABCD2 score is based on 5 parameters: age, blood pressure, clinical features, symptom duration and the presence of diabetes. Each item is scored and added to form a number ranging between 0 and 7. A score of 0-3 predicts a low risk of completed stroke at 2 days (1.0%), 3-4 predicts moderate risk (4.1%) and a score ≥ 5 carries high risk (8.1%). NICE recommends that patients with a score of 4 and above are seen by a stroke physician and investigated within 24 hours of onset. ‘C’, clinical features, is scored out of a maximum of 2 points. Unilateral weakness = 2, speech disturbance = 1, and other presenting symptom = 0. We hypothesised that while the ABCD2 is sensitive for anterior circulation TIA, posterior events will not score in this area, leading to inappropriate risk stratification.
Aim: The study aim was to establish if the ABCD2 score is equally effective in stratifying stroke risk in all categories of TIA.
Methods: Data was collected retrospectively from TIA clinic referral documentation for all patients presenting over a 7 month period (N=335). Patients scoring ‘0’ for the ‘C’ arm of the ABCD2 score (N=102) were isolated to establish whether TIA was confirmed as the final diagnosis by a stroke physician, and where patients were treated as TIA, the presenting symptom, and vascular territory involved.
Results: A ‘C’ score of 0 was present in 103 cases (30%), of which 38 (37%) were diagnosed and managed as TIA . The most common presenting feature in this group was visual disturbance, 20 cases (54%). The majority of these (50%) received a diagnosis of amaurosis fugax, and 25% posterior circulation TIA. The remainder were treated as TIA, but the vascular territory not specified. Facial paraesthesia was described in 5 cases (13%), attributed to carotid artery territory TIA. Ataxia was the presenting feature in 3 patients (8%), attributed to posterior circulation TIA. The remaining 25% had non specific symptoms and the vascular territory not specified on the clinic notes.
Conclusion: Our study demonstrates that a significant proportion of confirmed TIA cases do not present with classical symptoms of unilateral weakness and speech disturbance. Isolated visual disturbance appears to be a common presenting feature of a TIA, and amaurosis fugax, a known high risk predictor of subsequent completed stroke is not recognised in the ABCD2 score. Transient balance disturbance and ataxic symptoms are highly suggestive of a posterior circulation event and are again not accounted for. When used in isolation, application of the ABCD2 score in these patients may give an inappropriately low stroke risk prediction, and result in delayed referral for investigation and treatment.
- © 2012 by American Heart Association, Inc.