DEFENSIVE Stroke Scale: Novel Diagnostic Tool for Predicting Posterior Circulation Infarction in the Emergency Department.

BACKGROUND

Dizziness is the most common posterior circulation symptom; however, diagnosing a posterior circulation infarction is difficult due to a lack of typical symptoms. We aimed to investigate the frequency of misdiagnosis of a posterior circulation infarction in patients who presented with dizziness and to develop a new stroke scale that increased the diagnostic accuracy for stroke among these subjects.

METHODS

We retrospectively analyzed consecutive data from subjects hospitalized with ischemic stroke who presented with dizziness (the developmental phase). Based on these results, we created a novel stroke scale, which was used as a diagnostic procedure in the prospective validation phase. We compared the rate of misdiagnosis of ischemic stroke between phases.

RESULTS

During the development phase, 115 subjects were hospitalized for ischemic stroke accompanied by dizziness. Six ischemic stroke subjects were not properly diagnosed (6/115, 5.2%). We created the new DisEquilibrium, Floating sEnsation, Non-Specific dizziness, Imbalance, and VErtigo (DEFENSIVE) stroke scale to prevent underdiagnosis of a posterior circulation infarction. During the validation phase, 949 subjects with dizziness were examined with the DEFENSIVE stroke scale; among these subjects, 100 were hospitalized for ischemic stroke accompanied by dizziness. No subject with ischemic stroke was overlooked. The new DEFENSIVE stroke scale had a sensitivity of 100% and decreased the rate of improper diagnosis of stroke (5.2% versus 0%; P = .022).

CONCLUSIONS

Our new stroke recognition instrument for a posterior circulation infarction presenting with dizziness and related symptoms (the DEFENSIVE stroke scale) is easy to administer and has good diagnostic accuracy.