Walk Your Dizzy Patients! Gait Assessment as a Screening Tool for Posterior Circulation Stroke
Isaac Smith1, Eduard Valdes1, Jose Torres1, Kara Melmed1
1NYU Langone
To determine if objective gait abnormality (OGA) might be used as a cost-effective screening tool in the acute presentation of posterior circulation stroke (PSC).
The National Institutes of Health Stroke Scale (NIHSS) is less robust for patients with PCS due to lack of inclusion of signs and symptoms localizing to the posterior fossa. We previously showed that OGA was the most common presenting feature in this population. Our present hypothesis was that association with OGA would be greater in PCS patients than posterior stroke mimics, especially in those presenting with dizziness or subjective gait abnormality (SGA).

We completed a case-control study to determine odds of OGA in PCS patients and mimics, reported with confidence intervals(CI), sensitivity(SE), specificity(SP), positive predictive value(PPV), and negative predictive value(NPV). We defined PCS cases as acute ischemic strokes isolated to the posterior cerebral, basilar, or vertebral artery territories. Mimics were defined as acutely vertiginous patients from other causes. 


We identified 82 PCS patients (average age=67, 51%female) and 104 mimics (average age=63, 51%female) with gait assessment on arrival. OGA was documented in 69/82(84.1%) PCS cases vs. 18/104(17.3%) mimics (OR=25.4, CI=11.62-55.35, SE84%, SP82%, PPV79%, NPV87%). Stratified by dizziness, OGA was documented in 38/44(86%) PCS cases vs. 18/104(17.3%) mimics (OR=30.3, CI=11.13-82.23, SE86%, SP83%, PPV68%, NPV94%). Stratified by SGA, OGA was documented in 48/52(92%) PCS cases vs. 16/74(21.6%) mimics (OR=43.5, CI=13.63-138.83, SE92%, SP78%, PPV75%, NPV94%).

Patients at NYU Langone Hospitals with PCS were 25.4x more likely to have OGA than mimics, and 30.3x or 43.5x more likely to have OGA when presenting with dizziness or SGA. While SP and PPV remained low (<90%), NPV rose to 94% in patients with dizziness and SGA on admission. Gait assessment can be used as a cost-effective screening tool to rule out PCS on arrival. Prospective studies should be accomplished prior to recommendation.