Hoover's sign for the diagnosis of functional weakness: a prospective unblinded cohort study in patients with suspected stroke.
McWhirter L., Stone J., Sandercock P., Whiteley W.
ObjectiveHoover's sign - weakness of voluntary hip extension with normal involuntary hip extension during contralateral hip flexion against resistance - is a commonly used sign in the diagnosis of functional weakness of the lower limb. However, little is known about the performance of this sign in clinical practice.MethodsHoover's sign was tested as part of the diagnostic work-up of 337 patients presenting to hospital with suspected stroke. We made a gold-standard diagnosis of stroke, functional disorder, or other diagnosis based on clinical history and examination, imaging and clinical follow-up. We calculated the sensitivity, specificity, positive and negative predictive values of Hoover's sign for a diagnosis of functional weakness in patients who presented with leg weakness.ResultsWe consecutively recruited 337 consecutive patients with suspected stroke, 124 of whom presented with leg weakness. 8 of these patients had a diagnosis of functional disorder. The sensitivity of Hoover's sign for a diagnosis of functional weakness in those who presented with leg weakness was 63% (95% CI: 24 to 91), and the specificity was 100% (95% CI: 97 to 100).ConclusionsIn this cohort, Hoover's sign was moderately sensitive and very specific for a diagnosis of functional weakness. Further studies are required to assess inter-observer variability and performance of the test in larger numbers of patients with functional weakness.