Role of dynamic posturography (Equitest) in the identification of feigned balance disturbances.

ABSTRACT

Clinico-instrumental criteria to reliably detect simulated vertigo remain to be defined. Computed dynamic posturography (Equitest) has been used to identify additional factors to distinguish simulated, from real vertigo. The present study population comprised 23 normal subjects and 16 patients with documented vestibular impairment. Normal subjects were also studied during a state of simulated vertigo. In malingerers, the Equilibrium Score and the Composite Equilibrium Score showed a statistically significant reduction in all test conditions as compared to normal subjects, patients and "non-malingerers". Upon Sensory Analysis, statistically significant differences were found for the somatosensory component between malingerers and "non-malingerers". In 20/23 cases, Strategy Score values recorded in malingerers were 2 Standard Deviations lower than the mean obtained in "non-malingerers" in at least one of the six test conditions. By combining the latter observation with Goebel's 1st criterion it was possible to differentiate malingerers from non-malingerers with 86.9% sensitivity and 89.7% specificity. The Equitest, therefore, in combination with conventional methods, provides the clinician with an important tool, in the identification of a state of simulated vertigo.