Rp. Difabio, SENSITIVITY AND SPECIFICITY OF PLATFORM POSTUROGRAPHY FOR IDENTIFYINGPATIENTS WITH VESTIBULAR DYSFUNCTION, Physical therapy, 75(4), 1995, pp. 290-305
Sensitive and specific measures are needed to identify patients with v
estibular impairments. The purpose of this clinical perspective is to
describe the sensitivity and specificity of dynamic and static platfor
m posturography for detecting vestibular disorders. The sensory organi
zation test (SOT) of dynamic posturography (EquiTest), the motor ''per
turbation'' test, and Romberg's tests on a static (fixed) force platfo
rm each had over 90% specificity. This finding means that nearly all o
f the subjects who should have tested negative, did test negative on e
ach type of assessment. The sensitivity of the SOT was evaluated acros
s five studies involving a total of 836 patients with peripheral vesti
bular deficits (PVDs). Abnormalities in the SOT were detected in only
40% (n=338) of the cases. Static platform posturography sensitivity wa
s evaluated across six studies involving a total of 571 patients with
PVDs, and abnormalities were defected in 53% (n=302) of these cases. T
ests of spontaneous and positional nystagmus s and the horizontal comp
onent of the vestibuloocular reflex (VOR), by comparison, detected PVD
s in 48% of 738 patients with suspected vestibular impairment. For pat
ients with vestibular deficits associated with central nervous system
disease a total of 389 cases were identified in five studies and SOT a
bnormalities were found in 54% (n= 209) of these cases. The motor pert
urbation test was abnormal in 35% (n= 41) of 119 patients with central
vestibular disease. In conclusion the sensitivity of static posturogr
aphy appeared to be slightly better than that of dynamic posturography
for detecting PVDs, but the level of sensitivity for each posturograp
hy test, as well as for tests of horizontal VOR function, was consider
ed to be low. Combining either type of posturography with other tests
of vestibular function, however, increased the overall sensitivity of
detecting vestibular deficits to 61% to 89%. It was concluded that dyn
amic and static platform posturography as well as tests of VOR functio
n lack adequate sensitivity to detect vestibular impairment when appli
ed in isolation. Posturography appears to detect vestibular deficits i
n some patients who had normal VOR assessments and, therefore, provide
s supplemental rather than redundant information about vestibular dysf
unction. [Di Fabio RP. Sensitivity and specificity of platform posturo
graphy for identifying patients with vestibular dysfunction. Phys Ther
. 1995;75:290-305.]