POSTUROGRAPHIC EVIDENCE OF NONORGANIC SWAY PATTERNS IN NORMAL SUBJECTS, PATIENTS, AND SUSPECTED MALINGERERS

During the last 10 years, computerized dynamic posturography has yield ed various patterns of sway on the sensory organization test and the m otor control test that have been associated with a variety of organic balance disorders. Some aspects of performance during computerized dyn amic posturography, however, are under conscious control. Voluntary mo vements not indicative of physiologic response to balance system stimu lation can also affect computerized dynamic posturography results. Qua ntification of nonorganic or ''aphysiologic'' response patterns in nor mal subjects, patients, and suspected malingerers is crucial to justif y use of computerized dynamic posturography for identification of phys iologically inconsistent results, For this purpose the computerized dy namic posturography records of 122 normal subjects, 347 patients with known or suspected balance disorders, and 72 subjects instructed to fe ign a balance disturbance were critically evaluated by use of seven me asurement criteria, which were postulated as indicating aphysiologic s way, Each criterion was scored with a standard calculation of the raw data in a random, blinded fashion. The results of this multicenter stu dy show that three of the seven criteria are significantly different i n the suspected ''malingerer'' group when compared with either the nor mal or patient group. The relative strength of each criterion in disce rning organic from nonorganic sway provides the examiner with a measur e of reliability during platform posture testing. This study demonstra tes that computerized dynamic posturography can accurately identify an d document nonorganic sway patterns during routine assessment of postu re control.