Objectification of psychogenic postural instability by trunk sway analysis.
BACKGROUND
The attribution of balance or gait disorders to psychogenic origin can be exceedingly challenging, as clinical tests involving distraction maneuvers are prone to subjective bias. We tested the value of biomechanical balance analysis to identify psychogenic balance and gait (PBG) disorders.


METHODS
We quantified and compared the effects of distraction maneuvers on balance based on four stance conditions (eyes open, EO; eyes closed, EC; EO on foam, EOF; and EC on foam; ECF) in subjects with suspected PBG (n = 12), subjects with balance and gait disorder due to multiple sclerosis (MS; n = 12) and healthy controls (n = 12). We measured trunk inclination in transverse plane (°)(2) and the corresponding body angular velocity (°/s). Distractibility of postural stability was analysed using ANOVA with repeated measures.


RESULTS
In evident contrast to the MS group and healthy controls, the PBG group showed increased values of (°)(2) and (°/s) and significant distractibility in all four stance conditions.


CONCLUSIONS
Biomechanical balance analysis can help clinicians to get objective, quantified results of distraction maneuvers and confirm a positive diagnosis of PBG disorders. Large prospective studies are needed to confirm these results.
Department of Neurology, Academic Teaching Hospital Wagner-Jauregg, Linz, Austria. Electronic address: thomas.wolfsegger@gespag.at.
Thomas
T
Wolfsegger
Barbara
B
Pischinger
Raffi
R
Topakian
D001696:Biomechanical Phenomena / Q000502:physiology; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D020233:Gait Disorders, Neurologic / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D004856:Postural Balance / Q000502:physiology*
Biomechanical analysis; Distraction maneuver; Neurophysiology; Postural instability; Psychogenic movement disorder; Sway analysis