Comparison of upright balance in stroke, P arkinson and multiple sclerosis

Objective Multiple sclerosis ( MS ), Parkinson's disease ( PD ) and stroke ( ST ) subjects show balance impairments due to damage of the balance control system. The objective of the study was to assess the impact of MS , PD and ST on upright posture in eyes open condition and when visual and/or proprioceptive inputs are altered. Materials and methods A total of 188 subjects with MS ( n  = 80), PD ( n  = 58) and ST ( n  = 50), mean age ( SD ), 57.9 (14.6) years, and 32 healthy subjects ( HS ) aged 53.7 (15.7) years were assessed by a stabilometric platform in a cross‐sectional study. Results Compared to HS , MS showed large deviations from normal performances with respect to magnitude ( P  < 0.001) and regularity ( P  < 0.05) of body sway irrespective of the altered sensory information. Similarly to MS , PD showed large and abnormal levels of body sway ( P  < 0.001) and postural tremor ( P  < 0.05), while ST was the least impaired except for an asymmetrical distribution of body weight between legs ( P  < 0.001). Finally, the MS group compared to PD and ST showed the largest body instability after eye closure ( P  < 0.05) and when visual and proprioceptive inputs were removed ( P  < 0.05). PD showed instability mainly after the alteration of proprioceptive inputs ( P  < 0.05), while ST showed the smallest increase of body instability when sensory inputs were reduced. Discussion Objective assessment revealed pathology‐specific balance disorders and showed the differential impact of MS , PD and ST on the ability to use sensory information for balance control.