IDENTIFICATION OF STATIC AND DYNAMIC POSTURAL INSTABILITY FOLLOWING TRAUMATIC BRAIN INJURY

Objective: Quantitative evaluation of static and dynamic aspects of po stural instability as a long-term consequence of traumatic brain injur y (TBI). Design: Experimental two-group design. Setting: Outpatient re habilitation department. Patients and Other Participants: From a conse cutive sample of TBI patients at least 6 months after trauma, 20 subje cts were selected who complained of reduced gross motor skills but sho wed no sensorimotor impairments in a standard neurological examination (11 men, 9 women; mean age, 36.2 +/- 10.7 years). Thirteen patients h ad sustained mild, 2 moderate, and 5 severe TBI. Twenty healthy contro ls were matched for age and gender. Intervention: None. Main Outcome M easures: A dual-plate force platform recorded the amplitude and veloci ty of the center-of-pressure fluctuations in the anteroposterior (AP) and lateral (I,AT) sway directions during quiet standing. Also, the sp eed and fluency of weight shifting using visual feedback was registere d. Both balance tasks were combined with an arithmetic task, whereas q uiet standing was also tested with visual deprivation. Results: Compar ed to controls, TBI patients showed an increase of over 50% in AP and LAT sway, and a weight-shifting speed 20% lower. Dual-task interferenc e was never significant. Visual deprivation was most detrimental for t he TBI patients, particularly for LAT sway control. Conclusion: A long -term overall reduction in both static and dynamic control of posture can be present after TBI, even in patients without clear neurological deficits. Force-plate recordings can identify such (latent) balance pr oblems. Visual deprivation during quiet standing appears a simple, sen sitive test for postural instability related to sensory integration de ficits. (C) 1996 by the American Congress of Rehabilitation Medicine a nd the American Academy of Physical Medicine and Rehabilitation