Static and dynamic postural stability in veterans with combat-related mild XXXX .

@entity23806 @entity131 @entity8527 @entity10409
UNASSIGNED: Persistent post-concussive symptoms are reported by 10-15% of individuals who suffer mild @entity131 (mTBI), but their basis is often uncertain. One such symptom is disequilibrium, a sensation of impaired balance during standing and walking. The hypothesis for this study was that this subjective symptom is associated with objective and measurable deficits in static and dynamic postural stability. An infrared motion tracking system was used to record body motion during quiet standing and in response to waist perturbations in fourteen veterans (age 22-40 years, 13 male) of the Operations Enduring Freedom (OEF) and Iraqi Freedom ( @entity23806 ), who had a history of mTBI that occurred 7 months to 7 years prior to testing. We compared body sway between veterans with mTBI reporting persistent disequilibrium ( @entity8527 , n=8) and those with no vestibular symptoms (n=6), as well as to a group of non-veterans with no balance symptoms (n=10). Static postural stability was reduced in @entity8527 veterans in comparison to each of the other two groups (p<0.0002), most notably on a compliant surface with eyes closed. The @entity8527 group also had decreased dynamic stability of the upper trunk (p<0.05) and enhanced @entity10409 (p<0.02) following waist perturbations. Our findings support a physiological basis for persistent disequilibrium after mTBI and are consistent with impaired vestibular processing. Disruption of semicircular canal inputs is unlikely to be the cause, as head impulse responses were normal in all groups. The unexpected finding of dynamic @entity10409 requires further study but may indicate enhanced instability in sensorimotor networks responsible for postural control.
