Article

Persistent post-concussive symptoms are reported by 10-15% of individuals who
suffer mild traumatic brain injury (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 (OIF), 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 (TD, 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 TD veterans in comparison to
each of the other two groups (p<0.0002), most notably on a compliant surface with
eyes closed. The TD group also had decreased dynamic stability of the upper trunk
(p<0.05) and enhanced postural oscillations (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
postural oscillations requires further study but may indicate enhanced
instability in sensorimotor networks responsible for postural control.
CI - Published by Elsevier B.V.

Langue : ANGLAIS