Traditional Balance vs Vibrotactile Feedback Training for Vestibular Rehabilitation

Traumatic brain injury (TBI) occurs when physical trauma causes temporary or permanent neurological damage. In some cases, symptoms can continue over time and contribute to disability. Dizziness and vertigo are associated with nearly all reported studies of mild Traumatic Brain Injury (mTBI) and are a significant and functionally limiting component of the overall disability.

TBI is one of the many risks faced by military personnel in combat activities . In a RAND Corporation survey of service members who had been deployed to Iraq or Afghanistan, 19% reported probable TBI. Dizziness and vertigo are associated with nearly all reported studies of mTBI and are a significant and debilitating component of the overall disability. mTBI are currently caused by both blast and impact injuries resulting in variable disabilities . Overt symptoms may include balance and spatial disorientation problems (vertigo) related to vestibular dysfunction, vision disturbances, inner-ear edema, and/or other sensory integration deficits.

Treatment of this particular population group has several challenges which include: 1) difficulty with early and specific injury assessment 2) the determination of appropriate return-to-duty measures 3) selection of effective individualized balance rehabilitation and treatment tools 4) Prolonged length of rehabilitation and uncertain measureable endpoints. The group is also highly variable in the nature and extent of balance deficits and cognitive and / or related psychological impairments. It appears that almost all subjects with mTBI show some susceptibility to vestibular or vestibular/ocular disorders.

After assessment of disequilibrium, rehabilitation is often a course of remedial physical therapy (PT). To affect change in mobility by standard physical therapy, sensory and motor systems are "habituated" through exercise, with hope of rehabilitating the system and "compensating" by instructing the patient to alter skill sets associated with a task. Compensation (without immediate sensory feedback) is problematic and prone to patient (and caregiver) interpretation and error, because it may not address the underlying problems and may not have long term therapeutic benefits. There is also a very limited pool of PTs who specialize in the treatment of neurological problems resulting from brain injuries. Individual vestibular rehabilitation treatment programs are designed by these specialist PTs who also monitor and participate in each patient's recovery. This approach is labor intensive, time consuming (up to 14 weeks of therapy is often needed) and some patients do not recover fully .

The overall objective of this research effort is to use novel combinations of multi-modal sensory guided feedback (especially tactile) and traditional vestibular rehabilitation to retrain military personnel suffering balance disorders as a result of mTBI. The investigators therapeutic goal is to test technology that will return the patient, in the shortest period of time, to a level of balance performance consistent with return to the community and/or military duty.

The sense of touch is intrinsically linked with the neuro-motor channel, both at the reflex and higher cognitive regions, which makes it uniquely tied to orientation and localization. Vibrotactile arrays are therefore intuitive and are an effective sensory feedback pathway.

Recent research has also demonstrated that tactile cueing yield significantly faster and more accurate performance than comparable spatial auditory cues. Further research has demonstrated this finding is relatively stable across a variety of body orientations, even when spatial translation is required and under physiological stress.

Over a Phase I SBIR and current Phase II effort, Engineering Acoustics Inc. has developed the Sensory Kinetics (SK) Balance System. In the SK system, patients move on a force platform (see Figure 1) while movement and posture data is interpreted by advanced software a mapped to a wearable vibrotactile belt array and visual display. Vibrotactile cueing provides continuous and instantaneous feedback to the patient that compliments their postural and mobility decisions. The investigators believe that vibrotactile feedback can greatly increase spatial awareness and consequently mobility. Further, the ability of the brain to re-organize and relearn functional movement activities provides an intriguing potential pathway for the retention of learned functional mobility strategies.Vibrotactile cueing involves short duration bursts of mechanical vibration from actuators, or tactors, that are mounted within a torso worn belt. The person's position is measured and calculated using a force plate sensor and camera sensors. The computerized system is then used as part of physical therapy balance training to improve the patient's balance and potentially reduce their risk of falling.