Effects of Massed and Distributed Balance Training in Mild Traumatic Brain Injured Patients

Traumatic brain injury (TBI) may result in a variety of cognitive, behavioral and physical impairments. In recent years, some studies concluded that mild TBI accounts for 90% of TBIs whereas there were about 80% TBIs classified as mild severity group in Taiwan.literature. Mild TBIs often suffered from post-concussion syndrome, and the symptoms included dizziness, headache, unsteadiness, poor mental concentration, memory deficit, and irritability. However, dizziness and unsteadiness recovered slowly and often lasted for three months after injury.
The balance deficits following TBI may be due to poor sensory organization and the consequent improper and delayed muscle reactions. The traumatic vestibular lesion may lead to dizziness, which may impose limitations in daily functions. Past studies about mild TBI treatment intervetions were mostly phamacotherapy, cognitive rehabilitation, and patient education. Physical rehabilitation or balance training for the dizziness and balance deficits has not been a routine or common therapy for the mild TBIs.
One of the focus of recent clinical physical therapy research is to design an efficient and effective therapeutic program based upon motor learning theory. According to the concentration level of practice, treatment session can be categorized into massed and distributed practice given the same amount of practice. Reviewed literature illustrated no superiority of the above-mentioned categories over each other which could be due to different studied population or motor pattern. Since mild TBI patients go back to work or school shortly after hospitalization, efficient treatment program that reduces their frequency of coming back and forth between these to places will contribute beneficially to this extensive population.
The purpose of this study is to compare the immediate and long-term effects of either a two-hour massed or a two-hour distributed balance training relative to control group subjects on dizziness handicap inventory (DHI), dynamic gait index (DGI) and dynamic posturographic measures in mild TBI. This is assessor-blind randomized-control trial study. Eighteen mild TBI patients were randomly assigned to either the control group, massed balance training group or the distributed balance training group. In the massed balance training group, subjects received one 60-minute treatment session per week for two weeks. In the distributed balance training group, subjects received two 30-minute treatment sessions per week for two weeks. The control group received no additional treatment other than the pharmacological threatment as indicated by their clinical symptoms and signs. Every subject was evaluated at pre-training, post-training, and follow-up period (two weeks after training). The measurements included sensory organization test, limits of stability test, DGI and DHI. The balance training program combined functional training related to static and dynamic balance with sensory manipulation and vestibular adaptation exercise in various sensory environments, such as eyes open, eyes closed, soft surface, or firm surface.
The results showed that: (1) Our mild TBI subjects demonstrated similar exhibitions of typical symptoms and signs, including dizziness and headache, as the literature. (2) There was a trend toward improvement in the equilibrium score of the sensory organization test in the distributed balance training group from baseline to post-tests. (3) There was significant improvement of dynamic gait index in all three groups from baseline to post-tests. (4) There was a trend toward significant improvement in DHI score in the two balance training groups from baseline to post-tests.
Our study failed to demonstrate significant training effect on balance, gait stability and dizziness compared to the control group. This was possibly due to the small sample size, heterogeneity of the subjects, or the nonspecificity of balance training programs. However, there is a trend that the two training groups, and the distributed group more than the massed group, demonstrated more improvements on balance, gait stability, and dizziness after treatment. Furthermore, subjects in the 30-minute treatment group showed less signs of fatigue or inattention than the 60-minute group. Thus a tentative recommendation for clinical implication is that a distributed practice schedule may benefit mild TBI patients for reducing their dizziness and imbalance under sensory changing environment. Further study with more subjects is recommended to clarify the effects of sensory balance training on mild TBI patients.