Vestibular dysfunction if commonly overlooked when diagnosing an individual with TBI. Vertigo, balance problems, visual complaints (double vision, blurriness) and nausea are possible symptoms of vestibular injury. The most common persisting vestibular symptom after TBI is positional vertigo (symptoms caused by head movement). Vertigo is caused by dysfunction of the vestibular nerve or the labyrinth (Shepard & Telian 1995) and the inability of the central nervous system to effectively compensate for the dysfunction (Gurr & Moffat 2001). Provoked vertigo manifests as either unilateral peripheral hypofunction, bilateral peripheral hypofunction or benign paroxysmal positional vertigo (BPPV) (Godbout 1997).
Although it is common for the spontaneous resolution of vertigo to occur within 6 months of onset, in the TBI population natural recovery is constricted due to the frequent combination of central and peripheral vestibular structure injury. Vestibular rehabilitation following TBI is therefore needed in order to promote vestibular adaptation and recovery. Techniques which are typically used in vestibular rehabilitation are gaze stability exercises, vestibulo-ocular reflex gain adaptation, substitution exercises, habituation techniques and static and dynamic balance and gait exercises (Scherer & Schubert 2009). The optimal recovery of vestibular dysfunction is thought to be based on selecting the appropriate vestibular exercises for a specific individual and progressing gradually through the assigned exercises while increasing difficulty and intensity (Wee 2002).
Ponsford et al. (2014) explored function in 141 individuals post TBI in terms of function. The results showed that 60% of individuals experienced balance issues two years post injury, with the rates at five and ten years being 40.4% and 55%, respectively. Persistent dizziness was an issue for approximately one-third of the sample. In a sample of patients with TBI and BPPV, 24 were impacted by posterior semicircular canal BPPV and 11 by horizontal or lateral semicircular canal BPPV (Ahn et al. 2011). Post-traumatic BPPV requires more treatment sessions than when it is idiopathic; however, once the symptoms have been resolved recurrence rates are similar for both types (Ahn et al. 2011). Patients with TBI suffering from BPPV should be specifically treated with repositioning maneuvers until complete resolution (Motin et al. 2005). Vestibular rehabilitation, alone or in combination with pharmacological treatment (i.e., betahistine dihydrochloride), as a treatment for balance disorders post TBI has been shown to significantly reduce recovery time when compared to pharmacological management alone (Naguib & Madian 2014).
In a small sample of adults, aerobic dancing and slide-and-step training improved balance and coordination in patients many years following TBI, suggesting that long-term improvement of vestibular dysfunction is possible with the appropriate program (Dault & Dugas 2002). Further, Gurr and Moffat (2001) added a cognitive aspect to vestibular rehabilitation. The authors attempted to restructure the maladaptive thoughts and belief patterns associated with the symptoms of provoked vertigo. This multidimensional psychological approach was effective in improving vertigo symptoms, handicap, emotional distress, physical flexibility and postural stability (Gurr & Moffat 2001).
In terms of more familiar therapy interventions for balance, one study compared standard physiotherapy and standard therapy in addition to a home-based rehabilitation program. Both groups showed significant improvements on the Goal Attainment Scaling and the Balance Evaluation System Test (Peirone et al. 2014). When comparing between these interventions, those receiving home-based rehabilitation made significantly greater improvements on the Balance Evaluation System Test (Peirone et al. 2014). Despite these findings, this study was underpowered and further investigation is needed before definitive conclusions are made. Finally, Ustinova and Silkwood-Sherer (2014) examined whether upright posture could be stabilized by gripping an unfixed object. This study was conducted using a virtual environment. For individuals with TBI, holding a short wooden stick (the unfixed object) in the dominant hand was stabilizing, as it reduced the displacement and velocity of postural sway (Ustinova & Silkwood-Sherer 2014). Further studies using this technique in real world settings should be conducted.
There is Level 2 evidence that vestibular rehabilitation programs, alone or in combination with betahistine dihydrochloride, improve recovery time for balance disorders compared to betahistine dihydrochloride alone.
There is Level 2 evidence, from a single study, that gripping an unfixed object in the dominant hand can be beneficial in stabilizing an upright posture.
There is Level 2 evidence to support using a combined aerobic dancing, slide and step training program to reduce balance and coordination deficits post TBI.
There is Level 4 evidence that vestibular rehabilitation programs, such as a behavioural exposure program, improve symptoms of vertigo in patients after TBI.
Aerobic dance, slide and step programs improve balance and coordination post TBI.
A vestibular rehabilitation program is an effective method for improving symptoms of vertigo in patients following TBI.