Substitution strategies utilize alternate sensory inputs to drive motor output, alternate secondary motor responses instead of the primary motor responses, and incorporate strategies of prediction and anticipation of intended motor behavior. Several factors must be considered when designing a VRT program for an individual patient. Therapeutic efficacy may be limited by the extent and location of damage to the vestibular system. Status of visual and proprioceptive systems, physical strength, motor skills, and integrity of the cerebellum are critical to the successful application of a VRT program. Other factors that play a role in the outcome of a VRT program include general physical health, decision-making and cognitive abilities, age, memory, and the presence of psychological and anxiety disorders.
Individuals visit the therapist on a limited basis.
Patient engages in custom-designed exercises at home several times a day without therapist supervision. Patients have regular follow-up visits with the therapist until compensation and habituation are complete and optimal balance attained. Sensory evaluation should include visual and proprioceptive abilities since multisensory deficits can impede functional progress. Nystagmus can be observed, recorded, and quantified. By comparing sway to normative values for each condition, the patient's reliance on particular sensory information is determined.