Use of an electrotactile vestibular substitution system to facilitate balance and gait of an individual with gentamicin-induced bilateral vestibular hypofunction and bilateral transtibial amputation.

BACKGROUND AND
PURPOSE: This case report describes the use of an electrotactile vestibular substitution system (ETVSS; BrainPort Balance Device, Wicab, Inc., Middleton, WI) to facilitate balance and gait of an individual with bilateral vestibular hypofunction and bilateral transtibial amputation. CASE DESCRIPTION: A 69-year-old man with a 2.5-year history of bilateral vestibular hypofunction, due to gentamicin toxicity, participated in a rehabilitation program using an ETVSS. Because of lower extremity infection, the patient had bilateral prosthetic legs after bilateral transtibial amputation. INTERVENTION: Focused on the following three phases of training with the ETVSS during 12 months: orientation, clinical training, and in-home training. The patient was periodically assessed with balance and gait tests, in addition to surveys of patient confidence and perception of handicap. All testing was performed without ETVSS. OUTCOMES: : Improvements were demonstrated in all outcome measures used with this patient. Sensory Organization Test composite scores increased from 23 to 48, Dynamic Gait Index scores increased from 11/24 to 21/24, and distance walked during six minutes increased from 212 to 363 m. Standing balance with eyes-closed improved from less than two seconds to more than 20 minutes. The patient reported improved confidence and lower perception of handicap with fewer functional limitations. DISCUSSION: For this patient, an intervention program of sensory substitution using the ETVSS improved outcome measures beyond those previously achieved with vestibular rehabilitation therapy and balance training. The feedback provided by the ETVSS may have facilitated the patient's ability to use proprioception, thus allowing better balance control.