Getting around without the need to concentrate on every step is something most of us can take for granted because our inner ears drive reflexes that make maintaining balance automatic. However, for about 1.8 million adults worldwide with bilateral vestibular hypofunction (BVH) — loss of the inner ears’ sense of balance — walking requires constant attention to avoid a fall. Now, Johns Hopkins Medicine researchers have shown that they can facilitate walking, relieve dizziness and improve quality of life in patients with BVH by surgically implanting a stimulator that electrically bypasses malfunctioning areas of the inner ear and partially restores the sensation of balance.
To maintain balance while moving through the world around us, our brains receive and process data from multiple sensory systems, including vision, proprioception (muscles and joints) and vestibular sensation from the inner ears. People with BVH have difficulty keeping their eyes, head and body steady. Head movements make their vision jump and blur, and walking requires conscious effort. Forced to deal with this mental distraction, individuals with BVH suffer a more than thirtyfold increase in fall risk and the social stigma of appearing to walk like someone who’s intoxicated.
Current therapy for BVH is limited to vestibular rehabilitation exercises. Doctors advise their patients with BVH to avoid medications that damage the inner ear (ototoxic drugs) or suppress brain function (sedatives), and caution them to steer clear of activities that might endanger them or others, such as driving, swimming and walking in poorly lit areas.
