Many patients respond to first-line treatments of medication and changes to diet and activity. When those therapies fail to reduce the rate of attacks, surgery is often an effective option but it typically is ablative (destructive) in nature. In essence, the patient sacrifices function in the affected ear to halt the vertigo akin to a pilot who shuts down an erratic engine during flight. Forever after, the person's balance and, often, hearing are based on one ear's function.
With their device, Phillips and Rubinstein aim to restore the patient's balance during attacks while leaving natural hearing and residual balance function intact.
A patient wears a processor behind the affected ear and activates it as an attack starts. The processor wirelessly signals the device, which is implanted almost directly underneath in a small well created in the temporal bone. The device in turn transmits electrical impulses through three electrodes inserted into the canals of the inner ear's bony labyrinth.
"It's an override," Phillips said. "It doesn't change what's happening in the ear, but it eliminates the symptoms while replacing the function of that ear until it recovers."
The specific placement of the electrodes in the bony labyrinth is determined by neuronal signal testing at the time of implant. The superior semicircular canal, lateral semicircular canal and posterior semicircular canal each receive one electrode array.
A National Institutes of Health grant funded the development of the device and its initial testing at the Washington National Primate Research Center. The promising results from those tests led the U.S. Food and Drug Administration, in June, to approve the device and the proposed surgical implantation procedure. Shortly thereafter, the limited sur
|Contact: Mary Guiden|
University of Washington