Question
Could you please comment on auditory hair cell regeneration? Or perhaps, could you refer me to some recent studies on this topic? Submitted by an internist, father of a 4 year old girl with bilateral Large Vestibular Aqueduct Syndrome.
Answer
Restoration of inner ear hair cells damaged lost through disease, toxins or inherited problems is currently impossible in humans. However, studies in non-human animals show several areas of promise for treatment of hearing or vestibular loss.
For example, neural stems cells have been shown experimentally to 1) survive in the inner ear and 2) differentiate in to a number of different inner ear cell types. Using another approach, investigators reported in early 2005 how new inner ear hair cells in guinea pigs deafened by a hair cell toxin could be grown using gene therapy.
To date, all studies have been in animals and none in primates or humans. A large number of technical and safety issues need to be overcome before these forms of treatment will be available to humans.
References:
Kuehn, B. Gene-Tweaking Animal Studies Seen as Advances for Restoring Hearing, Vision. JAMA. 2005;293:1715-1716.
Izumikawa M, Minoda R, Kawamoto K, Abrashkin KA, Swiderski DL, Dolan DF, Brough DE, Raphael Y. Auditory hair cell replacement and hearing improvement by Atoh1 gene therapy in deaf mammals. Nat Med. 2005 Mar;11(3):271-6.
Eric Sargent, MD, is an Otologist/Neurotologist with the Michigan Ear Institute in Farmington Hills, Michigan.