Effects of aging on neuromotor processes of swallowing.

Isolated swallowing difficulties are present in a substantial percentage of elderly adults. Most have no known medical basis, although some may be caused by underlying, but undetected, medical conditions. Others may result from conditions that indirectly affect swallowing. After an overview of the neuroanatomy and neurophysiology of swallowing, this article reviews findings on changes in swallowing that accompany aging. Some of the differences reported have failed to be replicated consistently, and other changes are subtle, their significance unknown. Most studies, however, have found decreased sensitivity in both the oral and pharyngeal cavities. It is concluded that additional objective clinical measures are needed to isolate changes in swallowing due to age from those resulting from other causes. Clearly, further research is needed.