Effect of aging on bolus kinematics during the pharyngeal phase of swallowing.

Swallowing difficulty is a common complaint in the elderly and, although there are data for the biomechanics of liquid swallows, little is known about solid bolus motion, or kinematics, in the elderly. The aims of this study were as follows: 1) to characterize and compare solid and liquid bolus kinematics in the elderly and compare the findings with those in young subjects and 2) to correlate bolus kinematics and dynamics. Concurrent manometric-fluoroscopic techniques were used to study eight young and eight elderly subjects.

Cerebral cortical representation of external anal sphincter contraction: effect of effort.

The external anal sphincter (EAS) plays a critical role in maintaining fecal continence; however, cerebral cortical control of voluntary EAS contraction is not completely understood. Our aims were to determine the cortical areas associated with voluntary EAS contraction and to determine the effect of two levels of sphincter contraction effort on brain activity. Seventeen asymptomatic adults (ages 21-48, 9 male) were studied using functional magnetic resonance imaging (fMRI) to detect brain activity.