Age-related changes in cortical swallowing processing.

The cortical organization of swallowing has been mainly studied in young and healthy subjects. Aging effects on human deglutition have been found in several behavioral studies and are known to affect both the oral and pharyngeal phases of swallowing. The aim of this study was to evaluate a potential cortical compensation of age-related swallowing impairment. Whole-head MEG was employed in 9 healthy elderly subjects (mean age 71.6 years) and compared to 9 healthy young participants (mean age 23.8 years). Data were analyzed by means of time-frequency plots and synthetic aperture magnetometry (SAM). Group analysis of individual SAM data was performed using a permutation test. The main finding of this study was an increase of somatosensory cortical activation during swallowing execution in elderly subjects compared to the young control group. This effect was present in both hemispheres. These results point to adaptive cerebral changes in response to aging effects on the complex process of swallowing. Our finding underlines the relevance of age matched control groups in neuroimaging studies related to deglutition or other complex sensorimotor processes. Copyright 2008 Elsevier Inc. All rights reserved.