Does Cerebral Hemispheric Laterality Control Swallow Performance?

OBJECTIVES: It is well established that the brainstem regulates the act of swallow. However, the role of cortex and its influence on swallowing are still a question. Hence, the present study aimed to investigate if cerebral hemispheric laterality controls swallow activity. METHODS: Thirty normal right handed participants were subjected to time test of swallow using 100 ml of water. Dual paradigm was used to investigate hemispheric laterality for swallowing which involved listening to the speech or music stimuli presented binaurally while swallowing. The clinician measured total time taken and hyolaryngeal movement simultaneously which was used to calculate volume/time, volume/swallow, and time/swallow on an offline basis. RESULTS: Results revealed that swallow performance decreased with the dual task paradigm compared to baseline swallow. These results are suggestive of cortex playing a role during swallowing in the dual task paradigm. Moreover, quantitative parameters like volume/swallow and volume/time were affected more when speech was competing with swallowing. However, music exerted greater interference over the speech for time/swallow. CONCLUSIONS: These results suggests that there exists differential cue lateralization hypothesis which means volume related parameters are controlled by left hemisphere and time related swallowing parameters are controlled at the right hemisphere.