Patterns of lingual tissue deformation associated with bolus containment and propulsion during deglutition as determined by echo-planar MRI

Disordered lingual function is a common clinical attribute of patients with oropharyngeal dysphagia. To determine physiologic patterns of lingual tiss ue motion during swallowing, we imaged the actively deforming tongue during water bolus swallows with sequential single-slice sagittal orientation ech o-planar imaging. At rest, with the bolus contained in the oral cavity befo re swallow initiation, the tongue displayed a characteristic curved configu ration consisting of a convex surface (anterior to the bolus) in continuity with a concave surface (containing the bolus) and a posterior-located conv ex surface (comprising the tongue base). With swallow initiation, the previ ously deformed tongue underwent rapid biphasic displacement: [a] superior d isplacement of the anterior tongue and deepening of the midposterior-locate d bolus-containing concavity, resulting in a laterally beveled surface enco mpassing the bolus; and (b) retrograde displacement of the configured tissu e. resulting in clearance of the bolus from the oral cavity to the orophary nx. These findings indicate that deglutitive tongue action can be depicted by echo-planar imaging as a series of deformative surface modifications, wh ich are related to the activity of intrinsic and extrinsic lingual muscles.