Classification of Stroke Patients With Dysphagia Into Subgroups Based on Patterns of Submental Muscle Strength and Skill Impairment

To identify and characterize subgroups of stroke patients with clinical signs of dysphagia, based on swallowing-related strength and skill impairments of the submental muscle group. Prospective observational study. Inpatient rehabilitation centers and community dwellings. Individuals (N=114), including stroke patients with dysphagia (n=55) and 2 control groups including myopathic patients with dysphagia (n=19) and healthy volunteers (n=40) were included in this study. Not applicable. Novel clinical assessment of strength (force generation) and skill (spatial and temporal precision of muscle activation) of the submental muscle group during swallowing and nonswallowing behaviors, using surface electromyography and dynamometry. Hierarchical cluster analysis revealed 4 clusters, which could be broadly characterized as cluster 1: intact strength and skill, cluster 2: poor strength and poor nonswallowing skill, cluster 3: poor strength, and cluster 4: poor strength and poor swallowing skill. Membership in cluster was significantly associated with medical diagnosis (P