Clinical Characteristics of Swallowing Disorders Caused by Cerebrovascular Disease: A Study Using Newly-developed Indices for the Basic Elements of Swallowing Movement and Neck Range of Motion

The objective of this study was to elucidate the characteristics of swallowing disorder in cerebrovascular disease (CVD) patients in terms of newly developed indices for the basic elements of swallowing movement and muscle tone in the neck. A total of 133 patients participated in our study, 116 patients with CVD and 17 elderly patients who had no history of dysphagia and CVD. These patients were divided into 5 groups according to the existence of swallowing disorder and interval from onset. The effects of CVD and swallowing disorder were elucidated by two-group comparison. Measurement items consisted of and passive neck ROM in 4 directions (flexion, extension, lateral flexion, and rotation.) 5 newly developed indices: distance from the genion to the upper end of thyroid cartilage (GT), distance from the upper end of thyroid cartilage to the upper end of sternum (TS), length of the suprahyoid and infrahyoid muscles on neck extension (GT+TS), relative larynx position (GT/(GT+TS)), and strength of the suprahyoid muscles (GS grade). Patients with CVD of less than 90 days' duration exhibited GT shortening, decline in GS grade, and limitations in neck extension and rotation ROM. In the chronic phase, TS shortening, laryngeal lowering, and limitations in neck flexion and lateral flexion ROM were observed. Physical therapists should aim to improve the factors that might impede laryngeal movement and to conduct preparatory exercises that facilitate swallowing movements.