Patients enrolled were firstly numbered for privacy with software and divided into the observation group (n=33) and the control group (n=33) with a random number table. Additionally, the staffs involved in assessment would not participate in the intervention of the study. The treatment lasted 20 days.

Patients enrolled were firstly numbered for privacy with software and divided into the observation group (n=33) and the control group (n=33) with a random number table. Additionally, the staffs involved in assessment would not participate in the intervention of the study. The treatment lasted 20 days.

All the participants were provided with the comprehensive rehabilitation (routine rehabilitation and swallowing function training). The routine rehabilitation included intervention for risk factors (blood pressure, blood lipids, blood glucose, smoking and alcohol restriction, exercise, etc.) and pharmacological treatment (aspirin, statins, anticoagulants, etc.).

Regrading swallowing function training, both groups were given swallowing function training, including 1) exercises of closure of the vocal folds, pharyngeal, and laryngeal muscles exercises, and respiratory muscle strength training, for 15 min each time and twice per day. 2) isotonic／isometric swallowing exercises, supraglottic swallowing exercises, and the Mendelsohn maneuver, for 20 min each time and twice per day. 3) effortful swallowing exercises, and cough reflex training, for 10 min each time and twice per day.

The patient was required to take a sitting position with the head naturally upright. Under the guidance of the examiner, the patient first swallowed 5ml of iohexol solution (50ml:17.5g in iodine terms). If the patient exhibited aspiration, the test would stop. If not, the patient was instructed to swallow 10ml of iohexol solution mixed with breadcrumbs, and the patient's swallowing condition was observed with immediate measures ready to take for safety. Specially, the esophageal phase was not included in the study, because it was commonly regarded as an independent phase. The swallowing were divided into 3 phases in this assessment: Oral phase, Pharyngeal phase, and Aspiration, with maximum 3,3,4 points were given to each phase. The total score was calculated as the final result. The final score was positively correlated with the swallowing function.

During the test, patients were required to drink 30 ml of warm water. According to the situation, the swallowing function was rated from Level 1 (excellent) to Level 5 (poor). Specifically, Grade 1: The patient drank all the water at once without choking; Grade II: The patient drank all the water in two or more times without choking; Grade III: The patient drank all the water at once with choking; Grade IV: The patient drank all the water in two or more times with choking; Grade V: The patient exhibited difficulty drinking with frequent choking.