Patients enrolled are firstly numbered for privacy with software and divided into the observation group and the control group with. Additionally, the staffs involved in assessment would not participate in the intervention of the study. The treatment lasts 10 days.

Patients enrolled are firstly numbered for privacy with software and divided into the observation group and the control group with. Additionally, the staffs involved in assessment would not participate in the intervention of the study. The treatment lasts 10 days.

All the participants are 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.).

Regrading swallowing function training, both groups are 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, 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.

Based on VFSS, this assessment evaluated the patient's swallowing of contrast medium and whether there was retention, penetration, and aspiration. It included multiple items, each with the corresponding criteria, Specifically, whether the swallowed material entered the airway, passed through or contacted the vocal cords, and whether the patient exhibited the corresponding ability to clear. There were 8 levels in the results, with higher levels indicating more severe aspiration.