”Swallowing” is not only the passage of food masses (including liquid and solid foods, drugs and saliva) in the mouth through the pharynx, but should be defined as the entire process of smooth and safe transportation of swallowed objects to the stomach in close coordination with the muscles and nerves of the lips, tongue, palate, pharynx, larynx, esophagus and other organs that form the swallowing channel. It is a process of sensory and motor time sequence occurring to complete the transfer of food from the mouth to the stomach, while protecting the trachea. Swallowing can be structurally divided into three stages: mouth, pharynx, and esophagus; and functionally into four stages: mouth preparation, mouth, pharynx, and esophagus. Swallowing disorders are a group of clinical syndromes in which various symptoms occur due to damage to one or more stages of swallowing caused by damage to the nerves related to swallowing or damage to the swallowing organs. After the cranial nerve injury related to swallowing, it mainly leads to disorder of pharyngeal stage and prolongation of pharyngeal stage, which manifests as weak propulsion of pharyngeal muscle, incomplete laryngeal closure, and dysfunction of cricopharyngeal muscle. If swallowing disorders persist for a long time or are not treated properly a variety of complications ensues, such as aspiration pneumonia, dehydration, malnutrition and even death, which seriously affects the clinical outcome.
Mechanisms of swallowing.
(1) The mouth preparation stage is the stage of chewing food and preparing it for swallowing. This process involves the lips, tongue and cheeks enclosing the food in the mouth to avoid outflow or advancement across the base of the tongue into the pharynx.
(2) The mouth stage refers to the process of swallowing by sending the chewed food pieces formed into the pharynx.
(3) Pharyngeal stage is the stage when the food mass passes from entering the oropharynx through reflex movements to entering the esophagus through the upper esophageal sphincter;
(4) Esophageal stage, when the food mass is moved from the esophagus to the stomach by peristaltic movements.
Neural control of swallowing.
(1) Role of the vagus nerve
Vagus nerve. It can cause paralysis of the pharyngeal constrictor muscle, paralysis of the vocal cords, incomplete closure of the vocal folds during swallowing, and weakened cough. Its damage can have a devastating effect on swallowing. Injury to the laryngeal plexus can lead to decreased compliance of the CTES and decreased sensation of the tongue root and epiglottis can lead to early spillage of the food mass into the pharynx and aspiration.
(2) The role of trigeminal nerve
Stimulation of the trigeminal nerve motor nuclear energy induces swallowing. It and its surrounding areas act more as relay messages. Injury causes disruption of the subcortical pathway to swallowing and produces dysphagia. If its spinal bundle nucleus and spinal bundle are damaged, the mucosal sensation of the oral cavity, floor of the mouth, gingiva, tongue, and soft palate is diminished, with the result that the food mass enters the pharynx but fails to trigger swallowing, making the risk of aspiration increased.
(3) Role of the sublingual nerve
The tongue plays a major role in the oral phase, and its propulsion is also a functional component of the pharyngeal phase. Injury to the hypoglossal nerve can result in significant swallowing disorders.
(4) Role of the facial nerve
Damage to the facial nerve nucleus leads to dysfunction of the labial or facial muscles:, which can affect the mouth preparation and mouth autonomic phases. The lips are unable to maintain food in the mouth, resulting in food outflow or salivation. The cheek is unable to coordinate with the movement of the tongue, affecting the propulsion of the food mass in the oral cavity.
The treatment of swallowing disorders is to restore or improve the patient’s swallowing function, improve the body’s nutritional status, improve the psychological fear and depression caused by the inability to eat through the mouth, increase the safety of eating, reduce the chance of accidental aspiration of food into the lungs, and reduce the occurrence of complications such as aspiration pneumonia. the treatment of swallowing disorders in the 1870s was mainly the work of occupational therapists and nurses, and in the last 20 years has shifted to the responsibility of Speech therapists are responsible for this. Swallowing therapy can be given if the patient is mobile, appropriately awake, and has some degree of swallowing function. However, there is no evidence to support which treatment should be used for a particular swallowing disorder, and there are no uniform, clear treatment guidelines, either for overall treatment or for detailed treatment.
Commonly used approaches are as follows.
(1) Pharmacotherapy: In terms of pharmacotherapy, it was found that patients taking oral nifedipine extended-release tablets had shorter swallowing time and faster swallowing excitation, suggesting that the drug has a protective effect on post-stroke swallowing disorder.
(2) Rehabilitation therapy; functional recovery training, special swallowing techniques, feeding regulation, nasal feeding therapy, physiotherapy, psychotherapy.
(3) Surgical treatment: methods to promote the passage of the esophageal mass such as insertion of a bypass tube, upper esophageal sphincterotomy, mechanical fenestration in the esophagus, compensatory larynx-glottis-chin fixation, botulinum toxin injection in the upper and lower esophageal sphincter, etc.
(4) Acupuncture therapy: According to traditional Chinese medicine theory or according to modern neuroanatomical theory to select the corresponding acupuncture points, in the treatment of swallowing disorder in stroke disease, it was found that the patients’ drinking test score decreased and swallowing function improved after acupuncture. In addition, a variety of acupuncture-based therapies such as head acupuncture, traditional body acupuncture, tongue acupuncture, auricular acupuncture, electroacupuncture, acupuncture injection, acupuncture-drug combination method, prick and release method, posterior pharyngeal wall puncture method, and acupuncture with swallowing training method are also used in clinical practice.
The current status of research on this hot issue is that modern medical treatments have only been sorted out in recent years, and clinicians are mostly feeling their way forward, with more focus on rehabilitation treatment. The rehabilitation of post-stroke swallowing disorders has become one of the important research topics in the medical community today, both at home and abroad. In recent years, in the treatment of post-stroke swallowing disorder, the acupuncture therapy of Chinese medicine has shown unique efficacy in the treatment of this disorder and has played a good role in clinical practice. This project will conduct a clinical study on the treatment of post-stroke swallowing disorder by acupuncture, and evaluate its efficacy in detail; at the same time, we will use neurophysiological techniques to explore the effect of acupuncture on swallowing function and its mechanism, hoping to provide an objective basis for clinical treatment, which is a leap forward in terms of both the broadening of the research level and the depth of the research.