Due to the increase of human life span and the increase of disease injuries as well as the application of some drugs, the incidence of dysphagia (deglutition disorders, DD), including abnormal pharyngeal and esophageal functions and structural lesions, is increasing; meanwhile, with the improvement of people’s quality of life, dysphagia due to various conditions and the serious prognosis that may result from them have begun to attract the attention of clinical The swallowing difficulties caused by various conditions and the serious prognosis they may lead to have started to attract the attention of medical practitioners. We know that swallowing is a reflex action that requires good coordination of oral, pharyngeal and esophageal functions, and the coordination of the swallowing process is controlled by the swallowing center of the brainstem. Clinically common dysphagia are mainly true bulbar palsy produced by nuclear and subnuclear damage to the linguopharyngeal, vagus and sublingual nerves and/or pseudobulbar palsy produced by bilateral damage to the cortical brainstem tracts, i.e., medullary palsy and pseudomedullary palsy, mostly seen in post-stroke patients, in which swallowing is impaired mainly by delayed onset of random tongue movements and reduced coordination of muscle movements related to swallowing [1]. , transient swallowing disorders can also occur in those with damage to the unilateral cortical brainstem tract [2,3]. Dysphagia is a common post-stroke complication [4,5]. 30-65% of acute stroke patients have been reported to have detectable dysphagia [6], and 57-73% of stroke patients have been reported to have dysphagia [7], with a small proportion of patients presenting clinically with “asymptomatic” aspiration of food or liquid, i.e. silent aspiration [8]. A small proportion of these patients present clinically with “asymptomatic” aspiration of food or fluid, known as silent aspiration [8].
In the United States, dysphagia has attracted the attention of medical and sociologists, and for this reason, the American medical community founded and published the professional journal Dysphagia in 1986, and established the national Dysphagia Research Society and professional treatment centers in 1992. The diagnosis and treatment of dysphagia has become a major medical and social responsibility and a new hot topic in medicine. General guidelines for the treatment of dysphagia have been summarized [9], and guidelines for the evaluation and treatment of dysphagia have been developed by Scottish Academy guideline practitioners [10], but neither the general treatment nor the specific details are yet uniform. There are a few articles on this topic in China but it has not been given much attention in clinical management, whereas a lot of research has been done abroad in this area. This article reviews the progress in the treatment of stroke dysphagia and briefly discusses the physiopathological basis of dysphagia as follows.
1. Swallowing physiological oral phase.
Through the coordinated action of the teeth, tongue, lips and buccal muscles and sensation to form a masticatory movement, the material entering the oral cavity is formed into a food mass or liquid and pushed to the pharynx.
Pharyngeal phase: contraction of the palatal sail lifters and palatal sail tensioners lift the soft palate, contraction of the supraglottis muscle group lifts the hyoid bone anteriorly, the laryngeal structures lift and rotate forward along the longitudinal axis, the vocal cords close, the arytenoids contact the epiglottis to close the entrance to the larynx, and the arytenoid cartilage moves inward to close the laryngeal vestibule. Contraction of the tongue and pharyngeal constrictors combined with gravity allows the food mass to enter the esophagus through the cricopharyngeal muscle. The contraction of the pharyngeal muscle shortens the long axis, the laryngeal vestibule and the pear-shaped crypt disappear, and the sequential contraction of the pharyngeal sphincter pushes the food mass or liquid down and removes the food residue.
Esophageal phase: The upper esophageal sphincter (UES) relaxes by inhibiting the peripharyngeal and pharyngeal sphincters, thus allowing food to pass smoothly through the esophagus.
The basic features of normal swallowing can be summarized as follows: achieving and maintaining control of the food mass; pushing the food mass through the pharynx as quickly as possible by generating different pressures; minimizing the duration of apnea; preventing the extrusion of food or liquid into the nasopharynx or larynx; preventing reflux of gastric contents during esophageal emptying; and eliminating food residues in the pharynx and esophagus.
2, Swallowing pathology mouth stage abnormalities.
Loss of tongue sensation, tongue muscle paralysis and lip or facial muscle dysfunction can cause saliva accumulation, salivation and dysarthria; abnormal movement of the anterior 2/3 of the tongue can lead to impaired food lifting, shaping and propulsion, and ineffective movement of the tongue back and forth; various causes of reduced oral saliva secretion and dry mouth syndrome can cause dysphagia.
Abnormalities in the pharyngeal stage: inability to lift the soft palate or weak contraction or paralysis of the upper pharyngeal sphincter resulting in food retention in the pharynx; weakening of the posterior tongue; abnormal sensation in the pharynx or disorders in the pharyngeal muscles such as poor laryngeal closure during swallowing, poor UES diastole and uncoordinated UES diastole and pharyngeal propulsion, i.e., loss of innervation of the esophagus, etc. can all lead to dysphagia.
In conclusion, dysphagia can be caused by various causes such as paralysis or incomplete paralysis of the transverse muscles involved in swallowing, delayed or absent swallowing reflexes due to lesions of the cortical and brainstem swallowing centers, and impaired coordination of swallowing movements such as loss of high inhibition of the medulla oblongata center and hyperreflexia of the UES. In addition, coordination of breathing and swallowing is necessary to prevent food leakage into the airway [27].
3. treatment strategies Logemann
summarizes the treatment strategies into 3 categories [11]: (1) direct strategies (2) indirect strategies (3) compensatory strategies The first and most important thing to do before or simultaneously with these three treatment strategies is the improvement of oral care and general condition.
3.1 Direct strategy
3.1.1 Feeding position, such as supine position, should make the patient’s trunk up 30 degrees, head and neck forward flexion, hemiplegic side of the shoulder with a pillow pad to reduce the risk of nasal reflux and also reduce misopharyngeal; such as sitting position, make the trunk tilt forward about 20 degrees, the neck slightly forward flexion, so that the hyoid muscle tension increased, larynx up, so that food can easily enter the esophagus, to prevent misopharyngeal easy to induce swallowing reflex; feeding body tilt 45 degrees to the healthy side, so that the healthy side of the pharynx expanded to facilitate food. The body is tilted 45 degrees to the healthy side when eating, so that the healthy side of the pharynx is enlarged to facilitate the entry of food. In addition, the neck is turned 90 degrees to the hemiplegic side, which not only expands the pharynx on the healthy side but also reduces the residual food in the pear-shaped crypt.
3.1.2 Cold stimulation treatment is performed before swallowing by touching the anterior pharyngeal arch with a cold laryngoscope or using a frozen cotton swab dipped in a little water to gently and prolongedly touch and stimulate the anterior and posterior palatal arches, soft palate, palatal arch, posterior pharyngeal wall and posterior part of the tongue for 20 times in the morning and 20 times in the afternoon to make the area triggering the swallowing reflex sensitive and effectively strengthen the swallowing reflex, followed by empty swallowing action. Cold stimulation treatment before transoral ingestion can improve the sensitivity of food block perception and improve the attention to ingestion and swallowing through stimulation, thus reducing misgulping. If the vomiting reflex appears, it should be discontinued to avoid choking and accidental swallowing.
3.1.3 Nature of food mass, entrance position, and eating environment Rest 30 minutes before the meal and make preparations for eating, and the environment should be quiet, with sunlight and lighting in bright and comfortable. Choose foods that are easy for patients to accept [12] such as easy to swallow, appetizing in appearance, appropriate temperature that can stimulate the swallowing reflex, and make them into jelly or paste, sticky, not loose, and not remaining on the mucosa when passing through the pharynx and esophagus. The patient’s swallowing ability can be confirmed first, starting with paste-like foods such as rice paste, egg custard and porridge, and gradually increasing solids such as rotten rice and cooked radish, choosing smooth foods with uniform density, not too sticky and not loose; juice is better than water when feeding liquids. Use a thin and small spoon at the beginning of feeding, and gradually increase the amount of food from small to large. When feeding, pay attention to the appropriate size of the food mass, put it into the healthy side of the mouth, then use the back of the spoon to lightly press the tongue to stimulate the swallowing reflex, each time should be repeatedly swallowed several times, so that all the food through the pharynx, after eating to feed water to rinse the mouth, to avoid food residue caused by misopharynx.
3.2 Indirect strategy: that is, indirect swallowing training.
Firstly, ice massage of the neck, cheek and pharynx, neck joint range of motion training and relaxation exercises, active and passive exercises around the mouth and articulation training are performed for those with oral segment disorders; air or saliva swallowing training, breathing training and coughing training are performed for those with pharyngeal segment disorders [13], in addition to a variety of other indirect methods [14], such as supraglottic swallowing also called autonomous airway protection method, which requires patients to swallow before and The Mendelsohn method is a method to enhance the opening of the cricopharyngeal muscles by autonomously extending and strengthening the laryngeal supination and anterior motion during swallowing, which can be performed by holding the larynx with the hand while the pharyngeal head rises; transcutaneous electrical stimulation (TES (TES) is an electrode placed on the neck and electrically stimulated for one hour per day; pushing Cexercise: pushing the wall with both hands and vocalizing at the same time, or sitting, inhaling and then holding the breath, when the thorax is fixed and the vocal folds are tightly closed, then suddenly exhaling and vocalizing, the vocal folds open wide, (this action can train the function of vocal folds closure, strengthen the muscle strength of the soft palate and help to remove the residual food in the pharynx) [ 15]; Facilitating technique for swallowing (Facilitating technique for swallowing) aims to induce the swallowing reflex by stimulating the sensory restoration of the swallowing muscles, by rubbing the skin with the fingers up and down along the thyroid cartilage to the lower jaw; laryngeal retraction training, i.e., vocal fold closure training, and humming to induce vocal fold atresia [17, 18]; articulation training (basic training of swallowing function): pronouncing the “a” sound and moving to both sides to pronounce “yi”, then “wu”, then “f ” sound or whistling action, each time each sound 3 times, 5-10 times in a row, 2-3 times a day, through the opening and closing of the mouth action to promote the movement of the lip muscles; facial, jaw exercise: do sucking action to contract the cheek muscles and orbicularis oris muscle, then do the opening and closing of the mouth cheek exhalation action, and then do chewing action to move the jaw, repeatedly, three times a day [15]; and tongue muscle (1) let the patient extend the tongue outward, then do left and right movements to the corner of the mouth, then lick the lower lip with the tip of the tongue and then turn to lick the upper lip, and finally press the hard palate with the tongue upward, repeatedly, three times a day. (2) If the patient is unable to move the tongue, a tongue depressor or spoon can be used to massage the tongue, or gauze can be used to wrap the tongue to gently perform up and down and left and right extraoral movements [19].
3.3 Substitution strategy: is the posture and method used during swallowing. Swallowing is made safe by changing the channels through which food is passed and by specific swallowing methods [14].
3.3.1 Head turning method i.e. lateral swallowing.
Turning the head to the side of the pharyngeal muscle paralysis so that the food bypasses the anterior side of the larynx removes residual food from the “pear-shaped fossa” on both sides of the pharynx and enters the esophagus through the upper esophageal sphincter on the side of the normal pharyngeal muscle; chin-down position: (chin-down) expands the space in the epiglottis, displacing the epiglottis backward and placing it in a more protective position for the airway The cyclic ingestion, in which different forms of food are swallowed alternately, such as solid food and liquid food, helps to remove residues in the pharynx; nod-like swallowing [28]: the valley of the epiglottis is another area prone to residual food, when the neck is flexed back (chin-up) the valley of the epiglottis becomes narrow, and residual food can be squeezed out, followed by the neck as far as possible When the neck is flexed forward (chin-down), it resembles a nodding head, and at the same time doing empty swallowing action, the residual food can be removed; random coughing: the food that enters the airway is coughed out.
4. Gastrointestinal nutritional impairment, massive misaspiration or quiet misaspiration (asymptomatic misaspiration silent aspiration)
Those who cause recurrent respiratory infections, severe mental retardation, moderate to severe dysarthria, and severe swallowing disorders with loss of protective coughing must be fasted first, with intravenous nutrition [20] and adequate fluid replacement, followed by nasal feeding. After 2 weeks of nasogastric tube insertion (also after 4 weeks) [28], if recovery of dysfunction is not possible, the patient should be converted to gastrostomy (PEG) if possible, because the mechanical interference of the nasogastric tube, partially blocking the nasal airflow, forcing the mouth to breathe and causing dryness of the oral mucosa can aggravate swallowing difficulties [21], as well as during nasal feeding because the spout sphincter is always open and prone to gastric and esophageal In addition, the nasogastric tube still stimulates the patient’s appetite, so clinically the nasal feeding time should be shortened as much as possible, and the head of the bed should be elevated for 30-40 degrees for 2 hours after nasal feeding, and excessive feeding should be avoided. PEG, percutaneous endoscopic gastrostomy (PEG), is easy to perform and can be tolerated by patients in critical condition. The new gastrostomy tube can be used as the main tube feeding method for stroke patients with swallowing difficulties, which allows both transintestinal tube feeding and preserves gastrointestinal decompression, reducing the incidence of sinusitis and complications related to the placement of nasogastric tubes, especially aspiration pneumonia [23], PEG has few complications but when to start is still controversial, and it is generally believed that those who cannot resume transoral feeding in the short term should be changed to PEG after 2 weeks of nasogastric tube insertion [24].
5.Acupuncture and electroacupuncture treatment
Electrical stimulation can excite the muscles of the pharynx to prevent disuse atrophy, and by stimulating the brain nerves in the damaged area to increase their activity, repeated stimulation to excite the higher motor centers of the brain can help restore and reconstruct the normal reflex arc and promote the formation of new central to pharyngeal motor conduction pathways. The central nervous system has strong plasticity, and continuous stimulation can enhance or reconstruct the central synapses and realize the reassembly of the nervous system. Repeated electrical stimulation can enable dormant synapses to be used vicariously. Modern research suggests that acupuncture stimulation can produce infrared radiation, microparticle flow, electromagnetism and various “endogenous drug factors” in the body, which can increase mitochondrial catalase to enhance cell metabolism; electroacupuncture can improve the activity of superoxide dismutase (SOD) [25], so that the body can effectively scavenge free radicals, improve the body’s ability to attack from excess reactive oxygen species, reduce brain tissue damage, improve the compensatory capacity of brain tissue, increase brain metabolism nutrition, promote the recovery of neurotransmitter conduction function, and repair damaged brain tissue.
6.Other
6.1 Pharmacological and surgical treatments include drugs that inhibit salivary secretion such as antanas …… and shorten the delay in triggering the passage of swallowing and food mass: e.g. nifedipine [26]. Tracheotomy facilitates ventilation and airway clearance, but tracheal intubation should not be prolonged because it affects laryngeal supination and relaxation of the cricopharyngeal muscles. There are also cricopharyngeal myotomy, epiglottis remodeling, partial or total cricoid cartilage resection, laryngeal suspension, and laryngotracheal separation. Long-term severe swallowing difficulties should be treated with laryngeal closure or even laryngectomy to reconstruct respiratory access.
6.2 Psychological treatment [27]
Patients with stroke accompanied by dysphagia are prone to fear, inferiority complex and nervousness due to different degrees of limb paralysis or aphasia, unclear language and poor expression ability, so they have concerns about eating, for which medical staff and family members should comfort and care for them, patiently enlighten and inspire them, and patients should have confidence in overcoming the disease and try to eliminate the bad psychology, actively cooperate with doctors and eat on time and according to the amount in order to enhance physical fitness To promote health.
6.3 Drug-induced dysphagia For some drugs such as sedatives (delayed swallowing reflex), sleeping pills (central inhibition), anticholinergic agents (antagonizing ACH release), dopaminergic agents and drugs blocking the nerve-muscle junction: botulinum toxin A, etc., which cause dysphagia due to orofacial motility disorders, can be reduced or discontinued [28], which can relieve dysphagia within a certain period of time.
6.4 Precautions
6.4.1 Choking treatment When choking occurs, the patient should bend low, lean forward, and lower the jaw toward the forehead to prevent the residue from invading the airway again; if the food residue is stuck in the larynx and endangers breathing, the patient should bend low again, and the rehabilitator can tap the patient between the subscapularis in rapid succession to move the residue out; he or she can also stand behind the patient, wrap the arm around the lower thorax, cross the fingers of both hands, and apply an upward jerking force to the transverse septum The resulting stream of air passing through the epiglottis can expel the obstruction [1].
6.4.2 Anti-misaspiration prohibits drinking through a straw to avoid accidental entry into the trachea, using a cup of cited plain water, the water should be filled, if the water is less than half a cup, the patient will drink with the head tilted back, this posture increases the risk of misaspiration. Another way to prevent accidental aspiration: before eating, the patient is instructed to inhale enough air, hold the breath before and during swallowing, so that the vocal cords can be closed, and cough a little after swallowing to expel the gas from the lungs to spurt out the food residue remaining in the throat [29].
In summary, almost all domestic and international rehabilitation strategies for dysphagia have been refined. In specific clinical practice work, we choose some specific rehabilitation methods for patients: regardless of the functional abnormalities caused by diseases, they can be divided into 3 levels: disabling, disability, and handicap, and the rehabilitation methods of treatment, compensation, and adaptation are adopted respectively; for dysphagia, the purpose of treatment is to promote the recovery of function, for example, to improve the muscle strength and coordination of swallowing muscles through swallowing muscle training, and the purpose of compensation is to adopt For example, swallowing muscle training can be used to improve muscle strength and coordination, and compensatory therapy can be used to reduce the occurrence of aspiration and promote food intake by adopting a certain head position or swallowing strategy. In general, various levels of rehabilitation methods can be adopted simultaneously [30].