This information is for health professionals and service providers.
Dysphagia is difficulty in swallowing caused by weakness and paralysis of the lips, facial muscles, tongue, larynx and pharynx resulting from affected trigeminal, facial, glossopharyngeal, vagus, accessory and hypoglossal nerves.
Swallowing difficulties should be assessed and regularly reviewed by a speech pathologist. The goal of managing swallowing difficulties is to maintain optimal levels of nutrition and hydration and to reduce choking episodes.
Speech pathologists work with dietitians to provide advice concerning food and fluid consistency, modification of diet and gastrostomy.
Dysphagia eventually affects about two thirds of people with MND.
The effects of dysphagia include:
Which can result in:
Dysphagia is very frequent in ALS, affecting approximately 85% of patients. Bulbar onset ALS is more common in older individuals compared with younger individuals diagnosed with ALS. It may lead to complications such as malnutrition, dehydration, aspiration pneumonia, respiratory failure, and reduced quality of life and social isolation.
Swallowing is a complex act that involves oral, pharyngeal, and oesophageal stages and requires multiple elements to be effective; ALS patients may have a combination of spastic and flaccid weakness affecting their swallowing caused by degeneration of cortical motor neurons, corticobulbar tracts, and brainstem nuclei. The loss of supranuclear innervation to the brainstem nuclei results in spasticity of the jaw, facial, palatal, pharyngeal, laryngeal, and tongue muscles whereas degeneration of the brainstem nuclei causes flaccid paralysis in these muscles. The characteristic symptoms resulting from the combination of upper and lower motor neuron dysfunction include fatigue when chewing, leakage of food or liquid out of the mouth, nasal regurgitation, prolonged duration while swallowing, inability to clear the oral cavity, and coughing or choking when swallowing. In a typical ALS patient, both mechanisms are likely contributing the dysphagia and dysarthria (Epps et al 2020).
In ALS, factors that restrict adequate nutrition develop insidiously and progressively worsen. The functional consequences are choking, aspiration, weight loss, and dehydration. Dysphagia is a symptom experienced by the patient and is prima facie evidence of swallowing dysfunction (Miller et al 2009).
Swallowing difficulties should be assessed and regularly reviewed by a speech pathologist. Speech pathologists work with dietitians to monitor weight, provide advice concerning food and fluid consistency, modification of diet and the option of percutaneous endoscopic gastrostomy (PEG). The goal of managing swallowing difficulties is to reduce the risk of choking and aspiration and to help maintain optimal levels of nutrition and hydration.
Instrumental assessments provide the most comprehensive evaluation of swallowing physiology through visualization of the swallowing sequence, and/or measurement of swallowing function. Although 91.8% of studies describing Pharyngeal Phase Difficulties based their data on instrumental assessment, reports of Oral Phase Difficulties and Aspiration/Penetration were more likely to be based on clinical signs and patient-reported symptoms; instrumental assessments were cited as the source of these observations 65.5% and 62.1% of the time, respectively. As recent findings have identified that aspiration may be silent in individuals with MND this challenges the sensitivity and specificity of clinical observation and patient report, and highlights the importance of conducting instrumental assessment of swallowing with these individuals. In the clinical context, considerations regarding patient goals and priorities, rate of disease progression, and risks associated with repeat radiation exposure (i.e., video fluoroscopy) will help guide the use of instrumental assessment (Waito et al 2017).
Weight loss in ALS patients may occur because of dysphagia, muscle atrophy, poor appetite related to depression, and hypermetabolic state. In addition, caloric needs in an ALS patient may be underestimated using traditional equations in part because of increased work of using weak muscles, as well as energy expenditure associated with cramps, spasticity, fasciculations, and pseudobulbar manifestations. A potentially more accurate way to measure an ALS patient’s total daily caloric needs uses the Harris-Benedict equation but also incorporates scores of 6 items from the ALS functional rating scale relating to speech, handwriting, dressing and hygiene, turning in bed, walking and dyspnea.
Weight loss of greater than 10%, rapid changes in BMI from time of symptom onset to diagnosis, as well as greater BMI changes in the first 2 years of being diagnosed with ALS are all associated with a worse prognosis. Patients with a BMI classification of mild obesity at time of study entry had a better prognosis, and in a prospective nutritional and cancer study of over a half a million subjects followed for 14–28 years, higher body fat was associated with a lower risk of dying from ALS (Jackson et al 2015).
Video fluoroscopic evaluation of the swallowing mechanism may identify food textures that can be handled successfully. However, it is not a required test to establish the presence or absence of dysphagia (Miller et al 2009).
Dysphagia management requires a rapid, coordinated, interdisciplinary team approach and regular review to include:
Across the literature, the most common recommendation for dysphagia management in patients with MND is enteral nutrition. As MNDs are progressive with no known cure, enteral nutrition is a key management option to reduce the risk of secondary consequences resulting from dysphagia, and maintain optimal health status. Enteral nutrition has been shown to improve or maintain nutritional status, weight gain and prolonged survival provided that respiratory status is adequate. Current recommendations indicate that prophylactic introduction of an enteral nutrition method (e.g., PEG-tube) is preferred, in order to supplement nutrition early and ensure that respiratory capacity is adequate (e.g., FVC 50%) at the time of surgery. Still, enteral feeding does not directly treat the disordered swallow, but rather provides nutritional supplementation in the absence of a safe or efficient swallow. Research on direct management strategies to improve or mitigate swallowing function has been much more limited (Waito et al 2017).
Weight maintenance and nutritional support are critical in the routine management of MND. Weight loss in MND has complex origins and may be caused in some patients by a hypermetabolic state, with or without swallowing dysfunction, and is associated with more rapid disease progression. Conversely, nutritional interventions, including enteral feeding, although primarily intended to maintain well-being, are associated to a variable degree with improved survival. Optimisation of nutrition includes regular weight measurement, symptom enquiry and swallowing assessment for swallowing dysfunction, nutritional supplementation and dietary advice, and enteral feeding through a percutaneous endoscopic gastrostomy (PEG) tube if appropriate and desired by the patient. Discussions regarding PEG feeding should be instituted relatively early in the course of disease before severe dysphagia ensues. This is particularly relevant in patients with concomitant respiratory muscle weakness, as significant respiratory failure makes insertion of a PEG tube more hazardous and thus may preclude this intervention if delayed (Simon et al 2015).
Some weight loss is an inevitable consequence of muscle wasting, however, as MND progresses eating may become difficult, more exhausting and cause anxiety. The prevalance of hypermetabolism further compounds weight loss.
A coordinated interdisciplinary team approach and regular assessment is vital in maintaining nutrition:
Malnutrition and weight loss are well recognised poor prognostic factors in ALS. Reasons for weight loss are multifactorial and include muscle wasting secondary to denervation poor oral intake due to dysphagia, upper limb weakness and poor appetite and energy intake is lower than predicted daily requirements. Calorie ingestion of less than the recommended daily amount has been observed in 70% and 94% of patients with ALS in two cohorts. Low oral intake is compounded by an increased resting energy expenditure which occurs in up to 67% of patients with ALS. The cause of hypermetabolism in ALS is unknown with several unproven hypotheses including mitochondrial dysfunction .
Given the high prevalence of hypermetabolism and the association of weight loss and malnutrition with a poor prognosis in ALS a small pilot study of high calorie diets in gastrostomy fed patients with advanced disease has been undertaken. The results indicated a possible survival advantage with good tolerability of high calorie supplementation. This demonstrated the potential of a high calorie nutritional intervention to influence the disease course in ALS (Hobson and McDermott 2016).
Early swallowing problems are addressed with changes made while eating, including smaller bites, slowing down, and avoiding talking while eating. Consistency changes may be suggested, including blending solid foods or adding thickener to liquids. Speech therapists may provide instructions in chin tuck or head turning to improve the ease and safety of a swallow. As the disease progresses, these are frequently not sufficient, and a feeding tube is considered.
Reasons to recommend a gastrostomy tube include malnutrition/weight loss, long meal times, evidence for aspiration, and dehydration. Although the AAN practice guidelines supports placement when the vital capacity is above 50% because of concerns of increased risk as this value falls, recent data provides evidence that a gastrostomy tube can be safely placed with vital capacities below this value, particularly when non-invasive ventilation can be used during the procedure (Jackson et al 2015).
The initial management of dysphagia is based on the following: dietary counselling, modification of food and fluid consistency (blending food, adding thickeners to liquids), prescription of high-protein and high-caloric supplements, education of the patient and carers in feeding and swallowing techniques such as supraglottic swallowing and postural changes and flexing the neck forward on swallowing to protect the airway (‘chin-tuck manoeuvre’). Some patients with difficulty swallowing tap water can more easily drink carbonated fluids and/or ice-cold liquids. When tube feeding is needed, three procedures obviate the need for major surgery and general anaesthesia: percutaneous endoscopic gastrostomy (PEG), percutaneous radiologic gastrostomy (PRG, or radiologically inserted gastrostomy) and nasogastric tube (NGT) feeding (Andersen et al 2012).
Oral feeding may become a high risk activity due to increased risk of obstruction of the airway, aspiration and inability to meet nutritional requirements.
Best evidence to date supports the use of feeding via a percutaneous endoscopic gastrostomy (PEG) or radiologically inserted gastrostomy (RIG) to improve nutrition and potentially to provide a survival advantage for those with swallowing difficulties. Gastrostomy placement does not preclude oral feeding as well but offers an alternative way to administer medications and fluids and supplement intake of food to maintain weight.
An important consideration with gastrostomy insertion is that respiratory muscle weakness and malnutrition can affect recovery from the procedure.
It is important that the person living with MND be aware of gastrostomy options in good time in order to obtain maximum benefit. The person with MND, their carer and family should be guided and supported through the decision making process and have access to timely and trusted information.
Enteral feeding is commonly used to sustain intake of nutrition and medication but there is no convincing evidence that it improves survival, nutritional outcomes or quality of life. Given it is already extensively used in ALS, it is unlikely that a randomised controlled trial with a placebo arm to definitively explore this issue would be possible. However, evidence regarding the timing and method of gastrostomy have become clearer following a prospective cohort study of 345 patients undergoing gastrostomy insertion. Whilst expert consensus previously recommended that a loss of 10% of body weight should trigger insertion, this cohort study suggested that this may be too late. Those patients undergoing the procedure who had already lost more than 5% of their premorbid weight were unlikely to regain this weight with enteral feeding. It is therefore recommended that patients should be referred to a dietician and speech therapist at the onset of dysphagia and consider gastrostomy insertion early in the disease, ideally prior to the development of respiratory failure or significant weight loss.
Identifying the correct time for an individual to undergo the procedure is challenging and patients often chose to delay insertion, particularly those still enjoying the taste and the social importance of eating. Patients may view gastrostomy negatively, as it represents an important milestone in their disease and using a gastrostomy also places a major burden on carers. For some patients with severe cognitive impairment or who are frail or nearing the end of life, conservative management may be more appropriate. Alternatives such as nasogastric feeding, subcutaneous fluids or even parental nutrition may be considered (Hobson and McDermott 2016).
There are no randomised controlled trials to indicate whether enteral tube feeding is beneficial compared to continuation of oral feeding for any of the outcome measures. The 'best' evidence to date suggests a survival advantage for some people with amyotrophic lateral sclerosis/motor neuron disease, but these conclusions are tentative. Evidence for improved nutrition is also incomplete but tentatively favorable.
Quality of life has been addressed in studies and needs more attention. Based on a number of recent non-randomized studies comparing surgical and radiographic approaches to feeding tube insertion these two procedures for PEG tube insertion appear to be equivalent (Katzberg and Benatar 2011).
Percutaneous endoscopic gastrostomy is the standard procedure for enteral nutrition in ALS and is widely available. PEG improves nutrition, but there is no convincing evidence that it prevents aspiration or improves quality of life or survival (Class III). The procedure requires mild sedation and is therefore more hazardous in patients with respiratory impairment and/or at an advanced stage of the disease. Non-invasive ventilation during the PEG procedure may be feasible in patients with respiratory impairment (Class IV). The timing of PEG is mainly based on symptoms, nutritional status and respiratory function. To minimize risks, PEG should be performed before vital capacity falls below 50% of predicted (Class IV) (Andersen et al 2012).
Mouth care is very important for people with MND who have swallowing difficulties due to tongue and throat muscle weakness. Immobility of the tongue decreases the natural ability to move food particles around the mouth, food can become trapped in the cheek pockets and this can cause mouth ulceration. In addition the antibacteria, anti-viral and anti-fungal properties of saliva are not as effective when a person has drooling saliva, thick saliva or dry mouth.
Mouth care:
ALS patients may report jaw quivering or clenching due to spasticity, precipitated by pain, anxiety or cold. Jaw clenching can be severe enough to interfere with oral hygiene. Treatment includes benzodiazepines as listed in Table 4. Botulinum toxin injected at 2 sites within the masseters on each side has been reported anecdotally to be effective. Dental guards can alleviate cheek biting at night (Jackson et al 2015).
Swallowing will get more difficult over time and people with MND may experience episodes of severe
uncontrolled coughing which increases their choking risk. Impaired respiration and swallow reflex, weak
cough response, muscle spasm or stridor (due to acid reflux), and aspiration of food or fluids can increase
choking risk.
Severe uncontrolled coughing episodes are distressing for people with MND, their family and
carers. It is important to stress to the patient and their carer that death caused by a choking attack is rare.
In a study of the last month of life in ALS patients, the most common symptoms were difficulty communicating, dyspnea, choking episodes, insomnia, and pain. Many of these symptoms were often inadequately controlled (Jackson et al 2015).
Shortly after diagnosis, reassuring patients pro-actively that those with ALS do not ‘choke to death’ can help to allay a major concern, and set the scene for a better understanding of the purpose of gastrostomy if this becomes indicated later.
There are often fears of ‘choking to death’ , which can be justifiably allayed when studies have shown that this to be exceptional. Explanation and preparation for dying, including the provision of appropriate medication, advance care planning and support of the person and their family can alleviate these fears (Oliver et al 2010).
The fear of "choking to death" is on the mind of most patients suffering from amyotrophic lateral sclerosis (ALS). So far, however, there have been no systematic surveys concerning the dying phase in a general ALS population. We therefore performed a structured telephone interview with the relatives of 121 patients who died from ALS and were followed by the Motor Neuron Outpatient Clinic of the Department of Neurology, University of Munich, Germany. These data are compared with those obtained by a retrospective analysis of medical records of 50 ALS patients who were followed by the Wisdom Hospice, Rochester, UK. The data show that most ALS patients (Germany 88%, UK 98%) died peacefully, and no patient "choked to death" (Neudert et al 2001).
Laryngospasm is an uncommon symptom that may be experienced by patients with dysphagia. It can be very frightening as it may develop suddenly and results in the person with MND not being able to take a breath or call out for help.
Careful management of dysphagia and an interdisciplinary team approach that includes palliative care is vital for people living with MND in preventing or ameliorating this symptom.
Multidisciplinary input including speech and language therapy, physiotherapy and palliative care are important and improve outcome. Placement of a feeding gastrostomy and management of secretions is necessary to maintain nutrition and reduce risk of aspiration. A tracheostomy may be required in the presence of severe laryngeal spasm, or recurrent aspiration, but may not benefit quality of life if bulbar symptoms occur at end stage and if the care package consequences are significant. The advantages and disadvantages of performing a tracheostomy should be carefully explored as part of advance decision-making. No therapy or intervention, whether it is NIV, tracheostomy ventilation or MI-E, should be pursued if burdens outweigh benefit.
Laryngospasm is the sudden sensation that air can’t be moved in and out, usually lasting seconds accompanied by inspiratory stridor, or audible respirations due to a rapid and forceful contraction of laryngeal adductors. It is extremely frightening since the patient can’t take a breath or call for help. In a study on laryngospasm, 2 percent of a control group of 122 patients in the early stages of ALS reported laryngospasm, though up to 19% of patients have reported it in later stages. Common causes of laryngospasm in ALS are liquid or saliva in contact with the larynx, acid reflux, smoke, strong smells, emotion, alcohol, cold bursts of air, and even spicy foods.
Non-pharmacologic measures help in many patients. A rapid change to the upright position of the upper body, fixation of the arms to stabilize the body, breathing through the nose, swallowing repetitively and breathing with slow exhalation through lips have been reported to shorten episodes. If frequent enough and non-pharmacologic measures are ineffective, benzodiazepines bid or tid can be used. In the case of GERD, treat with anti-reflux therapy and prokinetic drugs like metoclopramide before meals and at bedtime (Jackson et al 2015).
The sphincter muscles themselves are not weakened by MND and therefore incontinence is not a common problem for people living with MND. However, people living with MND may experience problems with constipation and urinary urgency.
Autonomic symptoms have been reported in up to 29% of patients with ALS. Common symptoms involve urinary and gastrointestinal dysfunction (Jackson and others 2015).
Constipation can be caused by:
Management:
Note: Diarrhoea may be due to constipation with overflow.
Urinary frequency and urgency is a troubling symptom, particularly for people with limb weakness who may find getting to and from the toilet very difficult and time consuming.
Management:
Anticholinergic medications are used after urinary tract infections or an enlarged prostate is ruled out. Medications may improve urinary urgency and frequency in some patients, but not all. It is uncommon for symptoms to resolve completely. Oxybutynin is commonly tried first at 5 mg bid or tid. It is inexpensive and can be crushed and used with a PEG tube. Extended release oxybutynin at doses of 5, 10 and 15 mg are used once a day but can’t be crushed for PEG tube use. Oxytrol skin patch delivers a continuous amount of medication. Tolterodine tartrate (Detrol), Darifenacin (Enablex), Solifenacin (Vesicare), Tropsium (Sanctura) and Fesoterodine (Toviaz) are other options. Although beneficial, anticholinergics may produce dry mouth, constipation, blurred vision and drowsiness as well as confusion in elderly patients with dementia” (Jackson et al 2015).
Shoesmith et al 2021, Canadian best practice recommendations for the management of amyotrophic lateral sclerosis
See nutrition decision tree - figure 1
See nutritional management recommendations - table 1
National Institute for Health and Clinical Excellence (2016) NICE Guideline: Motor Neurone Disease Assessment and Management – see recommendation:
1.10 Nutrition and gastrostomy
Andersen et al 2012, EFNS guidelines on the Clinical Management of Amyotrophic Lateral Sclerosis (MALS) – revised report of an EFNS task force - Enteral nutrition in patients with ALS recommendations:
Miller et al 2009, Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: drug, nutritional, and respiratory therapies (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology:
Recommendation: PEG should be considered to stabilize weight and to prolong survival in patients with ALS (Level B)
See also:
MND Aware e-training program MND Hub – online training course for health professionals and service providers developed by MND NSW – Session 11: Symptom Management – Swallowing and nutrition
International Alliance of ALS/MND Association, 19th Allied Health Professionals Forum 2021:
MND NSW Ask the Experts 2020:
International Alliance of ALS/MND Association, 16th Allied Health Professionals Forum 2018:
Factsheet: Considering Gastrostomy – PEG and RIG
Breathing and MND
Equipment, assistive technology and home modifications
Eating, drinking and swallowing
Talking about end of life and planning ahead
MND Decision Assist Tool, Should I have a gastrostomy for my nutrition and hydration in MND?
MND NSW, Living well with MND 2019:
Healthtalk.org stories collected by academic researchers who interview people in their own homes, using their own words: