Multiple sclerosis can cause speech and/or swallowing changes at various points in the disease process, depending on the exact locus of damage in the central nervous system. The general approach to rehabilitation of speech and swallowing disorders in people with MS is to conduct a careful evaluation of each function and then to design an appropriate treatment protocol.
Speech evaluation generally involves an articulation test in which a speech-language pathologist asks the individual to produce words and sentences using all of the sounds of the person’s native language to assess whether or not they are produced correctly. The pathologist defines the range of lip, tongue, soft palate, throat (pharyngeal) and voice box (laryngeal) function, and evaluates voice quality, reflecting laryngeal function and palatal movement and fluency of speech. He or she examines the rate and rhythm of speech, since this is controlled by some parts of the central nervous system. Results of this evaluation identify the muscles that are not functioning correctly and the exact nature of the abnormality.
Assessment of swallowing dysfunction usually begins by interviewing the person regarding their awareness of any disorders while eating or drinking. A clinical assessment of the oropharyngeal area is important, and the range of motion of the lips, tongue, palate, and control of the larynx are assessed. In addition, the speech pathologist notes any particular eating habits, such as putting the chin down or pushing hard while swallowing. It is important to ask the person whether certain foods create more difficulties than other foods and whether swallowing is more difficult at various times of the day. At the end of this clinical assessment of oral and pharyngeal function, a special instrumental examination may be recommended. If the speech-language pathologist decides that there is risk of a pharyngeal stage problem that is not visible on clinical assessment because the pharynx (throat) is invisible beyond the back of the mouth, he or she may recommend an x-ray study (modified barium swallow) or an endoscopic examination.
Modified barium swallow, a moving x-ray, is able to assess the function of muscles in the mouth, pharynx, and larynx during the swallow and determine both the safety and efficiency of the individual’s swallowing. Safety is critical to ensure that aspiration, or food entering the airway, does not occur. Efficiency of eating is also important, as people with MS must take in adequate fluids and calories in order to maintain weight and health. The modified barium swallow is a simple procedure in which moving x-rays are taken while the individual completes two swallows of measured amounts of liquid: 1, 3, 5, 10 ml of thin liquids, cup drinking of thin liquids, 3 ml of pudding, and two small pieces of a cookie or biscuit coated with barium pudding which the person chews and then swallows. Fourteen swallows are usually visualised to assess swallow safety and efficiency. It is a simple test which takes less than five minutes of x-ray exposure. From this test, the clinician can identify the swallow disorders that are causing any difficulty. When the cause of a disorder has been identified, the clinician can introduce treatment strategies during the x-ray study to document the effectiveness of the treatments.
Treatments for swallowing difficulties
Treatments for swallowing difficulties (dysphagia) may include: 1) changes in head or body position to re-direct the flow of food, 2) heightening sensation prior to the swallow to elicit a faster swallow, 3) applying voluntary controls during the swallow to improve selected muscle functions, or 4) changing diet textures to reduce the risk of food going into the airway or to improve the efficiency of the swallow. Changing the food consistency is generally the last choice, since people often find it unpleasant to eliminate certain foods from the diet or to thicken liquids. At the end of the x-ray study, the speech-language pathologist writes a report that defines the swallow disorders present, the most effective treatments, and outlines a treatment/management programme.
Common swallowing disorders resulting from MS
The most common swallow disorder occurring in people with MS is a delay in triggering the pharyngeal stage of the swallow. This disorder results in food or liquid dropping into the pharynx before the pharyngeal motor actions have begun, including protection of the airway. The person can aspirate and may not cough. Even patients with MS who deny any dysphagia may exhibit a delay in the swallow.
Other swallowing problems include reduced laryngeal elevation, which leads to reduction in opening of the valve into the oesophagus, and reduction in movement of the lowest part of the tongue, the base of the tongue, which causes food to be left behind in the pharynx. Interventions for these disorders focus on therapy to improve the triggering of the pharyngeal swallow by heightening sensation prior to the swallow, exercise programmes to improve laryngeal lifting, and exercises to improve tongue base action. Unfortunately, studies of the effectiveness of all swallowrelated therapies in people with MS have not been done in large numbers of subjects. The effectiveness of treatment for an individual can be done during the radiographic study by introducing selected treatments and examining their immediate effects.
Applicability/relevance of various interventions
Few studies have examined the effectiveness of treatment for speech and swallowing problems in people with MS. Since there is no evidence that exercises can be harmful, it is not uncommon for aggressive therapy programmes involving exercises to be recommended.
Working with other disciplines
Speech-language pathologists often cooperate with a number of other disciplines in the management of speech and swallowing difficulties. Often, changes in head or body position can facilitate swallowing or improve breath support for speech production. Physical positioning may require intervention by a physical therapist or occupational therapist in conjunction with the speech-language pathologist. The old idea that swallowing required a specific posture with feet on the floor and the trunk upright has been found to be untrue. In fact, there are people who actually swallow best lying down. Speech language pathologists also interact with nurses, nursing aides, and dietitians in promoting an optimal diet and caloric intake. Collaboration with the individual, the family, nurses, physicians, and others on the care team is critical to help the care team better understand the nature of the individual’s speech and swallowing disorders and to determine the best ways to help promote adequate oral intake as well as to maximise oral communication. If alternative communication systems are needed due to speech becoming difficult to understand, a speech-language pathologist may recommend the appropriate instrument and provide training in its use.
Speech and swallowing therapy can be critical in achieving maximum function for the person with MS, especially as the disease progresses. Regular reassessments may be needed as the disease exacerbates or remits.
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