Speech and Swallowing Problems
By Donald A. Barone, DO
Associate Professor and Chief
Division of Neurology, Rowan University School of Osteopathic Medicine
Director, MS Center of South Jersey
From a neurological perspective, speech abnormalities may be due to a disturbance of primary language function (aphasia) or due to mechanical disturbances of word formation (dysarthria). With aphasia, an individual may partially or fully lose the ability to communicate verbally or with written words, either temporarily or permanently, and this may be related to a loss of memory. With dysarthria, an individual will have difficulties speaking due to reduced control of muscles, often a result of nerve damage.
Speech disturbances in MS typically result from dysarthria, with true aphasia to be uncommon in my experience. Disturbances of the nerve supply that weaken the muscles of the lower face, lips, tongue, and throat can result in dysarthria. These are due to lesions in the brainstem, a part of the nervous system between the brain and cervical spinal cord.
More commonly, multiple small lesions in either of the two large lobes of the brain, known as the cerebral hemisphere, result in poor motor control and coordination of these muscles. Slurring and slowness of speech, with altered pronunciation, characterize dysarthria.
“Scanning speech,” characterized by long pauses between syllables and words with loss of melody in speech production, is another type of dysarthria. The term “explosive speech” is sometimes used to describe intermittent episodes of loud, rapid speech production. These dysarthrias are attributed to lesions in the cerebellum, located in the lower-back region of the brain. Coordination between the muscles of articulation and exhalation, necessary for volume control, appears faulty in these dysarthrias. Speech pathologists are usually consulted to help manage these problems by training and coaching the patients to compensate for the deficits.
Some exercises can strengthen and improve the muscles involved in the production of speech, or improve breathing through relaxation of the affected muscles. A speech-language therapist can teach techniques to help slow speech so that it is more understandable, as well as techniques such as improving the way words are articulated and correctly pausing between words. One technique that is particularly helpful is to listen to your own voice using a tape recorder.
When speech difficulties are severe and cannot be corrected with exercise or speech modification, alternative means of speech production can restore the ability to communicate. These range from technology that amplifies the voice, to alternative communication systems such as computer boards.
No medications can specifically improve speech difficulties. However, medications that relieve symptoms such as spasticity may provide some improvement.
I remember being quite surprised when a survey of multiple sclerosis (MS) patients conducted by MSAA several years ago revealed that 39 percent of respondents indicated they had some degree of swallowing difficulty. Fortunately, most of the swallowing (medically known as dysphagia) problems are mild and are self-managed by the patients.
For individuals who are more severely affected with associated coughing, a choking sensation, or breathing difficulties, tests that include swallowing studies – utilizing x-ray imaging and direct endoscopic visualization of the throat – may yield important information. Such testing can identify specific issues and ensure that problems other than neurological ones are not present.
Swallowing is a complex process starting with jaw and tongue movements, which prepare the solid or liquid (known as the bolus) for transport. Coordination between the tongue and upper throat muscles allows the portion of bolus to be actively moved to the back of the mouth and received by the upper throat.
Coordinated contraction of some throat muscles is needed to protect the upper windpipe (larynx), while the relaxation of another muscle allows for the opening of the upper food transport tube (esophagus). This results in the transfer of the bolus to the esophagus. From this point, involuntary contraction of the esophageal smooth muscle moves the bolus down to the stomach, completing the process.
Disorders of the tongue and the throat muscles or their nerve supply will cause swallowing problems. MS patients may have lesions of the brainstem affecting the direct nerve supply to the tongue and throat muscles. More commonly in my experience, multiple lesions (MS plaques) involving both cerebral hemispheres of the brain cause a lack of coordination of the tongue and throat swallowing muscles. This results in a type of swallowing problem known as pseudobulbar palsy.
For many individuals with MS, altering the consistency of solid food and liquids may be very helpful and improve swallowing function. Retraining to swallow, usually carried out by speech pathologists to ensure advantageous head and neck posture during swallowing, is another useful tool for many people with MS. Other strategies for proper swallowing include: eating smaller, more frequent meals to avoid fatigue while eating; taking smaller bites and chewing these well to reduce the chance of choking; and consciously coordinating breathing with swallowing to reduce the risk of aspiration (inhaling food), which can result in pneumonia.