Speech Pathology in Degenerative Central

Speech Pathology in Degenerative Central Nervous System Diseases

Speech and Language in Adults with Diseases of the Central Nervous System

Speech and language difficulties accompany a number of diseases of the central nervous system in adults. Sometimes the speech difficulty might be the reason for seeking medical help, or it might be one of many factors that cause a person to seek medical attention. Speech difficulties might arise simultaneously with other symptoms, or they might arise at a different time. A myriad of problems fall under the category of speech and language difficulties. Symptoms range from slurred speech, slow speech and other problems that make it difficult to be understood to more serious difficulties, including a total loss of ability to speak at all. Speech difficulties arise from a number of central nervous system problems including Multiple Sclerosis, Parkinson's Disease, tumors or stroke. Regardless of the severity of the speech or language difficulty, or its cause, these problems make life difficult for patients and their caregivers.

The nervous system consists of two distinct components. The Central Nervous System (CNS) consists of the brain, spinal cord, and optic nerves. The peripheral Nervous System (PNS) consists of all other nerves in the body. Speech and language problems can arise from peripheral nerve problems, muscular problems or the central nervous system. Typically, speech and language problems that arise from the CNS are accompanied by other symptoms, which can complicate treatment. The following represents the most common causes of CNS system problems that can complicate speech and language.

Neurodebenerative Diseases

Alzheimer's disease (AD) causes the degeneration of the neurosystem. AD causes progressive cognitive deterioration. As AD progresses, daily life becomes difficult in many ways. In its early stages, short-term memory and minor details are easily forgotten. However, as the disease progresses language skills are affected, along with movement. The ability to recognize people and things becomes difficult (BayBio Institute 2007). These affects are caused by the atrophy of neurons in the temporoparietal and frontal cortex (BayBio Institute 2007). Plaques and neurofibrillary tangles cause the symptoms to worsen (BayBio Institute 2007). Currently there is no known cure for AD.

Amyotrophic lateral sclerosis (ALS) is also known as Lou Gehrig's Disease. Like AD, it is a progressive neurodegenerative disease in which the nerves slowly deteriorate until they die completely (BayBio Institute 2007). ALS affects the neurons that are responsible for the transference of signals from the brain to the muscles. The first symptoms are general weakness in the arms, legs, and the muscles responsible for speaking (BayBio Institute 2007). There is no known cure for this disease, but certain treatments, such as Amyotrophic, have been shown to slow the progression of the disease (BayBio Institute 2007).

Huntington's disease (HD) is another neurological disorder. This disorder is inherited and can be diagnosed via genetic testing. The mechanism of Huntington's disease derives from a gene mutation that produces a mutant protein responsible for cell death in the brain (BayBio Institute 2007). As the brain slowly dies, function and movement abilities decrease. There is no cure for HD, but medications can help to manage the disease (BayBio Institute 2007).

Multiple Sclerosis (MS) is a disease in which the protective tissue of the neurons in the CNS is damaged. In this disease, the person's own autoimmune system attacks the myelin sheaths around the nerves (BayBio Institute 2007). This damage renders the nerve no longer able to function properly. The symptoms of MS vary from person to person depending on the nerves that are affected. They can include language and speech dysfunctions. There are four different types progression categories, which range from occasional flare-ups to a form with constantly worsening of symptoms (BayBio Institute 2007). A related disease is Myasthenia Gravis. Myasthenia Gravis (MG) is a neuromuscular disease that is similar to MS where the antibodies that block receptors for certain proteins at the neuromuscular junction. This prevents the stimulative effect necessary for proper muscular function (BayBio Institute 2007). Immunosuppressors can help to slow the disease.

Parkinson's Disease is a dysfunction of the neurotransmitters between the nerve cells. Parkinson's disease destroys brain cells, resulting in a shortage of dopamine. The first signs of Parkinson's are typically subtle, such as softer or slower speech. As the disease progresses, tremors begin, which eventually worsen until hey cause considerable difficulty performing everyday tasks. Treatments to replace dopamine can help to slow the disease.

Brain injuries are typically not listed under the category of disease. However, they are included in this research because they can cause certain forms of neurological dysfunction that can have an effect of speech and language (BayBio Institute 2007). Brain injuries can trigger diseases such as epilepsy. Some forms of epilepsy can cause speech impairments. Typically, when one thinks of epilepsy, they think of a short-term grand mal seizure, in which case speech impairment is not the major concern. However, some forms of epilepsy have a more permanent effect of speech and language. They can cause progressive brain damage, if treatments are unsuccessful. In cases such as this, they would be similar to a CNS disease as far as treatment is concerned.

Traumatic brain injuries are classified into penetrating injuries and closed head injuries. Penetrating entries involve a foreign object that enters the brain from an outside force. Injuries from these types of objects are limited to the areas affected by the impact. Closed head injuries result from a blow to the head, such as strikes from a car accident. These types of injuries cause more widespread damage (ASHA, 2007d). After an accident, there is a certain amount of primary damage. This damage stops and is considered to be complete at the time of injury.

The second type of damage is called "secondary damage" and can occur progressively for days or hours after the initial trauma (ASHA, 2007d). This means that speech and language problems might not be apparent at the time of injury, but will develop as time passes. This is important in evaluation of a traumatic brain injury. Damage to the right hemisphere of the brain is more likely to cause communication problems associated with cognitive function than damage to the left (ASHA, 2007f). In addition, symptoms from damage to the right side of the brain are more subtle than those to the left hemisphere (ASHA, 2007f).

From a speech and language perspective, the primary difference in the various types of diseases that affect the CNS is the mechanism and part of the CNS that they attack. CNS diseases are unpredictable and it is difficult to determine how disease progression will occur in any patient. In some forms of CNS diseases language and speech difficulties will occur at early onset. In others language and speech difficulties will not appear until later stages of disease progression. One thing that is the same in all of the CNS diseases is that they are progressive. Medications can help slow the progression in some cases, but all of these diseases progress, except possibly with brain injury.

Speech and Language Therapy in CNS Diseases

Due to the progressive nature of CNS disease, it is safe to say that at some point, almost every patient will need the services of a speech and language therapist. The ability to speak and communicate with other human beings is an essential part of the patient's quality of life. Speech and language therapy can greatly improve many areas of the patient's condition. The most basic of these needs surrounds being able to communicate one's needs. Another important need is the ability to communicate with others for social contact and emotional needs. A third level is that preserving the ability to talk also helps improve other brain functions as well. Speech and language therapy is an important part in the maintenance of quality of life for patients with CNS diseases.

There are two considerations for speech and language in CNS diseases. The first is the ability to speak physically. The second involves the loss of cognitive abilities involved with language. For instance, with ALS the patient loses the ability to control their muscles. The muscles atrophy and then begin to twitch involuntarily. However, the patient never loses their cognitive function (NIH 2007). The progression of ALS cannot be stopped. Therefore, from a therapy standpoint, the person must be assisted in making continuing adaptations in the area of speech and language to help compensate for continued loss of function. ALS patients might experience difficulty speaking or forming words (dysarthria). Other problems might cause trouble with speaking such as exaggerated reflexes (hyperreflexia) or trouble swallowing (dysphagia) (NIH 2007).

With many progressive diseases of the CNS, as the disease progresses and the person loses their ability to speak, therapy might focus on non-verbal forms of language. Therapists might develop a method for responding to yes or no questions using their eyes. They can help the patient use speech synthesizers, and other computer-based communication devices (NIH 2007). There are a wide range of these devices available. They can be matched to the person's specific needs and physical abilities as the disease progresses.

For patients whose primary concern is a loss of language abilities due to loss of cognitive abilities therapies to help improve cognitive function will be combined with exercises that ask the patient to perform various language tasks. Speech and language therapy is only a small portion of the many different specialists that any patient with a CNS dysfunction will need.

Aphasia

Aphasia is the result of damage to the language centers of the brain (ASHA 2007a). The location of the language center is typically on the left side of the brain. This is true for almost all right handed people and almost 1/2 of all left handers (ASHA 2007a). When the language center of the brain is damaged, either by disease or trauma, a person might lose their ability to speak, listen, read or write (ASHA 2007a). Any type of damage to the brain can cause Aphasia.

Language is generally divided into two parts. We take about expressive language, which is the ability to produce speech and communicate. We also talk about receptive language, which is the ability to understand what is said by others. A person with a CNS disease might have problems with either one of these areas of speech or they might have problems in both areas (ASHA 2007a). Speech therapy must concentrate on both areas of communication in order to maintain the goals of the therapy.

There are many factors that can affect the progress and success of speech and language therapy. The educational level, age, health status (ASHA 2007a) and stage of disease progression affect the type of therapy used. These factors can have an effect on the success of the treatment program. Persons with severe aphasia might understand little of what is said to them at all. They might be limited to simple one word phrases, such as "yes" or "no" (ASHA 2007a). In some cases, the person might have problems with spoken language, but might be able to read or write (ASHA 2007a). Anomia is a form of aphasia where the person has trouble finding the word that they wish to use (ASHA 2007a). Forgetting the word for an object does not mean that the meaning of the object itself disappears, only the word for it.

Expressive aphasia can take many forms. A person might omit smaller words of speech, such as a, and, of, and the. The patient might put the words in the wrong order or use incorrect grammar (ASHA 2007a). Sounds in words might be switched. For instance, a glass may be called a fork. The person might switch the words around. A typewriter might become a write typer. The patient might make up nonsense words, or might string together sentences that do not make sense.

Receptive aphasia has just as many variations as expressive aphasia. A person might need more time to process spoken language. They might misinterpret common phrases, taking them literal, such as let the cat out of the bag. Phrases such as these might be confusing to a person with aphasia. They might wonder why the cat was in the bag in the first place. They need long pauses in speech in order to understand it.

Apraxia

Apraxia is a motor speech disorder caused by damage to parts of the nervous system that are used in speech. Apraxia is also referred to as apraxia of speech, verbal apraxia, and dyspraxia (ASHA, 2007b). This disorder produces difficulties sequencing the sounds in syllables and words. It can differ in severity depending on the extent and type of brain damage. People with apraxia know which words they need to use, but their brains have difficulty putting the muscles together to say them. The result is that instead of saying what the person wants to say, they say something completely different or something that makes no sense (ASHA, 2007b). For example the person might want to say "hello" but will say something such as "balpo" instead.

With aphasia, the person knows that they made an error. They might try to correct themselves, but once again, make another error. Aphasia can be frustrating and difficult for the person affected (ASHA, 2007b) and for those around them. Aphasia has many distinctive features that distinguish it from other speech and language disorders. The person might have difficulty imitating sounds and non-speech movements (ASHA, 2007b). They might have trouble making facial expressions or sticking out their tongue. They will grope for sound, or might not have the ability to produce sound at all (ASHA, 2007b). Error might be inconsistent and unpredictable to the person.

A person with aphasia may have a slow rate of speech, making it difficult for others to follow. They have difficulty with "automatic speech" such as greetings (ASHA, 2007b) or exclamatory remarks. Apraxia can occur in conjunction with dysarthria, which is a weakness of the muscles affecting speech production. It can also occur in conjunction with aphasia, which involves neurological damage (ASHA, 2007b).

In people with apraxia, speech abilities need to be retrained in order to teach them to produce sound correctly. The person must repeat sounds and words over and over again until their brain and muscles relearn them (ASHA, 2007b). The person might need to learn to slow their speech in order to give their brain time to think about what they wish to say. The person with apraxia may need assistive devices, especially if their condition is expected to worsen continually.

Dysarthria

Dysarthria occurs as the muscles of the face, mouth, and respiratory system become weak. They may move slowly, or fail to move at all. This results in slow or "slurred" speech called dysarthria (ASHA, 2007g). Dysarthria is characterized by speaking softly, or only being able to whisper. It can lead to mumbling, or abnormal intonation (rhythm). It can lead to changes in the quality of the sound, making it sound nasal or "stuffy." It can lead to hoarsenes, breathiness, drooling, or difficulty chewing or swallowing (ASHA, 2007g). Dysarthria can be caused by a number of degenerative diseases including tumors, Parkinson's disease, ALS, Huntington's disease, and multiple sclerosis (AHSA, 1007g). Dysarthria typically develops later in the disease progression, but can occur at any time. Treatment for dysarthria depends on the cause and severity of the symptoms.

Speech and Language problems in Huntington's Disease

Speech and language problems are a special problem in a person with Huntington's Disease (HD). With these persons, the speech and language centers are affected early in the disease cycle, as opposed to later with diseases such as Parkinson's or Alzheimer's. This is because Huntington's Disease typically attacks the left side of the brain first. Huntington's Disease usually begins in a part of the brain called the caudate nucleus and putamen (ASHA, 2007c). These structures are located in the center of the brain. The disease quickly spreads to surrounding structures, including the speech and language centers. Communication and swallowing problems might be one of the first symptoms to appear because of the close proximity to the damage center. Speech and communication will decline rapidly with Huntington's disease.

Everyone's symptoms will vary. Sometimes new symptoms will appear. In other people the same symptoms will remain throughout the course of the disease, but they will continue to worsen in severity (ASHA, 2007c). Speech and language problems associated with Huntington's disease can include dysarthria, apraxia, poor voice quality, difficulty coordinating breathing and voice, and difficulties finding words. They might only be able to respond with one or two words. They might mispronounce words, or demonstrate a lack of ability to initiate speech. They might become "stuck" on certain words or phrases, repeating them often or at inappropriate times (perseveration) (ASHA, 2007c). Other symptoms associated with Huntington's disease include echolalia (person keeps repeating back what the other person says), stuttering, or difficulty in switching topics in a conversation (ASHA, 2007c).

Cognitive problems add to the difficulties in someone with Huntington's disease. They might be affected by diminished memory, poor reasoning or judgment, difficulty sequencing or organizing ideas, poor concentration, or diminished ability to learn new material (ASHA, 2007c). A person with Huntington's Disease might have problems with numbers or computational skills (ASHA, 2007c). The variety of symptoms depends on the areas of the brain that are affected and in which order they are affected. The speech and language pathologist can help in all of the areas that are affected by Huntington's disease. The role of the speech and language pathologist is to help maintain the highest level of functional speech possible (ASHA, 2007c).

Vocal Fold Paralysis

Vocal fold paralysis can result from a number of causes including neck injuries, tumors, a number of diseases, surgery, stroke, or damage to the vagus nerve (ASHA, 2007e). The vagus nerve branches from the brainstem to the larynx and regulates movement of the vocal folds. Degenerative diseases can lead to vocal fold paralysis. The symptoms of vocal fold paralysis include hoarseness, a breathy voice, the inability to speak loudly, limited pitch and loudness variation (ASHA, 2007e). The person with vocal fold paralysis might experience voicing that only lasts for a second. This leaves them able to render a sound, but little more. They might choke or cough while eating. They might develop pneumonia that is the result of food or beverages being aspirated into the lungs (ASHA, 2007e).

Vocal fold paralysis is classified into bilateral and unilateral forms. The bilateral form involves both vocal folds. The folds become stuck half way between open and closed. They do not move in either direction. This condition requires a tracheotomy to prevent aspiration when the person eats (ASHA, 2007e). With unilateral vocal fold paralysis only one side of the vocal fold is paralyzed. The paralyzed fold does not move in a coordinated effort with the other fold. The person will run out of breath and will be unable to speak loudly enough to be understood (ASHA, 2007e).