Parkinson’s Disease (PD)

PD is the result of the deterioration of the substantia nigra, an area of the brain involved in the production of the neurotransmitter dopamine. The depletion of dopamine that results from this deterioration causes PD. In fact, some professionals have begun to call the disease by the name Dopamine Deficiency Disorder. Major features of PD include resting tremor, bradykinesia, and rigidity, as well as hypokinetic dysarthria. Medications used most frequently to treat PD follow three different treatment strategies, though they are often used in various combinations with one another:

1. Replenish deficient dopamine levels using levodopa (Doparâ , Larodopaâ ), a drug that is converted to dopamine once in the central nervous system. Desired effects of levodopa include decreased rigidity, increased facility of movement, and decrease of resting tremor. Unfortunately, high doses of levodopa cause side effects like nausea and vomiting, as well as gastrointestinal disturbances, postural hypotension, syncope, and other undesirable effects. In an effort to combat these side effects, levodopa is now usually combined with a dopa-decarboxylase inhibitor that diminishes or lessens the side effects of levodopa. Examples include Sinemetâ and Prolopaâ .

 

2. Monoamine Oxidase (MAO) is an enzyme in the brain that breaks down dopamine, causing it to be inactivated. In a normal brain this is necessary to control dopamine levels, but people with PD need extra dopamine. Eldeprylâ , Deprenylâ , and Selegilineâ are MAO inhibitors, drugs designed to prevent MAO from breaking down dopamine. Desired effects of these drugs include mild relief of symptoms and slowed progression of the illness, while some of the more severe side effects include dyskinesias, confusion, hallucinations, depression, and psychosis.

 

3. Pharmocologists have also developed drugs that mimic dopamine, known as dopamine agonists. These drugs stimulate the dopamine receptor sites in the corpus striatum, helping to offset the symptoms of PD. Two dopamine agonists are Parlodelâ and Permaxâ . These drugs are primarily used to relieve the symptoms of PD when tolerance to levodopa develops. Undesirable side effects include gastrointestinal disturbance, postural hypotension, and fatigue.

Effects of Drugs on Communication: These medications, although reducing some of the symptoms of PD, do not reduce speech and voice abnormalities. Possible side effects of these medications that may negatively impact communication skills include auditory and visual hallucinations, paranoid thinking, impaired concentration, confusion, and disorientation.

More information on PD at The Parkinson’s Web. Just click below…

http://pdweb.mgh.harvard.edu/
 

Myasthenia Gravis

Autoimmune diseases are diseases in which the patient’s body produces antibodies that attack the patient’s own proteins. Myasthenia Gravis is an autoimmune disease that causes rapid fatigue in muscles with use and recovery with rest. It is caused by a disturbance at the neuromuscular junction involving the neurotransmitter acetylcholine. Flaccid dysarthria is often a presenting sign of Myasthenia Gravis. Medications used to treat the disease follow two strategies:

1. Some drugs are designed to enhance the action of the neurotransmitter acetylcholine by inhibiting the action of the enzyme acetylcholinesterase. The most commonly used acetylcholinesterase inhibitor is Mestinonâ . This drug’s desired effect is to increase muscular strength and improve the response to repetitive nerve stimulation. Undesirable side effects include diarrhea, excessive salivation, and gastrointestinal disturbance.

 

2. Other drugs work as immunosuppressants, suppressing the immune response of the patient. This is because their own body is producing the antibodies that cause the disease. These drugs are usually corticosteroids, primarily Prednisoneâ and Dexamethasoneâ . The desired effect of these drugs is to decrease muscle weakness. Although short-term use of these drugs is usually well tolerated, long-term use may show an increase in more serious side effects.

Effects of Drugs on Communication: Medication to treat Myasthenia Gravis decreases dysarthria and improves the intelligibility of speech by improving musculature strength and endurance. However, corticosteroids have been shown to cause confusion, disorientation, and impaired concentration with use over extended periods.

More information on Myasthenia Gravis at The Myasthenia Gravis Directory. Just click below…

http://pages.prodigy.com/myasthenia/
 
 

Amyotrophic Lateral Sclerosis (ALS)

ALS is a progressive and fatal disease involving the motor neurons of the cortex, brainstem, and spinal cord that results in the gradual loss of muscle function. ALS results in a mixed, spastic-flaccid dysarthria due to the involvement of both upper and lower motor neurons. Attempts to treat ALS with drug treatment have been unsuccessful. Most ALS patients benefit from the use of medications primarily in the management of spasticity. A variety of drugs are used to treat spasticity, including Lioresalâ , Valiumâ , and Dantriumâ . These drugs reduce spasticity, with the most commonly noted side effect of drowsiness. Medications to stop the progression of the disease and treat flaccid weakness are not available.

Effects of Drugs on Communication: Medication used to treat ALS has not been shown to decrease dysarthria.

 
More information on ALS at The ALS Association. Just click below…

http://www.alsa.org/home.html
 

Multiple Sclerosis (MS)

MS is an autoimmune disease of the central nervous system that results in the demyelination of nerve fibers. The course of the disease fluctuates with exacerbations followed by periods of remission. Symptoms of MS include sensory and visual problems, as well as motor abnormalities. A mixed flaccid, spastic, and/or ataxic dysarthria is often a feature of MS. There are no medications that can cure MS. Drug therapy usually focuses on reducing the duration of the exacerbations with immunosuppressant drugs like Prednisoneâ , Decadronâ , Imuranâ , and Cytoxanâ . The desired effects of these drugs are to decrease or eliminate the demylination process. Lioresalâ , Valiumâ , and Dantriumâ are used to control spasticity.

Effects of Drugs on Communication: Communication problems relating to depression, emotional lability, and psychosis may be related to drug therapy or may be symptoms of the disease. Medications designed to shorten the length and severity of the exacerbation may increase the severity of dysarthria.

More information on MS at The Multiple Sclerosis Foundation, Inc. Just click below…

http://www.msfacts.org/
 

Wilson’s Disease

Wilson’s Disease is a hereditary disease, which, due to the body’s diminished ability to metabolize copper, results in accumulation of copper in the brain, liver, and kidneys. Dysarthria is often one of the presenting signs of Wilson’s Disease. Cupremineâ is the most common choice to treat Wilson’s Disease. The drug removes excess copper from the body and prevents further accumulation in body organs, retarding the progression of the disease. Side effects include nausea, vomiting, skin rash, joint pain, as well as other undesirable effects.

Effects of Drugs on Communication: Medication used to treat Wilson’s Disease has not been shown to decrease dysarthria.

More information on Wilson’s Disease at the American Liver Foundation. Just click below…

http://sadieo.ucsf.edu/ALF/ALFfinal/infowilsons.html

            Abboud, L., Moe, H., Johnson, E., Harms, K., & Ellison, A. (1997). Myasthenia

Gravis: Description, disorder, and autoimmune involvement. Myasthenia Gravis

Directory [On-line]. Available: http://macalester.edu/~psych/whathap/UBNRP/

Gravis/real_mg_directory.html

             Bernstein, K. A primer on PD medications (parts 1 & 2). (1997). The Parkinson’s

Web [On-line]. Available: http://pdweb.mgh.harvard.edu

             Vogel, D., & Carter, J. (1995). The effects of drugs on communication disorders. San

Diego, CA: Singular Publishing Group.

            Willis, C. A. (1996). Medical terminology: The language of health care. Baltimore,

MD: Williams & Wilkins.