Dysarthria
Dysarthria is a motor speech disorder characterized by slowed or slurred speech due to weakness in the muscles involved in speaking. This condition can arise from various brain and nerve diseases, including developmental conditions like cerebral palsy and acquired conditions such as Parkinson's disease, multiple sclerosis, or following strokes. Individuals with dysarthria often struggle to articulate words clearly, resulting in speech that may sound hoarse or nasally, with uneven rhythms and volumes. Diagnosis typically involves evaluation by a speech-language pathologist, who assesses muscle strength and speech patterns, followed by referrals to neurologists for further testing, including imaging and neuropsychological assessments.
Treatment primarily focuses on speech therapy to improve muscle control and speech clarity, although some patients may need alternative communication methods if their condition is severe. Family members and caregivers play a crucial role in supporting individuals with dysarthria by creating a conducive communication environment, such as minimizing distractions and being patient during conversations. Resources from organizations like the American Speech-Language-Hearing Association can offer additional guidance on managing dysarthria and enhancing communication strategies.
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Dysarthria
Dysarthria is a motor speech disorder characterized by slowed or slurred speech. It is directly caused by severe weakness in the muscles used for speech and can result from several types of brain damage or nerve diseases. Dysarthria is generally treated with both speech therapy and physical therapy to strengthen the muscles that control speaking and improve the individual’s ability to articulate intelligible sounds.
Symptoms and Causes
Individuals suffering from dysarthria experience great difficulty speaking. Their speech is usually slow and slurred, and their speech patterns, rhythms, and volumes may be uneven. When speaking, these individuals often sound nasally or hoarse, and they may breathe heavily and excessively.
This impaired speech is caused by weakness in speech muscles such as the lips, tongue, jaw, vocal cords, or diaphragm. When this weakness is caused by brain or nerve diseases before or at birth, the dysarthria is known as developmental. Brain diseases that can cause dysarthria at birth include cerebral palsy and muscular dystrophy.
When nerve diseases that form later in life ultimately cause dysarthria, the dysarthria is called acquired. Nerve diseases that can arise at any point in life include Parkinson’s disease, Lou Gehrig’s disease (also known as amyotrophic lateral sclerosis, or ALS), multiple sclerosis, and Huntington’s disease. Strokes, brain tumors, head injuries, and some types of narcotics can also cause brain damage that leads to the development of dysarthria.
Diagnosis
Because dysarthria can be caused by such a wide variety of brain and nerve diseases, it is difficult to track the frequency of its occurrence in the United States or any other country. Renowned medical research facilities such as the Mayo Clinic recommend that individuals who observe signs of speech difficulty in themselves or their loved ones should seek medical attention promptly to determine if these signs indicate the presence of dysarthria. Family doctors usually refer these patients to speech-language pathologists (SLP), who identify and evaluate speech disorders and then report the results to neurologists, or physicians who specialize in diseases of the nervous system.
SLPs observe and chart the movements of a patient’s lips, tongue, and face. They also evaluate the strength of the patient’s breath for speaking and voice control. SLPs may then ask patients to speak in several different contexts to diagnose their speech disabilities more accurately. The therapists may then submit their reports to neurologists, who begin searching for the root causes of the dysarthria.
Neurologists first order several imaging tests to be performed on the patient. Tests such as magnetic resonance imaging (MRI) and computerized axial tomography (CAT) scans use X-rays to generate highly detailed images of the patient’s brain, head, and neck. By examining these images, neurologists may be able to locate the source of the brain damage that caused the dysarthria.
Neurologists can also perform electroencephalogram tests on a patient. These studies detect electrical activity in the nerves of a patient’s brain to evaluate the speed and strength with which motor signals are sent from the nerves to the speech muscles. This test is also used to locate the source of the patient’s speech disorder.
Several other tests are designed to determine if the dysarthria was caused by cancer of either the brain or spinal cord. Neurologists begin this process by performing a lumbar puncture, also known as a spinal tap. This involves the doctor drawing a small amount of cerebrospinal fluid from the patient’s lower back with a needle.
Laboratory testing of this fluid can reveal whether cancer or a central nervous system disorder is responsible for the dysarthria. If brain cancer is detected, the doctor performs a brain biopsy, which removes part of the tumor for further testing and diagnosis.
Finally, neurologists can perform neuropsychological tests on patients with dysarthria. These determine the patient’s cognitive, or intellectual, abilities, including the capacity to read, write, and comprehend speech. Dysarthria does not affect these faculties.
Treatment
If neurologists can identify the cause of the dysarthria in the patient’s brain, they can attempt to correct the problem through surgery or other neurological means. In many cases, the best treatment for individuals with dysarthria is speech therapy with a speech-language pathologist.
Through regular instruction, pathologists can teach dysarthria patients how to slow their rates of speaking, modify their breathing for better speech control, clarify their speech sounds, strengthen their speaking muscles, and train their tongues and lips to produce more intelligible sounds.
In some instances, this therapy can prove sufficient in helping individuals with dysarthria improve their speaking skills enough to communicate effectively with others. In other cases, the dysarthria may be so advanced that speech therapy cannot help the individual to speak more clearly. These patients may then learn to use alternative forms of communication to interact with people. These include hand gestures, alphabet boards, and computers or other electronic devices that can convert typed text to speech.
Speech therapists can also teach patients’ families, friends, caregivers, and educators how to interact more effectively with the patients. For example, when speaking to someone with dysarthria, family and friends can ensure their environment is free of distracting noises and keep writing tools nearby in case the individual experiences particular difficulty communicating. Looking directly at individuals with dysarthria when they are speaking, as well as not interrupting them or correcting their mistakes, can also help them communicate more effectively.
The websites of organizations such as the American Speech-Language-Hearing Association (ASHA), the Mayo Clinic, and the National Library of Medicine (NLM) contain resources on dysarthria and various related speech disorders and brain diseases.
Bibliography
"Dysarthria." American Speech-Language-Hearing Association, www.asha.org/public/speech/disorders/dysarthria/#what‗is‗dysarthria. Accessed 4 Jan. 2016.
"Dysarthria." Mayo Clinic, www.mayoclinic.org/diseases-conditions/dysarthria/basics/definition/con-20035008. Accessed 4 Jan. 2016.
"Dysarthria." MedlinePlus, US National Library of Medicine, www.nlm.nih.gov/medlineplus/ency/article/007470.htm. Accessed 4 Jan. 2016.
"Dysarthria." National Aphasia Association, www.aphasia.org/aphasia-resources/dysarthria/. Accessed 20 Feb. 2018.
"Dysarthria (Difficulty Speaking)." NHS Choices, Department of Health, United Kingdom, www.nhs.uk/conditions/dysarthria/Pages/Introduction.aspx. Accessed 4 Jan. 2016.