Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences
Definition of Dysarthria
Have you ever known someone who suffered from a stroke and had trouble speaking afterwards? Sometimes this difficulty is due to a condition called dysarthria. Dysarthria is a speech impediment that prevents a person from speaking clearly because the muscles that control their mouth are not functioning properly. These muscles could be in the tongue, lips, or even the diaphragm. A person with dysarthria can be difficult to understand because they physically struggle to control how their words are spoken. Dysarthria does not affect their mental state, so they are probably frustrated, since they know what they want to say but are struggling to say it.
Causes of Dysarthria
Dysarthria occurs when damage occurs to the muscles that control speech, and this damage can be done by a number of conditions. These include stroke, brain tumors, brain injuries, a serious head injury, Lyme disease, Parkinson's disease, Wilson's disease, multiple sclerosis, cerebral palsy, and Huntington's disease, among others. The severity of the dysarthria depends on which part of the body is most affected by the underlying disease. In rare situations, adverse reactions to certain medications may also cause dysarthria.
Symptoms of Dysarthria
We've already learned about the main symptom of dysarthria: difficulty speaking. Once a person loses control over their muscles, it's hard or impossible to regain that strength. The specific symptoms a person experiences from dysarthria depends on their personal situation and the condition causing dysarthria to develop in the first place.
The most common symptoms are:
- Slow speech
- Slurred speech
- Improper or abnormal volume control
- Improper or abnormal speed control
- A strained voice
If symptoms develop rapidly and without explanation, it can be a sign of a serious underlying medical condition, and it is probably best to seek out the advice of a doctor. Side effects of the symptoms can include feeling anxious in social situations and even feeling depressed. Patients with dysarthria often feel emotional anguish over losing the ability to easily communicate with the people around them.
Types of Dysarthria
There are six main types of dysarthria: spastic, hyperkinetic, hypokinetic, ataxic, flaccid, and mixed dysarthria.
- Spastic: results from damage to the upper motor neuron nerve fibers. The upper motor neurons start in the cerebral cortex or brain stem and transfer information to specific areas of the spinal cord. From the spinal cord, the information is then transferred via spinal lower motor neurons.
- Hyperkinetic: results from lesions on the basal ganglia (which helps control voluntary motor movements).
- Hypokinetic: results from lesions on the substantia nigra (a structure in the mid-brain partially responsible for movement); this form is usually due to Parkinson's disease but may also develop after a type of head injury.
- Ataxic: results from damage to the cerebellar control unit (the cerebellum is largely responsible for motor movements).
- Flaccid: results from damage to the lower motor neuron nerve fibers. All voluntary movement is controlled by lower motor neurons in the spinal column. Lower motor neurons found in the brain are responsible for chewing, swallowing, and talking.
- Mixed: results from damage to both the upper and lower motor neuron nerve fibers.
Dysarthria is diagnosed by both a speech pathologist and a neurologist. The speech pathologist can verify the symptoms, while a neurologist is able to identify the underlying cause of the symptoms. Once the underlying cause is identified, the best results are gleaned from treating that cause, rather than only treating the symptoms.
If dysarthria is due to the use of a medication, that medication's use will most likely be discontinued if another medication is available. With other patients, speech therapy might be used. In cases where speech therapy doesn't work, the patient may learn other forms of communication (such as sign language). Unfortunately, many of the causes of dysarthria do not have cures, so the patient will need to learn to cope with the dysarthria if speech therapy isn't effective.
Dysarthria is a speech disorder characterized by the inability to control the muscles responsible for speech. A person with dysarthria may be difficult to understand, and their speech may be too fast or too slow, lack volume control, or be slurred. There are a number of conditions that can cause dysarthria and identifying that underlying condition is key to finding the best treatment option. Typically, the underlying cause is treated rather than the symptom. However, if the underlying medical condition can't be treated, then speech or language therapy may be used to help the patient cope and learn new forms of communication.
Medical Disclaimer: The information on this site is for your information only and is not a substitute for professional medical advice.
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