Dysarthria is a motor speech disorder that can result from an injury to the motor nerves. It is characterized by impaired articulatory ability or poor articulation, that can result from the loss of control over the muscles, which are used for speaking. In other words, a patient suffering from this condition can lose control over the lips, throat, tongue, or the jaw muscles, which in turn, can impair speech. This condition can be classified into several types, of which the most common types are, spastic dysarthria, flaccid dysarthria, unilateral motor syndrome, ataxic dysarthria, and hyperkinetic and hypokinetic dysarthria.
Spastic dysarthria is a disorder that results from an injury or damage to the primary voluntary motor pathway, which begins from the frontal lobe of the brain, and then moves downward to the brain stem and the spinal cord. Unilateral motor syndrome is caused by the damage to either side of the upper motor neuron tract, while ataxic form of the disease is associated with the damage to the cerebellum.
On the other hand, damage to the nerves that originate from the brainstem or the spinal cord can cause flaccid dysarthria. Hypokinetic dysarthria is related with the damage to the upper brainstem, where the nigra nerve cells are present, while hyperkinetic form of the disorder is caused by the damage to basal ganglia.
Causes and Symptoms
This condition is usually caused by brain injuries, metabolic and degenerative diseases, and strokes. Some of the most common causes of this condition are, a brain or head injury, brain tumors, Lyme disease, cerebral palsy, Huntington's disease, myasthenia gravis, Parkinson's disease, multiple sclerosis, strokes, Guillain-Barre syndrome, and Wilson's disease. Apart from these, certain drugs like narcotics and sedatives can also cause this condition at times.
It usually manifests in slurred or slow rate of speech, as the affected person fails to control the muscles that are used while speaking. This can bring about a change in vocal quality, and make one unable to speak louder. The victims of severe dysarthria could barely whisper, and their voice can become nasal or strained. Some other common symptoms are, drooling or loss of control over saliva, hoarseness, difficulty in chewing, as well as swallowing, and abnormal rhythm of speech.
This condition is diagnosed with a number of tests and examinations, which include, CT scans, MRI, electroencephalogram, lumbar puncture, brain biopsy, blood and urine tests, and a number of neuropsychological tests. The treatment of this condition can vary to an extent depending on the underlying causes and the severity of the condition.
In general, a problem in articulation is addressed with the help of some techniques and speech musculature exercises. The aim of this type of treatment is to strengthen the tongue, lips, jaws, and the vocal muscles, and improve their coordination and range of motion. Techniques based on the principle of motor learning are also employed for the treatment of motor speech disorders. Respiratory effort therapy, on the other hand, can prove helpful in treating hypokinetic dysarthria.
However, if all such treatment options fail to improve the condition or enable a person to communicate effectively, then alternative or augmentative alternative communication devices may be required. Some such augmentative and alternative communication devices are, computerized speech synthesizers, alphabet board, and gestures.
Along with speech and language therapy, the patients of dysarthria often require the help of physical and occupational therapists to improve their balance, range of motion, and limb and trunk coordination. On the other hand, neuropsychologists can help improve memory and perceptual processes with the proper treatment options.
Sometimes, this condition can be treated by addressing the underlying causes, if it is still possible to do so. If the specific underlying cause can be treated, it can help improve speech. Sometimes, this condition is associated with degenerative diseases like Parkinson's disease. So, it is important to prevent or slow down the development or progression of such diseases. Along with treatment, support from family and friends is equally important to improve speech and communication skills in dysarthria patients.
Disclaimer: This article is for informative purposes only, and should not be treated as a substitute for professional medical advice.