Dysarthria: causes, symptoms, types and treatment

Communication disorders include disorders such as dyslalia, stammering, and phonological disorder, better known as dysarthria. The basic sign that leads to the diagnosis of dysarthria is the presence of marked difficulty in correctly articulating phonemes due to muscle problems.

In this article we will describe the causes and symptoms of the main types of dysarthria. We will also briefly explain what are the most common treatments for this disorder.

    What is dysarthria

    Dysarthria is a disorder that affects the muscles of speech: Lips, tongue, vocal cords and / or diaphragm. Difficulty controlling these muscles or their weakness means that people with dysarthria cannot articulate phonemes properly, so they have pronunciation problems or speak slower than normal. Unlike motor aphasia, it is an impairment of pronunciation and not of the language.

    The term “dysarthria” comes from the Greek and can be literally translated as “articulatory dysfunction”. It is a speech disorder and not a language disorder; this means that the problem does not arise at the cognitive level but at later stages of sound production. When the person is completely unable to articulate sounds, it is called anarchy.

    The DSM-IV collects dysarthria under the label “phonological disorder”, While in the DSM-5, it is called “speech sound disturbance”. The basic criterion of diagnosis according to these classifications is that the person is unable to utter phonemes that one would expect them to have learned to articulate at a given age.

    Causes of this disorder

    Dysarthria can have many different causes. Nervous system disorders are among the most common, like brain damage and tumors or emboli that paralyze the face or tongue. When it occurs at birth, it is usually the result of cerebral palsy or muscular dystrophy.

    Certain alterations favor the appearance of symptoms of dysarthria in adulthood, such as amyotrophic lateral sclerosis or Parkinson’s, Huntington’s and Wilson’s diseases. Certain medicines can also cause dysarthria, particularly strong sedatives and narcotics; in these cases, discontinuation of consumption relieves the disorder.

      Symptoms and signs

      Symptoms and signs of this disorder can vary depending on the cause and type of dysarthria. The most common are:

      • Difficulty moving the muscles of the face, lips and tongue.
      • bad pronunciation.
      • Monotonous prosody.
      • Modified stamp.
      • He speaks too slowly or too fast.
      • He came nasal or snoring.
      • Excessively high or low volume.
      • Irregular rhythm (eg intermittent speech).
      • Associated breathing difficulties.

      When it comes to pronunciation difficulties, four main types of errors are usually detected: replacement, omission, insertion and distortion. Substitution, which consists of replacing the correct phoneme with another incorrect phoneme, is the most common, especially when pronouncing “d” or “g” instead of “r”.

      While the consonantal articulation is affected in all cases of dysarthria, inadequate pronunciation of vowels is considered an indicator of severity.

      Types of dysarthria

      The types of dysarthria that we will see in this section differ from each other mainly by the location of the lesion at the level of the central nervous system.

      1. Spastic

      Spastic dysarthria it is due to injuries in the pyramidal tracts, Related to fine motor control of the muscles of the face and neck.

      In this type of dysphasia hypernasalidad and sudden increases in the volume of speech occur. The voice tends to be strained and strained.

      2. Ataxic

      Injury to the cerebellum causes ataxic dysarthria, the most characteristic signs being presence of a flat and monotonous prosody and slow vocalization and uncoordinated, similar to that which occurs in the state of intoxication. The typical speech of this type of dysarthria has sometimes been described as “explosive”.

      3. Flask

      In this type of dysarthria the vagus nerve is affected, Which allows the movement of the larynx and therefore the vocal cords. Dysfunctions also occur in other facial muscles.

      In flaccid dysarthria, the muscles may atrophy or partially paralyze, causing spasms, drooling, and muscle tension.

        4. Hyperkinetic

        Hyperkinetic dysarthria is usually caused by damage to the basal ganglia, subcortical structures involved in involuntary movements.

        The symptoms of this type of dysarthria are similar to those of spasticity: the voice tends to have a rough quality and also hypernasality occurs.

        5. Hypokinetics

        Usually hypokinetic dysarthria appears as a result of Parkinson’s diseaseAlthough it is also common for the cause to be the continued use of antipsychotic drugs.

        In this case, the volume is usually very low, the tone flat and the prosody monotonous. The reduction in the speed of movement caused by damage to the region known as dark matter explains these symptoms.

        6. Mixed

        This category is used when the clinical features are a combination of more than one of the types of dysarthria we have described. Mixed dysarthria they are due to deficiencies in different motor systems.

        Treatment and intervention

        Much of the treatment for dysarthria depends on the alteration caused by the disorder because, where possible, correcting the ultimate cause eliminates symptoms. However, there are interventions to improve speech in cases where the underlying problem cannot be changed.

        The main objectives of speech therapy and language therapy in cases of dysarthria are to strengthen the muscles involved in speech, improve breathing, achieve correct pronunciation and facilitate communication between the affected person and his relatives.

        In cases where the speech impairment is severe, external media, such as speech synthesizers and alphabetic charts, are very helpful. Learning gestures and even sign language it can also be used to some extent to compensate for the communication deficits inherent in dysarthria.

        Leave a Comment