What is "dysarthria"

n. Difficulty in articulating words due to disturbance in the form or function of the structures that modulate voice into speech. One of first indicative symptoms of myasthenia gravis brought about by an auto-immune response to acetylcholine receptor.

n. impaired articulatory ability resulting from defects in the peripheral motor nerves or in the speech musculature

Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes ( cf. aphasia: a disorder of the content of language). In other words, it is a condition in which problems effectively occur with the muscles that help produce speech, often making it very difficult to pronounce words. It is unrelated to any problem with understanding cognitive language. Any of the speech subsystems ( respiration, phonation, resonance, prosody, and articulation) can be affected, leading to impairments in intelligibility, audibility, naturalness, and efficiency of vocal communication. Dysarthria that has progressed to a total loss of speech is referred to as anarthria.

Neurological injury due to damage in the central or peripheral nervous system may result in weakness, paralysis, or a lack of coordination of the motor-speech system, producing dysarthria. These effects in turn hinder control over the tongue, throat, lips or lungs for example; swallowing problems ( dysphagia) are also often present.

Dysarthria does not include speech disorders from structural abnormalities, such as cleft palate, and must not be confused with apraxia of speech, which refers to problems in the planning and programming aspect of the motor-speech system. Just as the term "articulation" can mean either "speech" or "joint movement", so is the combining form of arthr- the same in the terms "dysarthria", "dysarthrosis", and " arthropathy"; the term "dysarthria" is conventionally reserved for the speech problem and is not used to refer to arthropathy, whereas "dysarthrosis" has both senses but usually refers to arthropathy.

Cranial nerves that control the relevant muscles include the trigeminal nerve's motor branch (V), the facial nerve (VII), the glossopharyngeal nerve (IX), the vagus nerve (X), and the hypoglossal nerve (XII). The term is from Ancient Greek δυσ- dys, "hard, difficult, bad" and arthrosis, "articulation".