Motor speech disorders are a class of speech disorders that disturb the body's natural ability to
due to neurologic impairments. These neurologic impairments make it difficult for individuals with motor speech disorders to plan, program, control, coordinate, and execute speech productions.Duffy, J. R. (2013). Motor speech disorders (3rd ed.)St. Louis, MO: Elsevier Mosby. Disturbances to the individual's natural ability to speak vary in their
etiology Etiology (pronounced ; alternatively: aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, ΕΠ...
based on the integrity and integration of cognitive, neuromuscular, and
musculoskeletal The human musculoskeletal system (also known as the human locomotor system, and previously the activity system) is an organ system An organ system is a biological system A biological system is a complex biological network, network which conne ...
activities. Speaking is an act dependent on thought and timed execution of airflow and oral motor / oral placement of the
lip Lips are a visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be an ...

tongue The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...

, and
jaw The jaw is any opposable articulated structure at the entrance of the , typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serving t ...

that can be disrupted by weakness in oral musculature (
dysarthria 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 phoneme In phonology and linguistics, a phoneme is a unit of sound t ...
) or an inability to execute the motor movements needed for specific speech sound production (
apraxia of speech Apraxia of speech (AOS) is an acquired oral motor speech disorder affecting an individual's ability to translate conscious speech plans into motor plans, which results in limited and difficult speech ability. By the definition of apraxia Apraxia ...
developmental verbal dyspraxia Developmental verbal dyspraxia (DVD), also known as childhood apraxia of speech (CAS) and developmental apraxia of speech (DAS), is a condition in which children have problems saying sounds, syllables and words. This is not because of muscle weakne ...
). Such deficits can be related to pathology of the nervous system (central and /or peripheral systems involved in
motor planningIn psychology and neuroscience Neuroscience (or neurobiology) is the scientific study of the nervous system In Biology, biology, the nervous system is a Complex system, highly complex part of an animal that coordinates its Behavior, actions ...
) that affect the timing of respiration, phonation, prosody, and articulation in isolation or in conjunction.


Dysarthria is the reduced ability to motor plan volitional movements needed for speech production as the result of weakness/paresis and/or paralysis of the musculature of the oral mechanism needed for
respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellular ...
phonation The term phonation has slightly different meanings depending on the subfield of phonetics Phonetics is a branch of that studies how humans produce and perceive sounds, or in the case of s, the equivalent aspects of sign. Phoneticians—lingu ...
resonance Resonance describes the phenomenon of increased amplitude The amplitude of a Periodic function, periodic Variable (mathematics), variable is a measure of its change in a single Period (mathematics), period (such as frequency, time or Wavelen ...

, and/or
prosody Prosody may refer to: * Sanskrit prosody, Prosody (Sanskrit), the study of poetic meters and verse in Sanskrit and one of the six Vedangas, or limbs of Vedic studies * Prosody (Greek), the theory and practice of Greek versification * Prosody (Lati ...


There are two types of Apraxia. Developmental (or Childhood Apraxia of speech) or acquired Apraxia. Childhood apraxia of speech (CAS) is a neurological childhood speech sound disorder that involves impaired precision and consistency of movements required for speech production without any neuromuscular deficits (ASHA, 2007a, Definitions of CAS section, para. 1). Both are the inability to plan volitional motor movements for speech production in the absence of muscular weakness. Apraxia is not a result of sensory problems, or physical issues with the articulatory structures themselves, simply the way the brain plans to move them.

Developmental verbal dyspraxia

Developmental verbal dyspraxia is a developmental inability to motor plan volitional movement for the production of speech in the absence of muscular weakness. Research has suggested links to the
FOXP2 Forkhead box protein P2 (FOXP2) is a protein Proteins are large s and s that comprise one or more long chains of . Proteins perform a vast array of functions within organisms, including , , , providing and , and from one location to ano ...


See also

KE family The KE family is a medical name designated for a British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, t ...


{{citation, last=Duffy , first=Joseph , date=2013 , title=Motor speech disorders , edition=3rd , publisher=St. Louis, MO: Elsevier Mosby Neurological disorders Communication disorders Symptoms and signs: Speech and voice