Motor Speech Disorders

6

Ta n ner, D. C.

Case Studies in Communication Sciences and Disorders,

Second Edition (pp. 111-129).

(^) © 2017 SLACK Incorporated.
Disease often tells its secrets in a casual parenthesis.
— Wilfred Trotter
In this chapter, the motor speech disorders of apraxia of speech and the dysarthrias are
examined. There is a review of motor speech programming and the five basic motor speech pro-
cesses. Respiration, phonation- resonance, articulation, and prosody are discussed, emphasizing
the effects certain diseases and disorders have on them. The case studies include communication
disorders associated with apraxia of speech and several dysarthrias. There is also a case study of
alleged medical malpractice involving a child born with spastic ce re bral palsy.
In motor speech disorders, motor refers to the neural structures causing muscle fibers to con-
tract. These disorders include pathologies of the motor cortex, the nerves (efferent, descending
nerve fibers), and the muscles involved in speech production. Clinicians also refer to these types of
disorders as neuromuscular speech disorders. Hundreds, if not thousands, of neurological deficits
and diseases can cause motor speech disorders. Before the mid-1970s, college courses on motor
speech disorders addressed par tic u lar diseases or defects such as ce re bral palsy, multiple sclero-
sis, or muscular dystrophy; alternatively, several of these conditions were covered in an umbrella
course on organic disorders. In 1975, Darley, Aronson, and Brown at the Mayo Clinic in Rochester,