CHAPTER 1
Chapter Overview
Speech motor disorders is a collection of speech production deficits, caused
by abnormal functioning of the motor system. Motor refers to the part of the
nervous system that controls voluntary movements (motor system), speech
refers to communication through the use of vocal symbols, sometimes
referred to as the physical production of language, and disorders means an
abnormality of function. In all, speech motor deficits consist of seven types
of dysarthria and one type of apraxia. Dysarthria, meaning “disordered
utterance” comes from the Greek dys (disordered or abnormal) and arthria
(to utter distinctly). Dysarthria is the impaired production of speech due to
Studying historical accounts of the subject gives one a depth and continuity
that is otherwise difficult to gain. Some of the earliest accounts of speech
and language disorders appear in the Hippocratic Corpus, a collection of
Greek texts thought to be written by a group of physicians from a school
founded by Hippocrates. The case studies from the Hippocratic Corpus
show that the ancient Greeks understood speech difficulties could result
from physical injury. Most importantly, the writings indicate the Greeks’
Motor Speech Disorders, Second Edition
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In a published work in 1906, Wernicke describes nonverbal oral apraxia.
Darley, Aronson, and Brown are credited for their accomplishments in the
field of acquired speech and language deficits. Recent contributions have
been made by Duffy, Kent, LaPointe, McNeil, Robin, Yorkston, and
Wambaugh.