Motor Speech Disorders

[Dr. Linton Hutchinson]

Motor speech disorders are disorders of speech resulting in disruptions
in motor programming. They are caused by neurologic impairment. Motor
speech disorders encompass apraxia of speech and the dysarthrias. The
former (apraxia), a disorder in planning resulting from an impairment in
the ability to carry out sensorimotor commands for the purposes of
positioning and moving muscles for the volitional production of speech.
The latter (dysarthria), a movement disorder resulting from an
impairment of muscular control over the speech mechanism.

In dysarthria, there is observable weakness or paralysis. In apraxia,
there is no evidence of weakness or paralysis. However, an appropriate
diagnosis cannot be made by relying on this simple explanation alone.
The clinician must perform a motor speech examination. The motor
speech examination can be divided into 5 parts.

1) history
2) examination of the oral mechanism during both speech and non speech
tasks
3) assessment of perceptual speech characteristics
4) assessment of intelligibility
5) an acoustic and physiologic analysis