Which feature is commonly observed in AOS but not typical of pure dysarthria?

• A. Groping with inconsistent substitutions in articulation.
• B. Purely weak jaw movements without planning deficits.
• C. Severe hypernasality with normal consonant accuracy.
• D. Complete inability to imitate any actions.

Answer: (A)

The feature being tested is the motor planning difficulty that characterizes apraxia of speech. People with AOS often exhibit groping for the right articulatory position and produce inconsistent substitutions from attempt to attempt. This means their pronunciation may vary across attempts for the same word, especially with longer or more complex sequences, because the planning and programming of the speech movements is disrupted rather than the muscles themselves. In pure dysarthria, the issue is execution—weakness, slowness, or incoordination of the speech muscles—so errors tend to be more consistent and tied to the actual neuromuscular limitation rather than the trial-to-trial search for the correct movement. So the seen groping with inconsistent articulatory substitutions best fits AOS, whereas the other options align more with execution issues or unrelated deficits rather than planning difficulties.