Which feature best distinguishes AOS from weakness-based motor disorders?

• A. Groping and inconsistent errors
• B. Pure vowel distortions only
• C. Rapid fluent speech
• D. Normal intelligibility at all times

Answer: (A)

Groping and inconsistent errors reflect a planning and programming problem in speech production. In apraxia of speech, the brain has trouble arranging the precise movement sequences for articulation, so speakers search for the right tongue, lip, and jaw placements. This leads to visible hesitation, attempts to “find” the right posture, and errors that vary from attempt to attempt or even within a single utterance. The hallmark is variability and self-correction as the motor plan is refined on the fly.

In contrast, weakness-based motor disorders affect the muscles’ ability to execute movements. Articulatory errors there tend to be more uniform and linked to reduced strength or fatigue, rather than a trial-and-error search of articulatory goals. So you don’t see the same kind of groping or erratic error pattern.

Among the other options, distortions limited only to vowels aren’t unique to AOS, rapid fluent speech is not typical of AOS (speech is usually slowed or halting), and being intelligible all the time contradicts what is usually observed in AOS.