Which category contains the items used to determine a correct diagnosis of AOS?

• A. Primary clinical characteristics.
• B. Non-discriminative clinical characteristics.
• C. Behaviors usually found in disorders other than AOS.
• D. Behaviors that rule out presence of AOS.

Answer: (A)

Diagnosing apraxia of speech is grounded in the features that directly reflect how the brain plans and programs the movements needed for speech. These primary clinical characteristics are the signs that most clearly distinguish AOS from other speech disorders: consistent difficulties in planning sequences of sounds for speech, distorted or substituted sounds that vary across attempts, noticeable groping as the person searches for the correct articulation, and disrupted coarticulatory transitions that make smooth, rapid speech unusually hard, especially with longer or more complex words. Because these features arise from impaired planning and programming rather than from muscular weakness or purely linguistic processing, they are the most informative for a correct diagnosis.

The other options describe signs that don’t specifically differentiate AOS. Non-discriminative characteristics don’t help confirm AOS because they can appear in other conditions or vary widely. Behaviors typical of disorders other than AOS don’t support the diagnosis, and behaviors that would rule out AOS would suggest another diagnosis entirely. So the best choice is the set of primary clinical characteristics, the signs that most directly indicate the motor planning/programming issue at the heart of apraxia of speech.