Which speech disorder impairs the planning and positioning of speech muscles involved in articulation?

The disorder that specifically impairs the planning and positioning of speech muscles involved in articulation is apraxia. Apraxia of speech is a motor speech disorder that affects the ability to coordinate the movements necessary for speech production. Individuals with apraxia may know what they want to say but struggle with the precise movements required to produce the sounds correctly, often leading to inconsistent speech errors, difficulty transitioning between sounds, and challenges with prosody.

In contrast, dysarthria involves weakness or paralysis of the speech muscles, resulting in slurred or slow speech rather than a planning issue. Huntington's disease, which is a genetic disorder that causes progressive degeneration of nerve cells in the brain, can lead to dysarthria but is not primarily a speech planning disorder. Opportunistic diseases refer to illnesses that occur more frequently and are more severe in individuals with weakened immune systems, which do not specifically relate to speech or articulation planning.

Understanding apraxia's impact on speech production helps clarify the distinction between motor planning disorders and other types of speech disorders, such as those caused by muscle weakness or systemic health issues.