What is a crucial sign of hyperkinetic dysarthria?

A crucial sign of hyperkinetic dysarthria is excessive pitch variability accompanied by involuntary movements. This type of dysarthria is characterized by the presence of abnormal, involuntary movements that can affect speech production. These movements may be seen as spasms, tics, or tremors, which contribute to a speech pattern that is marked by fluctuations in pitch and loudness.

Individuals with hyperkinetic dysarthria often display unpredictable changes in their voice quality and pitch, leading to a rich variety of intonation. This variability is not just a simple alteration; rather, it reflects the underlying neurological mechanisms that disrupt normal speech control. Thus, the presence of these involuntary movements combined with excessive pitch variability is a distinctive feature that helps differentiate hyperkinetic dysarthria from other types, such as spastic or ataxic dysarthria.