Which of the following describes the motor components of spastic dysarthria?

• A. Hyperreflexia and improved range of motion
• B. Weakness in distal muscles and loss of inhibitory control
• C. Increased muscle strength and coordination
• D. Improved reflexes and full range of motion

Answer: (B)

The correct response highlights the motor components of spastic dysarthria as characterized by weakness in distal muscles and a loss of inhibitory control. Spastic dysarthria arises from damage to the central nervous system, particularly affecting the upper motor neurons. This type of dysarthria typically results in increased muscle tone (spasticity) and reduced control over fine motor movements.

Weakness in distal muscles refers specifically to the difficulty individuals may experience when trying to perform precise or delicate tasks, such as articulating speech sounds. The loss of inhibitory control means that there is an imbalance in the muscular control pathways; normally, inhibitory signals help to regulate muscle activity and tone, but in spastic dysarthria, this regulation is compromised, leading to hypertonicity and limited flexibility.

Understanding these components helps clarify the speech characteristics commonly seen in spastic dysarthria, which may include strained-strangled quality, slow speech rates, and imprecise articulation. In contrast, the other options—mentioning improved range of motion, increased muscle strength, or improved reflexes—do not accurately reflect the nature of spastic dysarthria and are inconsistent with the established clinical features of this speech disorder.