Which symptom is often present in UUMN dysarthria?

In UUMN (Unilateral Upper Motor Neuron) dysarthria, one of the hallmark symptoms is the presence of irregular articulatory breakdowns. This type of dysarthria typically results from damage to the upper motor neurons that control speech muscles. Because of this unilateral damage, the coordination and timing of muscle movements can become disrupted. As a result, speech may exhibit breakdowns that are irregular in nature, leading to difficulty in articulating sounds clearly.

Irregularity in articulatory breakdowns may manifest as inconsistent pronunciation, where some sounds are produced more clearly than others, which can make speech harder to understand. This phenomenon occurs due to the uneven distribution of muscle tone and control between the left and right sides of the mouth and vocal tract, affected by the lesion's location.

While other symptoms associated with dysarthria may also appear, such as issues with pitch or muscle tone, they do not specifically characterize UUMN dysarthria in the way that irregular articulatory breakdowns do.