Which type of dysarthria results from damage to the lower motor neuron?

Flaccid dysarthria is the type that results from damage to the lower motor neuron (LMN). The LMN consists of motor neurons that originate in the spinal cord and brainstem and directly innervate skeletal muscles. When these neurons are damaged, it leads to muscle weakness, reduced muscle tone, and reduced reflexes, all of which are characteristic of flaccid dysarthria.

In individuals with flaccid dysarthria, the speech may be slurred and breathy due to the lack of control over muscle contractions needed for clear articulation and effective voice production. This occurs because the muscles responsible for speech may be too weak or unable to contract fully, leading to the distinctive speech patterns associated with this form of dysarthria.

The other types mentioned, such as hyperkinetic, spastic, and ataxic dysarthria, stem from different neurological origins. Hyperkinetic dysarthria is associated with excess movement, often linked to basal ganglia dysfunction, while spastic dysarthria is the result of bilateral upper motor neuron damage leading to increased muscle tone. Ataxic dysarthria involves motor control issues arising from cerebellar dysfunction, affecting coordination. These distinctions highlight why flaccid dysarth