In dysarthria, hypernasality may occur in which types of dysarthria?

Hypernasality is a common speech characteristic associated with dysarthria, which is a motor speech disorder resulting from neurological problems affecting the muscles used for speech production. In both flaccid and spastic dysarthria, the mechanisms of speech production are impacted in a way that can lead to an inadequate seal of the velopharyngeal port.

In flaccid dysarthria, which is often caused by damage to the lower motor neurons or the neuromuscular junction, the muscles of the soft palate may be weak or paralyzed. This weakness can prevent the velum (the soft part of the roof of the mouth) from effectively elevating, leading to a failure to block nasal airflow during oral speech sounds. Consequently, this results in hypernasality.

In spastic dysarthria, which is typically associated with upper motor neuron lesions, there can also be reduced control over the velopharyngeal mechanism due to increased muscle tone and spasticity of the muscles involved in speech. This can similarly lead to hypernasality due to the inability to regulate the airflow properly.

Therefore, since both types of dysarthria can cause issues with velopharyngeal closure, hypernasality can be found in both fl