Language Disorders

• Dysarthria: impairment in pronunciation with errors that are consistent and predictable secondary to disturbances in muscle function, whether it be due to weakness, paralysis, or incoordination.
• Apraxia of speech: Articulatory errors are variable and effect the prosody of speech.

Types of dysarthria

Flaccid (bulbar palsy)

• Occurs with lower motor neuron disease/neuromuscular junction disease:
  • Commonly seen in patients with bulbar predominant myasthenia gravis.
• Presents with hypernasal speech and imprecise consonants.

Spastic (pseudobulbar palsy)

• Secondary to bilateral lesion in corticobulbar (upper motor neuron (UMN)) tracts.
• Occurs in patients with primary lateral sclerosis (PLS), amyotrophic lateral sclerosis (ALS), progressive supranuclear palsy (PSP), stroke, and other disorders.
• Presents with a harsh, hypernasal, mono-pitched voice, dysarthria, dysphagia, facial and tongue weakness, and emotional lability.
• Jaw jerk reflex will be positive and fasciculations are absent (because UMN affected).

Ataxic

• Presents due to the inaccuracy of muscle movements from cerebellar dysfunction.
  • Seen with acute alcohol intoxication but can be irreversible with chronic use.
• Speech can be described as imprecise and scanning, with inconsistent errors in articulation.

Hypokinetic

• Seen in patients with Parkinson’s disease.
• The speech is described as monotonous and hypophonic.

Hyperkinetic

• Seen with dystonia and chorea which cause hypotonia and incoordination.