1) Disorders of speech articulation caused by imperfect coordination of pharynx, larynx, tongue, or face muscles. This may result from cranial nerve diseases, neuromuscular diseases, cerebellar diseases, basal ganglia diseases, brain stem diseases, or diseases of the corticobulbar tracts. The cortical language centres are intact in this condition.

2) Articulation disorder resulting from central nervous system disease, especially brain damage.

3) Difficulty in articulating words due to disease of the central nervous system.