Hyperventilation as a variant of tardive dyskinesia.

Respiratory dyskinesia, a variant of tardive dyskinesia, may mimic chronic psychogenic hyperventilation syndrome, hence pseudopsychogenic hyperventilation. Respiratory alkalosis and sympathetic discharge may occur in both conditions. Neurological symptoms, dyspnea, chest pain, muscle spasms may also occur. Ventilation increases with stress and disappears with sleep in both conditions. However, respiratory dyskinesia has been seen in association with other choreiform movement disorders. Speech is interrupted by breathing and breathing is interrupted by grunts and groans. Respiratory dyskinesia is under partial voluntary control and is not due to a "psychological problems."