Ventilatory disorders.

Breathing is a primal homeostatic neural process, regulating levels of oxygen and carbon dioxide in blood and tissues, which are crucial for life. Rhythmic respiratory movements must occur continuously throughout life and originate from neural activity generated by specially organized macro- and microcircuits in the brainstem. In the respiratory network there is a spatial and dynamic hierarchy of interacting circuits, each of which controls different aspects of respiratory rhythm generation and pattern formation, which can be revealed as the network is progressively reduced. The motor pattern during normal breathing is considered to consist of three phases: inspiration, post-inspiration and expiration. The expression of each rhythmogenic mechanism is state-dependent and produces specific motor patterns likely to underpin distinct motor behaviors. Vascular neurological disorders affecting these areas or the respiratory motor unit may lead to impaired respiratory activity. Manifestations associated with disorders of this network include sleep apnea and dysrhythmic breathing frequently associated with disturbances of cardiovagal and sympathetic vasomotor control. Respiratory dysfunction constitutes an early and relatively major manifestation of vascular neurologic disorders; ventilation control and breathing behavior correction are necessary to improve stroke management.