Respiratory function after lesions in medulla oblongata.

OBJECTIVES

To evaluate the correlation of lesions of the brain as visualized in cranial magnetic resonance imaging (MRI) and the ability of spontaneous respiration.

METHODS

In a prospective concept, cranial MRI after traumatic brain injury or spontaneous intracerebral hemorrhage was performed in 250 subjects at an early stage. All MRI findings were correlated with respiratory conditions on the day of examination. Sedation was performed only to facilitate toleration of the artificial ventilation, as and when necessary. Spontaneous respiration could hence be registered clinically.

RESULTS

Thirteen subjects (5.2%) had no spontaneous respiration. In these cases, a bilateral lesion of the distal medulla oblongata could be displayed. In four of these cases, no additional injuries of the brainstem were detected. These subjects awoke 2 days after the impact with tetraparesis and apnea. Combined lesions of the medulla oblongata and other brainstem regions were found in nine subjects. All these patients died without awakening. In the absence of a bilateral lesion of the caudal medulla oblongata, spontaneous respiration was always possible. A unilateral lesion of the caudal medulla oblongata was visualized in one patient who had the ability of spontaneous respiration.

CONCLUSIONS

This work confirms the presence of autonomous respiratory centers within the caudal medulla oblongata that allows sufficient adequate respiration in coma. Respiration ceases in the presence of a bilateral lesion of this area.