Ultrasonic evaluation of movement of the diaphragm after acute cerebral infarction.

Respiratory dysfunction is an important complication of acute stroke but its mechanisms are poorly understood. Previous indirect assessments suggest that paralysis of the diaphragm occurs contralateral to the cerebral lesion. Diaphragmatic excursion was studied with real time ultrasound during quiet and deep breathing in 50 patients within 72 hours of acute stroke and 40 controls. During quiet breathing, hemidiaphragmatic movements were not significantly different between right hemispheric stroke, left hemispheric stroke, and controls. During deep inspiration, there was a significant bilateral reduction in hemi-diaphragmatic excursion in patients with stroke, for both right hemispheric stroke and left hemispheric stroke when compared with controls (both P < 0.001). Thus isolated hemidiaphragmatic paresis does not occur but maximal excursion of the diaphragm is reduced bilaterally in patients with acute stroke. This is a likely contributor to the respiratory dysfunction after acute stroke.