Combined assessment of obstructive sleep apnea syndrome with dynamic MRT and parallel EEG registration - Initial results

RATIONALE AND OBJECTIVES. To detect obstructive pharyngeal changes in sleep ing patients with obstructive sleep apnea syndrome by dynamic MRI and concu rrent EEG monitoring during true apneic episodes. METHODS. Five volunteers and eight patients with clinically diagnosed obstr uctive sleep apnea were polysomnographically monitored inside the scanner b efore, during, and after sleep discontinuation. After sleep interruption, t he Mueller maneuver was performed to compare induced pharyngeal collapse wi th real collapse during sleep. RESULTS. In all patients, on-line EEG registration was achieved in the stat ic magnetic field. Sleep was proved in four of the eight patients who showe d typical EEG findings. A complete pharyngeal collapse was shown in two of the four sleeping patients. The other patients predominately showed local e pi- and oropharyngeal obstructions in the apneic state. Compared with the a pneic episodes, the Mueller maneuver did not reveal the same extent of phar yngeal narrowing, nor a complete collapse. CONCLUSIONS. Polysomnographically monitored MRI can directly assess finding s induced by the pathophysiology of sleep apnea and shows promise for use i n sleep investigation and therapy planning and monitoring.