Pavel Kavcic1, Ales Koren1, Blaz Koritnik2,3, Igor Fajdiga4, Leja D Groselj2. 1. Clinical Radiology Institute, University Medical Centre Ljubljana, Ljubljana, Slovenia. 2. Institute of Clinical Neurophysiology, Division of Neurology, University Medical Centre Ljubljana, Ljubljana, Slovenia. 3. Department of Neurology, Faculty of Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia. 4. Clinic of Otorhinolaryngology and Cervicofacial Surgery, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Abstract
OBJECTIVE: To evaluate the mechanism and level of upper airway obstruction in obstructive sleep apnea (OSA) patients during natural sleep, together with synchronous electroencephalogram and respiratory events registration at 3-Tesla magnetic resonance imaging (MRI) platform with high spatial and temporal resolution. STUDY DESIGN: A prospective cohort study of 20 randomly selected OSA patients. METHODS: Fifteen of 20 patients were able to complete spontaneous sleep during MRI. While asleep, dynamic MR images of pharynx were obtained in the midline sagittal view. During the scan, nasal and oral airflow, thoracoabdominal wall effort, and electroencephalogram were synchronously recorded. The physiologic data were retrospectively scored to identify periods of apneas and synchronized with dynamic MR images. RESULTS: In all 15 patients, the site of complete airway obstruction occurred at the retropalatal space. We noticed different positions of the soft palate during apneic events. In seven of 15 patients (47%), the soft palate was attached to the tongue base and moved backward, compressing the airway. In five of 15 patients (33%), the soft palate was detached from the tongue base and solely moved backward, compressing the airway. In three patients (20%), we recorded both mechanisms of complete airway obstruction. In cases with attached soft palate to the tongue base, we noticed significant narrowing of the retrolingual space during apneic events. CONCLUSION: We describe a novel mechanism of obstruction dependent on the position of soft palate. This mechanism might play an important role in selecting candidates for surgery or treatment with hypoglossal nerve stimulation. LEVEL OF EVIDENCE: 2b.
OBJECTIVE: To evaluate the mechanism and level of upper airway obstruction in obstructive sleep apnea (OSA) patients during natural sleep, together with synchronous electroencephalogram and respiratory events registration at 3-Tesla magnetic resonance imaging (MRI) platform with high spatial and temporal resolution. STUDY DESIGN: A prospective cohort study of 20 randomly selected OSA patients. METHODS: Fifteen of 20 patients were able to complete spontaneous sleep during MRI. While asleep, dynamic MR images of pharynx were obtained in the midline sagittal view. During the scan, nasal and oral airflow, thoracoabdominal wall effort, and electroencephalogram were synchronously recorded. The physiologic data were retrospectively scored to identify periods of apneas and synchronized with dynamic MR images. RESULTS: In all 15 patients, the site of complete airway obstruction occurred at the retropalatal space. We noticed different positions of the soft palate during apneic events. In seven of 15 patients (47%), the soft palate was attached to the tongue base and moved backward, compressing the airway. In five of 15 patients (33%), the soft palate was detached from the tongue base and solely moved backward, compressing the airway. In three patients (20%), we recorded both mechanisms of complete airway obstruction. In cases with attached soft palate to the tongue base, we noticed significant narrowing of the retrolingual space during apneic events. CONCLUSION: We describe a novel mechanism of obstruction dependent on the position of soft palate. This mechanism might play an important role in selecting candidates for surgery or treatment with hypoglossal nerve stimulation. LEVEL OF EVIDENCE: 2b.
Authors: Roberta M Kato; Yoon-Chul Kim; Biswas Joshi; Shirleen Loloyan; Choo Phei Wee; Ziyue Wu; Winston H Tran; Thomas G Keens; Michael C K Khoo; Krishna S Nayak; Sally L Davidson Ward Journal: Ann Am Thorac Soc Date: 2018-12
Authors: Chantal Darquenne; Ann R Elliott; Bastien Sibille; Erik T Smales; Pamela N DeYoung; Rebecca J Theilmann; Atul Malhotra Journal: Physiol Rep Date: 2018-05