Rebecca A Quest | PubMed Health

PubMed2003

Changes in brain morphology associated with obstructive sleep apnea.

OBJECTIVE: Obstructive sleep apnea (OSA) causes hypoxemia and fragmented sleep, which lead to neurocognitive deficits. We hypothesised that focal loss of cortical gray matter generally within areas associated with memory processing and learning and specifically within the hippocampus would occur in OSA. METHODS: Voxel-based morphometry, an automated processing technique for magnetic resonance images, was used to characterise structural changes in gray matter in seven right handed, male patients with newly diagnosed OSA and seven non-apneic, male controls matched for handedness and age. RESULTS: The analysis revealed a significantly lower gray matter concentration within the left hippocampus (p=0.004) in the apneic patients. No further significant focal gray matter differences were seen in the right hippocampus and in other brain regions. There was no difference in total gray matter volume between apneics and controls. CONCLUSION: This preliminary report indicates changes in brain morphology in OSA, in the hippocampus, a key area for cognitive processing.

Brain↗

PubMed2003

Studies of the human oropharyngeal airspaces using magnetic resonance imaging. I. Validation of a three-dimensional MRI method for producing ex vivo virtual and physical casts of the oropharyngeal airways during inspiration.

The oropharyngeal region of the human airways has been scanned using 3D MRI and the data used to produce a model cast. The scanning method used a triggering device, which enabled data collection at the same pressure drop in each breathing cycle to produce clear images free of motion-related artefacts. A comparison between two differing MR acquisition strategies was made in a single subject, multi-session study. 3D FISP MR imaging was found to produce the most reliable data. Excluding the buccal cavity, where tongue position was critical, the reproducibility of measured airway volumes and cross sectional areas between sessions was demonstrated. Inter-session total airway volume (excluding the mouth) reproducibility was of the order of 5% and for minimum cross sectional areas at the epiglottis and vocal cords was 10%. The production of a physical cast from the images led to a 5% increase in airway volume compared with the anatomical images but with some loss of fine detail. The data demonstrated the robustness of an ex-vivo means of studying oropharyngeal dimensions and dynamics which may contribute to advancements in the understanding of aerosol delivery of therapeutic agents.

Aerosols↗