Reduced brain gray matter concentration in patients with obstructive sleep apnea syndrome (original) (raw)
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Brain Morphology Associated with Obstructive Sleep Apnea
American Journal of Respiratory and Critical Care Medicine, 2002
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.
Sleep Medicine Reviews, 2015
Cognitive impairment related to obstructive sleep apnea might be explained by subtle changes in brain anatomy. This has been mainly investigated using magnetic resonance brain scans coupled with a voxel-based morphometry analysis. However, this approach is prone to several methodological pitfalls that may explain the large discrepancy in the results reported in the literature. We critically reviewed twelve papers addressing grey matter volume modifications in association with obstructive sleep apnea. Finally, based on strict methodological criteria, only three studies reported robust, but conflicting, results. No clear evidence has emerged and exploring brain alteration due to obstructive sleep apnea should thus be considered as an open field. We provide recommendations for designing additional robust voxel-based morphometry studies, notably the use of larger cohorts, which is the only way to solve the underpowered issue and the underestimated role of confounders in neuroimaging studies.
Brain structural changes in obstructive sleep apnea
Sleep, 2008
Determine whether obstructive sleep apnea (OSA) subjects show indications of axonal injury. We assessed fiber integrity in OSA and control subjects with diffusion tensor imaging (DTI). We acquired four whole-brain DTI series from each subject. The four series were realigned, and the diffusion tensor calculated at each voxel. Fractional anisotropy (FA), a measure of fiber integrity, was derived from the diffusion tensor, resulting in a whole brain FA "map." The FA maps were spatially normalized, smoothed, and compared using voxel-based statistics to determine differences between OSA and control groups, with age as a covariate (P < 0.05, corrected for multiple comparisons). University medical center. We studied 41 patients with untreated OSA (mean age +/- SD: 46.3 +/- 8.9 years; female/male: 7/34) with apnea-hypopnea index 15 to 101 (mean +/- SD: 35.7 +/- 18.1 events/hour), and 69 control subjects (mean age +/- SD: 47.5 +/- 8.79 years; female/male: 25/44). Multiple region...
Cognitive profile and brain morphological changes in obstructive sleep apnea
Neuroimage, 2011
Obstructive sleep apnea (OSA) is accompanied by neurocognitive impairment, likely mediated by injury to various brain regions. We evaluated brain morphological changes in patients with OSA and their relationship to neuropsychological and oximetric data. Sixteen patients affected by moderate-severe OSA (age: 55.8 ± 6.7 years, 13 males) and fourteen control subjects (age: 57.6 ± 5.1 years, 9 males) underwent 3.0 Tesla brain magnetic resonance imaging (MRI) and neuropsychological testing evaluating short-and long-term memory, executive functions, language, attention, praxia and non-verbal learning. Volumetric segmentation of cortical and subcortical structures and voxel-based morphometry (VBM) were performed. Patients and controls differed significantly in Rey Auditory-Verbal Learning test (immediate and delayed recall), Stroop test and Digit span backward scores. Volumes of cortical gray matter (GM), right hippocampus, right and left caudate were smaller in patients compared to controls, with also brain parenchymal fraction (a normalized measure of cerebral atrophy) approaching statistical significance. Differences remained significant after controlling for comorbidities (hypertension, diabetes, smoking, hypercholesterolemia). VBM analysis showed regions of decreased GM volume in right and left hippocampus and within more lateral temporal areas in patients with OSA. Our findings indicate that the significant cognitive impairment seen in patients with moderatesevere OSA is associated with brain tissue damage in regions involved in several cognitive tasks. We conclude that OSA can increase brain susceptibility to the effects of aging and other clinical and pathological occurrences.
Obstructive sleep apnea and cortical thickness in females and males
PloS one, 2018
Obstructive sleep apnea (OSA) affects approximately 10% of adults, and alters brain gray and white matter. Psychological and physiological symptoms of the disorder are sex-specific, perhaps related to greater injury occurs in female than male patients in white matter. Our objective was to identify influences of OSA separated by sex on cortical gray matter. We assessed cortical thickness in 48 mild-severe OSA patients (mean age±std[range] = 46.5±9.0[30.8-62.7] years; apnea-hypopnea index = 32.6±21.1[6-102] events/hour; 12 female, 36 male; OSA severity: 5 mild, 18 moderate, 25 severe) and 62 controls (mean age = 47.7±8.9[30.9-65.8] years; 22 female, 40 male). All OSA patients were recently-diagnosed via polysomnography, and control subjects screened and a subset assessed with sleep studies. We used high-resolution magnetic resonance imaging to identify OSA-related cortical thinning, based on a model with condition and sex as independent variables. OSA and OSA-by-sex interaction effect...
European Journal of Radiology, 2012
Proton magnetic resonance spectroscopy T2 relaxometry Obstructive sleep apnea syndrome (OSAS) Cerebral metabolism Diffusion MR a b s t r a c t Purpose: To evaluate neurochemical and structural changes in the patients with newly diagnosed obstructive sleep apnea syndrome (OSAS) by MR spectroscopy (MRS), T2 relaxometry, and diffusion weighted imaging (DWI). Material and methods: Following the acquisition of routine cranial MR, MRS, T2 relaxometry, and DWI images; spectroscopic metabolite ratios and DWI-T2 relaxometry findings of the thalami, hippocampi, frontal white matter (FWM) and frontal cortex of 24 OSAS patients and 9 controls were statistically compared. The relationship between two groups was evaluated with Mann-Whitney test. Results: Spectroscopic measurements in the frontal cortex and frontal white matter of the OSAS patients revealed significantly lower NAA/Cr ratios than those of the control group (P = 0.004 and P = 0.006, respectively). The measurements in the frontal white matter of the OSAS patients exhibited significantly lower NAA/Cho ratios compared with those of the control group (P = 0.005). Thalamic Cho/Cr ratios of the patient group were significantly higher than those of the control group (P = 0.002). In terms of the ADC-T2 relaxometry values, there was no significant relationship between the patient and the control groups (P > 0.05). Conclusion: MRS is a useful and non-invasive modality in showing neurochemical changes in various regions of the brain but our data does not show any change on diffusion weighting or T2 quantification in the OSAS group. DWI and T2 relaxometry appear to be not effective techniques to evaluate the brain structural changes of the patients with newly diagnosed OSAS.
Fully automated morphological analysis of patients with obstructive sleep apnea
TURKISH JOURNAL OF MEDICAL SCIENCES, 2016
Background/aim: Obstructive sleep apnea syndrome (OSAS) is a disease characterized by episodic hypoxia. We aimed to use the Freesurfer program for global evaluation of morphological changes in OSAS patients. Materials and methods: Three-dimensional T1-weighted images were obtained, and intracranial morphology was assessed in 18 patients with OSAS and 20 controls. Results of the volume and the cortical thickness analyses of both groups were compared statistically. Results: The total cortical, left-right hemispheres gray matter (GM), corpus callosum, and total GM volumes were lower in OSAS patients when compared with the control group (P < 0.001). The average cortical thickness was lower in OSAS patients bilaterally in pars orbitalis, paracentral, rostral middle frontal, middle frontal, orbital, and superior frontal gyri when compared with the control group (P < 0.05). Furthermore, the volume and average cortical thickness of multiple anatomic regions, apart from the brain parts mentioned above, were decreased unilaterally (e.g., hippocampus, cingulum, putamen, thalamus) in OSAS patients (P < 0.05). Conclusion: Multiple morphologic changes occur in the cerebral structures of OSAS patients due to intermittent ischemia episodes. Detection of those areas with Freesurfer is easier. New studies with large series would be needed for these subjects.
American Journal of Respiratory and Critical Care Medicine, 2011
Rationale: Obstructive sleep apnea (OSA) is commonly associated with neurocognitive impairments that have not been consistently related to specific brain structure abnormalities. Knowledge of the brain structures involved in OSA and the corresponding functional implications could provide clues to the pathogenesis of cognitive impairment and its reversibility in this disorder. Objectives: To investigate the cognitive deficits and the corresponding brain morphology changes in OSA, and the modifications after treatment, using combined neuropsychologic testing and voxelbased morphometry. Methods: A total of 17 patients treatment-naive to sleep apnea and 15 age-matched healthy control subjects underwent a sleep study, cognitive tests, and magnetic resonance imaging. After 3 months of treatment, cognitive and imaging data were collected to assess therapy efficacy. Measurements and Main Results: Neuropsychologic results in pretreatment OSA showed impairments in most cognitive areas, and in mood and sleepiness. These impairments were associated with focal reductions of gray-matter volume in the left hippocampus (entorhinal cortex), left posterior parietal cortex, and right superior frontal gyrus. After treatment, we observed significant improvements involving memory, attention, and executive-functioning that paralleled gray-matter volume increases in hippocampal and frontal structures. Conclusions: The cognitive and structural deficits in OSA may be secondary to sleep deprivation and repetitive nocturnal intermittent hypoxemia. These negative effects may be recovered by consistent and thorough treatment. Our findings highlight the importance of early diagnosis and successful treatment of this disorder.
Changes in brain morphology in patients with obstructive sleep apnoea
Background: Obstructive sleep apnoea (OSA) is a common disease that leads to daytime sleepiness and cognitive impairment. Attempts to investigate changes in brain morphology that may underlie these impairments have led to conflicting conclusions. This study was undertaken to aim to resolve this confusion, and determine whether OSA is associated with changes in brain morphology in a large group of patients with OSA, using improved voxel-based morphometry analysis, an automated unbiased method of detecting local changes in brain structure. Methods: 60 patients with OSA (mean apnoea hypopnoea index 55 (95% CI 48 to 62) events/h, 3 women) and 60 non-apnoeic controls (mean apnoea hypopnoea index 4 (95% CI 3 to 5) events/h, 5 women) were studied. Subjects were imaged using T1-weighted 3-D structural MRI (69 subjects at 1.5 T, 51 subjects at 3 T). Differences in grey matter were investigated in the two groups, controlling for age, sex, site and intracranial volume. Dedicated cerebellar analysis was performed on a subset of 108 scans using a spatially unbiased infratentorial template. Results: Patients with OSA had a reduction in grey matter volume in the right middle temporal gyrus compared with non-apnoeic controls (p<0.05, corrected for topological false discovery rate across the entire brain). A reduction in grey matter was also seen within the cerebellum, maximal in the left lobe VIIIb close to XI, extending across the midline into the right lobe. Conclusion: These data show that OSA is associated with focal loss of grey matter that could contribute to cognitive decline Specifically, lesions in the cerebellum may result in both motor dysfunction and working memory deficits, with downstream negative consequences on tasks such as driving.
Gray Matter Hypertrophy and Thickening with Obstructive Sleep Apnea in Middle-aged and Older Adults
American Journal of Respiratory and Critical Care Medicine, 2017
Ms. Baril contributed to the study's conception and design and to data acquisition, analysis, and interpretation; she drafted the paper and revised it following the author's comments. Ms. Gagnon and Ms. Brayet contributed to the study's design, to data acquisition and interpretation, and to critical revision of the work. Drs. De Beaumont, Montplaisir, Lafond, Carrier, and Gagnon contributed to the study's conception and to data interpretation, and revised the work critically. Mr. L'Heureux contributed to data acquisition and analysis, and revised the work critically. Dr. Gosselin contributed to the study's conception and design and to data interpretation; she also helped draft the paper and revised it critically. All authors approved the final version for publication and are accountable for all aspects of the work.