A combined neuropsychological and brain imaging study of obstructive sleep apnea

Abstract

SUMMARY Patients with obstructive sleep apnea (OSA) show neuropsychological impairments ranging from vigilance decrements, attentional lapses and memory gaps to decreased motor coordination, but their cognitive profile, and the origin of the impairments, remain unclear. We sought to establish the neuropsychological profile of 16 newly diagnosed apneics and to highlight both their morphological and functional brain abnormalities. We used an extensive neuropsychological test battery to investigate attention and vigilance, executive functions, episodic memory and motor domains. For brain imaging, we used the optimized voxel-based morphometry procedure for the MRI data, resting-state 18 F-fluoro-2-deoxy-D-Glucose positron emission tomography ( 18 FDG-PET) with correction for partial volume effects (PVEs) and voxel-based analyses. In terms of neurobehavioral performance, our patients displayed objective daytime somnolence but little impairment in memory and motor domains. Cerebral data revealed gray matter loss in the frontal and temporo-parieto-occipital cortices, the thalamus, hippocampal region, some basal ganglia and cerebellar regions, mainly in the right hemisphere. The decrease in brain metabolism was also right-lateralized, but more restricted than the gray matter density changes, and involved the precuneus, the middle and posterior cingulate gyrus, and the parieto-occipital cortex, as well as the prefrontal cortex. To conclude, despite the presence of only minor memory and motor impairments, our patients displayed significant cerebral changes in terms of both gray matter density and metabolic levels, and may have benefited from cognitive reserve and compensatory mechanisms. Thus, cerebral changes in OSA patients may precede the onset of notable neuropsychological consequences.k e y w o r d s cognitive reserve, magnetic resonance imaging, neuropsychology, positron emission tomography, resting state

Cognitive Effects of Adenotonsillectomy for Obstructive Sleep Apnea

“…6,7,14,[16][17][18] Weaknesses in motor dexterity have also been reported in children with snoring or OSAS and adults with OSAS. 24,43,44 The present results offer support for small effects of treatment in these same domains. The effects of sleep disturbance on cognition and behavior have been attributed to sleepiness and to adverse effects of intermittent hypoxia and sleep fragmentation on neural development and brain functioning.…”

Impact of obstructive sleep apnea on cognitive performance

“…Although the authors did observe only little deficits in the functions assessed (mainly memory and motor function), functional brain changes could be detected, suggesting that such modifications precede the clinical manifestations 22 .…”

“…Previous studies investigating cognitive performance in patients with OSA have been able to distinguish the impairment resulting from EDS from that determined by chronic obstructive pulmonary disease, which traditionally assumes the occurrence of ischemic prefrontal lesions [21][22][23] .…”

Emerging co-morbidities of obstructive sleep apnea: cognition, kidney disease, and cancer

“…An early study assessing changes in patients with OSA reported diffuse changes in the frontal, temporal and parietal cortices, as well as in the anterior cingulate gyrus, hippocampus, and cerebellum (67). Subsequently, a combined VBM and PET imaging study demonstrated hypotrophic changes in wider circuitry, as well as a decrease in cortical metabolism despite no clinically overt cognitive deficits being present (64). This has been argued to suggest early processes likely leading to later clinically measurable cognitive changes.…”

“…Historically, a number of voxel based morphometry (VBM) studies have investigated areas of the brain affected in patients with OSA with diverse regions being highlighted as more or less impacted (62)(63)(64)(65)(66). An early study assessing changes in patients with OSA reported diffuse changes in the frontal, temporal and parietal cortices, as well as in the anterior cingulate gyrus, hippocampus, and cerebellum (67).…”