Neural alterations associated with anxiety symptoms in obstructive sleep apnea syndrome.
BACKGROUND
Neuropsychological comorbidities, including anxiety symptoms, accompany obstructive sleep apnea (OSA); structural and functional brain alterations also occur in the syndrome. The objective was to determine whether OSA patients expressing anxiety symptoms show injury in specific brain sites.


METHODS
Magnetic resonance T2-relaxometry was performed in 46 OSA and 66 control subjects. Anxiety symptoms were evaluated using the Beck Anxiety Inventory (BAI); subjects with BAI scores >9 were classified anxious. Whole brain T2-relaxation maps were compared between anxious and nonanxious groups using analysis of covariance (covariates, age and gender).


RESULTS
Sixteen OSA and seven control subjects showed anxiety symptoms, and 30 OSA and 59 controls were nonanxious. Significantly higher T2-relaxation values, indicating tissue injury, appeared in anxious OSA versus nonanxious OSA subjects in subgenu, anterior, and mid-cingulate, ventral medial prefrontal and bilateral insular cortices, hippocampus extending to amygdala and temporal, and bilateral parietal cortices. Brain injury emerged in anxious OSA versus nonanxious controls in bilateral insular cortices, caudate nuclei, anterior fornix, anterior thalamus, internal capsule, mid-hippocampus, dorsotemporal, dorsofrontal, ventral medial prefrontal, and parietal cortices.


CONCLUSIONS
Anxious OSA subjects showed injury in brain areas regulating emotion, with several regions lying outside structures affected by OSA alone, suggesting additional injurious processes in anxious OSA subjects.
Kumar
Rajesh
R
Department of Neurobiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095-1763, USA.
Macey
Paul M
PM
Cross
Rebecca L
RL
Woo
Mary A
MA
Yan-Go
Frisca L
FL
Harper
Ronald M
RM
D000328:Adult; D001007:Anxiety / Q000503:physiopathology* / Q000523:psychology; D001143:Arousal / Q000502:physiology*; D001369:Axons / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D001925:Brain Damage, Chronic / Q000503:physiopathology / Q000523:psychology; D002545:Brain Ischemia / Q000503:physiopathology / Q000523:psychology; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000523:psychology