title: Brain putamen volume changes in newly-diagnosed patients with obstructive sleep apnea.
abstract: Obstructive sleep apnea (OSA) is accompanied by cognitive, motor, autonomic, learning, and affective abnormalities. The putamen serves several of these functions, especially motor and autonomic behaviors, but whether global and specific sub-regions of that structure are damaged is unclear. We assessed global and regional putamen volumes in 43 recently-diagnosed, treatment-naïve OSA (age, 46.4 ± 8.8 years; 31 male) and 61 control subjects (47.6 ± 8.8 years; 39 male) using high-resolution T1-weighted images collected with a 3.0-Tesla MRI scanner. Global putamen volumes were calculated, and group differences evaluated with independent samples t-tests, as well as with analysis of covariance (covariates; age, gender, and total intracranial volume). Regional differences between groups were visualized with 3D surface morphometry-based group ratio maps. OSA subjects showed significantly higher global putamen volumes, relative to controls. Regional analyses showed putamen areas with increased and decreased tissue volumes in OSA relative to control subjects, including increases in caudal, mid-dorsal, mid-ventral portions, and ventral regions, while areas with decreased volumes appeared in rostral, mid-dorsal, medial-caudal, and mid-ventral sites. Global putamen volumes were significantly higher in the OSA subjects, but local sites showed both higher and lower volumes. The appearance of localized volume alterations points to differential hypoxic or perfusion action on glia and other tissues within the structure, and may reflect a stage in progression of injury in these newly-diagnosed patients toward the overall volume loss found in patients with chronic OSA. The regional changes may underlie some of the specific deficits in motor, autonomic, and neuropsychologic functions in OSA.
authors.affiliation: Department of Anesthesiology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA ; Department of Radiological Sciences, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA ; The Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Salar
authors.initials: S
authors.lastname: Farahvar
authors.affiliation: UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Ogren
authors.affiliation: UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA 90095, USA ; The Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Macey
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA ; Department of Psychiatry, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.affiliation: UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Woo
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Frisca L
authors.initials: FL
authors.lastname: Yan-Go
authors.affiliation: Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095, USA ; The Brain Research Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Harper
mesh_terms: D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011699:Putamen / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020181:Sleep Apnea, Obstructive / Q000473:pathology*
keywords: 3D surface morphometry; 3D, Three dimensional; AHI, Apnea–hypopnea index; Autonomic; BAI, Beck Anxiety Inventory; BDI-II, Beck Depression Inventory II; Basal ganglia; CSF, Cerebrospinal fluid; Cognition; ESS, Epworth Sleepiness Scale; FA, Flip angle; FOV, Field of view; GRAPPA, Generalized autocalibrating partially parallel acquisition; Intermittent hypoxia; MNI, Montreal Neurological Institute; MPRAGE, Magnetization prepared rapid acquisition gradient-echo; MRI, Magnetic resonance imaging; Magnetic resonance imaging; Motor; OSA, Obstructive sleep apnea; PD, Proton density; PSQI, Pittsburgh Sleep Quality Index; TE, Echo time; TIV, Total intracranial volume; TR, Repetition time