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.

The impact of sleep and hypoxia on the brain

“…It has been previously suggested that a constellation of symptoms frequently encountered in OSA patients, such as depression, disturbances in attention, dysmetria of thought and affect, executive and verbal memory deficits [24][25][26], point to similarities with the spectra of two other well recognized neurological clinical syndromes, thalamocortical dysrhythmia and cerebellar cognitive affective syndrome [9,27,28]. Correspondingly, the neuroanatomical regions most commonly reported in clinical and animal studies as affected in OSA suggest that both the cerebellar modulation of neural circuits and the normal state-dependent flow of information between thalamus (and basal ganglia) and frontoparietal cortex are likely to be affected in susceptible patients [10,[29][30][31][32][33][34][35] (Fig. 1).…”

Grey matter differences associated with age and sex hormone levels between premenopausal and perimenopausal women: A voxel‐based morphometry study

“…In addition, Brown et al revealed that the signal reduction in the putamen could be a symptom for multiple system atrophy and pure autonomic failure. Moreover, the putamen volume alteration was found in postural tachycardia, syndrome obstructive sleep apneoa and depression patients during a DARTEL‐VBM study, and a relationship between increased volume in the putamen and autonomic hyperactivity was confirmed . The menopausal transition is accompanied by a reduction in ovarian hormones, which plays an important role in autonomic control and homeostasis of the autonomic neural mechanisms .…”

Disrupted functional brain network organization in patients with obstructive sleep apnea

“…; Kumar et al. , ). Thus, aberrant FC in OSA subjects may contribute to deficient autonomic regulation in the condition (Somers et al.…”

“…; Kumar et al. , ). Altered functional networks appeared in sensorimotor processing areas and may contribute to these functional impairments in the condition.…”