Functional Connectivity Changes in Amygdala Subregions of Obstructive Sleep Apnea Patients After Six Months of Continuous Positive Airway Pressure Treatment

Figures & data

Figure 1 The amygdala subregions.

Abbreviations: ROI, region of interest; DA, dorsal amygdala; MA, medial amygdala; VA, ventral amygdala; MNI, Montreal Neuroscience Institute; R, right, L; left.

Table 1 Characteristics of Participant Demographics and Clinical Assessment Information

Characteristics	Pre-CPAP OSA (N=15)	Post-CPAP OSA (N=15)	t-value/z-value	p-value
Gender (Male/Female)	14/1	14/1	/	/
Age, years	41.5±7.4	/	/	/
BMI, Kg/m2	27.6 (24.4,29.7)	26.0 (24.1,29.9)	−0.534	0.594
ESS, scores	10.0±5.5	6.4±2.8	−2.460	0.027*
MoCA, scores	25.0 (20.0,26.0)	26.0 (22.0,28.0)	−2.463	0.014*
Visual space and execution	4.1±1.0	4.5±0.8	0.939	0.364
Naming	3.0 (3.0,3.0)	3.0 (3.0,3.0)	−1.000	0.317
Delayed memory	2.0 (1.0,3.0)	3.0 (2.0,3.0)	−2.521	0.012*
Attentional function	6.0 (5.0,6.0)	6.0 (5.0,6.0)	−0.378	0.705
Language	3.0 (2.0,3.0)	2.0 (2.0,3.0)	−0.302	0.763
Abstract	2.0 (1.0,2.0)	2.0 (1.0,2.0)	−1.000	0.317
Orienteering	6.0 (6.0,6.0)	6.0 (6.0,6.0)	−0.816	0.414
HAMA, scores	7.0 (5.0,8.0)	3.0 (1.0,4.0)	−3.106	0.002*
HAMD, scores	4.0 (3.0,7.0)	3.0 (1.0,4.0)	−2.200	0.028*
PSQI, scores	5.0 (5.0,8.0)	5.0 (4.0,6.0)	−1.476	0.169
AHI, /h	47.7±18.3	/	/	/
Nadir SaO2, %	71.5±10.6	/	/	/
Mean SaO2, %	94.3±2.5	/	/	/
SaO2 <90%	12.9±10.9	/	/	/
Sleep efficiency, %	81.3±8.7	/	/	/
Mean CPAP use, h/night	/	6.4±0.6	/	/
Days of CPAP use>4h, %	/	86.0±8.0	/	/
Mean CPAP pressure, cm H2O	/	8.2±1.4	/	/

Note: *Significant group difference p < 0.05.

Abbreviations: pre-CPAP OSA, OSA patients at baseline; post-CPAP OSA, OSA patients after CPAP treatment; BMI, body mass index; ESS, Epworth sleepiness scale; MoCA, Montreal cognitive assessment; HAMA, Hamilton anxiety scale; HAMD, Hamilton depression scale; PSQI, Pittsburgh sleep quality index; AHI, apnea hypopnea index; SaO₂, oxygen saturation; SaO₂ < 90%, percentage of total sleep time spent at oxygen saturation < 90%.

Table 2 Brain Areas Showing Functional Connectivity Disparities with Amygdala Subregions Between Pre-CPAP OSA and Post-CPAP OSA

Seed-ROIs	Brain Areas	MNI Coordinates			Num. of Voxels	t-values
		x	y	z
Left DA	Right posterior cingulate cortex	6	−42	24	171	4.416
Left MA	Right postcentral gyrus	24	−36	66	213	−6.394
Right MA	Left middle frontal gyrus	−39	−3	42	212	−5.805

Notes: Gaussian random field theory (GRF) two-tail corrected with voxel level p < 0.01 and cluster level p < 0.05.

Abbreviations: ROI, region of interest; DA, dorsal amygdala; MA, medial amygdala; MNI, Montreal Neuroscience Institute.

Figure 2 The functional connectivity patterns of OSA patients at baseline and after six monthsCPAP treatment (single sample t-test).

Abbreviations: pre-CPAP, OSA patients at baseline; post-CPAP, OSA patients after CPAP treatment; DA, dorsal amygdala; MA, medial amygdala; VA, ventral amygdala; FC, functional connectivity; L, left; R, right.

Figure 3 The altered FC in the amygdala subregions of OSA, the increased FC in post-CPAP compared to pre-CPAP OSA (warm color), the decreased FC in post-CPAP compared to pre-CPAP OSA (cold color); Gaussian random field theory (GRF) two-tail corrected with voxel level p < 0.01 and cluster level p < 0.05.

Abbreviations: DA_L, left dorsal amygdala; MA_L, left medial amygdala; MA_R, right medial amygdala; PCC_R, right posterior cingulate cortex; PoCG_R, right postcentral gyrus; MFG_L, left middle frontal gyrus.

Figure 4 Correlation analyses between altered FC and HAMA in pre-CPAP patients with OSA.

Abbreviations: FC, functional connectivity; DA_L, left dorsal amygdala; PCC_R, right posterior cingulate cortex; HAMA, Hamilton anxiety scale.