Disrupted resting-state spontaneous neural activity in stable COPD

Figures & data

Table 1 Demographic and clinical characteristics of COPD patients and NCs

Characteristic	COPD (n=19)	NC (n=20)	P-value
Age, years	62.7±5.9	60.8±6.3	0.361
Male/female, n	14/5	15/5	–
Education, years	5.5±3.2	6.3±4.5	0.135
Disease duration (years)	4.5±5.6	–	–
SaO2 (%)	95.5±2.6	97.8±1.8	0.008
Pack-years	32.2±21.7	8.5±8.9	<0.001
PaO2 (mmHg)	82.6±16.5	98±19.5	<0.001
PaCO2 (mmHg)	49.3±8.0	38.5±4.3	<0.001
Respiratory rate, times/minute	19.5±0.6	18.5±1.2	0.654
FVC (% predicted)	67.5±19.9	96.5±15.8	<0.001
FEV1 (% predicted)	46.1±20.6	97.1±16.9	<0.001
FEV1/FVC (%)	55.8±16.3	81.2±8.3	<0.001
MoCA	18.4±4.3	26.4±3.2	<0.001
MMSE	22.4±3.6	27.2±2.2	<0.001
Naming	2.6±0.5	2.9±0.2	0.026
Visuospatial and executive function	3.6±1.1	4.3±0.9	0.012
Attention	5.3±1.0	5.8±0.7	0.075
Language	1.4±0.8	1.8±0.6	0.235
Memory	2.6±1.3	3.9±1.2	<0.001
Abstraction	1.2±0.7	1.4±0.6	0.231
Orientation	5.5±0.6	5.9±0.1	0.356
Intracranial volume (cm^3)	1,540.20±110.49	1,542.79±99.17	0.895

Note: Data presented as mean ± SD, n/n, or P-value.

Abbreviations: MMSE, Mini-mental State Examination; MoCA, Montreal Cognitive Assessment; NCs, normal controls; PaCO₂, arterial partial pressure of carbon dioxide; PaO₂, partial pressure of oxygen; SaO₂, blood oxygen saturation.

Table 2 Two-sample t-test differences between COPD patients and NCs using ReHo method (GRF-corrected, voxel-level P <0.01, and cluster level of P <0.05)

Conditions	Brain areas	R/L	BA	MNI			Cluster (voxel)	t-value
				X	Y	Z
COPD < NC	Occipital lobe	L	17	−9	−105	−6	65	−3.859
COPD < NC	Lingual	R	18	12	−69	−6	52	−3.772
COPD < NC	Precuneus	R/L	5/7	12	−63	39	163	−4.158
COPD < NC	Precentral gyrus	R	4	45	−39	48	138	−4.129

Abbreviations: BA, Brodmann’s area; GRF, Gaussian random field theory; MNI, Montreal Neurological Institute; NCs, normal controls; R/L, right/left hemicerebrum; ReHo, regional homogeneity.

Figure 1 The differences map in ReHo between COPD patients and NC groups (two-tailed GRF correction, voxel-level P <0.01, and cluster-level P <0.05) is shown in axial position. The blue areas indicate lower ReHo values.

Abbreviations: GRF, Gaussian random field theory; NC, normal control; ReHo, regional homogeneity.

Figure 2 Significant abnormal activity map observed in the left occipital lobe, the right lingual, the bilateral precuneus, and the right precentral gyrus between patients with COPD and NCs (two-tailed, GRF correction, voxel-level P <0.01, and cluster-level P <0.05) in three-dimensional image.

Abbreviations: GRF, Gaussian random field theory; NCs, normal controls.

Figure 3 Mean ReHo signal values for altered regional brain areas between COPD patients and NCs.

Abbreviations: NCs, normal controls; ReHo, regional homogeneity.

Figure 4 ROC curve analysis of the mean ReHo values for abnormal activity brain regions.

Notes: The AUCs were 0.829 for the occipital lobe, 0.784 for the lingual, 0.866 for the precuneus, and 0.85 for the precentral gyrus. The sensitivity and specificity of the occipital lobe were 85.0% and 73.7%. The sensitivity and specificity of the lingual were 95.0% and 63.2%. The sensitivity and specificity of the precuneus were 75.0% and 89.5%. The sensitivity and specificity of the precentral gyrus were 70.0% and 94.7%.
Abbreviations: AUC, area under the curve; ReHo, regional homogeneity; ROC, receiver operating characteristic.

Figure 5 There was a significant correlation between the ReHo values in the precuneus and the clinical parameters (PaCO₂, FEV₁/FVC, FEV₁%, orientation) in the stable COPD patients.

Abbreviations: PaCO₂, arterial partial pressure of carbon dioxide; ReHo, regional homogeneity.