Objective To explore the relationship between reduction of regional cerebral blood flow in the normal appearing white matter (NAWM) and the extent of age-related white matter lesions (WML).Methods We used Fazekas scale to divide all participants into four groups (normal,mild,moderate,severe) according to the extent of the lesions showed on MRI.Regional cerebral blood flow (rCBF) in the area of WML and NAWM was measured by xenon contrast CT examination.Results A total of 56 cases were selected.The average rCBF (ml · 100 g-1 · min-1) in the lesions (WML) around ventricle,in right centrum ovale and in left centrum ovale respectively was 20.33 ± 2.52,21.27 ± 1.02,21.03 ± 1.83 for mild; 16.33 ±2.03,15.55 ±1.71,15.91 ±0.98 for moderate; 14.05 ±2.63,14.46 ±2.17,14.23 ± 1.95 for severe.The average rCBF (ml · 100 g-1 · min-1) in the NAWM around ventricle,in right centrum ovale and in left centrum ovale respectively was 20.79 ± 2.78,22.26 ± 1.9,22.15 ± 2.4 for normal; 21.12 ± 2.95,22.17 ± 1.50,22.25 ± 2.13 for mild,18.02 ± 2.41,19.45 ± 1.94,19.62 ± 1.54for moderate; 16.38 ± 3.22,18.18 ± 2.84,16.74 ± 2.97 for severe.The decrease of rCBF in the severe and moderate lesion areas was more serious than that in the mild lesion areas and reached statistic significance (P ＜ 0.05) ; The decrease of rCBF in the severe and moderate lesion areas was more serious than that in the area of NAWM in the same grade and reached statistic significance (P ＜ 0.05).The decrease of rCBF in the area of NAWM around severe and moderate lesion areas was more serious compared with that around mild lesion areas or normal areas (P ＜ 0.05) ; But the difference of rCBF in the area of NAWM around mild lesion areas and normal areas did not show any statistic significance.Conclusions Chronic ischemia was found to be existed not only in the lesions (WML) but also in the area of NAWM around the lesions,and was related to the extent of the lesions.Chronic ischemia may play a key role in the mechanism of aged-related WML.

Objective To investigate the efficacy and the collective brain responses of acupuncture for post-stroke limb numbness.Methods A total of 24 patients with post-stroke limb numbness and 23 matched healthy participants were recruited.Both groups received coordinated acupuncture treatment to regulate their physical and mental state,three times a week for 4 weeks.Changes in limb numbness assessed by the visual analog scale(VAS)were observed before and after acupuncture.Functional magnetic resonance imaging(fMRI)scans were conducted on the participants during the scanning process with acupuncture intervention.Blood oxygen level-dependent(BOLD)data were collected in three states:resting state,acupuncture task state,and needle retention state.Data processing was performed using software such as fMRIPrep and brainIAK.Intersubject correlation(ISC)analysis was conducted to compare the ISC values of different brain regions between the two groups under different conditions.Results Acupuncture treatment significantly reduced the VAS scores of limb numbness.No significant changes in ISC values in both groups during resting state.Under acupuncture conditions,the patient group exhibited significantly increased ISC values in the left precentral gyrus,left paracentral lobule,left postcentral gyrus,left insula,left anterior cingulate gyrus,right middle frontal gyruss and right anterior cingulate gyrus.Under the needle retention condition,a slight negative activation was observed in the bilateral precentral gyrus of the control group.In the patient group,the ISC values of the left superior frontal gyrus,left precentral gyrus,left paracentral lobule,left precuneus,left postcentral gyrus,left insula,left anterior cingulate gyrus,left thalamus,right superior frontal gyrus,right middle frontal gyrus,right precentral gyrus,and right anterior cingulate gyrus showed a significant increase compared to the resting state.Conclusion Acupuncture can improve post-stroke limb numbness symptoms and induce a specific pattern of collective brain activation in patients.This activation involves the precentral gyrus,postcentral gyrus,thalamus,insula,frontal lobe and cingulate gyrus.Acupuncture may enhance the processing of sensory information by activating the somatosensory-motor network and the cortical-thalamic-cortical loop.It may also modulate the central executive network and the descending pain control pathway to promote the relief of pain symptoms.