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.

BACKGROUNDAlthough there were criteria for diagnosis of neuromyelitis optica (NMO) and multiple sclerosis (MS), it is still difficult to differentiate NMO from MS, due to the overlapping clinical manifestations. Therefore it is necessary to characterize clinical features of NMO and MS patients in the mainland of China, to simplify the process of disease diagnosis, and to identify criteria for the differential diagnosis of NMO and MS.

METHODSA total of 138 Chinese Han patients from the mainland of China including 73 NMO, 60 MS and 5 MS-like patients with positive NMO-IgG were included in the study. Clinical records were reviewed retrospectively and the results of clinical examination, laboratory experiments, magnetic resonance imaging (MRI) and evoked potentials (EPs) were compared between NMO and MS patients. In addition, the relationship between the NMO-IgG serologic status and clinical characteristics were analyzed.

RESULTSCompared with MS patients (1.3: 1.0), more female prevalence was observed in NMO patients (4.2: 1.0; P = 0.003). There were also statistically significant differences in visual EPs, oligoclonal bands, brainstem lesions in MRI and longitudinally extensive spinal cord lesions (LESCLs) between NMO and MS patients. Brainstem lesions observed in brain MRI were found in 17.9% of MS patients, over 3.7 times higher than in NMO patients (4.8%, P = 0.024). When stratified NMO patients by NMO-IgG, LESCLs were found in 42.1% of NMO-IgG-negative NMO patients, over 3.5 times higher than in NMO-IgG-positive patients (11.9%, P = 0.008). Statistical difference was also observed in CD4+/CD8+ ratios between NMO-IgG-positive and -negative NMO patients.

CONCLUSIONSComprehensive analysis of MRI, laboratory and EPs data can facilitate differential diagnosis of MS and NMO. In addition, the combination of LESCLs and brain MRI findings failing to satisfy MRI criteria for MS is highly sensitive and specific for NMO.

Adult ; China ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Multiple Sclerosis ; diagnosis ; Neuromyelitis Optica ; diagnosis ; Retrospective Studies