| BackgroundThe primary demyelinating diseases include multiple sclerosis (MS), neuromyelitis optica (NMO), acute demyelinating encephalomyelitis (ADEM) and so on. MS is one of the most important neurological diseases, which is the leader cause of non-trauma disability among youths in developed country. Now China is considered as a medium incident area. At present, the pathogenesis of MS is not clear and the diagnostic criteria for MS change constantly. Magnetic resonance imaging (MRI) is the most important and most sensitive imaging diagnostic tool. It is important value to diagnose, follow up after therapy and explain the patho-physiology for MS with the conventional and functional MRI, and is unable to be substituted.No final conclusion has yet been reached for NMO and MS, and no golden diagnostic criteria for NMO are found. NMO is an idiopathic inflammatory demyelinating disorder that was thought to preferentially affect the optic nerves and spinal cord but without brain MRI abnormalities. Lots of other evidences suggested that NMO differs MS from clinical presentations, experimentation findings, image features, immunopathologic characteristics and therapeutics. It is of great importance to display brain abnormalities of NMO and discriminate diagnosis for NMO and MS with MRI scans.PurposesThis study was to identify image characteristics and metabolite changes in patients with MS in the district of Chongqing with the conventional MRI and 1H-proton MR spectroscopy (1H-MRS), to explore the values of diffusion-weighted imaging(DWI)and apparent diffusion coefficient (ADC) measurements in various pattern lesions of MS, to identify brain abnormalities in NMO by MRI, which are helpful to the revision of diagnostic criteria for NMO. At last this study was to evaluate the correlations between the various image features and clinical scores of MS patients.Methods1. The following-up outpatients and hospitalization of clinically diagnosed patients with MS and NMO were included at the First Affiliated Hospital of Chongqing Medical University and other hospitals in Chongqing.2. 180 Patients who fulfilled the MS diagnostic criteria of McDonald et al were selected to perform MRI scans of the brain, spinal cord and optic nerves. The brain and spinal cord images were analyzed. 3. Some patients with MS who can endure a long time MRI scans were selected to perform 1H-MRS. The metabolite difference of various pattern lesions and subtypes of patients with MS were analyzed with multiple-voxel long and short echoes, single-voxel short echo magnetic resonance spectrum.4. 60 patients with clinically diagnosed remitting-relapsing MS (RRMS) were included and underwent conventional brain MRI and DWI scans, mean ADC values were measured for various lesions of MS. The statistical analyses were performed to determine the differences of mean ADC values among various lesions of MS.5. Patients who fulfilled the latest diagnostic criteria of NMO proposed by Wingerchuk et al were selected to perform standard MRI scans of the brain, spinal cord and optic nerves. The normal and abnormal brain images were analyzed.6. Expanded Disability Status Scale (EDSS), Multiple sclerosis quality of life-54 instrument (MSQOL-54) and Mini-Mental State Examination (MMSE) of all patients were scored within the same day of MRI scans by a professional neurologist. The correlations were analyzed between MRI findings and clinical various scores.Results1. The patients with simple brain lesions were involved in 82 cases (45.56%), for spinal cords , 53 case(s29.44%),for both brain and spinal cord, 45 cases(25%),based on the locations of lesion involvements.2. The lower cervical and upper thoracic spinal cords for patients with MS were easily involved; the length of cord lesions which were less than three vertebral segments was 74.49%, for more than three vertebral segments, 25.52%.3. The detection rates with PD/T2WI and FLAIR imagings were no statistical differences among infratentorium, surroundings of cerebral lateral ventricles and deep white matter(p>0.05).The statistical difference was found between the FLAIR and T2WI in cortical and subcortical lesions(p<0.05).4. The metabolite ratios of NAA/Cr,Cho/NAA and Cho/Cr in normal-appearing white matter (NAWM) are statistical differences among RRMS, progressive MS and the control group (P<0.01). The metabolite ratios of NAA/Cr and Lac+Lip/Cr are significant different between the enhanced lesions, non-enhanced lesions and the control group (p < 0.05) , The Cho and Lac + Lip peaks are revealed elevatation markedly in acute plagues and NAA peak is displayed decrease. However, the metabolite ratios of NAA/Cr and Cho/Cr are not statistical different between the cingulate gyrus and the control group (p>0.05).5. The ADC values of hypointense lesions were significantly higher than that of isointense lesions ( P < 0.001 ) , the ADC values were (127.54±9.31)×10-5 mm2/sec and(95.71±6.25)×10-5 mm2/sec respectively. The ADC values of confluent lesions had a substantially higher than that of discrete lesions(P<0.001), the ADC values were(141.35±6.51)×10-5 mm2/sec and(105.38±13.89)×10-5 mm2/sec respectively. No correlation was found between ADC values of lesions and EDSS scores(P>0.05).6. Brain abnormal findings of NMO were detected in 28 out of 33 patients (84.8%). 22 patients (66.7%) showed well-defined brain parenchymal lesions. In the supratentorial lesions,most were punctate or small round dots and nonspecific hyperintensities in juxtacortical,subcortical and deep white matter regions. In the infratentorium,brainstem was an easily involved region (14/33, 42.4%), especially in medulla (7/33, 21.2%).7. The EDSS scores were statistical difference among the patients with simple brain involvement, simple spinal cord involvement, both brain and spinal cord involvement(sP<0.05). The MSQOL-54 scores of MS with simple brain involvement were significantly higher than those of the two later subtype(sP<0.05). There was no correlation between the spinal cord atrophy and EDSS scores (r=2.31,P=0.2516), but rather than that of disease course (r=0.40, P=0.0267). There was negative correlation between the NAA/Cr ratio and EDSS scores, (p<0.05). A significant correlation was found between the NAA/Cr ratio of the cingulate gyrus and cognition function (p<0.05), but for that of EDSS scores, no correlation was found (p>0.05).Conclusions1. The conventional MRI is the most important tool for diagnosis of MS. It is helpful to renew the concept that only brain white matter was involved. In fact, the whole brain is diffusing involved in patients with MS. Spinal cord MRI scans can improve the sensitivity of the diagnosis and differential diagnosis of MS from other diseases.2. The PD, T2WI and FLAIR can improve the quantity diagnostic ability of the lesions for MS; especially the cortical and subcortical lesions are detected well by FLAIR images. The lesions of the posterior cranial fossa are displayed well by PD and T2WI.3. The pathophysiological heterogeneities including the axial damages, myelinolysis, gliosis and inflammatory reactions are explained well by the 1H-MR spectrum among the subtypes MS and various pattern lesions.4. DWI and quantitative ADC measurements are useful tools to explain the pathological changes in different lesions and monitor the disease duration of MS.5. Non-specific abnormalities in brain MRI are common in Chinese NMO patients, and the patients with brain lesions do not exclude the diagnosis of NMO. The observation of brain lesions is helpful to improve and revise diagnostic criteria of NMO.6. The scores of EDSS and cognition function in the subtypes (simple spinal cord involvement, simple brain involvement, both brain and spinal cord involvement) are all different. The MSQOL-54 is observed the best in simple brain involvement. The different correlations are found between the different metabolite ratios and EDSS scores, and disease courses and MSQOL-54 scores.
|
PDF Full Text Request