Randomized controlled trials (RCTs) are the gold standard for the design of clinical trials. Because of some practical difficulties, more and more researchers think that the appropriate use of non-randomized controlled trials may make up for the weakness of RCT and will achieve the same research purpose. Therefore, non-RCTs are also very important. Taking studies on multiple sclerosis for example, this article briefly introduces the significance of non-randomized contolled trials.
Objective To evaluate the efficacy and safety of FTY720 (fligolimod) in different dosages in the treatment of Relapsing-Remitting Multiple Sclerosis (RRMS), so as to provide references for clinical practice. Methods Such databases as MEDLINE, EMbase, The Cochrane Liabrary, CBM and CNKI were searched for collecting randomized controlled trials (RCTs) of FTY720 in the treatment of RRMS, which were published from January 1, 2001 to December 31, 2010. The studies were retrieved and the data were extracted according to the predefined inclusion and exclusion criteria, the quality of included studies was evaluated with improved Jadad scale, and the Meta-analyses were performed with RevMan5.1 software. Results Three high quality RCTs were included. The Meta-analyses showed that: a) compared with the control group, orally taking FTY720 could obviously decreased the annualized relapse rate (OR=-6.67, 95%CI -10.75 to -2.60, P=0.001), the confirmed disability progression rate (OR=0.64, 95%CI 0.47 to 0.87, P=0.004), and the incidence rate of intensified lesion on T2-weighted magnetic resonance imaging scans (OR=0.28, 95%CI 0.21 to 0.37, Plt;0.00001); b) There was no significant difference (P=0.55) between the small dosage (0.5mg/d) group and the big dosage (1.25mg/d) group of FTY720; and c) The incidence of adverse events was significantly different among the 3 dosage groups (5mg/d, 1.25mg/d and 0.5mg/d), and the minimum dosage group (0.5mg/d) was safer than the other groups. Conclusion FTY720 is safe to treat RRMS, and it can obviously decrease the annualized relapse rate, confirmed disability progression rate and incidence rate of intense lesion on T2-weighted magnetic resonance imaging scans. There is no dosage-effect relationship found in treating RRMS with FTY720 in different dosages, but the 0.5mg/d FTY720 as the minimum dosage is the safest.
A multi-label based level set model for multiple sclerosis lesion segmentation is proposed based on the shape, position and other information of lesions from magnetic resonance image. First, fuzzy c-means model is applied to extract the initial lesion region. Second, an intensity prior information term and a label fusion term are constructed using intensity information of the initial lesion region, the above two terms are integrated into a region-based level set model. The final lesion segmentation is achieved by evolving the level set contour. The experimental results show that the proposed method can accurately and robustly extract brain lesions from magnetic resonance images. The proposed method helps to reduce the work of radiologists significantly, which is useful in clinical application.
ObjectiveTo observe the features of the manifestations of fundus fluorescein angiography （FFA） in multiple sclerosis （MS） and their value in clinical diagnosis.MethodsThe clinical data of 42 patients (84 eyes) with MS diagnosed by magnetic resonance imaging (MRI) and examination of cerebrospinal fluid (CSF) were retrospectively analyzed. The clinical data included visual acuity, ocular fundus examined by direct ophthalmoscope after mydriasis, FFA, visual field, CSF，visual evoked potential (VEP) and MRI examination.ResultsIn 42 patients (84 eyes),the positive detectable rate of examination of direct ophthalmoscope, CSF, visual field, VEP, and MRI was 36.9%, 21.4%, 71.4%, and 83.3% respectively. Abnormal results of FFA were found in 44 eyes (52.38%), including papillitis in 4 eyes（4.76%）at the early stage with extended physiological scotoma and central scotoma; neuroretinitis in 7 eyes （8.33%）at the medium stage with central or para-central scotoma; optic atrophy in 33 eyes（39.29%） at the late stage with centripetal constriction and even tubular visual field. ConclusionThe main angiographic features of MS are papillitis, neuroretinitis and optic atrophy. The manifestations of FFA combined with the results of examination of CSF，visual field, VEP and MRI is helpful for comprehensive and exact diagnosis of MS.(Chin J Ocul Fundus Dis, 2005,21:300-302)
ObjectiveTo study whether the pattern visual evoked potential (P-VEP) under different spatial frequency in patients with multiple sclerosis (MS) is different from normal people. MethodsP-VEP examination under high (15') and low (60') spatial frequency was performed on 18 MS patients (36 eyes) treated in our department from September 2011 to April 2012 and 20 normal volunteers (40 eyes). Then, we analyzed the difference between the two groups under the above-mentioned two kinds of spatial frequency. ResultsThe latency of P100 of P-VEP under high spatial frequency in MS patients was (120.50±13.04) ms which was significantly different from (109.21±5.38) ms of normal volunteers (P < 0.05). The latency of P100 of P-VEP under low spatial frequency in MS patients was (109.57±12.87) ms, which was also significantly different from (103.31±5.45) ms of normal volunteers (P < 0.05). The amplitude of P100 of P-VEP under high spatial frequency in MS patients was (9.17±5.69)μV and it was significantly lower than that[(15.69±8.45)μv] of normal volunteers (P < 0.05). The amplitude of P100 of P-VEP under low spatial frequency in MS patients was (11.93±16.75)μV and it was not significantly different from normal volunteers[(13.47±9.24μV)]. Based on different corrected vision, the MS patients were divided into two groups (vision≥1.0 and vision < 1.0). For patients with vision≥1.0, the latency of P100 and the amplitude of P100 of P-VEP under high spatial frequency was (113.43±8.28) ms and (12.94±5.46)μV; the latency of P100 and the amplitude of P100 of P-VEP under low spatial frequency was (111.13±11.50) ms and (11.57±5.60)μV. For patients with vision < 1.0, the latency of P100 and the amplitude of P100 of P-VEP under high spatial frequency was (126.69±13.49) ms and (5.87±3.43)μV; the latency of P100 and the amplitude of P100 of P-VEP under low spatial frequency was (108.26±14.11) ms and (12.24±5.82)μV. There was no significant difference in the latency and amplitude of P100 under low spatial frequency between the two groups with different corrected vision (P > 0.05), but the latency and amplitude of P100 under high spatial frequency were both significantly different between those two groups (P < 0.05). ConclusionsCompared with normal people, MS patients feature latency delay and amplitude reduction of the P-VEP, which was more severe under high spatial frequency. P-VEP under high spatial frequency may become an important evidence to evaluate visual function of MS patients.
Objective To study the regulations of visual evoked potential(VEP) changes in 30 patients with multiple sclerosis (MS). Methods VEP were performed in 30 MS patients,and the results were compared with normal subjects. Results The abnormality rate of VEP were 76.7%. 82.6% of patients with abnormal VEP showed clinical visual symptoms; 17.4% among those patients have no clinical visual symptoms. Conclusion The rate of VEP abnormal in MS patients is more high. It may help more in the diagnosis of MS.
Magnetic resonance (MR) images can be used to detect lesions in the brains of patients with multiple sclerosis (MS). An automatic method is presented for segmentation of MS lesions using multispectral MR images in this paper. Firstly, a Pd-w image is subtracted from its corresponding T1-w images to get an image in which the cerebral spinal fluid (CSF) is enhanced. Secondly, based on kernel fuzzy c-means clustering (KFCM) algorithm, the enhanced image and the corresponding T2-w image are segmented respectively to extract the CSF region and the CSF-MS lesions combinatoin region. A raw MS lesions image is obtained by subtracting the CSF region from CSF-MS region. Thirdly, based on applying median filter and thresholding to the raw image, the MS lesions were detected finally. Results were tested on BrainWeb images and evaluated with Dice similarity coefficient (DSC), sensitivity (Sens), specificity (Spec) and accuracy (Acc). The testing results were satisfactory.