Objective To explore the relationship between muscle fatigue and pain in lumbar muscle fatigue induced test. Methods From July to October, 21 healthy female volunteers were subjected to the fatigue induced test. Their root mean square (RMS) and median frequency (MF) of the surface electromyography were collected, their fatigue were assessed with Borg Fatigue Scale and Visual Analogue Scale (VAS), and their maximal voluntary contraction (MVC) and pressure pain threshold (PPT) were measured, before, during and after ex-periment. They were divided into pain or no-pain groups according to the symptom, and the differences before and after test were compared. Results There was significant difference in the scores of Borg Fatigue Scale and VAS, MVC, RMS, and MF after test (Z>6.064, P<0.001). There was significant difference between two groups in all the data before test, and there was significant difference between two groups in the difference before and after test of the VAS score (t=-4.112, P=0.001) and RMS (t>2.385, P<0.05) in some points. Receiver operating characteristic curve analysis showed that the optimal cut-off point of VAS score difference was 3.45 in predicting the pain onset, with sensi-tivity of 100％and specificity of 81.8％. Conclusion For the fatigue induced test, the fatigue VAS score difference may predict the induced pain, and RMS difference associate with the occurrence of pain. No significant is observed of the Borg Fatigue Scale and PPT.

Objective:To explore a solution for the construction of the CCI index with an example of cerebral infarction to provide a guide for adjusting the policy of Diagnosis-Intervention Packet.Methods:Lasso regression was used to screen for comorbidities to construct the model,K-means clustering was used for case severity categorization.CCI indices were calculated as one plus the sum of standardized regression coefficients.Results:According to the analysis,five key variables were found,including other disorders of the lungs,non-insulin-dependent diabetes mellitus with ketoacidosis,systemic inflammatory response syndrome of non-infectious etiology with organ failure,acute duodenal ulcer with bleeding,and chronic obstructive pulmonary disease with acute lower respiratory tract in-fection,with CCI indices of 1,1,1.026,1.034,and 1.101.Simulated calculation's result showed a decrease in medical insurance pay-ment losses after applying CCI indices.Conclusion:The CCI index construction scheme based on Lasso regression and K-means clus-tering is reasonable and effective.

Objective To analyze the magnetic resonance imaging (MRI) of the spinal cord and clinical characteristics in patients with autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy.Methods A total of 1 040 samples of cerebrospinal fluid (CSF) and sera collected in the Second Affiliated Hospital of Guangzhou Medical University from March 2013 to June 2018 were tested with tissue-and cell-based assays,and 42 patients were found positive for GFAP-IgG.The clinical data and MRI characteristics of the spinal cord of 19 patients who were positive for GFAP-IgG in CSF with autoimmune GFAP astrocytopathy and lesions in the spinal cord were retrospectively reviewed.Results There were 12 females and seven males among the 19 patients,with onset age of (44±17) years.The main manifestations of these patients included limb weakness (14/19),abnormal vision (5/19),headache (4/19),seizure (4/19),dementia (3/19),etc.On MRI of the spinal cord,five patients showed involvement in the cervical cord alone,eight showed involvement in the thoracic cord alone and six had both cervical and thoracic segment involvement.Fifteen patients had longitudinally extensive myelitic abnormalities (≥3 vertebral segments long).Seven enhancement patterns were encountered.Lesions were displayed in the spinal cord and brain in eight patients.Central gray matter involvement in the spinal cord was found in all the 19 patients.Conclusions Autoimmune GFAP astrocytopathy more frequently presents in females than in males.MRI of the spinal cord has complex presentations and longitudinally extensive myelitic abnormalities usually.Patients often show central gray matter involvement in the spinal cord.Myelitic abnormalities present more often in thoracic segment than in cervical segment.Abnormalities in lumbar segment are less encountered.

Objective Our study aimed to delineate the clinical and radiological features of patients with anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab)positive neuromyelitis optica spectrum disorder (NMOSD). Methods Fifty-seven patients with NMOSD and 29 patients with multiple sclerosis (MS) were collected. Data on clinical and radiological features of MOG-Ab positive patients with were analyzed retrospectively. Results MOG-Abs were present in 9/57 (15.8%) NMOSD patients and 2/29 (6.9%) MS patients. Both MOG and aquaporin-4 (AQP4) antibodies were positive in one case of NMOSD. There was no significant difference between the two groups (P＞0.05). There were more females than males having MOG-Ab positive NMOSD (females: males=7:1) and the average onset age was 41.4 ± 11.5 years. There was no significant difference in gender and age between MOG-Ab negative and AQP4-Ab positive groups(P＞0.05). The durations of disease were significantly shorter in either MOG-Ab positive NMOSD patients or MOG-Ab negative NMOSD patients than in AQP4-Ab positive group (P<0.05). Recurrence was the main disease pattern of all three groups and the frequency of recurrence was not significant different among three groups (P＞0.05). The incidence of optic neuritis was 62.5% in NMOSD patients with MOG-Ab positive and 43.5% in AQP4-Ab positive NMOSD patients (P＞0.05). There was no significant difference in the morphology and location of brain lesions among the three groups (P＞0.05). MOG-Ab positive NMOSD patients had long segment spinal cord lesions. The median length of the spinal cord lesions in the MOG-Ab positive group was similar to the other two groups (P＞0.05). Conclusions MOG-Ab positive NMOSD patients have higher proportion of females with shorter recurrence course, more likely complicated with optic neuritis. And the radiological features of brain and spinal cord were not specific to patients with AQP4-Ab positive.

【Objective】 To construct and validate a risk prediction model for cognitive impairment after stroke based on demographic, clinical, and neuroimaging characteristics. 【Methods】 Through the medical record system, we collected all data of the patients. We finished cognitive function testing three months after the indexed stroke. The Mini-Mental State Examination Scale score≤26 was defined as cognitive dysfunction. Optimal subset regression analysis was used to screen variables, Logistic regression analysis was used to construct a predictive model for cognitive impairment, and C-index, calibration chart and clinical decision curve analyses were used to evaluate the discrimination, consistency, and clinical availability of the model. And nomograms were used to express the performance of the model. 【Results】 Seven variables were selected: cognitive function before stroke, age, years of education, National Institutes of Health Stroke Scale score at admission, history of ischemic heart disease, the number of old lacunar infarct lesions, and medial temporal lobe atrophy scale. The prediction model had a C-index of 0.845 (95% CI: 0.805-0.885). The clinical decision curve showed that the model had a positive net benefit when the threshold probability was 9.0%-90.0%. 【Conclusion】 The predictive model of cognitive impairment in stroke patients has good predictive efficiency and provides an effective assessment tool for screening high-risk cases of cognitive impairment in patients with stroke of various subtypes.