Electrophysiological characteristics of subacute combined degeneration of spinal cord in patients with nitrous oxide poisoning / 中国医师进修杂志

Objective:To analyze the electrophysiological characteristics of subacute combined degeneration of spinal cord in 10 patients with nitrous oxide poisoning.Methods:Ten patients with nitrous oxide poisoning (case group) and 20 controls (control group)treated in Dalian Municipal Central Hospital Affiliated of Dalian Medical University from January 2016 to January 2020 were included in this study. MRI and electrophysiological examinations were performed on the head, cervical spine and thoracic spine, including distal motor latency (DML), motor nerve amplitude (CMAP), motor conduction velocity (MNCV), sensory conduction velocity (SNCV), sensory nerve amplitude (SNAP), N20 latency of upper limb cortical somatosensory evoked potential and P40 latency of lower limb cortical somatosensory evoked potential. The above indexes were compared between the two groups.Results:In the case group, DML of motor nerve was prolonged, MNCV was slowed down, CMAP was decreased, SNCV was slowed down and SNAP was decreased compared with the control group, the differences were statistically significant ( P<0.05). The incubation periods of N20 and P40 in the case group were longer than those in the control group: (32.70 ± 3.34) ms vs. (18.85 ± 1.37) ms, (57.00 ± 4.08) ms vs. (38.40 ± 1.54) ms, the differences were statistically significant ( t = 16.20, 18.20, P<0.01). The inverted "V" type T 2 long signal of cervical spinal cord and thoracic spinal cord could be seen on MRI of cervical or cervical and thoracic vertebrae in 5 patients. Conclusions:Nitrous oxide poisoning can cause obvious subacute combined degeneration of spinal cord, involving peripheral nerve and spinal cord damage. Peripheral nerve damage can involve motor fibers and sensory fibers, mainly axonal damage, accompanied by demyelination damage, especially in both lower limbs.

Subacute combined degeneration of the spinal cord with concomitant autoimmune disease: report of 2 cases

The etiology of subacute combined degeneration (SCD) of the spinal cord is closely associated with vitamin B12 (VitB12) deficiency. The clinical manifestations of SCD are complex and vary substantially. Due to some SCD patients with atypical manifestations and concomitant autoimmune disorders, the probability of misdiagnosis and missed diagnosis is still relatively high in the early stage. We report the cases of two patients who were missed or misdiagnosed at another hospital because of the normal initial VitB12 level and partial overlap of clinical manifestations, finally diagnosed as SCD with atypical manifestations and concomitant autoimmune disorders, pharyngeal-cervical-brachial Guillain-Barre syndrome in Case 1 and SCD with autoimmune thyroiditis in Case 2. After undergoing corresponding treatment, death was reported in Case 1 and improvement in Case 2. Analysis of the clinical manifestations and investigation of the underlying pathogenesis in such patients could help improve the rate of early diagnosis and allow timely treatment of SCD, thereby preventing disease progression and poor clinical outcomes.

Relevant Factors of Clinical Neural Lesions and Electrodiagnostic Features on Patients with Subacute Combined Degeneration of Spinal Cord / 中国医科大学学报

Objective To retrospectively study the clinical and electrodiagnostic features in subacute combined degeneration of spinal cord (SCD)patients. Methods The clinical and electrodiagnostic recordings of all SCD patients conformed in our Neurology Department from Janu?ary 2013 to July 2015 were retrospectively reviewed. Totally 29 patients diagnosed as SCD,whom received no treatment before admitted in our hos?pital,were recruited for the study. Correlation analysis between serum level of vitamin B12(VB12),course of disease and degree of neural lesion was performed,and the electrodiagnostic features were summarized and analyzed. Results The course of disease had significant correlation with the degree of neural lesion(P=0.001),but there was no significant relevance between serum VB12 level and neural damage(P>0.05). Electrodi?agnostic examination revealed:The abnormal rate of motor nerve(15.20%)was lower than that of sensory nerve(42.75%,P<0.001)and the up?per limb nerve(27.1%)was lower than that of lower limb nerve(30.87%,P=0.578). There was no remarkable difference of abnormal rate in all kinds of nerves of motor and sensory nerve(P1=0.320,P2=0.755). In the analysis of the parameters of electromyograph,there was statistical signif?icance of the abnormal rates of compound muscle action potential(CAMP)between each motor nerve(P=0.005). There was statistical signifi?cance of the abnormal rates of CAMP and no function between each sensory nerve(all P<0.001). Conclusion The course of disease has signifi?cant correlation with the degree of neural lesion. Sensory nerve is tended to be betreffend than motor nerve. Phil.always nervous are more likely to be affected than others in motor nerve at CAMP. Tibial nerve is easier to be influenced at CAMP in sensory nerve ,and the lesion is more serious.