Clinical Study On Nervous System Damage Caused By Recreational Nitrous Oxide Abuse

Objectives: To summarize and analyze the clinical characteristics of nervous system damage caused by nitrous oxide abuse for entertainment,so as to provide a basis for the diagnosis and treatment of this kind of disease.Methods: A total of 87 patients with nervous system damage caused by recreational nitrous oxide abuse were collected from January 2016 to June 2020 in the Department of Neurology of Shengjing Hospital affiliated to China Medical University.the demographic characteristics,history of exposure to nitrous oxide,symptoms,signs,imaging and laboratory results,treatment,prognosis were summarized.50 patients with spinal cord subacute combined degeneration(SCD)caused by nitrous oxide abuse and improved spinal cord magnetic resonance image(MRI)were selected,and 48 patients with spinal cord subacute combined degeneration unrelated to nitrous oxide abuse were collected at the same time.The clinical features of the two groups were compared and analyzed.Results:(1)During this period,87 patients with nervous system damage caused by recreational nitrous oxide abuse were diagnosed and treated,with an average age of21.7±4.5 years old,including 45 males and 42 females.The time of exposure to nitrous oxide ranges from 20 days to 4 years.The common symptoms are paresthesia(78.2%),weakness(51.7%),unsteady gait(35.6%),and so on.The most common abnormal indicators were increased serum homocysteine levels(86.7%)and decreased vitamin B12levels(61.7%).The main electromyographic changes were peripheral nerve injury.In80% of the patients who underwent spinal cord MRI,a long strip of high signal intensity of the posterior cord was seen on T2 sequence,and the lesion showed an inverted "V"sign on the axis.After supplementary VB12 treatment,the symptoms of all patients were relieved in varying degrees.(2)During this period,a total of 50 patients with nitrous oxide-related SCD(male / female: 22/28)and 48 patients with non-nitrous oxide-related SCD(male / female: 27/21)were collected.The most common clinical symptoms of both groups were paresthesia,weakness,unsteady gait,but the occurrence rates of weakness,unsteady gait,urination and defecation disorders,loss of appetite,loss of deep sense,positive Romberg sign and positive Babinski sign in the nitrous oxide group were lower than those in the non-nitrous oxide group.Compared with the non-nitrous oxide group,the level of serum VB12 was higher,the decrease rate of VB12 and the incidence of megaloblastic anemia in the nitrous oxide group were lower than those in the non-nitrous oxide group.The positive rate of spinal cord MRI,the width of sagittal lesions and the proportion of inverted "V" sign on axial images in nitrous oxide group were higher than those in non-nitrous oxide group,while the number of spinal cord segments involved in sagittal image and the proportion of cervical and thoracic spinal cord accumulation in nitrous oxide group were significantly lower than those in non-nitrous oxide group(P<0.05).Conclusions:Abuse of nitrous oxide can cause nervous system damage,and polyneuropathy and SCD are the most common.Timely diagnosis and withdrawal of nitrous oxide and supplementation of VB12 have a better prognosis.Compared with patients with non-nitrous oxide-related SCD,the clinical symptoms of patients with nitrous oxide-related SCD were milder,the detection rate of MRI in myelopathy was higher,and the range of lesions was shorter and wider.