The clinical and subclinical features of spinal cord injury on magnetic resonance imaging of patients with N2O intoxication

Abstract

Nitrous oxide (N2O) is a weak anesthetic gas that was first used in 1844 in the field of dental anesthesia. However, currently, N2O is being abused for entertainment purposes in the form of N2O-filled balloons, called funky balls, which can cause many adverse effects, especially nervous system injury. This study aimed to investigate the detailed clinical and subclinical features associated with N2O intoxication. We retrospectively reviewed 47 patients diagnosed with N2O intoxication, from May 2018 to July 2019, and collected demographic data, clinical and laboratory tests, and spinal cord magnetic resonance imaging (MRI) findings. The mean time of funky ball use was 8.8 months, with a mean use of 36.3 balls per day. All patients presented with superficial sensory disorders. Reductions in muscle strength, decreased vibration sensation, and decreased or lost tendon reflexes were the most common clinical signs of N2O intoxication. Romberg sign and Lhermitte sign were observed in 39 patients (83%) and 21 patients (44.7%), respectively. Spinal cord lesions on MRI were observed in 32 patients (68.1%), which mostly presented with an inverted V sign. The total duration of N2O use, the number of days of using N2O per week, and the presence of Lhermitte sign (P<0.05) were significantly different between patients with and without spinal cord lesions on MRI. Serum levels of homocysteine and vitamin B12 were significantly different between the time of admission and discharge (P<0.05). Our study indicated that the days of using N2O per week was significantly associated with Spinal Cord Injuries (SCI) on MRI. According to the Receiver Operating Characteristic (ROC) curve analysis, a cutoff days of using per week value of 2.5 days could predict SCI with a sensitivity of 81.3%, a specificity of 73.3%, and an area under the ROC curve (AUC) of 0.813. Changes in the serum levels of homocysteine and vitamin B12 were effective markers for the evaluation of treatment response.

Nitrous Oxide-Induced Neuropathy among Recreational Users in Vietnam

“…Myelin impairment was the typical electromyography finding. Our findings are similar to those reported in other studies [ 4 , 6 , 9 , 10 , 11 , 12 ].…”

Clinical epidemiological characteristics of nitrous oxide abusers: A single‐center experience in a hospital in China

“…The data show that the patients with N 2 O abuse have the following demographic characteristics: (1) the overall age is younger, there are more men than women, and the average age of women is lower than that of men; (2) the proportion of unmarried patients is higher; (3) the overall level of education is not high; and (4) most of the patients have no stable occupation. In previous studies, the patients of N 2 O abuse were mainly adolescents (Bao et al., 2020; Garakani et al., 2016; Li et al., 2016; Tuan et al., 2020), and no significant gender differences were mentioned. However, whether there are significant gender differences in patients with N 2 O abuse still needs a large sample study.…”

“…epidemiologic investigations despite the importance of data from such studies for the development and implementation of effective interventions by health authorities (Bao et al, 2020;Garakani et al, 2016;Kaar et al, 2016;Lan et al, 2019;Li et al, 2016;Tuan et al, 2020). In order to collect epidemiologic data on N 2 O abuse, the present study analyzed the general epidemiological and clinical characteristics of 61 patients who were abusing N 2 O and were treated at the Affiliated Hospital of Xuzhou Medical University from January 2017 to December 2020.…”

“…However, the risks associated with N 2 O abuse—which include subacute combined lesions of spinal cord, toxic encephalopathy, peripheral neuropathy, and mental disorders—are not fully recognized by society and clinicians. Previous studies have focused on the pathogenesis and clinical characteristics of diseases caused by N 2 O abuse, and there have been few epidemiologic investigations despite the importance of data from such studies for the development and implementation of effective interventions by health authorities (Bao et al., 2020; Garakani et al., 2016; Kaar et al., 2016; Lan et al., 2019; Li et al., 2016; Tuan et al., 2020). In order to collect epidemiologic data on N 2 O abuse, the present study analyzed the general epidemiological and clinical characteristics of 61 patients who were abusing N 2 O and were treated at the Affiliated Hospital of Xuzhou Medical University from January 2017 to December 2020.…”

Lethal nitrous oxide (N2O) intoxication during surgery: the contribution of immunohistochemistry in identifying the cause of death: a case report

“…N 2 O is also known as "laughing gas" for its euphoric, joyful, and sometimes hallucinogenic effects; these are associated with an alarming and increasing spread of gas as a substance of abuse [ 2 , 3 ]. Generally, for recreational purposes, the inhalation occurs through bottles or N 2 O-filled balloons, called funky balls [ 4 ].…”