Nitrous oxide-induced polyneuropathy, pancytopenia and pulmonary embolism: a case report.

BACKGROUND: Nitrous oxide is a medical and household gas that has seen its use drift to recreational purpose among the young population in recent years. Significant neurological, hematological and psychiatric side effects, generally related to an induced functional vitamin B12 deficiency, have been described separately in the literature. CASE REPORT: A 22-year-old woman of North African origin experienced an exceptional combination of polyneuropathy, bilateral pulmonary embolism and severe pancytopenia related to vitamin B12 deficiency and hyperhomocysteinemia induced by recreational nitrous oxide use. After treatment with vitamin B12 supplementation and intensive rehabilitative management, the patient progressively regained the ability to walk and her biological parameters gradually returned to normal. The pathophysiological mechanisms related to a decrease in vitamin B12 activity are the reduction of products needed for synthesis of deoxyribonucleic acid, carbohydrate or fatty acids, and the increase of hyperhomocysteinemia. Other mechanisms involving a direct action of N2O are also suspected. CONCLUSION: This case report brings elements to support our knowledge about pathological pathway, recovery and prognosis of recreational N2O abuse complications. The general and medical population should be aware to the serious consequences of this type of consumption.

Efficacy of exercise as a treatment for Obstructive Sleep Apnea Syndrome: A systematic review.

INTRODUCTION: Obstructive Sleep Apnea Syndrome (OSAS) is a prevalent condition associated with numerous adverse health consequences. Exercise therapy was described as a valuable OSAS treatment alternative to continuous positive airway pressure. OBJECTIVE: The objective of the present systematic review was to assess the efficacy of exercise in reducing OSAS severity and associated comorbidities. SETTING: We queried MEDLINE and SCOPUS and ScienceDirect databases with the following keywords: "sleep apnea" and "sleep disordered breathing" for the population and "physical activity", "fitness" and "exercise" for the intervention. RESULTS: Eight studies including a total number of 354 patients showed that OSAS severity was significantly reduced after intervention. This reduction was associated with significant improvement in cardio-vascular fitness, sleep quality and quality of life. Conversely, this effect was not directly related to body weight reduction. CONCLUSION: This systematic review suggests that physical activity should be recommended as a treatment for OSAS patients. However, further research is necessary to demonstrate this long-term efficiency with a higher level of confidence and to better understand the underlying physiological mechanisms.