[Acute and chronic toxicities associated with the use and misuse of nitrous oxide: An update]. / Toxicités aiguës et chroniques associées à l'usage et au mésusage du protoxyde d'azote : mise au point.

Nitrous oxide (N2O) is used since the eighteenth century as an anesthetic and analgesic but also for recreational use. If the labelled uses of N2O and their modalities are nowadays perfectly framed, the misuse of N2O takes very alarming proportions among teenagers and young adults. This misuse is the cause of acute (hypoxia, barotrauma, burns, neuropsychiatric disorders) and chronic complications if repeated (myeloneuropathy, anemia, thrombosis, inhalant use disorder). The main mechanism of the latter is mainly related to a functional deficit in vitamin B12 induced by N2O. The management of acute complications is symptomatic. The management of chronic complications is based on vitamin B12 supplementation. The best biomarker of chronic N2O exposure is the elevation of the plasmatic level of methylmalonic acid. In all cases of recreational misuses, addiction treatment is necessary to prevent complications or their worsening by providing information in order to stop consumption.

[Interest of transcranial stimulation in pelvic and perineal disorders]. / Intérêt de la stimulation transcrânienne dans les troubles pelvi-périnéaux.

OBJECTIVE: The aim of this article was to describe the diagnostic and therapeutic value of transcranial stimulation in pelvic and perineal disorders. METHODS: A literature review (Medline database and Google scholar) with no time limit was performed using keywords: "transcranial direct stimulation", "transcranial magnetic stimulation", "neurogenic bladder", "urinary incontinence", "Parkinson disease", "multiple sclerosis", "stroke", "muscle spasticity", "pelvic pain", "visceral pain". RESULTS: Twelve articles have been selected. Transcranial magnetic or electrical stimulation is a noninvasive neuromodulation technique widely used to establish brain maps to highlight causal relationships between brain and function. Regarding pelvic-perineal disorders, repeated transcranial stimulation has shown significant effects for the treatment of overactive bladder in Parkinson's disease (P<0.05) and multiple sclerosis, but also for the treatment of refractory chronic pelvic pain (P=0.026). Finally, therapeutic effects have also been demonstrated in irritable bowel syndrome. No evidence of efficacy was found on genito-sexual disorders. CONCLUSION: Data from the literature suggest that transcranial stimulation is a noninvasive treatment that may have a role in the management of pelvic and perineal disorders. Its promising field of action would require prospective and randomized studies on a larger scale.