Marked increase in severe neurological disorders after nitrous oxide abuse: a retrospective study in the Greater Paris area.

BACKGROUND: Recreational nitrous oxide (N2O) use has become more widespread worldwide, leading to an increase in myelopathies and peripheral neuropathies. The aim of this study was to describe clinical and socioeconomical characteristics of severe N2O-induced (NI) neurological disorders (NI-NDs), to determine its incidence in the Greater Paris area and to compare it with that of similar inflammatory neurological disorders. METHODS: We performed a retrospective multicentric cohort study of all adult patients with severe NI-NDs in the neurology and general internal medicine departments of the Greater Paris area from 2018 to 2021. The incidence was compared with that of non-NI-myelitis and Guillain-Barré syndrome (GBS) using a sample of 91,000 hospitalized patients sourced from health insurance data. RESULTS: Among 181 patients, 25% had myelopathy, 37% had peripheral neuropathy and 38% had mixed disease. Most were aged between 20 and 25 years, lived in socially disadvantaged urban areas, and exhibited high rates of unemployment (37%). The incidence of NI-NDs increased during 2020 and reached a peak mid-2021. The 2021 incidence in 20-25-year-olds was 6.15 [4.72; 8.24] per 100,000 persons for NI-myelopathy and 7.48 [5.59; 9.37] for NI-peripheral neuropathy. This was significantly higher than for non-NI-myelitis (0.35 [0.02; 2.00]) and GBS (2.47 [0.64; 4.30]). The incidence of NI-NDs was two to three times higher in the most socially disadvantaged areas. CONCLUSION: The recent increase in recreational N2O use has led to a rise in the incidence of severe NI-NDs, particularly in young adults with low socioeconomic status for whom NI-NDs strongly outweigh similar neurological disorders.

Clinical and Radiological Follow-Up of a Pfizer-BioNTech COVID-19 Vaccine-Induced Hemichorea-Hemiballismus.

Background: Hemichorea-hemiballismus is a rare hyperkinetic movement disorder. Case Report: A 90-year-old male developed left hemichorea-hemiballismus after his second dose of the Pfizer-BioNTech COVID-19 vaccine. A wide range of investigations including magnetic resonance imaging did not reveal an alternative cause. [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) showed increases in right putamen fixation compared to the left side. The patient showed significant improvement after five days of intravenous corticosteroids, with a normal FDG-PET. Discussion: This hemichorea-hemiballismus case shows dynamic restoration of putamen metabolism mirroring clinical evolution after administration of corticosteroids, suggesting an autoimmune COVID-19 vaccine-induced reaction.

Neurological consequences of recreational nitrous oxide abuse during SARS-CoV-2 pandemic.

INTRODUCTION: Recreational use of nitrous oxide (N2O) is a growing practice in France and all around the world and is often associated with neurological complications. We report detailed clinical and paraclinical presentations of 12 patients with combined degeneration of the spinal cord and peripheral neuropathies in relation to N2O consumption, possibly favored by lockdowns due to SARS-CoV-2 pandemic. RESULTS: With variable levels of consumption, the 12 patients presented spinal cord and/or peripheral nerve damage, with mostly motor and ataxic symptoms, motor axonal nerve damage, and medullary T2-weighted hyperintensities on MRI. There was a clear improvement in symptoms after vitamin B12 substitution, although some sequelae remained, particularly sensory. DISCUSSION: We report detailed clinical, electrophysiological, radiological, and biological consequences of N2O abuse in 12 patients. Our data support the clinical and paraclinical observations reported in the literature. The mechanisms of neurological N2O toxicity are still debated. There is currently no precise recommendation on the therapeutic management. The clinical evolution after vitamin B12 substitution seems sufficient but could depend on early management. Effective messages targeting at risk population, but also the health professionals involved, seem crucial as does a better legal framework for this growing practice.

Multiple sclerosis: Is there a risk of worsening after yellow fever vaccination?

BACKGROUND: Yellow fever vaccine (YFV) is not advised for multiple sclerosis (MS) patients because of the potential risk of post-vaccine relapses. OBJECTIVE: To assess the risk of relapsing-remitting multiple sclerosis (RR-MS) worsening after YFV. METHODS: Non-interventional observational retrospective, exposed/non-exposed cohort study nested in the French national cohort including MS. RESULTS: 128 RR-MS were included. The 1-year annualized relapse rate (ARR) following YFV did not differ between exposed: 0.219 (0.420) and non-exposed subjects: 0.208 (0.521) (p = 0.92). Time to first relapse was not different between groups (adjusted hazard ratio (HR) = 1.33; 95% confidence interval (CI) = 0.53-3.30, p = 0.54). CONCLUSION: These results suggest that YFV does not worsen the course of RR-MS.

Reintroduction of immune-checkpoint inhibitors after immune-related meningitis: a case series of melanoma patients.

Immune-checkpoint inhibitors (ICIs) targeting cytotoxic T lymphocyte-associated antigen-4 and programmed cell death ligand-1) are associated with several immune-related neurological disorders. Cases of meningitis related to ICIs are poorly described in literature and probably underestimated. Several guidelines are available for the acute management of these adverse events, but the safety of resuming ICIs in these patients remains unclear. We conducted a retrospective case series of immune-related meningitis associated with ICIs that occurred between October 1 2015 and October 31 2019 in two centers: Saint-Louis and Cochin hospitals, Paris, France. Diagnosis was defined by a (1) high count of lymphocytes (>8 cells/mm3) and/or high level of proteins (>0.45 g/L) without bacteria/virus or tumor cells detection, in cerebrospinal fluid and (2) normal brain and spine imaging. Patients were followed-up for at least 6 months from the meningitis onset. Seven cases of immune-related meningitis are here reported. Median delay of meningitis occurrence after ICIs onset was 9 days. Steroid treatment was introduced in four patients at a dose of 1 mg/kg (prednisone), allowing a complete recovery within 2 weeks. The other three patients spontaneously improved within 3 weeks. Given the favorable outcome, ICIs were reintroduced in all patients. The rechallenge was well tolerated and no patients experienced meningitis recurrence. In conclusion, in our series, the clinical course was favorable and steroids were not always required. Resuming ICIs in these patients appeared safe and can thus be considered in case of isolated meningitis. However, a careful analysis of the risk/benefit ratio should be done on a case-by-case basis.

Mapping French people and health professionals' positions regarding the circumstances of morphine use to relieve cancer pain.

BACKGROUND: Cancer patients suffer in part because some health professionals prescribe or administer amounts of analgesics, namely opioids, which are too small or too widely spaced to be fully effective. Patients' reluctance to use opioids for pain treatment is often mentioned as a reason not to apply the official guidelines, but very few studies have been conducted on people's attitudes about opioid use to relieve cancer pain. METHODS: One hundred twenty lay participants and 30 health professionals (7 physicians and 23 nurses) were presented with a set of vignettes describing a terminally ill woman with cancer who is in pain. The vignettes were composed according to a four within-subject factor design: (a) level of pain reported by the patient, (b) patient's explicit request for additional administration of analgesics, (c) the physicians' final decision (e.g., to use a stronger analgesic combining paracetamol and codeine), and (d) the way the decision was made (collectively or not). Participants were asked to assess the extent to which the physician's decision was, in their view, acceptable. RESULTS: Seven qualitatively different positions were found among participants. They were called as follows: tend to disagree with any decision (9%), increase the strength of the painkiller in any case (16%), give morphine preferentially (9%), partly depends on pain level (23%), fully depends on pain level (6%), depends on decision process and on pain level (22%), and tend not to disagree with any collective decision (25%). CONCLUSIONS: Overall, 91% of participants agreed with the use of morphine in terminally ill cancer patients when the pain level was high (score of 7) and the decision to increase the strength of the painkiller was taken collectively. This percentage dropped to 69% when the team was not involved in the decision and to 40% when the pain level was lower (score of 4). If opposition to the use of morphine exists, it is not opposition to morphine itself but opposition to the circumstances of its use.

French laypeople's and health professionals' views on the acceptability of terminal sedation.

AIM: To study the views on the acceptability of terminal sedation (TS) of laypeople and health professionals in France. METHOD: In November 2013-June 2015, 223 laypeople and 53 health professionals (21 physicians and 32) judged the acceptability of TS in 48 realistic scenarios composed of all combinations of four factors: (a) the patients' life expectancy, (b) their request for sedation, (c) the decision-making process and (d) the type of sedation. In all scenarios, the patients were women with a terminal illness suffering from intractable pain and receiving the best possible care. The ratings were subjected to cluster analysis and analyses of variance. RESULTS: Five qualitatively different positions were found that were termed TS acceptable if decision taken collectively (15%), TS acceptable if patient explicitly requested it (19%), TS acceptable if patient did not explicitly oppose it (47%), 24-hour sedation not acceptable (6%) and TS always acceptable (13%). The percentage of older participants in the 'always acceptable' cluster was higher than the percentage of younger participants. CONCLUSIONS: Laypeople and health professionals do not appear to be systematically opposed to TS. The most important factors in increasing its acceptability were the patients' request for sedation and the collective character of the decision-making process.