Neurological Manifestations Induced by Nitrous Oxide Abuse: A Case Series and Review of Literature.

INTRODUCTION: Nitrous oxide (NO) abuse is increasing among young people. This can result in severe neurological disorders such as myelopathy and/or peripheral neuropathy. We report the clinical presentations, biological, radiologic and electrophysiological findings of 5 patients hospitalized with neurological symptoms consecutive to NO abuse. In addition, a literature review was conducted to describe the neurological characteristics and to identify factors associated with a poor recovery. CASE REPORT: Among the 5 patients included, 2 had a myeloneuropathy, 2 had a sensorimotor neuropathy, and 1 had a normal spinal cord magnetic resonance imaging and electromyography despite neurological manifestations consistent with myeloneuropathy. After vitamin B 12 supplementation, recovery was reported in 4 patients, and 1 was lost to follow-up.From the literature review, 154 patients were included [94 males; median age 22 (19 to 26) y; NO exposure 9 (3 to 18) mo]. A myelopathy was identified in 116 patients (75%) and a peripheral neuropathy was documented in 89 patients (58%). Compared with patients who recovered, those with sequelae were more likely to have a motor deficit at presentation ( P <0.001), to use NO regularly ( P <0.001), to have a lower vitamin B 12 level ( P =0.04), and a higher concentration of homocysteine ( P =0.04). A less extensive myelopathy was more frequently found in the group with favorable outcomes ( P =0.002). CONCLUSION: Neurological disorders caused by NO may be challenging with severe clinical patterns. We identified several factors associated with a poor recovery, to make clinicians aware of NO-induced neurotoxicity.

Molecular characterization of Staphylococcus aureus isolates derived from severe pneumonia: a retrospective monocentre study.

BACKGROUND: Staphylococcus aureus is endowed with a repertoire of virulence factors potentially implicated in its pathogenicity and ability to cause invasive disease. The main objective of this study was to describe the bacterial genotype, including virulence genes and affiliation to clonal complexes (CCs), encountered in severe pneumonia. METHODS: DNA microarray was used to analyse 18 S. aureus isolates from patients hospitalized with severe pneumonia between 2017 and 2019. RESULTS: Among 18 S. aureus isolates, 14 were methicillin-susceptible S. aureus (MSSA), and 4 methicillin-resistant S. aureus (MRSA). There were 14 community-acquired, 3 healthcare-associated, and 1 hospital-acquired infections. Different radiological presentations were observed: necrotizing pneumonia (n = 8, 44%), alveolar consolidation (n = 7, 39%), alveolar-interstitial infiltrates (n = 3, 17%). Sixteen patients (89%) required ICU hospitalization, 13 (72%) an invasive mechanical ventilation, and 12 (67%) a vasopressor support. Mortality affected 6 patients (33%). Panton-Valentine leukocidin (PVL), staphylococcal enterotoxins, toxic shock syndrome toxine-1 (TSST-1) encoding genes were documented in nine (50%), 12 (67%), one (6%) of the isolates, respectively. Accessory regulator gene group I was the most reported (n = 9, 50%) and was found in five deaths. The majority of isolates were affiliated to CC152 (n = 6), followed by CC15 (n = 3), CC45 (n = 2), CC30 (n = 2), CC1 (n = 2), CC8 (n = 1), CC9 (n = 1), and CC25 (n = 1). All the CC152 isolates were PVL-positive. CONCLUSION: CC152-PVL positive S. aureus strains were the most prevalent in severe pneumonia. Other virulence gene profiles were found coupled to additional clonal lineages. A genotyping strategy contributes to describe the current circulating strains and bacterial genetic backgrounds.

Aspergillus flavus malignant external otitis in a diabetic patient: case report and literature review.

PURPOSE: Malignant external otitis is an aggressive and potentially life-threatening infection. This rare disorder is typically caused by Pseudomonas aeruginosa and affects almost exclusively elderly diabetic patients. However, fungal malignant external otitis have been identified, especially in immunocompromised hosts. METHODS: We report a rare case of invasive malignant external otitis caused by Aspergillus flavus in a diabetic patient without other underlying immunosuppression. A review of Aspergillus spp. malignant external otitis since voriconazole became the first line for invasive aspergillosis was performed. RESULTS: A 72-year-old man with diabetes mellitus developed invasive malignant external otitis with a vascular involvement. The patient was treated with empiric courses of antibiotics until a fungal infection was diagnosed. Proven Apsergillus infection was based on histopathological examination and isolation of A. flavus from culture of osteo-meningeal biopsies. Despite optimal antimicrobial therapy with voriconazole, the patient presented with cerebral infarction in the setting of an angioinvasive fungal infection leading to a fatal outcome. From a review of the literature, we found 39 previously published cases of proven Aspergillus spp. malignant external otitis treated with new triazoles. CONCLUSION: Given our experience and the literature review, a fungal etiology should be considered early in the course of malignant external otitis unresponsive to a conventional broad spectrum antibiotic therapy, with the need for a tissue biopsy to confirm the diagnosis.