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.

Efficacy and safety profile of memantine in patients with cognitive impairment in multiple sclerosis: A randomized, placebo-controlled study.

UNLABELLED: Memantine, an uncompetitive antagonist of N-methyl-D-aspartate (NMDA)-type glutamate receptors that was approved for the treatment of moderate to severe Alzheimer's disease, has been negatively evaluated for the treatment of cognitive disorders of multiple sclerosis, but these studies were conducted only during short-term administration and on a heterogeneous group of patients with different forms of the disease. In addition, many adverse reactions were observed in these patients. AIMS: The purpose of the "EMERITE" (NCT01074619) study was to examine the efficacy and safety of the long-term administration of memantine as a symptomatic treatment for cognitive disorders in patients with relapsing-remitting multiple sclerosis (RR-MS). METHODS: The study was supported by the French Ministry of Health and received additional support from Lundbeck. In this double-blind, placebo-controlled, parallel group, randomized trial, the participants were assigned to receive memantine (20 mg/day) or a placebo for 52 weeks. The participants included males and females, 18-60 years of age, with a diagnosis of RR-MS and presenting with a cognitive complaint and/or demonstrating moderate cognitive impairment. The data were collected in the Department of Neurology in 19 French centers. The primary outcome was the Paced Auditory Serial Addition Test (PASAT) score at week 52. Secondary measurements included additional neuropsychological tests and the annualized relapse rate. The scores were adjusted according to the baseline scores in the analysis. The safety was assessed by the number of adverse events. The random sequence was generated using the Excel software. At each center, only the pharmacist had access to the allocation sequence and could be asked to unblind the trial. RESULTS: Fifty patients were allocated to the memantine group, and 43 to the placebo group. The intent-to-treat (ITT) population included 31 patients in each group. After adjusting for the PASAT scores at baseline, the PASAT scores at the end point did not differ between the memantine and the placebo groups (p=0.88). Adjusted mean score difference (memantine minus placebo), was -0.40 (95% confidence interval: -5.5; +4.7). No significant differences were observed for the secondary outcomes (short term memory and attention scores, EDSS, and relapse rate). The findings remained unchanged after multiple imputation of the missing values. Neurological and psychiatric adverse events were significantly higher in the memantine group than in the placebo group, and these parameters were higher than those reported in the product literature of memantine. CONCLUSIONS: No differences between the placebo and memantine groups were observed. Nevertheless, the tolerability of memantine was significantly worse than expected.

Evolution of the Karnosky Performance Status throughout life in glioblastoma patients.

Functional independence in glioblastoma (GBM) patients is a key factor in measuring the quality of life. Progression free survival (PFS) and overall survival (OS) have been largely described. However, the evolution over time of the performance status during the patients' life remains understudied. We thus studied the time to loss of functional independence as assessed by a Karnosky Performance Status (KPS) below 70 % in GBM patients. We analysed all GBM patients treated in our institution between 2008 and 2013 and meeting the following criteria: age >18 years, supratentorial location, post-surgical KPS ≥ 70 %, initially treated with concomitant radiotherapy (RT) and Temozolomide. Within the 84 patients studied, the median PFS was 9 months and the median OS was 18.7 months. The median survival time with functional independence (KPS ≥ 70 %) was 14.5 months. On average, the patients spent 73 % of their lifespan with a KPS ≥ 70 %. Surgical resection and low steroid dosage were statistically associated with increased survival time with KPS ≥ 70 % (p = 0.015 and p = 0.03, respectively). Sixty-two (62) patients received one or several lines of chemotherapy at recurrence. Under treatment with Bevacizumab (42 Bev-based regimens), radiological responses were seen in 35 % and improvement in KPS occurred in 24 % whereas no response and rare improvement of KPS (3 %) were seen with other type of chemotherapy (97 non Bev-based regimens). In GBM patients, median survival with KPS ≥ 70 % largely exceeds PFS. Surgical resection and low steroids dosage at RT-onset appeared as good prognosis factors for survival with functional independence.

Upfront association of carboplatin plus pemetrexed in patients with brain metastases of lung adenocarcinoma.

Approximately 10% of patients with non-small cell lung cancer (NSCLC) have brain metastases at the time of diagnosis. When surgical resection is not possible, whole brain radiotherapy is the standard of care, with a cerebral response rate of approximately 30%. We report our experience with an upfront association of carboplatin and pemetrexed (areas under the curve, 5 and 500 mg/m(2), respectively), every 3 weeks, in 30 patients presenting with newly diagnosed brain metastases and NSCLC. Cerebral MRIs were performed every 6-9 weeks. The radiologic response rates were assessed according to Response Evaluation Criteria in Solid Tumors. Overall survival was also determined. Twenty-six patients were evaluable for response, and the objective cerebral response rate (complete and partial response) in the intent-to-treat population was 40% (12 of 30 patients). Event-free survival was 31 weeks, and median overall survival was 39 weeks. The upfront association of carboplatin plus pemetrexed allows simultaneous treatment of cerebral and systemic disease in patients with NSCLC with newly diagnosed brain metastases and appears to be particularly interesting in terms of radiologic response and overall survival. Further clinical studies are warranted.

Steroid requirements during radiotherapy for malignant gliomas.

Radiotherapy (RT) is the standard treatment for high-grade gliomas. However, toxicity may develop during RT, such as brain edema or worsening of neurological symptoms. Surprisingly, no dedicated study had focused on steroid requirements during RT in adult patients with malignant gliomas. We evaluated prospectively all patients with malignant gliomas treated by RT in a single center from July 2006 to May 2009. Age, sex, initial Karnofsky performance status (KPS), tumor localization and histology, type of surgical resection, clinical target volume, total dose and duration of RT, concomitant treatment with temozolomide, and steroid dosage during RT and at 1 and 3 months after RT were recorded in all patients. Most of the 80 patients (70%) were already taking steroids before RT. Half of them (55%) required initiation or further steroids increase during RT. The median time to steroid increase was 8 days. Only 13% of patients remained free of steroids during RT, and the mean maximal dosage of prednisone was 55 ± 48 mg. At 3 months after RT, 29% of patients were free of steroids, and the mean prednisone dosage was 32 ± 50 mg. Unresected tumors and initial KPS ≤80% were the only variables associated with higher steroid requirements on multivariate analysis. In our series, almost all patients required steroids during RT. Poor initial KPS and biopsy were associated with higher steroid requirements.

Axonal signals in central nervous system myelination, demyelination and remyelination.

Axonal signals are key players in central nervous system myelination. During development, the onset of myelination depends on a balance between positive and negative axonal signals. Among negative signals are inhibitory adhesion molecules that need to be removed from the cell surface for the myelination process to proceed. Positive signals necessary to initiate myelination consist of both interactions with specific adhesion molecules and electrical activity-induced release of promyelinating factors. In multiple sclerosis, demyelination induces major modifications of axonal surface components. The disruption of these factors might participate to the failure of the myelin repair process.

Parkinson's disease patients with bilateral subthalamic deep brain stimulation gain weight.

Weight, body mass index (BMI) and energy expenditure/energy intake (EE/EI) was studied in 19 Parkinson's disease (PD) patients after subthalamic deep brain stimulation (STN-DBS) versus 14 nonoperated ones. Operated patients had a significant weight gain (WG, + 9.7 +/- 7 kg) and BMI increase (+ 4.7 kg/m2). The fat mass was higher after STN-DBS. Resting EE (REE; offdrug/ON stimulation) was significantly decreased in STN-DBS patients, while their daily energy expenditure (DEI) was not significantly different. A significant correlation was found among WG, BMI increase, and pre-operative levodopa-equivalent daily dose, their reduction after STN-DBS, and the differential REE related to stimulation and the REE in the offdrug/OFF stimulation condition. In conclusion, STN-DBS in PD induces a significant WG associated with a reduction in REE without DEI adjustment.