How to distinguish Guillain-Barré syndrome from nitrous oxide-induced neuropathy: A 2-year, multicentric, retrospective study

International audienceBackground: Recreational use of nitrous oxide (N2O) has dramatically increased in recent years, resulting in numerous cases of acute sensorimotor tetraparesis secondary to nitrous oxide-induced neuropathy (N2On). Challenging clinical features can mimic Guillain-Barré syndrome (GBS), the main differential diagnosis upon admission. The most sensitive biomarkers for distinguishing between these two conditions remain to be determined. Methods: Fifty-eight N2On patients from three referral centers were retrospectively included over a 2-year period and compared to GBS patients hospitalized during the same timeframe (47 patients). Collected demographic, clinical, biological, and electrophysiological data were compared between the two groups. Results: The typical N2On clinical pattern included distal sensorimotor deficit in lower limbs with absent reflexes, proprioceptive ataxia, and no cranial involvement (56.7% of our cohort). Misleading GBS-like presentations were found in 14 N2On patients (24.1%), and 13 patients (22.4%) did not report N2O use during initial interview. Only half the N2On patients presented with reduced vitamin B12 serum levels upon admission. A slightly increased cut-off (<200 pmol/L) demonstrated 85.1% sensitivity and 84.5% specificity in distinguishing N2On from GBS. Only 6.9% of N2On patients met the criteria for primary demyelination (p < 0.01), with only one presenting conduction blocks. A diagnostic algorithm combining these two biomarkers successfully classified all GBS-like N2On patients. Conclusions: Vitamin B12 serum level < 200 pmol/L cut-off and conduction blocks in initial electrophysiological study are the two most sensitive biomarkers for rapidly distinguishing N2On from GBS patients. These two parameters are particularly useful in clinically atypical N2On with GBS-like presentation

225th ENMC international workshop:: A global FSHD registry framework, 18â20 November 2016, Heemskerk, The Netherlands

On 18–20 November 2016, the 225th ENMC Workshop on ‘A global FSHD Registry framework’ took place in Heemskerk, the Netherlands. Twenty-two participants from 11 different countries gathered, including clinicians, researchers, policy makers and representatives from patient advocacy groups and industry. Facioscapulohumeral muscular dystrophy (FSHD) is an inherited muscle disorder. Expansion of our knowledge on the (epi)genetic mechanism underlying FSHD has led to advances in identifying (targeted) therapeutic strategies. Consequently it is now important to develop a ‘clinical trial toolbox’, consisting of patient registries, biomarkers and clinical outcome measures to ensure resources are utilized effectively The wide phenotypic expression in rare diseases, such as FSHD, means that patient registries are particularly important for clinical trial readiness. The aims of this workshop were to analyze the experience and results of the existing FSHD patient registries, update the Treat-NMD recommended dataset for FSHD, increase collaboration among established research groups and patient advocacy organizations and create the foundation on which to establish a global registry for FSHD

Characteristics of Patients with Late-Onset Pompe Disease in France: Insights from the French Pompe Registry in 2022

International audienceBackground and ObjectivesThe French Pompe disease registry was created in 2004 for study of the natural course of the disease in patients. It rapidly became a major tool for assessing the long-term efficacy of enzyme replacement therapy (ERT) after the market release of alglucosidase-alfa.MethodsApproximately 10 years after publication of the baseline characteristics of the 126 initial patients of the French Late-Onset Pompe Disease registry, we provide here an update of the clinical and biological features of patients included in this registry.ResultsWe describe 210 patients followed at 31 hospital-based French neuromuscular or metabolic centers. The median age at inclusion was 48.67 ± 14.91 years. The first symptom was progressive lower limb muscle weakness, either isolated (50%) or associated with respiratory symptoms (18%), at a median age of 38 ± 14.9 years. At inclusion, 64% of the patients were able to walk independently and 14% needed a wheelchair. Positive associations were found between motor function measure, manual motor test, and 6-minute walk test (6MWT) results, and these parameters were inversely associated with the time taken to sit up from a lying position at inclusion. Seventy-two patients had been followed for at least 10 years in the registry. Thirty-three patients remained untreated a median of 12 years after symptom onset. The standard ERT dose was administered for 177 patients.DiscussionThis update confirms previous findings for the adult population included in the French Pompe disease registry, but with a lower clinical severity at inclusion, suggesting that this rare disease is now diagnosed earlier; thanks to greater awareness among physicians. The 6MWT remains an important method for assessing motor performance and walking ability. The French Pompe disease registry provides an exhaustive, nationwide overview of Pompe disease and can be used to assess individual and global responses to future treatments