Diagnostic accuracy of nerve excitability and compound muscle action potential scan-derived biomarkers in amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE: The lack of reliable early biomarkers still causes substantial diagnostic delays in amyotrophic lateral sclerosis (ALS). The aim was to assess the diagnostic accuracy of a novel electrophysiological protocol in patients with suspected motor neuron disease (MND). METHODS: Consecutive patients with suspected MND were prospectively recruited at our tertiary referral centre for MND in Utrecht, The Netherlands. Procedures were performed in accordance with the Standards for Reporting of Diagnostic Accuracy. In addition to the standard diagnostic workup, an electrophysiological protocol of compound muscle action potential (CMAP) scans and nerve excitability tests was performed on patients' thenar muscles. The combined diagnostic yield of nerve excitability and CMAP scan based motor unit number estimation was compared to the Awaji and Gold Coast criteria and their added value was determined. RESULTS: In all, 153 ALS or progressive muscular atrophy patients, 63 disease controls and 43 healthy controls were included. Our electrophysiological protocol had high diagnostic accuracy (area under the curve [AUC] 0.85, 95% confidence interval [95% CI] 0.80-0.90), even in muscles with undetectable axon loss (AUC 0.78, 95% CI 0.70-0.85) and in bulbar-onset patients (AUC 0.85, 95% CI 0.73-0.95). Twenty-four of 33 (73%) ALS patients who could not be diagnosed during the same visit were correctly identified, as well as 8/13 (62%) ALS patients not meeting the Gold Coast criteria and 49/59 (83%) ALS patients not meeting the Awaji criteria during this first visit. CONCLUSIONS: Our practical and non-invasive electrophysiological protocol may improve early diagnosis in clinically challenging patients with suspected ALS. Routine incorporation may boost early diagnosis, enhance patient selection and generate baseline measures for clinical trials

Assessment of the reliability of the motor unit size index (MUSIX) in single subject “round-robin” and multi-centre settings

Objective The motor unit size index (MUSIX) is incorporated into the motor unit number index (MUNIX). Our objective was to assess the intra-/inter-rater reliability of MUSIX in healthy volunteers across single subject “round robin” and multi-centre settings. Methods Data were obtained from i). a round-robin assessment in which 12 raters (6 with prior experience and 6 without) assessed six muscles (abductor pollicis brevis, abductor digiti minimi, biceps brachii, tibialis anterior, extensor digitorum brevis and abductor hallucis) and ii). a multi-centre study with 6 centres studying the same muscles in 66 healthy volunteers. Intra/inter-rater data were provided by 5 centres, 1 centre provided only intra-rater data. Intra/inter-rater variability was assessed using the coefficient of variation (COV), Bland-Altman plots, bias and 95% limits of agreement. Results In the round-robin assessment intra-rater COVs for MUSIX ranged from 7.8% to 28.4%. Inter-rater variability was between 7.8% and 16.2%. Prior experience did not impact on MUSIX values. In the multi-centre study MUSIX was more consistent than the MUNIX. Abductor hallucis was the least reliable muscle. Conclusions The MUSIX is a reliable neurophysiological biomarker of reinnervation. Significance MUSIX could provide insights into the pathophysiology of a range of neuromuscular disorders, providing a quantitative biomarker of reinnervation

Patient-reported daily functioning after SARS-CoV-2 vaccinations in autoimmune neuromuscular diseases

Background and purpose: There are concerns for safety regarding SARS-CoV-2 vaccines for patients with autoimmune neuromuscular disease. We compared daily functioning using disease-specific patient-reported outcome measures (PROMs) before and after SARS-CoV-2 vaccinations. Methods: In this substudy of a prospective observational cohort study (Target-to-B!), patients with myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and idiopathic inflammatory myopathy (IIM) vaccinated against SARS-CoV-2 were included. Surveys of daily functioning (Myasthenia Gravis Activities of Daily Living, Inflammatory Rasch-Built Overall Disability Scale, Multifocal Motor Neuropathy Rasch-Built Overall Disability Scale, and Health Assessment Questionnaire-Disability Index) were sent before first vaccination and every 60 days thereafter for up to 12 months. Regression models were constructed to assess differences in PROM scores related to vaccination, compared to scores unrelated to vaccination. We also assessed the proportion of patients with deterioration of at least the minimal clinically important difference (MCID) between before first vaccination and 60 days thereafter. Results: We included 325 patients (median age = 59 years, interquartile range = 47-67, 156 [48%] female sex), of whom 137 (42%) had MG, 79 (24%) had CIDP, 43 (13%) had MMN, and 66 (20%) had IIM. PROM scores related to vaccination did not differ from scores unrelated to vaccination. In paired PROMs, MCID for deterioration was observed in three of 49 (6%) MG patients, of whom none reported a treatment change. In CIDP, MCID for deterioration was observed in eight of 29 patients (28%), of whom two of eight (25%) reported a treatment change. Conclusions: SARS-CoV-2 vaccination had no effect on daily functioning in patients with autoimmune neuromuscular diseases, confirming its safety in these patients

230th ENMC International Workshop:: Improving future assessment and research in IgM anti-MAG peripheral neuropathy: A consensus collaborative effort, Naarden, The Netherlands, 24–26 February 2017

The 230th European Neuromuscular Center (ENMC) international workshop occurred in Naarden, the Netherlands, from February 24th to 26th, 2017. The aims of the workshop were: 1) to create an IgM associated peripheral neuropathy study group and achieve consensus regarding the registration of patients with IgM associated peripheral neuropathy in a patient-based registry, 2) to improve future assessment of patients with IgM associated peripheral neuropathy from hematological markers to clinical trials, and 3) to discuss promising therapies for future clinical trials. Seventeen clinicians and researchers (sixteen neurologists and one hematologist) from nine countries (Belgium, Curaçao, France, Italy, the Netherlands, Spain, Switzerland, the United Kingdom, and the United States of America) were present. A patient with IgM associated peripheral neuropathy, a representative of the GBS/CIDP Foundation International, and a PhD student, who received support from the ENMC Young Scientist Program, also attended

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity

Background: Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs. Methods: IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies. Results: In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p Pathophysiology and treatment of rheumatic disease

Meeting needs: Value chain collaboration in stabilization and reconstruction operations

Purpose From the perspective of value chains, the purpose of this paper is to analyse the organization of stabilization and reconstruction operations, most notably in Afghanistan, with the intention to improve the way the beneficiaries are involved. Design/methodology/approach Case study The paper first develops a theoretical framework that draws upon value chain literature. To gather empirical data fieldwork was done within the Dutch provincial reconstruction team (PRT) in Afghanistan. Methods that were used include interviews, participatory observation and desk study. Findings In the value chain process six steps are identified: early warning, file and analysis, appraisal/qualification, assignment/management, execution and evaluation. Different categories of personnel (military, reservists, civilians) bring with them different backgrounds. This led to different opinions on who can be considered as the customer of the value chain. Moreover, personnel received different signals in the early warning step as to what needed to be done. From there on, different values and perspectives developed during the sequence of the various stages in the value chain that were not easily aligned. The formal structure of the work activities in the PRT was clear but did not match with the everyday reality. This showed another, much more fuzzy picture. Many mutual contacts were needed to overcome the coordination problems, but that required considerable additional efforts. Originality/value The paper applies value chain literature to stabilization and reconstruction operations and focuses on the customers. It uses unique data and demonstrates the usefulness of a multidisciplinary approach. Keywords: Civil-military co-operation, Inter-organizational co-ordinatio