A 4He vector zero-field optically pumped magnetometer operated in the Earth-field.

Low intrinsic noise, high bandwidth, and high accuracy vector magnetometers are key components for many ground or space geophysical applications. Here, we report the design and the test of a 4He vector optically pumped magnetometer specifically dedicated to these needs. It is based on a parametric resonance magnetometer architecture operated in the Earth magnetic field with closed-loop compensation of the three components of the magnetic field. It provides offset-free vector measurements in a ±70 µT range with a DC to 1 kHz bandwidth. We demonstrate a vector sensitivity up to 130 fT/√Hz, which is about ten times better than the best available fluxgate magnetometers currently available for the same targeted applications.

Native versus deglycosylated IgM in anti-MAG neuropathy: Correlation with clinical status - Study of 10 cases.

BACKGROUND/PURPOSE: In anti-myelin associated glycoprotein (anti-MAG) neuropathies, there is evidence that anti-MAG antibodies are pathogenic but numerous studies report the absence or a weak correlation between the titers of these antibodies and disease course. In this study we assessed the relationships between MAG and glycosylated moieties located on Fc fragment of IgM anti-MAG. MATERIAL AND METHODS: IgM were extracted from the serum of 8 patients with anti-MAG neuropathy and in 2 patients with anti-MAG antibodies without anti-MAG neuropathy. Anti-MAG activity was performed with pre- and post-deglycosylated IgM extracts using indirect immunofluorescence (IIF) and ELISA. Sera from 49 patients with IgM monoclonal gammopathy without neurological disease were tested as control group (CG). Results were compared to clinical scores. For 4 patients the affinity constant of IgM with MAG was analyzed pre- and post-deglycosylated, using surface plasmon resonance technology (SPR). RESULTS: The relationships between MAG and glycosylated moieties of IgM anti-MAG were confirmed by kinetic and immunological assays. Deglycosylation resulted in a decrease in anti-MAG titers. Post-deglycosylation anti-MAG titers trended with changes in IgM titers and allowed quantifying anti-MAG antibodies without a saturation of the testing method. After deglycosylation, the titers better represented pathogenic activity and help to follow a given patient's clinical status prospectively. Six patients from CG (12.2%) had anti-MAG antibody titers over positive threshold: 1000 Bühlmann-Titer-Units (BTU) supporting the hypothesis of neutral intermolecular interactions between IgM and MAG. Deglycosylation allowed distinguishing infra clinical forms from neutral relationships forms, when the titers are weak but this assay remains essentially a diagnostic tool.

Diagnostic usefulness of plexus magnetic resonance imaging in chronic inflammatory demyelinating polyradiculopathy without electrodiagnostic criteria of demyelination.

BACKGROUND AND PURPOSE: The usefulness of plexus magnetic resonance imaging (MRI) in the diagnosis of chronic inflammatory demyelinating polyradiculopathy (CIDP) without definite European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria is currently unclear. METHODS: Data from consecutive patients with clinical manifestations suggesting CIDP, with or without (CIDP-D and CIDP-ND, respectively) definite EFNS/PNS electrodiagnostic criteria, and referred for plexus MRI in our imaging centre were retrospectively analysed. An expert committee of neurologists compared the level of suspicion of CIDP in CIDP-ND patients to the blinded/unblinded MRI findings. Plexus MRI was reviewed by a neuroradiologist blinded to the final diagnosis. RESULTS: In all, 38 patients were assessed with suspected CIDP-ND [7/38 (18%) probable; 13/38 (34%) possible; 18/38 (47%), no EFNS/PNS electrodiagnostic criteria], plus 10 with CIDP-D. Thirty-six of the 38 (95%) fulfilled clinical criteria of CIDP variants, including pure sensory neuropathy in 22/36 (61%). Plexus MRI showed abnormalities in 22/38 (58%) patients including increased nerve signal intensity on T2-weighted images in 22/22 (100%), nerve enlargement in 20/22 (91%) and contrast enhancement in 8/22 (36%). Plexus MRI enabled the expert committee's final diagnosis to be adjusted in 7/38 (18%) patients, and in conjunction with nerve conduction studies was a supportive criterion to classify 7/24 (29%) patients as definite CIDP. MRI abnormalities were more asymmetrical (P = 0.03) and less diffuse (P = 0.1) in CIDP-ND than in CIDP-D. CONCLUSIONS: Our observations suggest that plexus MRI makes a valuable contribution to the diagnosis of CIDP-ND patients. Further studies are needed to investigate inter-rater reliability of clinical and imaging criteria of CIDP in these patients, and the impact on outcomes.

Mimicking muscle fiber structure and function through electromechanical actuation of electrospun silk fiber bundles.

Here we detail the fabrication and testing of artificial muscles fabricated from composites of the natural biopolymer silk fibroin and conducting polymers. Aligned nanofiber bundles of silk that mimic the structure of skeletal muscles were produced via electrospinning, and the fibers were infused with conducting polymers using chemical and electrochemical in situ polymerization methods. The resulting bundles of individual, electroactive fibers underwent electromechanical actuation in biologically-relevant electrolyte solutions when low potentials were applied, thus mimicking the contractile function of native muscles. The fabrication methods, bulk mechanical properties, stress and strain generation, and stability under repeated actuation for fiber bundles coated with different conducting polymer formulations are presented.

High dose subcutaneous immunoglobulin for idiopathic inflammatory myopathies and dysimmune peripheral chronic neuropathies treatment: observational study of quality of life and tolerance.

BACKGROUND: In patients with autoimmune diseases who still derive benefit from high dose intravenous immunoglobulin (IVIg) treatment, some physicians resort to subcutaneous (SC) Ig as a replacement therapy. OBJECTIVE: To collect quality of life (QoL) and tolerance data on SCIg in patients for whom the switch from IVIg to SCIg is essential to maintain treatment. METHODS: This observational study included patients with either idiopathic inflammatory myopathies (IIM) or chronic dysimmune peripheral neuropathies (CDPN) treated with IVIg, who had been switched to SCIg administration for at least three months. The main objective was to describe the impact of SCIg on QoL after six months, using the generic Short-Form 36 questionnaire (SF-36). The secondary objectives were to evaluate SCIg tolerance and clinical efficiency. RESULTS: Eight centres recruited 12 IIM patients and two centres recruited 11 CDPN patients. Neither the physical nor the mental health SF-36 component summaries showed any QoL deterioration during the six-month study period and all IIM and CDPN patients remained clinically stable during the same period. The most frequent adverse effects were injection site reactions (50%), cutaneous tissue disorders (18.2%), and nervous system disorders (13.6%). Two serious adverse events (myocarditis and cerebrovascular accident) occurred in two patients. CONCLUSION: In these rare inflammatory diseases, high dose SCIg administration (which can be home based) has no deleterious effect on patient QoL. It appears to be a safe and efficient alternative to hospital-based IVIg.

[American Academy of Neurology, Washington, 18-25 April 2015]. / American Academy of Neurology, Washington, 18-25 avril 2015.

CEREBROVASCULAR DISEASES: The benefit of the thrombectomy using stents retrievers in the acute stroke phase is now demonstrated when there is a proximal occlusion of an intracranial artery, whatever its mechanism. The place of the anticoagulants in the management of cervical artery dissections remains uncertain, while the benefit of the blood pressure control in the secondary prevention of deep and lobar intracerebral hemorrhages is critical. The development of cardiac MRI, prolonged cardiac monitoring and transcranial doppler seems to improve the diagnosis of cardio-embolic sources of stroke. EPILEPSY: A specialized urgent-access single seizure clinic represents a model which reduces wait-times and improves patient access after a first fit. Co-locating a psychiatrist within outpatient epilepsy center leads to a reduction in psychiatric symptoms and people with psychogenic non-epileptic seizures. When neurologists around the world assess identical case scenarios for the diagnosis of epilepsy, concordance is between moderate and poor, showing that epilepsy diagnosis remains difficult. More than one third of elderly with new-onset epilepsy of unknown etiology exhibit temporal lobe atrophy on brain imaging. MOVEMENT DISORDERS: There is no major progress in the therapeutic approach of Parkinson's disease but the discovery of new genetic markers such as glucocerebrosidase mutations may greatly change our knowledge of the disease process and may induce new therapeutic strategies in the future. The natural history of the disease is also better understood from the prodromal phase to the post-mortem analysis of the brain and the classification of the processes based on abnormal protein deposits. DEMENTIA: The respective value of biomarkers (amyloid imaging versus CSF biomarkers) for in vivo diagnosis of Alzheimer's disease (AD) has been detailed. Therapeutic expectations mainly rely on anti-Aß immunization trials performed in preclinical (and no longer prodromal) stages of AD, with the aim of slowing the evolution of neuronal loss. Besides a lot of communications on dementia genetics or physiopathogeny, fascinating and promising results were presented on deep brain stimulation for depression resistant to medical treatment. PERIPHERAL NEUROPATHY: Ibudilast, administered with riluzole, is safe and tolerable in patients with amyotrophic lateral sclerosis (ALS), improves ALS function and delays progression. Patients with painful small fiber neuropathy have a high rate of mutations in the SCN9A gene, coding for Nav1.7 voltage-gated sodium-channels. Peripheral nerve lymphoma (NL) is a multifocal painful neuropathy that causes endoneurial inflammatory demyelination: primary NL is less severe than secondary NL, which occurs after remission, suggesting that nerve may be considered a "safe lymphoma haven". MULTIPLE SCLEROSIS (MS): Biotin in progressive forms of MS and daclizumab in relapsing-remitting forms appear to be promising treatments. In case of failure of current first-line and/or second-line therapeutics, alemtuzumab may be an interesting alternative treatment. Teriflunomide, dimethyl fumarate and fingolimod are oral treatments with confirmed efficacy and acceptable safety. Besides vitamin D insufficiency and smoking, which are confirmed risk factors for the disease, testosterone insufficiency (in males) and obesity are emerging risk factors, which could also be corrected.

Segmental somatosensory-evoked potentials as a diagnostic tool in chronic inflammatory demyelinating polyneuropathies, and other sensory neuropathies.

PURPOSE OF THE STUDY: Somatosensory-evoked potentials with segmental recordings were performed with the aim of distinguishing chronic inflammatory demyelinating polyneuropathy from other sensory neuropathies. PATIENTS AND METHODS: Four groups of 20 subjects each corresponded to patients with (1) possible sensory chronic inflammatory demyelinating polyneuropathy, (2) patients with sensory polyneuropathy of unknown origin, (3) patients with amyotrophic lateral sclerosis and (4) normal subjects. The patients selected for this study had preserved sensory potentials on electroneuromyogram and all waves were recordable in evoked potentials. Somatosensory-evoked potentials evaluations were carried out by stimulation of the posterior tibial nerve at the ankle, recording peripheral nerve potential in the popliteal fossa, radicular potential and spinal potential at the L4-L5 and T12 levels, and cortical at C'z, with determination of distal conduction time, proximal and radicular conduction time and central conduction time. RESULTS: In the group of chronic inflammatory demyelinating polyneuropathy, 80% of patients had abnormal conduction in the N8-N22 segment and 95% had abnormal N18-N22 conduction time. In the group of neuropathies, distal conduction was abnormal in most cases, whereas 60% of patients had no proximal abnormality. None of the patients in the group of amyotrophic lateral sclerosis had an abnormal N18-N22 conduction time. CONCLUSION: Somatosensory-evoked potentials with segmental recording can be used to distinguish between atypical sensory chronic inflammatory demyelinating polyneuropathy and other sensory neuropathies, at the early stage of the disease. Graphical representation of segmental conduction times provides a rapid and accurate visualization of the profile of each patient.

Challenges in the treatment of chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic idiopathic demyelinating polyradiculoneuropathy (CIDP) is a rare disease, the most frequent one within the spectrum of the so-called "chronic immune-mediated neuropathies". Challenges in the treatment of CIDP firstly concern its diagnosis, which may be difficult, mainly for the atypical forms. Secondly, challenges encompass the choice of the first-line treatment, such as corticosteroids, intravenous immunoglobulins (IVIg), and plasma exchanges (PE) that have been proven as efficacious by several randomized controlled trials (RCT). Recent reports have focused on both different regimens of corticosteroids, and the occurrence of relapses following treatment with either corticosteroids or IVIg. These data may be helpful for the choice of the first-line treatment and may result in changing the guidelines for treatment of CIDP in clinical practice. The third and more difficult challenge is to manage long-term treatment for CIDP, since no immunomodulatory treatment has to date been proven as efficacious in this situation. Lastly, challenges in the treatment concern the choice of the best outcome measure for CIDP in RCT and clinical practice. The aim of this article is to overview the results of the more recently reported published trials for CIDP, and to give some insights for the current and future management of CIDP.