Whole-body magnetic resonance neurography in patients with chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION/AIMS: Whole-body magnetic resonance neurography (MRN) is an imaging modality that shows peripheral nerve signal change in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). We aimed to explore the diagnostic potential of whole-body MRN and its potential as a monitoring tool after immunotherapy in treatment-naïve CIDP patients. METHODS: Whole-body MRN using coronal 3-dimensional short tau inversion recovery (STIR) sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) techniques was performed in patients being investigated for CIDP and in healthy controls. Baseline clinical neuropathy scales and electrophysiologic parameters were collected, and MRN findings were compared before and after CIDP treatment. RESULTS: We found highly concordant symmetrical thickening and increased T2 signal intensities in the brachial/lumbosacral plexus, femoral, or sciatic nerves in five of the eight patients with a final diagnosis of CIDP and none of the healthy controls. There were no treatment-related imaging changes in five patients with CIDP who completed a follow-up study. Diffuse, symmetrical thickening, and increased T2 signal in root, plexus, and peripheral nerves were found in two patients ultimately excluded due to a diagnosis of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) syndrome in addition to signal changes in the muscles, bony lesions, organomegaly, and lymphadenopathy. DISCUSSION: Whole-body MRN imaging shows promise in detecting abnormalities in proximal nerve segments in patients with CIDP. Future studies evaluating the role of MRN in assessing treatment response should consider follow-up scans after treatment durations of more than 4 months.

Phase 2 trial in acetylcholine receptor antibody-positive myasthenia gravis of transition from intravenous to subcutaneous immunoglobulin: The MGSCIg study.

BACKGROUND AND PURPOSE: Data on maintenance therapy with subcutaneous immunoglobulin (SCIg) in myasthenia gravis (MG) are limited. We report on transitioning acetylcholine receptor (AChR) antibody-positive (Ab+) MG patients on stable intravenous immunoglobulin (IVIg) regimens as part of routine clinical care to SCIg 1:1.2. METHODS: This multicenter North American open-label prospective investigator-initiated study had two components: the IVIg Stabilization Period (ISP) enrolling patients already on IVIg as part of routine clinical care (Weeks -10 to -1), followed by transition of stable MG subjects to SCIg in the Experimental Treatment Period (ETP; Weeks 0 to 12). We hypothesized that >65% of patients entering the ETP would have a stable Quantitative Myasthenia Gravis (QMG) score from Week 0 to Week 12. Secondary outcome measures included other efficacy measures, safety, tolerability, IgG levels, and treatment satisfaction. RESULTS: We recruited 23 patients in the ISP, and 22 entered the ETP. A total of 12 subjects (54.5%) were female, and 18 (81.8%) were White, with mean age 51.4 ± 17 years. We obtained Week 12 ETP QMG data on 19 of 22; one subject withdrew from ETP owing to clinical deterioration, and two subjects withdrew due to dislike of needles. On primary analysis, 19 of 22 participants (86.4%, 95% confidence interval = 0.72-1.00) were treatment successes using last observation carried forward (p = 0.018). Secondary efficacy measures supported MG stability. SCIg was safe and well tolerated, and IgG levels were stable. Treatment satisfaction was comparable between ISP and ETP. CONCLUSIONS: MG patients on IVIg as part of their routine clinical care remained stable on monthly IVIg dosage, and most maintained similar disease stability on SCIg.

Randomized trial of three IVIg doses for treating chronic inflammatory demyelinating polyneuropathy.

Intravenous immunoglobulin treatment for chronic inflammatory demyelinating polyneuropathy usually starts with a 2.0 g/kg induction dose followed by 1.0 g/kg maintenance doses every 3 weeks. No dose-ranging studies with intravenous immunoglobulin maintenance therapy have been published. The Progress in Chronic Inflammatory Demyelinating polyneuropathy (ProCID) study was a prospective, double-blind, randomized, parallel-group, multicentre, phase III study investigating the efficacy and safety of 10% liquid intravenous immunoglobulin (Panzyga®) in patients with active chronic inflammatory demyelinating polyneuropathy. Patients were randomized 1:2:1 to receive the standard intravenous immunoglobulin induction dose and then either 0.5, 1.0 or 2.0 g/kg maintenance doses every 3 weeks. The primary end point was the response rate in the 1.0 g/kg group, defined as an improvement ≥1 point in adjusted Inflammatory Neuropathy Cause and Treatment score at Week 6 versus baseline and maintained at Week 24. Secondary end points included dose response and safety. This trial was registered with EudraCT (Number 2015-005443-14) and clinicaltrials.gov (NCT02638207). Between August 2017 and September 2019, the study enrolled 142 patients. All 142 were included in the safety analyses. As no post-infusion data were available for three patients, 139 were included in the efficacy analyses, of whom 121 were previously on corticosteroids. The response rate was 80% (55/69 patients) [95% confidence interval (CI): 69-88%] in the 1.0 g/kg group, 65% (22/34; CI: 48-79%) in the 0.5 g/kg group, and 92% (33/36; CI: 78-97%) in the 2.0 g/kg group. While the proportion of responders was higher with higher maintenance doses, logistic regression analysis showed that the effect on response rate was driven by a significant difference between the 0.5 and 2.0 g/kg groups, whereas the response rates in the 0.5 and 2.0 g/kg groups did not differ significantly from the 1.0 g/kg group. Fifty-six per cent of all patients had an adjusted Inflammatory Neuropathy Cause and Treatment score improvement 3 weeks after the induction dose alone. Treatment-related adverse events were reported in 16 (45.7%), 32 (46.4%) and 20 (52.6%) patients in the 0.5, 1.0 and 2.0 g/kg dose groups, respectively. The most common adverse reaction was headache. There were no treatment-related deaths. Intravenous immunoglobulin (1.0 g/kg) was efficacious and well tolerated as maintenance treatment for patients with chronic inflammatory demyelinating polyneuropathy. Further studies of different maintenance doses of intravenous immunoglobulin in chronic inflammatory demyelinating polyneuropathy are warranted.

Building the Bridge From Pediatric to Adult Neurological Care.

In this brief communication, we discuss the current landscape and unmet needs of pediatric to adult transition care in neurology. Optimizing transition care is a priority for patients, families, and providers with growing discussion in neurology. We also introduce the activities of the University of Toronto Pediatric-Adult Transition Working Group - a collaborative interdivisional and inter-subspeciality group of faculty, advanced-practice providers, trainees, and patient-family advisors pursuing collaboration with patients, families, and universities from across Canada. We envision that these efforts will result in a national neurology transition strategy that will inform designation of health authority attention and funding.

Outcomes of Cerebral Venous Thrombosis due to Vaccine-Induced Immune Thrombotic Thrombocytopenia After the Acute Phase.

BACKGROUND: Cerebral venous thrombosis (CVT) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe condition, with high in-hospital mortality rates. Here, we report clinical outcomes of patients with CVT-VITT after SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination who survived initial hospitalization. METHODS: We used data from an international registry of patients who developed CVT within 28 days of SARS-CoV-2 vaccination, collected until February 10, 2022. VITT diagnosis was classified based on the Pavord criteria. Outcomes were mortality, functional independence (modified Rankin Scale score 0-2), VITT relapse, new thrombosis, and bleeding events (all after discharge from initial hospitalization). RESULTS: Of 107 CVT-VITT cases, 43 (40%) died during initial hospitalization. Of the remaining 64 patients, follow-up data were available for 60 (94%) patients (37 definite VITT, 9 probable VITT, and 14 possible VITT). Median age was 40 years and 45/60 (75%) patients were women. Median follow-up time was 150 days (interquartile range, 94-194). Two patients died during follow-up (3% [95% CI, 1%-11%). Functional independence was achieved by 53/60 (88% [95% CI, 78%-94%]) patients. No new venous or arterial thrombotic events were reported. One patient developed a major bleeding during follow-up (fatal intracerebral bleed). CONCLUSIONS: In contrast to the high mortality of CVT-VITT in the acute phase, mortality among patients who survived the initial hospitalization was low, new thrombotic events did not occur, and bleeding events were rare. Approximately 9 out of 10 CVT-VITT patients who survived the acute phase were functionally independent at follow-up.

Canadian Guidelines for Hereditary Transthyretin Amyloidosis Polyneuropathy Management.

Hereditary transthyretin-mediated (hATTR) amyloidosis is a progressive disease caused by mutations in the TTR gene leading to multisystem organ dysfunction. Pathogenic TTR aggregation, misfolding, and fibrillization lead to deposition of amyloid in multiple body organs and frequently involve the peripheral nerve system and the heart. Common neurologic manifestations include: sensorimotor polyneuropathy (PN), autonomic neuropathy, small-fiber PN, and carpal tunnel syndrome. Many patients have significant progression due to diagnostic delays as hATTR PN is not considered within the differential diagnosis. Recently, two effective novel disease-modifying therapies, inotersen and patisiran, were approved by Health Canada for the treatment of hATTR PN. Early diagnosis is crucial for the timely introduction of these disease-modifying treatments that reduce impairments, improve quality of life, and extend survival. In this guideline, we aim to improve awareness and outcomes of hATTR PN by making recommendations directed to the diagnosis, monitoring, and treatment in Canada.

Lignes directrices sur la prise en charge de l'amylose héréditaire à transthyrétine, accompagnée de polyneuropathie, au Canada.L'amylose héréditaire à transthyrétine (ATTRh) est une maladie évolutive, causée par des mutations du gène de la transthyrétine (TTR), qui entraînent un dysfonctionnement plurisystémique. L'agrégation, le mauvais repliement et la fibrillisation pathogènes de la TTR aboutissent au dépôt de protéines amyloïdes dans plusieurs organes, et affectent souvent le système nerveux périphérique et le cœur. Les troubles neurologiques fréquents comprennent une polyneuropathie sensorimotrice (PN), une neuropathie autonome, une polyneuropathie des petites fibres et le syndrome du canal carpien. Chez bon nombre de patients, la maladie a connu une évolution importante en raison de la pose tardive du diagnostic, la PN-ATTRh ne faisant pas l'objet d'un diagnostic différentiel. Santé Canada a approuvé, depuis peu, deux nouveaux médicaments modificateurs de la PN-ATTRh et efficaces contre l'affection, soit l'inotersen et le patisiran. La pose précoce du diagnostic revêt une importance cruciale dans l'instauration, en temps opportun, de ces tout nouveaux traitements qui atténuent les troubles, améliorent la qualité de vie et prolongent la survie. Les auteurs, par l'élaboration de la nouvelle ligne directrice, espèrent sensibiliser la communauté médicale à la PN-ATTRh, et améliorer les résultats cliniques qui y sont associés, en formulant des recommandations sur le diagnostic et le traitement de la maladie au Canada ainsi que sur la surveillance de son évolution.

European Federation of Neurological Societies cutoff values significantly reduce creatine kinase sensitivity for diagnosing neuromuscular disorders.

INTRODUCTION: Elevated creatine kinase (CK) level was redefined by the European Federation of Neurological Societies)EFNS(as 1.5 times the upper limit of normal. In the current study we sought to determine the sensitivity and specificity of CK testing for the diagnosis of neuromuscular disorders. METHODS: Demographics and CK levels were retrospectively extracted from an electronic database for 234 patients with neuromuscular disorders. Sensitivity, specificity, and likelihood ratios and the area under curve were determined for each diagnosis and different cutoff CK values. RESULTS: Using the EFNS cutoff values significantly reduced CK test sensitivity. Creatine kinase values >1000 IU/L showed a high likelihood (11.04) for myopathies and a low likelihood for polyneuropathies (0). DISCUSSION: European Federation of Neurological Societies cutoff values significantly reduce CK sensitivity for diagnosing neuromuscular disorders. While low CK values cannot exclude a neuromuscular disease, values >1000 IU/L are associated with a high likelihood of myopathy.

Qualitative, Patient-Centered Assessment of Muscle Cramp Impact and Severity.

BACKGROUND: There is an urgent need for new therapeutic options to treat muscle cramps; however, no patient-reported measures exist that capture the entire cramp experience. We conducted a qualitative study to assess the experience of patients suffering muscle cramps, aiming to understand what factors determine the impact cramps have in patients' lives to guide the development of a patient-centered outcome measure of cramp severity and impact. METHODS: We enrolled patients with cramps due to several etiologies, including motor neuron disease, pregnancy-induced cramps, cirrhosis and hemodialysis, and idiopathic and exercise-induced cramps. Patients participated in semistructured interviews about their experiences with muscle cramps and their responses were recorded and transcribed. Data were analyzed with content analysis using data saturation to determine the sample size. We subsequently developed a conceptual framework of cramp severity and overall cramp impact. RESULTS: Ten patients were interviewed when data saturation was reached. The cramp experience was similar across disease and physiological states known to cause muscle cramps. The main themes that compose the overall cramp impact are cramp characteristics, sleep interference, daytime activities interference, and the effect on mental health. CONCLUSIONS: This framework will be used to develop a patient-reported outcome of cramp severity and impact.

Évaluer qualitativement l'impact et la gravité des crampes musculaires tout en étant axé sur les patients qui en souffrent. Contexte : Il existe un besoin urgent de mettre en œuvre de nouvelles options thérapeutiquespour le soulagementdes crampes musculaires. Cela dit, aucun patient qui en souffre ne semble avoir fait état d'optionstenant compte de la totalité de leurexpérience. À cet égard, nous avons effectué une étude qualitative afin justement de mieux cerner l'expérience de ces patients et de comprendreles facteurs qui déterminentl'impact que les crampes peuvent avoir dans leur vie. Nous voulons du coup orienter l'élaboration d'indicateursaxés sur les patients eux-mêmes, indicateurs visant à mesurer l'impact et la gravité de leurs crampes musculaires. Méthodes : Nous avons recruté des patients atteints de crampes musculaires en raison de plusieurs étiologies, par exemple des pathologies du motoneurone, des crampes liées à une grossesse, des cas de cirrhosenécessitant une hémodialyse, des crampes idiopathiquesou déclenchées par l'exercice, etc. Les patients recrutés ont participé à des entrevues semi-structurées portant sur leur expérience en lien avec des crampes musculaires, leurs réponses étant enregistrées et par la suite transcrites. En plus déterminer la taille de notre échantillon à l'aide de la saturation de données, nous avons ensuite analysé ces dernières au moyen de la méthode d'analyse de contenu. Enfin, nous avons élaboré un cadre conceptuel de la gravité des crampes musculaires et de leur impact général. Résultats : Une fois nos données saturées, dix patients ont été interviewés. Les expériences liées à leurs crampes se sont révélées comparables peu importe les maladies et les états physiologiques. Parmi les principaux aspects caractérisant l'impact général des crampes, mentionnons les suivants : les caractéristiques des crampes, les perturbations du sommeil qu'elles entraînent, leur interférence dans des activités de jour et leurs effets sur la santé mentale. Conclusions : Ce cadre de référence sera utilisé pour élaborer un outil mesurant la gravité et l'impact des crampes musculaires, et ce, en fonction de l'apport des patients eux-mêmes.

Uric Acid Levels Correlate with Sensory Nerve Function in Healthy Subjects.

BACKGROUND: High levels of uric acid (UA) are associated with various peripheral neuropathies. Furthermore, uric acid levels have been found to correlate with both the clinical and electrophysiological severity of diabetic sensorimotor polyneuropathy, mainly with sensory functions. OBJECTIVES: To determine whether higher UA levels are associated negatively with nerve function in healthy subjects. METHODS: A total of 126 healthy subjects recruited prospectively for another study were included. We extracted demographic data, body mass index (BMI), blood pressure, Toronto Clinical Neuropathy Score (TCNS), electrophysiological findings, vibration perception thresholds (VPT), and laboratory test results including UA, hemoglobin A1c (HbA1c), estimated glomerular filtration rate (eGFR), and lipid levels. RESULTS: The mean age of the cohort was 56 ± 17 years with 56% females. Males had higher UA values compared with females. Univariate beta regression coefficient analysis between UA levels and demographic, clinical, electrophysiological, and laboratory findings showed significant positive correlations with male gender, components of the metabolic syndrome, and with VPT, while an inverse correlation was found with electrophysiological sensory parameters. A multivariate regression model showed positive correlations only with BMI, finger VPT, and triglycerides. CONCLUSION: Higher UA levels correlate with lower sensory nerve function in healthy subjects, expanding the evidence of possible negative influence of UA on peripheral nerves, although a causative role has not yet established.

Ultrasound-Assisted Lumbar Puncture in a Neuromuscular Clinic has a High Success Rate and Less Pain.

BACKGROUND: Lumbar puncture (LP) performed with the assistance of ultrasound (US) may improve success rate, with fewer puncture attempts and less pain. OBJECTIVES: To explore the utility of US-assisted LP in a neuromuscular clinic. METHODS: We performed a prospective, randomized, open-label study between May 2016 and January 2017. The primary outcome measure was LP success rate, and the secondary outcome measures included procedure time, number of attempts, and the levels of pain, anxiety, and satisfaction. RESULTS: Lumbar puncture was performed in 40 consecutive patients. Ultrasound-assisted LP had a 100% success rate, compared with 85% (95% confidence interval: 58%-96%) without US assistance, although this difference failed to reach statistical significance. Ultrasound-assisted LP was associated with less pain and, also in patients >60 years of age, with fewer needle insertions. Both groups reported high satisfaction rates, regardless of the use of US. CONCLUSION: Ultrasound-assisted LP has a high success rate and less pain than unassisted LP, and can be accomplished easily in the outpatient neuromuscular clinic setting equipped with US.

CONTEXTE: En plus de diminuer le nombre de tentatives de ponction alors nécessaires et la douleur qui en résulte, il est possible qu'un examen de ponction lombaire effectué avec l'aide d'appareils à ultrasons obtienne un plus haut taux de réussite. OBJECTIFS: Dans le cadre d'une clinique neuromusculaire, se pencher sur l'utilité des examens de ponction lombaire assistés par des appareils à ultrasons. MÉTHODES: De mai 2016 à janvier 2017, nous avons mené une étude prospective sans insu à répartition aléatoire. La principale mesure de nos résultats a porté sur le taux de succès des examens de ponction lombaire. D'autres mesures de résultats ont inclus les aspects suivants: la durée des examens, le nombre de tentatives de ponction ainsi que les niveaux de douleur, d'anxiété et de satisfaction des patients. RÉSULTATS: Des examens de ponction lombaire ont été effectués chez 40 patients consécutifs. Ceux menés à l'aide d'appareils à ultrasons ont donné à voir un taux de succès de 100 % comparativement à 85 % (IC 95 % : 58 % - 96 %) dans le cas de ceux effectués sans ces appareils. Rappelons toutefois que cette différence ne s'est pas révélée significative sur le plan statistique. Les examens de ponction lombaire au moyen d'appareils à ultrasons ont aussi été associés à moins de douleurs ressenties et, chez des patients âgés de plus de 60 ans, à moins d'insertions d'aiguilles. Enfin, ces deux groupes ont rapporté des taux de satisfaction élevés, et ce, sans égard à l'utilisation d'appareils à ultrasons. CONCLUSIONS: Les examens de ponction lombaire assistés par des appareils à ultrasons possèdent un haut taux de succès et entraînent moins de douleurs que ceux menés sans ces appareils. Ils peuvent aussi être effectués facilement dans le cadre de cliniques neuromusculaires externes qui en sont munies.

Quantitative sonographic assessment of myotonia.

INTRODUCTION: This study explores ultrasound imaging for qualitative and quantitative assessment of myotonia. METHODS: Sixteen patients with myotonia and 16 controls underwent sonographic evaluation of the thenar eminence muscles to assess the relaxation time after muscle percussion. RESULTS: The mean time for complete muscle relaxation in patients with myotonia was longer than that of controls. A cutoff of > 0.9 s for myotonia detection had a sensitivity of 88% and a specificity of 100%. The interrater reliability was moderate for qualitative assessment but was high for quantitative assessment. The relaxation time did not correlate with the number of trinucleotide repeats in patients with myotonic dystrophy. DISCUSSION: Sonographic evaluation for the presence of myotonia is feasible, sensitive, and specific but does not correlate with disease severity in myotonic dystrophy. Muscle Nerve 57: 146-149, 2018.

Fatigue is a relevant outcome in patients with myasthenia gravis.

INTRODUCTION: Patients with myasthenia gravis often experience fatigue, but its effect on quality of life (QoL) is underestimated, and fatigue is rarely measured in clinical trials. METHODS: Two hundred fifty-seven myasthenic patients completed the Neuro-QoL-Fatigue and measures of disease severity and QoL. We studied the relationship between fatigue and clinical and demographic variables. Finally, we studied the responsiveness of the Neuro-QoL-Fatigue in 95 patients receiving treatments for myasthenia and estimated the minimal important difference (MID). RESULTS: Fatigue correlated with greater disease severity (r = 0.52-0.69, P < 0.0001) and worse QoL (r = 0.65-0.75, P < 0.0001). Patients in remission, with minimal manifestations, and pure ocular symptoms reported minimal fatigue. Regression modeling showed that, in addition to its relationship with disease severity, fatigue was worse in females, patients with generalized disease, and those with anxiety/depression. Fatigue improved after immunomodulation (P < 0.0001), and the MID was 5.3 points. DISCUSSION: Fatigue in myasthenia correlates with disease severity, affects QoL, and can improve after treatment. Muscle Nerve 58: 197-203, 2018.

The utility of a single simple question in the evaluation of patients with myasthenia gravis.

INTRODUCTION: Assessing myasthenia gravis (MG) can be challenging, and multiple scales are available to evaluate disease severity. We evaluated the utility of a single, simple question, as part of the MG evaluation: "What percentage of normal do you feel regarding your MG, 0%-100% normal?" METHODS: A retrospective chart review of patients attending the neuromuscular clinic from January 2014 to December 2015 was performed. Responses were correlated with symptoms and signs, the Quantitative Myasthenia Gravis Score (QMGS), the Myasthenia Gravis Impairment Index (MGII), and the 15-item Myasthenia Gravis Quality of Life scale (MG-QOL15). RESULTS: The total cohort included 169 patients. The percentage of normal correlated strongly with limb muscle weakness and MG scales, moderately with bulbar and respiratory symptoms, and weakly with ocular manifestations. DISCUSSION: The question, "What percentage of normal do you feel regarding your MG?" is feasible and valid, and can be incorporated easily into routine clinical evaluation. Muscle Nerve 57: 240-244, 2018.

High frequency of MGUS in DSP.

INTRODUCTION: Monoclonal gammopathy has been reported in several polyneuropathies. In this study, we sought to explore the frequency and characteristics of monoclonal gammopathy in patients with diabetic sensorimotor polyneuropathy (DSP). METHODS: Patients with type 1 and type 2 diabetes mellitus (DM 1, DM 2) and controls without diabetes were evaluated between November 2008 and December 2013. RESULTS: Fifty controls, 66 patients with DM 1, and 106 patients with DM 2 were included, with average ages of 43 ± 18, 45 ± 17, and 65 ± 10 years, respectively; the frequency of monoclonal gammopathy was 0%, 8%, and 15%, respectively. In patients with DSP, the frequency of monoclonal gammopathy increased to 14% in DM 1 and 21% in DM 2; the most common monoclonal proteins were immunoglobulin (Ig) M and IgG, respectively. DISCUSSION: DSP might be associated with a high frequency of monoclonal gammopathy, with different characteristics in DM 1 and in DM 2. Muscle Nerve 57: 1018-1021, 2018.

A randomised, multi-centre phase III study of 3 different doses of intravenous immunoglobulin 10% in patients with chronic inflammatory demyelinating polyradiculoneuropathy (ProCID trial): Study design and protocol.

Patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) show varying degrees of response to intravenous immunoglobulin (IVIg) therapy. This randomised phase III study in patients with CIDP (ProCID trial) will compare the efficacy and safety of 3 different doses (0.5, 1.0, and 2.0 g/kg) of IVIg 10% (panzyga) administered every 3 weeks for 24 weeks. The primary efficacy endpoint is the rate of treatment response, defined as a decrease in adjusted inflammatory neuropathy cause and treatment disability score of ≥1 point, in the IVIg 1.0 g/kg arm at week 24. Patients with definite or probable CIDP according to European Federation of Neurological Sciences/Peripheral Nerve Society criteria with IVIg or corticosteroid dependency and active disease are eligible. All potentially eligible patients will undergo IVIg or corticosteroid dose reduction (washout phase) over ≤12 weeks or until deterioration of CIDP (active disease). Patients with deterioration during the washout phase will be randomised to receive study treatment during a dose-evaluation phase starting with a loading dose of IVIg 2.0 g/kg followed by maintenance treatment with IVIg 0.5, 1.0, or 2.0 g/kg every 3 weeks. Rescue medication (2 doses of IVIg 2.0 g/kg given 3 weeks apart) will be administered to patients in the IVIg 0.5 and 1.0 g/kg groups who deteriorate after week 3 and before week 18 or who do not improve at week 6. Safety, tolerability and quality of life will be assessed. The ProCID study will provide new information on the best maintenance dose of IVIg for patients with CIDP.

Laboratory Abnormalities in Polyneuropathy and Electrophysiological Correlations.

To study the frequency of laboratory test abnormalities, and electrophysiological correlations, we performed a retrospective chart review of 226 patients with polyneuropathy. The frequency of laboratory test abnormalities, and correlations with electrophysiological findings were explored. Abnormal glucose handling tests were the most common findings (54%), followed by paraproteinemia (21%) and anemia (21%). The frequencies of paraproteinemia and anemia in our cohort were significantly higher than previously reported. In addition, several laboratory abnormalities correlated with electrophysiological findings of median neuropathy at the wrist, expanding current knowledge about the deleterious effects of various metabolic and hematologic derangements at this site.

Repetitive nerve stimulation cutoff values for the diagnosis of myasthenia gravis.

INTRODUCTION: Repetitive nerve stimulation (RNS) showing ≥ 10% decrement is considered the cutoff for myasthenia gravis (MG), but this has never been validated. The objective of this study was to find an optimal validated cutoff value for decrement on RNS. METHODS: We performed retrospective chart review of patients who had electrophysiological assessment for possible MG from 2013 to 2015. RESULTS: A total of 122 patients with MG and 182 controls were identified. RNS sensitivities for generalized and ocular MG using the traditional ≥10% cutoff value were 46% and 15%, respectively, for frontalis recordings, and 35% and 19%, respectively, for nasalis recordings. Using a decrement cutoff value of 7% for frontalis and 8% for nasalis increased the sensitivities by 6-11%, with specificities of 95-96%. CONCLUSIONS: For RNS in facial muscles, we suggest a cutoff value of 7-8%, which increases test sensitivity by 6-11%, while preserving high specificity for the diagnosis of MG. Muscle Nerve, 2016 Muscle Nerve 55: 166-170, 2017.