Neuroprognostication: Guillain-Barré Syndrome.

Guillain-Barré syndrome is an immune-mediated disease of the peripheral nerves characterized by rapidly progressing symmetric weakness, areflexia, and albuminocytological dissociation. Most patients reach their nadir within 2 weeks. Disease severity can be mild to severe, with 20% of patients requiring mechanical ventilation. Intravenous immunoglobulin and plasma exchange are equally effective treatments. Monitoring strength, respiratory function, blood pressure, and heart rate, as well as pain management and rehabilitative therapy are important aspects of management. About 20% of patients require assistance to walk at 6 months. Older age, preceding diarrhea, and lower Medical Research Council (MRC) sum scores predict poor outcome. Death from cardiovascular and respiratory complications can occur in the acute or recovery phases of the illness in 3 to 7% of the patients. Risk factors for mortality include advanced age and disease severity at onset. Neuropathic pain, weakness, and fatigue can be residual symptoms; risk factors for these include axonal loss, sensory involvement, and severity of illness.

Risk Factors for Infection and Health Impacts of the Coronavirus Disease 2019 (COVID-19) Pandemic in People With Autoimmune Diseases.

BACKGROUND: People with autoimmune or inflammatory conditions taking immunomodulatory/suppressive medications may have higher risk of novel coronavirus disease 2019 (COVID-19). Chronic disease care has also changed for many patients, with uncertain downstream consequences. METHODS: We included participants with autoimmune or inflammatory conditions followed by specialists at Johns Hopkins. Participants completed periodic surveys querying comorbidities, disease-modifying medications, exposures, COVID-19 testing and outcomes, social behaviors, and disruptions to healthcare. We assessed whether COVID-19 risk is higher among those on immunomodulating or suppressive agents and characterized pandemic-associated changes to care and mental health. RESULTS: In total, 265 (5.6%) developed COVID-19 over 9 months of follow-up (April-December 2020). Patient characteristics (age, race, comorbidity, medications) were associated with differences in social distancing behaviors during the pandemic. Glucocorticoid exposure was associated with higher odds of COVID-19 in models incorporating behavior and other potential confounders (odds ratio [OR]: 1.43; 95% confidence interval [CI]: 1.08, 1.89). Other medication classes were not associated with COVID-19 risk. Diabetes (OR: 1.72; 95% CI: 1.08, 2.73), cardiovascular disease (OR: 1.68; 95% CI: 1.24, 2.28), and kidney disease (OR: 1.76; 95% CI: 1.04, 2.97) were associated with higher odds of COVID-19. Of the 2156 reporting pre-pandemic utilization of infusion, mental health or rehabilitative services, 975 (45.2%) reported disruptions therein, which disproportionately affected individuals experiencing changes to employment or income. CONCLUSIONS: Glucocorticoid exposure may increase risk of COVID-19 in people with autoimmune or inflammatory conditions. Disruption to healthcare and related services was common. Those with pandemic-related reduced income may be most vulnerable to care disruptions.

Improving the efficacy of exome sequencing at a quaternary care referral centre: novel mutations, clinical presentations and diagnostic challenges in rare neurogenetic diseases.

BACKGROUND: We used a multimodal approach including detailed phenotyping, whole exome sequencing (WES) and candidate gene filters to diagnose rare neurological diseases in individuals referred by tertiary neurology centres. METHODS: WES was performed on 66 individuals with neurogenetic diseases using candidate gene filters and stringent algorithms for assessing sequence variants. Pathogenic or likely pathogenic missense variants were interpreted using in silico prediction tools, family segregation analysis, previous publications of disease association and relevant biological assays. RESULTS: Molecular diagnosis was achieved in 39% (n=26) including 59% of childhood-onset cases and 27% of late-onset cases. Overall, 37% (10/27) of myopathy, 41% (9/22) of neuropathy, 22% (2/9) of MND and 63% (5/8) of complex phenotypes were given genetic diagnosis. Twenty-seven disease-associated variants were identified including ten novel variants in FBXO38, LAMA2, MFN2, MYH7, PNPLA6, SH3TC2 and SPTLC1. Single-nucleotide variants (n=10) affected conserved residues within functional domains and previously identified mutation hot-spots. Established pathogenic variants (n=16) presented with atypical features, such as optic neuropathy in adult polyglucosan body disease, facial dysmorphism and skeletal anomalies in cerebrotendinous xanthomatosis, steroid-responsive weakness in congenital myasthenia syndrome 10. Potentially treatable rare diseases were diagnosed, improving the quality of life in some patients. CONCLUSIONS: Integrating deep phenotyping, gene filter algorithms and biological assays increased diagnostic yield of exome sequencing, identified novel pathogenic variants and extended phenotypes of difficult to diagnose rare neurogenetic disorders in an outpatient clinic setting.

Inpatient Diagnosis and Management of Neuromuscular Disorders.

Although many neuromuscular conditions are evaluated on an outpatient basis owing to their chronic or progressive nature, more urgent evaluation and management is often required for the inpatient presenting with acute to subacute focal or generalized numbness or weakness. This review focuses on clinical pattern recognition and basic anatomic localization principles to aid in the identification of common, as well as some less frequently encountered, neuromuscular disorders in hospitalized patients. The characteristic clinical and diagnostic features, associated complications, and recommended treatments of key neuromuscular conditions with acute and subacute manifestations are discussed. These conditions can be life-threatening in some cases, such as in Guillain-Barré syndrome, owing to associated oropharyngeal weakness, respiratory failure, or marked dysautonomia. Prompt recognition of the clinical and pathologic features is therefore necessary to reduce associated morbidity and mortality.

Assessing mNIS+7Ionis and international neurologists' proficiency in a familial amyloidotic polyneuropathy trial.

INTRODUCTION: Polyneuropathy signs (Neuropathy Impairment Score, NIS), neurophysiologic tests (m+7Ionis ), disability, and health scores were assessed in baseline evaluations of 100 patients entered into an oligonucleotide familial amyloidotic polyneuropathy (FAP) trial. METHODS: We assessed: (1) Proficiency of grading neurologic signs and correlation with neurophysiologic tests, and (2) clinometric performance of modified NIS+7 neurophysiologic tests (mNIS+7Ionis ) and its subscores and correlation with disability and health scores. RESULTS: The mNIS+7Ionis sensitively detected, characterized, and broadly scaled diverse polyneuropathy impairments. Polyneuropathy signs (NIS and subscores) correlated with neurophysiology tests, disability, and health scores. Smart Somatotopic Quantitative Sensation Testing of heat as pain 5 provided a needed measure of small fiber involvement not adequately assessed by other tests. CONCLUSIONS: Specially trained neurologists accurately assessed neuropathy signs as compared to referenced neurophysiologic tests. The score, mNIS+7Ionis , broadly detected, characterized, and scaled polyneuropathy abnormality in FAP, which correlated with disability and health scores. Muscle Nerve 56: 901-911, 2017.

Neurophysiology simplified for imagers.

Electrodiagnostic studies are powerful diagnostic tools that complement the clinical evaluation of patients with neuromuscular disease. However, their proper interpretation requires a hypothesis-driven approach that depends on clinical information and physical examination findings. In principle, Bayesian methods of reasoning determine both the plan of examination and interpretation of results. Thus neuromuscular disease training with an understanding of peripheral nervous system anatomy, nerve and muscle physiology, pathophysiology, pathology, management, and prognosis are as important as technical training for performance of the test. In this article, geared toward imagers, we review the basic principles of electrodiagnostic studies, typical measurements, and their interpretation both in normal and common disease states.

Interventions for preventing neuropathy caused by cisplatin and related compounds.

BACKGROUND: Cisplatin and several related antineoplastic drugs used to treat many types of solid tumours are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought. OBJECTIVES: To examine the efficacy and safety of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related drugs. SEARCH METHODS: On 4 March 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS, and CINAHL Plus for randomised trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related drugs among human patients. SELECTION CRITERIA: We included randomised controlled trials (RCTs) or quasi-RCTs in which the participants received chemotherapy with cisplatin or related compounds, with a potential chemoprotectant (acetylcysteine, amifostine, adrenocorticotrophic hormone (ACTH), BNP7787, calcium and magnesium (Ca/Mg), diethyldithiocarbamate (DDTC), glutathione, Org 2766, oxcarbazepine, or vitamin E) compared to placebo, no treatment, or other treatments. We considered trials in which participants underwent evaluation zero to six months after completing chemotherapy using quantitative sensory testing (the primary outcome) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary outcomes). DATA COLLECTION AND ANALYSIS: Two review authors assessed each study, extracted the data and reached consensus, according to standard Cochrane methodology. MAIN RESULTS: As of 2013, the review includes 29 studies describing nine possible chemoprotective agents, as well as description of two published meta-analyses. Among these trials, there were sufficient data in some instances to combine the results from different studies, most often using data from secondary non-quantitative measures. Nine of the studies were newly included at this update. Few of the included studies were at a high risk of bias overall, although often there was too little information to make an assessment. At least two review authors performed a formal review of an additional 44 articles but we did not include them in the final review for a variety of reasons.Of seven eligible amifostine trials (743 participants in total), one used quantitative sensory testing (vibration perception threshold) and demonstrated a favourable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Furthermore the change measured was subclinical. None of the three eligible Ca/Mg trials (or four trials if a single retrospective study was included) described our primary outcome measures. The four Ca/Mg trials included a total of 886 participants. Of the seven eligible glutathione trials (387 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing but reported disparate results; meta-analyses of three of these trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. Similarly, none of the three eligible vitamin E trials (246 participants) reported quantitative sensory testing. The eligible single trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), oxcarbazepine (32 participants), and retinoic acid (92 participants) did not perform quantitative sensory testing. In all, this review includes data from 2906 participants. However, only seven trials reported data for the primary outcome measure of this review, (quantitative sensory testing) and only nine trials reported our objective secondary measure, nerve conduction test results. Additionally, methodological heterogeneity precluded pooling of the results in most cases. Nonetheless, a larger number of trials reported the results of secondary (non-quantitative and subjective) measures such as the National Cancer Institute Common Toxicity Criteria (NCI-CTC) for neuropathy (15 trials), and these results we pooled and reported as meta-analysis. Amifostine showed a significantly reduced risk of developing neurotoxicity NCI-CTC (or equivalent) ≥ 2 compared to placebo (RR 0.26, 95% CI 0.11 to 0.61). Glutathione was also efficacious with an RR of 0.29 (95% CI 0.10 to 0.85). In three vitamin E studies subjective measures not suitable for combination in meta analysis each favoured vitamin E. For other interventions the qualitative toxicity measures were either negative (N-acetyl cysteine, Ca/Mg, DDTC and retinoic acid) or not evaluated (oxcarbazepine and Org 2766).Adverse events were infrequent or not reported for most interventions. Amifostine was associated with transient hypotension in 8% to 62% of participants, retinoic acid with hypocalcaemia in 11%, and approximately 20% of participantss withdrew from treatment with DDTC because of toxicity. AUTHORS' CONCLUSIONS: At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, retinoic acid, or vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients, as determined using quantitative, objective measures of neuropathy. Amifostine, calcium and magnesium, glutathione, and vitamin E showed modest but promising (borderline statistically significant) results favouring their ability to reduce the neurotoxicity of cisplatin and related chemotherapies, as measured using secondary, non-quantitative and subjective measures such as the NCI-CTC neuropathy grading scale. Among these interventions, the efficacy of only vitamin E was evaluated using quantitative nerve conduction studies; the results were negative and did not support the positive findings based on the qualitative measures. In summary, the present studies are limited by the small number of participants receiving any particular agent, a lack of objective measures of neuropathy, and differing results among similar trials, which make it impossible to conclude that any of the neuroprotective agents tested prevent or limit the neurotoxicity of platinum drugs.

A comprehensive study of skeletal muscle imaging in FHL1-related reducing body myopathy.

OBJECTIVE: FHL1-related reducing body myopathy is an ultra-rare, X-linked dominant myopathy. In this cross-sectional study, we characterize skeletal muscle ultrasound, muscle MRI, and cardiac MRI findings in FHL1-related reducing body myopathy patients. METHODS: Seventeen patients (11 male, mean age 35.4, range 12-76 years) from nine independent families with FHL1-related reducing body myopathy underwent clinical evaluation, muscle ultrasound (n = 11/17), and lower extremity muscle MRI (n = 14/17), including Dixon MRI (n = 6/17). Muscle ultrasound echogenicity was graded using a modified Heckmatt scale. T1 and STIR axial images of the lower extremity muscles were evaluated for pattern and distribution of abnormalities. Quantitative analysis of intramuscular fat fraction was performed using the Dixon MRI images. Cardiac studies included electrocardiogram (n = 15/17), echocardiogram (n = 17/17), and cardiac MRI (n = 6/17). Cardiac muscle function, T1 maps, T2-weighted black blood images, and late gadolinium enhancement patterns were analyzed. RESULTS: Muscle ultrasound showed a distinct pattern of increased echointensity in skeletal muscles with a nonuniform, multifocal, and "geographical" distribution, selectively involving the deeper fascicles of muscles such as biceps and tibialis anterior. Lower extremity muscle MRI showed relative sparing of gluteus maximus, rectus femoris, gracilis, and lateral gastrocnemius muscles and an asymmetric and multifocal, "geographical" pattern of T1 hyperintensity within affected muscles. Cardiac studies revealed mild and nonspecific abnormalities on electrocardiogram and echocardiogram with unremarkable cardiac MRI studies. INTERPRETATION: Skeletal muscle ultrasound and muscle MRI reflect the multifocal aggregate formation in muscle in FHL1-related reducing body myopathy and are practical and informative tools that can aid in diagnosis and monitoring of disease progression.

Mass spectrometry analysis reveals non-mutated apolipoprotein A1 lumbosacral radiculoplexus amyloidoma.

INTRODUCTION: In rare instances, amyloidosis presents as a focal, macroscopic lesion involving peripheral neural tissues (amyloidoma). In all known reported cases, peripheral nerve amyloidomas have had immunoglobulin light-chain fibril composition and occurred in the context of paraproteinemia. METHODS: A 46-year-old man presented with progressive insidious-onset right lumbosacral radiculoplexus neuropathy without paraproteinemia. MRI-targeted fascicular nerve biopsy was performed on an enlarged sciatic nerve after earlier distal fibular nerve biopsy was nondiagnostic. Laser dissected mass spectroscopy of the discovered amyloid protein was performed after immunohistochemistry failed to identify the specific amyloid protein. Complete gene sequencing of apolipoprotein A1 (ApoA1) was performed. RESULTS: Only wild-type ApoA1 amyloid was found in the congophilic component in the nerve. CONCLUSIONS: This case highlights the utility of MRI-guided fascicular nerve biopsy combined with laser-dissected mass spectrometric analysis. Importantly, the case expands the known causes of amyloidomas to include wild-type ApoA1.

Interventions for preventing neuropathy caused by cisplatin and related compounds.

BACKGROUND: Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought. OBJECTIVES: To examine the efficacy of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related agents. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Specialized Register (25 August 2010), the Cochrane Central Register of Controlled Trials (Issue 3, 2010 in The Cochrane Library), MEDLINE (January 1966 to August 2010), EMBASE (January 1980 to August 2010), LILACS (January 1982 to August 2010), CINAHL (January 1982 to August 2010) for randomized trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related agents among human patients. SELECTION CRITERIA: Quasi-randomized or randomized controlled trials whose participants received cisplatin (or related compounds) chemotherapy with or without a potential chemoprotectant (acetylcysteine, amifostine, ACTH, BNP7787, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, or vitamin E) and were evaluated zero to six months after completing chemotherapy using quantitative sensory testing (primary) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary). DATA COLLECTION AND ANALYSIS: We identified 16 randomized trials involving five possible chemoprotective agents in the initial 2006 review. Each study was reviewed by two authors who extracted the data and reached consensus. The 2010 update identified 11 additional randomized trials consisting of nine possible chemoprotective agents, including three treatments (acetylcysteine, calcium and magnesium, and oxcarbazepine) not among those described in the 2006 review. The included trials in the updated review involved eight unrelated treatments and included many disparate measures of neuropathy, resulting in insufficient data for any one measure to combine the results in most instances. MAIN RESULTS: One of four eligible amifostine trials (541 total participants in all four trials) used quantitative sensory testing and demonstrated a favorable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Of the six eligible glutathione trials (354 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing reported disparate results; meta-analyses of three trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. The single eligible trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), calcium and magnesium (33 participants), and oxcarbazepine (32 participants) and the two eligible trials involving vitamin E (57 participants) did not perform quantitative sensory testing. In all, data from 1,537 participants were included. AUTHORS' CONCLUSIONS: At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxycarbazepine, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Multifocal motor neuropathy.

Multifocal motor neuropathy (MMN) is a unique disorder characterized by slowly progressive, asymmetric, distal and upper limb predominant weakness without significant sensory abnormalities. Electrophysiology is crucial to the diagnosis, revealing the hallmark partial conduction block. MMN is considered immune mediated due to the association with anti-GM1 antibodies and the response to immunomodulatory treatment. It is paramount to recognize MMN from other motor neuronopathies or peripheral neuropathies as it is treatable. Advances in pathogenesis, clinical features, electrophysiology, diagnostic studies and treatment are reviewed. References for this review were identified from literature search on Pubmed limited to dates from 1988 to 2011. Papers were selected if relevant to the review topic and published in English.

Atypical inflammatory demyelinating syndrome with central and peripheral nerve involvement.

We report a patient who has peripheral demyelination in the form of chronic inflammatory demyelinating polyneuropathy (CIDP) with central demyelination following a relapsing-remitting disease course. The patient developed bilateral sequential optic neuritis predating the diagnosis of CIPD, then developed a profound brainstem syndrome with ataxia, dysarthria, a complex eye movement disorder, visual disturbance and urinary incontinence. Interval imaging fulfilled McDonald criteria for multiple sclerosis (MS) with a right parieto-occipital tumefactive lesion showing contrast enhancement and new lesions in the right temporal white matter and midbrain tegmentum. Oligoclonal bands (OCBs) were matched and serum antibodies against aquaporin-4 (AQP-4) and myelin oligodendrocyte glycoprotein (MOG) were negative. Genetic sequence analysis and deletion/duplication testing revealed variants of uncertain significance with compound heterozygosity for point mutations in two genes, DYNC1H1 and SH3TC2, which are associated with Charcot-Marie-Tooth (CMT) disease though the patient was negative for known CMT mutations. The patient responded poorly to steroids and regular intravenous immunoglobulin (IVIg) but clinically improved following aggressive immunomodulatory therapy with pulsed steroids and plasmapheresis, followed by Rituximab. Combined central and peripheral demyelination (CCPD) is rare. Autoimmune mechanisms are postulated in the pathogenesis. Whether overlap of central and pe- ripheral demyelination is coincidental or caused by a shared epitope in both the peripheral and central nervous systems still remains to be elucidated. There is no clear therapeutic consensus in the treatment of both central and peripheral demyelination, though immunomodulating treatment strategies may minimise disability and improve prognosis.

RISK FACTORS FOR INFECTION AND HEALTH IMPACTS OF THE COVID-19 PANDEMIC IN PEOPLE WITH AUTOIMMUNE DISEASES.

Background: People with autoimmune or inflammatory conditions who take immunomodulatory/suppressive medications may have a higher risk of novel coronavirus disease 2019 (COVID-19). Chronic disease care has also changed for many patients, with uncertain downstream consequences. Objective: Assess whether COVID-19 risk is higher among those on immunomodulating or suppressive agents and characterize pandemic-associated changes to care. Design: Longitudinal registry study. Participants: 4666 individuals with autoimmune or inflammatory conditions followed by specialists in neurology, rheumatology, cardiology, pulmonology or gastroenterology at Johns Hopkins. Measurements: Periodic surveys querying comorbidities, disease-modifying medications, exposures, COVID-19 testing and outcomes, social behaviors, and disruptions to healthcare. Results: A total of 265 (5.6%) developed COVID-19 over 9 months of follow-up (April-December 2020). Patient characteristics (age, race, comorbidity, medication exposure) were associated with differences in social distancing behaviors during the pandemic. Glucocorticoid exposure was associated with higher odds of COVID-19 in multivariable models incorporating behavior and other potential confounders (OR: 1.43; 95%CI: 1.08, 1.89). Other medication classes were not associated with COVID-19 risk. Diabetes (OR: 1.72; 95%CI: 1.08, 2.73), cardiovascular disease (OR: 1.68; 95%CI: 1.24, 2.28), and chronic kidney disease (OR: 1.76; 95%CI: 1.04, 2.97) were each associated with higher odds of COVID-19. Pandemic-related disruption to care was common. Of the 2156 reporting pre-pandemic utilization of infusion, mental health or rehabilitative services, 975 (45.2%) reported disruptions. Individuals experiencing changes to employment or income were at highest odds of care disruption. Limitations: Results may not be generalizable to all patients with autoimmune or inflammatory conditions. Information was self-reported. Conclusions: Exposure to glucocorticoids may increase risk of COVID-19 in people with autoimmune or inflammatory conditions. Disruption to healthcare and related services was common. Those with pandemic-related reduced income may be most vulnerable to care disruptions.

Effect of Ezogabine on Cortical and Spinal Motor Neuron Excitability in Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial.

Importance: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of the motor nervous system. Clinical studies have demonstrated cortical and spinal motor neuron hyperexcitability using transcranial magnetic stimulation and threshold tracking nerve conduction studies, respectively, although metrics of excitability have not been used as pharmacodynamic biomarkers in multi-site clinical trials. Objective: To ascertain whether ezogabine decreases cortical and spinal motor neuron excitability in ALS. Design, Setting, and Participants: This double-blind, placebo-controlled phase 2 randomized clinical trial sought consent from eligible participants from November 3, 2015, to November 9, 2017, and was conducted at 12 US sites within the Northeast ALS Consortium. Participants were randomized in equal numbers to a higher or lower dose of ezogabine or to an identical matched placebo, and they completed in-person visits at screening, baseline, week 6, and week 8 for clinical assessment and neurophysiological measurements. Interventions: Participants were randomized to receive 600 mg/d or 900 mg/d of ezogabine or a matched placebo for 10 weeks. Main Outcomes and Measures: The primary outcome was change in short-interval intracortical inhibition (SICI; SICI-1 was used in analysis to reflect stronger inhibition from an increase in amplitude) from pretreatment mean at screening and baseline to the full-dose treatment mean at weeks 6 and 8. The secondary outcomes included levels of cortical motor neuron excitability (including resting motor threshold) measured by transcranial magnetic stimulation and spinal motor neuron excitability (including strength-duration time constant) measured by threshold tracking nerve conduction studies. Results: A total of 65 participants were randomized to placebo (23), 600 mg/d of ezogabine (23), and 900 mg/d of ezogabine (19 participants); 45 were men (69.2%) and the mean (SD) age was 58.3 (8.8) years. The SICI-1 increased by 53% (mean ratio, 1.53; 95% CI, 1.12-2.09; P = .009) in the 900-mg/d ezogabine group vs placebo group. The SICI-1 did not change in the 600-mg/d ezogabine group vs placebo group (mean ratio, 1.15; 95% CI, 0.87-1.52; P = .31). The resting motor threshold increased in the 600-mg/d ezogabine group vs placebo group (mean ratio, 4.61; 95% CI, 0.21-9.01; P = .04) but not in the 900-mg/d ezogabine group vs placebo group (mean ratio, 1.95; 95% CI, -2.64 to 6.54; P = .40). Ezogabine caused a dose-dependent decrease in excitability by several other metrics, including strength-duration time constant in the 900-mg/d ezogabine group vs placebo group (mean ratio, 0.73; 95% CI, 0.60 to 0.87; P < .001). Conclusions and Relevance: Ezogabine decreased cortical and spinal motor neuron excitability in participants with ALS, suggesting that such neurophysiological metrics may be used as pharmacodynamic biomarkers in multisite clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT02450552.

A phase II trial of talampanel in subjects with amyotrophic lateral sclerosis.

Our objective was to determine if chronic treatment with the non-competitive AMPA antagonist talampanel is efficacious and safe in subjects with ALS. A double-blind, placebo-controlled, multicenter, randomized clinical trial of nine months treatment duration was conducted in 59 subjects with ALS, with 40 subjects receiving talampanel 50 mg p.o. t.i.d, and 19 subjects receiving placebo. Primary outcome measure was rate of decline in isometric arm strength (as measured by change in arm strength megaslope of the Tufts Quantitative Neuromuscular Exam (TQNE)). Other efficacy endpoints included rate of decline in respiratory function, isometric leg strength, bulbar function, fine motor function, the ALS Functional Rating Scale (ALSFRS), and survival. Secondary safety outcome measures were frequency of adverse events, neurological status, plasma concentration of talampanel, vital signs, routine laboratory tests, and electrocardiograms. Decline in muscle strength was 15% less in talampanel treated subjects, and decline in ALSFRS was 30% slower in talampanel treated subjects. Talampanel was safe in subjects with ALS. Mortality rates (8% talampanel, 5% placebo) and drug discontinuation rates (25% talampanel, 16% placebo) were similar in active treatment and placebo groups. Dizziness and somnolence occurred significantly more often in talampanel treated subjects. Although no efficacy measure reached statistical significance, there was a repeated trend toward slower decline in ALSFRS and isometric muscle strength in talampanel treated subjects. Talampanel was well tolerated in subjects with ALS. Although certain adverse events occurred more frequently in the active treatment group, the rate of subject drop-out after nine months did not exceed that seen in other trials. These findings provide strong support for a phase III trial to determine the efficacy of talampanel in subjects with ALS.

An open-label trial of rituximab (Rituxan®) in multifocal motor neuropathy.

Multifocal motor neuropathy (MMN) is an acquired demyelinating motor neuropathy. Intravenous immunoglobulin (IVIg) has been found to be safe and effective. Rituximab, a genetically engineered monoclonal antibody against CD-20 antigen, has been reported effective in immune disorders including MMN. We performed an open-label trial to determine if rituximab would reduce the IVIg requirement, disability, and impairment, and be safe in patients with MMN. Six MMN patients, who were on periodic IVIg treatments, received two doses of IV rituximab (1,000 mg) given 2 weeks later. Assessments were performed at baseline and at 2, 4, 6, 8, 10, and 12 months. The primary outcome was total amount of IVIg used during the 12-month study compared to the 12 months prior. Secondary outcomes included changes in Medical Research Council (MRC) sum scores, grip strength, disability and handicap scores, and safety. There was no significant change in IVIg use, MRC sum score, grip strength, overall disability sum score, or Rotterdam handicap scale. One patient developed a hypersensitivity reaction during the first infusion that responded to adjustments in the infusion rate and treatment with diphenhydramine and acetaminophen. We conclude that rituximab can be safely given to people with MMN but in this pilot study we were unable to reduce the amount of IVIg required, at least in the regimen used.

Epidemiological evidence for a hereditary contribution to myasthenia gravis: a retrospective cohort study of patients from North America.

OBJECTIVES: To approximate the rate of familial myasthenia gravis and the coexistence of other autoimmune disorders in the patients and their families. DESIGN: Retrospective cohort study. SETTING: Clinics across North America. PARTICIPANTS: The study included 1032 patients diagnosed with acetylcholine receptor antibody (AChR)-positive myasthenia gravis. METHODS: Phenotype information of 1032 patients diagnosed with AChR-positive myasthenia gravis was obtained from clinics at 14 centres across North America between January 2010 and January 2011. A critical review of the epidemiological literature on the familial rate of myasthenia gravis was also performed. RESULTS: Among 1032 patients, 58 (5.6%) reported a family history of myasthenia gravis. A history of autoimmune diseases was present in 26.6% of patients and in 28.4% of their family members. DISCUSSION: The familial rate of myasthenia gravis was higher than would be expected for a sporadic disease. Furthermore, a high proportion of patients had a personal or family history of autoimmune disease. Taken together, these findings suggest a genetic contribution to the pathogenesis of myasthenia gravis.

Characteristics of bortezomib- and thalidomide-induced peripheral neuropathy.

Dose-limiting peripheral neuropathy (PN) is frequently reported with the use of thalidomide and bortezomib, novel proteasome inhibitors. While these two agents have significant activity in multiple myeloma (MM), the combination and the associated PN have not been fully examined in untreated patients. The objective of this study was to report the baseline prevalence and occurrence of PN in newly diagnosed MM patients treated with bortezomib and thalidomide. Twenty-seven patients (11 men and 16 women) with previously untreated MM were prospectively monitored for PN. Total neuropathy score reduced (TNSr) was calculated at baseline and after every two cycles of bortezomib treatment. The median cumulative dose of bortezomib was 35.6 mg/m(2) (median 8 cycles) and of thalidomide was 16.8 g. Only three subjects showed mild PN at baseline (whole group median TNSr 0). At the end of treatment, PN developed in 26 patients (median TNSr 8). PN was of mild to moderate severity (TNSr grade 1 = 11, grade 2 = 10, grade 3 = 5, and grade 4 = 0). Nerve conduction studies showed axonal physiology in all except three subjects in whom demyelinating physiology was noted. The median TNSr was 17 in the demyelinating group and 9 in the axonal group. There was no significant correlation of TNSr with cumulative bortezomib or thalidomide dose. At follow-up, 80% of patients had become asymptomatic after discontinuation of the chemotherapy. We conclude that bortezomib and thalidomide combination chemotherapy induces a reversible length-dependent sensory>motor, predominantly axonal, large-fiber>small-fiber polyneuropathy. In a subset, a more severe demyelinating polyneuropathy may develop.

Decompressive surgery of lower limbs for symmetrical diabetic peripheral neuropathy.

BACKGROUND: Symmetrical peripheral neuropathy is a common complication of diabetic neuropathy. No treatments are known to be effective for progressive pain and sensory loss associated with diabetic neuropathy. Alternative effective treatment strategies have been sought. OBJECTIVES: To systematically review the evidence from randomized controlled trials concerning the role of decompressive surgery of lower limbs for symmetrical diabetic peripheral neuropathy. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Trials Register (May 2006), CENTRAL (The Cochrane Library, Issue 2 2006), MEDLINE from (January 1966 to August 2006), EMBASE (from January 1980 to August 2006), LILACS (from January 1982 to August 2006), and CINAHL (from January 1982 to August 2006). SELECTION CRITERIA: We included all randomized or quasi-randomized controlled human trials in which any form of decompressive surgery of the lower limbs nerves had been used to treat diabetic symmetrical distal polyneuropathy (DSDP) compared with no treatment or medical therapy. Patients with DSDP were included if they had decompression (with or without neurolysis) of at least two of the following nerves in both lower limbs, for the treatment of DSDP: the posterior tibial nerve (including calcaneal, medial and lateral plantar nerves), deep peroneal nerve at the ankle, common peroneal nerve at the knee, lateral femoral cutaneous nerve and sural nerves in the posterior calf region. The primary outcome measure was the change in pain measured by the visual analogue scale (VAS) between the baseline and a follow-up period of greater than three months. DATA COLLECTION AND ANALYSIS: We identified 142 publications from the above search strategies. The three authors of this manuscript reviewed abstracts of all papers independently. Only eight of these were considered relevant to the question at hand. The data from these 8 studies were entered onto standardized data extraction forms. We planned to use Review Manager to pool the results from appropriate studies comparing the same treatments; dichotomous outcomes to obtain pooled relative risks (RR); measured outcomes to obtain pooled weighted mean differences; and a fixed-effect analysis unless there was evidence of serious heterogeneity between studies sufficient to justify the use of random-effects analysis. MAIN RESULTS: This review failed to identify a single randomized controlled trial or any other well designed prospective study controlling for the non-operated limb that showed improvements in pre defined end points after decompressive surgery. AUTHORS' CONCLUSIONS: The results of this review suggest that the role of decompressive surgery for diabetic symmetric distal neuropathy is unproven.