News Express

Science News: Nitrous Oxide-Induced Myeloneuropathy

March 06, 2022

Nitrous oxide (NO, also known as laughing gas, balloons, whippets) abuse is increasingly recognized as an issue worldwide. Prolonged NO misuse inactivates vitamin B12, causing combined subacute degeneration. The authors studied a cohort of 20 patients with NO misuse. The average patient age was 24 years and mean canister consumption was 148 per day for 9 months. Common presentation included sensory symptoms with paresthesias and gait unsteadiness. In severe cases, patients were bedbound.
 

Science News: Variable Presentation of Hereditary Transthyretin-Mediated Amyloidosis at a Single Center

March 06, 2022

This is a retrospective study of 12 patients with a diagnosis of hereditary transthyretin-mediated (hATTR) amyloidosis at a single center in Austin, Texas. All patients were initially diagnosed with either polyneuropathy (83%) or myopathy (25%). Eventually these patients were all diagnosed with haTTR amyloidosis. The median time to diagnosis for these patients was 5 years (up to 10 years) during which their mobility had declined significantly.

Science News: An Approach to Assessing Immunoglobulin Dependence in Chronic Inflammatory Demyelinating Inflammatory Polyneuropathy

March 06, 2022

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a peripheral nerve disease coursing with weakness and impaired sensation. The course tends to be relapsing-remitting or progressive if left untreated. While there is evidence to support treatment with IVIg, plasma exchange, or steroid therapy and consensus on how to identify and monitor patients needing a protracted treatment course, data on when and how to stop therapy and identify remission is lacking. The authors of this paper sought to elucidate IVIg treatment cessation strategies in CIDP.

Science News: Pure Motor Onset and IgM-Gammopathy Occurrence in Multifocal Acquired Demyelinating Sensory and Motor Neuropathy

February 20, 2022

This study investigates patients with multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy with and without monoclonal gammopathy of uncertain significance (MGUS). Of 76 patients with MADSAM, 53% had pure motor, 16% pure sensory, 30% sensory-motor and 1% cranial. Motor onset patients were initially diagnosed with multifocal motor neuropathy (MMN). MGUS occurred in 25% (89% IgM) associating with ganglioside autoantibodies. Median time to sensory involvement in motor onset patients was 18 months.

Science News: IgG1 Pan-Neurofascin Antibodies Identify a Severe Yet Treatable Neuropathy With a High Mortality

February 20, 2022

The authors in this study tested patients with suspected inflammatory neuropathies for IgG antibodies against nodal (NF186) and paranodal (NF155, CNTN1 and Caspr1) cell adhesion molecules using a live, cell-based assay (CBA) and found eight patients (1.2%) with IgG1 antibodies to both NF186/NF140 isoforms and NF155 isoforms, but no IgG3 or IgG4 subclass antibodies. Clinical and laboratory and histopathological features were assessed and compared with seronegative and patients with other nodal/paranodal antibodies.

Science News: Prediagnostic Neurofilament Light Chain Levels in Amyotrophic Lateral Sclerosis

February 06, 2022

This study focused on pre-diagnostic biomarkers in amyotrophic lateral sclerosis (ALS). This matched case-control study included 84 individuals who developed ALS during follow-up and had available plasma samples prior to disease diagnosis. For each ALS case, a randomly matched control was selected. Neurofilament (NfL) in these pre-diagnostic plasma samples were measured and adjusted for body mass index, smoking physical activity, etc. Higher NfL levels were found to be associated with a high ALS risk within 5 years of ALS diagnosis. 

Science News: Ratio of Urinary N-terminal Titin Fragment to Urinary Creatinine is a Novel Biomarker for Amyotrophic Lateral Sclerosis

February 06, 2022

Sensitive and specific disease biomarkers for amyotrophic lateral sclerosis (ALS) are lacking. There has been ongoing research in the past several years looking for them. Titin is a giant myofibrillar protein in skeletal muscle. Elevated levels of urinary N-terminal fragment of titin has been reported in degenerative conditions, such as Duchene muscular dystrophy (DMD). This study looked at the validity and reliability of urinary N-terminal titin fragment as a biomarker in ALS.

Science News: Frequency of Neurologic Manifestations in COVID-19: A Systematic Review and Meta-Analysis

January 25, 2022

More than 1 year into the coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has caused more than 200 million cases and 4.28 million deaths across 220 countries as of August 9, 2021. This article is a systemic review and meta-analysis to obtain pooled prevalence estimates to understand the variation in reported frequencies of various neurologic manifestations in patients with COVID-19 across different groups in literature published from December 31, 2019, to December 15, 2020.

Science News: Association Between SARS-CoV-2 Infection and Immune-Mediated Myopathy in Patients Who Have Died

January 25, 2022

This is a case-control, postmortem (within 6 days) study in Germany focusing on the skeletal (either deltoid or quadriceps) and cardiac muscle pathology in SARS-CoV-2 patients. This study shows SARS-CoV-2 may be associated with a post-infectious, immune-mediated myopathy. 

Science News: Free-Living Physical Activity and Sedentary Behavior in Autoimmune Myasthenia Gravis: A Cross-Sectional Study

January 06, 2022

Physical activity in patients with myasthenia gravis (MG) can be limited due to fatigability and undertreated disease. This prospective cross-sectional study looked at physical activity patterns of women with MG.

Science News: European Academy of Neurology/Peripheral Nerve Society Guideline on Diagnosis and Treatment of Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Report of a Joint Task Force-Second Revision

December 28, 2021

CIDP diagnosis is based on clinical, electrophysiological and other laboratory investigations. The EFNS/PNS diagnostic criteria (2010) for CIDP has been found to have high sensitivity and specificity. The second revision has been recently published with goal in improving diagnostic accuracy and treatment outcome.

Science News: Critical Illness Polyneuropathy, Myopathy and Neuronal Biomarkers in COVID-19 Patients: A Prospective Study

December 14, 2021

This article determines the risk factors for developing critical illness neuropathy (CIN) and/or myopathy (CIM) in 111 COVID patients admitted to an ICU in Sweden, as well as differences between COVID and non-COVID patients with ICU weakness.

Science News: Clinical Features and Treatment Response in Immune-Mediated Small Fiber Neuropathy with Trisulfated Heparin Disaccharide or Fibroblast Growth Factor Receptor 3 Antibodies

December 14, 2021

The objective of the article was to describe clinical features and treatment responses in cryptogenic small fiber neuropathy (SFN) cases harboring novel antibodies to trisulfated heparin disaccharide (TS-HDS) and fibroblast growth factor receptor 3 (FGFR-3).

Science News: Diagnostic Utility of Gold Coast Criteria in Amyotrophic Lateral Sclerosis

November 30, 2021

Existing diagnostic criteria for amyotrophic lateral sclerosis (ALS) such as El Escorial criteria (rEEC) and Awaji criteria have certain limitations, particularly for early disease or atypical presentations of ALS. A new diagnostic criterion has been proposed, with the goal of making it simpler to implement and include atypical presentations.

Science News: Charcot-Marie-Tooth Disease Misdiagnosed as a Chronic Inflammatory Demyelinating Polyradiculoneuropathy: An International Multicentric Retrospective Study

November 30, 2021

Charcot–Marie–Tooth (CMT) disease, a common hereditary polyneuropathy, has no treatment besides symptomatic relief. Authors performed a large retrospective study in 16 university hospitals in three European countries (France, Belgium, and Switzerland). Among 1,104 chronic inflammatory demyelinating polyneuropathy (CIDP) cases, there were 35 CMT patients (3.2%) misdiagnosed as CIDP.

Science News: Assessing Diagnostic and Severity Grading Accuracy of Ultrasound Measurements for Carpal Tunnel Syndrome Compared to Electrodiagnostics

November 15, 2021

This is a prospective study of 95 18 to 80-year-old patients referred for electrodiagnostic (EDX) testing of idiopathic carpal tunnel syndrome (CTS). Exclusion criteria for prior CTS and other concomitant confounding factors. The combined sensory index (CSI) and Bland criteria were used to assess for severity.

Science News: Effect of High-Frequency (10-kHz) Spinal Cord Stimulation in Patients With Painful Diabetic Neuropathy: A Randomized Clinical Trial

November 15, 2021

Nevro's SENZA-PDN study, RCT of spinal cord stimulation treatment conducted for PDN-painful diabetic polyneuropathy, compares 10 kHz SCS plus Conventional Medical Management (CMM) to CMM alone in 216 patients at 18 centers in the United States.

Science News: Skeletal Muscle and Peripheral Nerve Histopathology in COVID-19

November 03, 2021

This study discusses spectrum of skeletal muscle and nerve pathology of patients who died following SARS-CoV-2 infection.

Science News: Impact of Coronavirus Disease 2019 in a French Cohort of Myasthenia Gravis

November 03, 2021

Among 3,558 patients with MG registered in the French database for rare disorders, 34 (0.96%) had COVID-19. The mean age at COVID-19 onset was 55.0 ± 19.9 years (mean MG duration: 8.5 ± 8.5 years). By the end of the study period, 28 patients recovered from COVID-19, 1 remained affected, and 5 died.

Science News: Childhood Amyotrophic Lateral Sclerosis Caused by Excess Sphingolipid Synthesis

October 19, 2021

Amyotrophic lateral sclerosis (ALS) is a devastating disease with poorly understood underlying pathophysiology. This article describes a rare cause of the early onset of motor neuron disease in children due to mutation in SPLTC1, a subunit of the SPT (serine palmitoyltransferase).