Assessment of diagnostic criteria for multifocal motor neuropathy in patients included in the Italian database.

BACKGROUND AND PURPOSE: This study aimed to assess the diagnostic criteria, ancillary investigations and treatment response using real-life data in multifocal motor neuropathy (MMN) patients. METHODS: Clinical and laboratory data were collected from 110 patients enrolled in the Italian MMN database through a structured questionnaire. Twenty-six patients were excluded due to the unavailability of nerve conduction studies or the presence of clinical signs and symptoms and electrodiagnostic abnormalities inconsistent with the MMN diagnosis. Analyses were conducted on 73 patients with a confirmed MMN diagnosis and 11 patients who did not meet the diagnostic criteria. RESULTS: The European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria were variably applied. AUTHOR: When applying the American Association of Electrodiagnostic Medicine criteria, an additional 17% of patients fulfilled the criteria for probable/definite diagnosis whilst a further 9.5% missed the diagnosis. In 17% of the patients only compound muscle action potential amplitude, but not area, was measured and subsequently recorded in the database by the treating physician. Additional investigations, including anti-GM1 immunoglobulin M antibodies, cerebrospinal fluid analysis, nerve ultrasound and magnetic resonance imaging, supported the diagnosis in 46%-83% of the patients. Anti-GM1 immunoglobulin M antibodies and nerve ultrasound demonstrated the highest sensitivity. Additional tests were frequently performed outside the EFNS/PNS guideline recommendations. CONCLUSIONS: This study provides insights into the real-world diagnostic and management strategies for MMN, highlighting the challenges in applying diagnostic criteria.

Impact of 2021 European Academy of Neurology/Peripheral Nerve Society diagnostic criteria on diagnosis and therapy of chronic inflammatory demyelinating polyradiculoneuropathy variants.

BACKGROUND AND PURPOSE: There are different criteria for the diagnosis of different variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) guidelines provide specific clinical criteria for each CIDP variant even if their therapeutical impact has not been investigated. METHODS: We applied the clinical criteria for CIDP variants of the 2021 EAN/PNS guidelines to 369 patients included in the Italian CIDP database who fulfilled the 2021 EAN/PNS electrodiagnostic criteria for CIDP. RESULTS: According to the 2021 EAN/PNS clinical criteria, 245 patients achieved a clinical diagnosis of typical CIDP or CIDP variant (66%). We identified 106 patients with typical CIDP (29%), 62 distal CIDP (17%), 28 multifocal or focal CIDP (7%), four sensory CIDP (1%), 27 sensory-predominant CIDP (7%), 10 motor CIDP (3%), and eight motor-predominant CIDP (2%). Patients with multifocal, distal, and sensory CIDP had milder impairment and symptoms. Patients with multifocal CIDP had less frequently reduced conduction velocity and prolonged F-wave latency and had lower levels of cerebrospinal fluid protein. Patients with distal CIDP more frequently had reduced distal compound muscle action potentials. Patients with motor CIDP did not improve after steroid therapy, whereas those with motor-predominant CIDP did. None of the patients with sensory CIDP responded to steroids, whereas most of those with sensory-predominant CIDP did. CONCLUSIONS: The 2021 EAN/PNS criteria for CIDP allow a better characterization of CIDP variants, permitting their distinction from typical CIDP and more appropriate treatment for patients.

Parkinson-ALS with a novel MAPT variant.

The mutations on microtubule associated protein tau (MAPT) gene manifest clinically with behavioural frontotemporal dementia (FTD), parkinsonism, such as progressive supranuclear palsy and corticobasal degeneration, and rarely with amyotrophic lateral sclerosis (ALS). FTD-parkinsonism and FTD-ALS are clinical overlaps included in the spectrum of MAPT mutation's phenotypes. The mutations on MAPT gene cause the dysfunction of tau protein determining its accumulation in neurofibrillary tangles. Recent data describe frequently the co-occurrence of the aggregation of tau protein and α-synuclein in patients with parkinsonism and Parkinson disease (PD), suggesting an interaction of the two proteins in determining neurodegenerative process. The sporadic description of PD-ALS clinical complex, known as Brait-Fahn-Schwarz disease, supports the hypothesis of common neuropathological pathways between different disorders. Here we report the case of a 54-year-old Italian woman with idiopathic PD later complicated by ALS carrying a novel MAPT variant (Pro494Leu). The variant is characterized by an amino acid substitution and is classified as damaging for MAPT functions. The case supports the hypothesis of tau dysfunction as the basis of multiple neurodegenerative disorders.

Unclassified clinical presentations of chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND: To assess the ability of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) clinical criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) to include within their classification the whole spectrum of clinical heterogeneity of the disease and to define the clinical characteristics of the unclassifiable clinical forms. METHODS: The 2021 EAN/PNS clinical criteria for CIDP were applied to 329 patients fulfilling the electrodiagnostic (and in some cases also the supportive) criteria for the diagnosis of CIDP. Clinical characteristics were reviewed for each patient not strictly fulfilling the clinical criteria ('unclassifiable'). RESULTS: At study inclusion, 124 (37.5%) patients had an unclassifiable clinical presentation, including 110 (89%) with a typical CIDP-like clinical phenotype in whom some segments of the four limbs were unaffected by weakness ('incomplete typical CIDP'), 10 (8%) with a mild distal, symmetric, sensory or sensorimotor polyneuropathy confined to the lower limbs with cranial nerve involvement ('cranial nerve predominant CIDP') and 4 (1%) with a symmetric sensorimotor polyneuropathy limited to the proximal and distal areas of the lower limbs ('paraparetic CIDP'). Eighty-one (65%) patients maintained an unclassifiable presentation during the entire disease follow-up while 13 patients progressed to typical CIDP. Patients with the unclassifiable clinical forms compared with patients with typical CIDP had a milder form of CIDP, while there was no difference in the distribution patterns of demyelination. CONCLUSIONS: A proportion of patients with CIDP do not strictly fulfil the 2021 EAN/PNS clinical criteria for diagnosis. These unclassifiable clinical phenotypes may pose diagnostic challenges and thus deserve more attention in clinical practice and research.

Risk of disease relapse, safety and tolerability of SARS-CoV-2 vaccination in patients with chronic inflammatory neuropathies.

BACKGROUND AND PURPOSE: The aim was to evaluate the risk of relapse after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, and its safety and tolerability, in patients with chronic inflammatory neuropathies. METHODS: In this multicenter, cohort and case-crossover study, the risk of relapse associated with SARS-CoV-2 vaccination was assessed by comparing the frequency of relapse in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) patients who underwent or did not undergo vaccination. Frequency of relapse in the 3 months prior to and after vaccination, and safety and tolerability of SARS-CoV-2 vaccination, were also assessed. RESULTS: In all, 336 patients were included (278 CIDP, 58 MMN). Three hundred and seven (91%) patients underwent SARS-CoV-2 vaccination. Twenty-nine patients (9%) did not undergo vaccination. Mild and transient relapses were observed in 16 (5%) patients (13 CIDP, 3 MMN) after SARS-CoV-2 vaccination and in none of the patients who did not undergo vaccination (relative risk [RR] 3.21, 95% confidence interval [CI] 0.19-52.25). There was no increase in the specific risk of relapse associated with type of vaccine or diagnosis. Comparison with the 3-month control period preceding vaccination revealed an increased risk of relapse after vaccination (RR 4.00, 95% CI 1.35-11.82), which was restricted to CIDP patients (RR 3.25, 95% CI 1.07-9.84). The safety profile of SARS-CoV-2 vaccination was characterized by short-term, mild-to-moderate local and systemic adverse events. CONCLUSIONS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in CIDP and MMN patients does not seem to be associated with an increased risk of relapse at the primary end-point, although a slightly increased risk in CIDP patients was found compared to the 3 months before vaccination.

Comparison of the diagnostic accuracy of the 2021 EAN/PNS and 2010 EFNS/PNS diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy.

OBJECTIVES: To compare the sensitivity and specificity of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with those of the 2010 European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS). METHODS: Sensitivity and specificity of the two sets of criteria were evaluated in 330 patients with CIDP and 166 axonal peripheral neuropathy controls. Comparison of the utility of nerve conduction studies with different number of nerves examined and of the sensitivity and specificity of the two criteria in typical CIDP and its variants were assessed. RESULTS: EFNS/PNS criteria had a sensitivity of 92% for possible CIDP and 85% for probable/definite CIDP, while the EAN/PNS criteria had a sensitivity of 83% for possible CIDP and 74% for CIDP. Using supportive criteria, the sensitivity of the EAN/PNS criteria for possible CIDP increased to 85% and that of CIDP to 77%, remaining lower than that of the EFNS/PNS criteria. Specificity of the EFNS/PNS criteria was 68% for possible CIDP and 84% for probable/definite CIDP, while the EAN/PNS criteria had a specificity of 88% for possible CIDP and 98% for CIDP. More extended studies increased the sensitivity of both sets of criteria by 4%-7% but reduced their specificity by 2%-3%. The EFNS/PNS criteria were more sensitive for the diagnosis of typical CIDP while the EAN/PNS criteria were more specific for the diagnosis of distal and sensory CIDP. CONCLUSIONS: In our population, the EAN/PNS criteria were more specific but less sensitive than the EFNS/PNS criteria. With the EAN/PNS criteria, more extended nerve conduction studies are recommended to obtain an acceptable sensitivity while maintaining a high specificity.

Validation of the DYALS (dysphagia in amyotrophic lateral sclerosis) questionnaire for the evaluation of dysphagia in ALS patients.

BACKGROUND: Dysphagia is a common symptom during the trajectory of ALS, and it can significantly impact on the quality of life and prognosis of patients. Nowadays, no specific tool for the screening of dysphagia in ALS is validated, and the approach is heterogeneous across the Italian centres. OBJECTIVE: To validate the DYALS (dysphagia in amyotrophic lateral sclerosis) questionnaire, adapting the DYMUS (dysphagia in multiple sclerosis) questionnaire, for the assessment of dysphagia in ALS patients, in order to uniform the evaluations across the Italian ALS network. METHODS: We included 197 patients diagnosed with ALS following the El Escorial criteria, in sixteen Italian ALS centres between 1st December 2019 and 1st July 2020. For each patient, we collected clinical and demographic data and obtained ALSFRS-r score, ALSAQ-5 score, DYMUS score, and EAT-10 score. RESULTS: Across the 197 patients, the ratio M/F was 113/84, and the median age was 64 years (IQR 56-72.5). Bulbar patients were 20%, and spinal patients 80%. The median ALSFRSr total score of patients was 35 (IQR 28-39). DYALS score was statistically higher in bulbar ALS than in spinal ALS (median = 6, IQR 4.5-9 vs median = 1, IQR 0-5, z = 6.253, p < 0.0001). DYALS questionnaire showed a high internal consistency (Cronbach's alpha = 0.88). There was a statistically significant correlation between DYALS and EAT-10 (rho = 0.90, p < 0.0001). CONCLUSIONS: DYALS scale is reliable, manageable, and easily usable for the screening of dysphagia in ALS. It can be shared with all the Italian ALS centres in order to collect uniform data for therapeutic strategies and clinical trials.

A Schematic Approach to Defining the Prevalence of COL VI Variants in Five Years of Next-Generation Sequencing.

OBJECTIVE: To define the prevalence of variants in collagen VI genes through a next-generation sequencing (NGS) approach in undiagnosed patients with suspected neuromuscular disease and to propose a diagnostic flowchart to assess the real pathogenicity of those variants. METHODS: In the past five years, we have collected clinical and molecular information on 512 patients with neuromuscular symptoms referred to our center. To pinpoint variants in COLVI genes and corroborate their real pathogenicity, we sketched a multistep flowchart, taking into consideration the bioinformatic weight of the gene variants, their correlation with clinical manifestations and possible effects on protein stability and expression. RESULTS: In Step I, we identified variants in COLVI-related genes in 48 patients, of which three were homozygous variants (Group 1). Then, we sorted variants according to their CADD score, clinical data and complementary studies (such as muscle and skin biopsy, study of expression of COLVI on fibroblast or muscle and muscle magnetic resonance). We finally assessed how potentially pathogenic variants (two biallelic and 12 monoallelic) destabilize COL6A1-A2-A3 subunits. Overall, 15 out of 512 patients were prioritized according to this pipeline. In seven of them, we confirmed reduced or absent immunocytochemical expression of collagen VI in cultured skin fibroblasts or in muscle tissue. CONCLUSIONS: In a real-world diagnostic scenario applied to heterogeneous neuromuscular conditions, a multistep integration of clinical and molecular data allowed the identification of about 3% of those patients harboring pathogenetic collagen VI variants.

Expanding the clinical and genetic spectrum of pathogenic variants in STIM1.

INTRODUCTION/AIMS: Stromal interaction molecule 1 (STIM1) is a reticular Ca2+ sensor composed of a luminal and a cytosolic domain. Autosomal dominant mutations in STIM1 cause tubular aggregate myopathy and Stormorken syndrome or its variant York platelet syndrome. In this study we aimed to expand the features related to new variants in STIM1. METHODS: We performed a cross-sectional study of individuals harboring monoallelic STIM1 variants recruited at five tertiary centers involved in a study of inherited myopathies analyzed with a multigene-targeted panel. RESULTS: We identified seven individuals (age range, 26-57 years) harboring variants in STIM1, including five novel changes: three located in the EF-hand domain, one in the sterile α motif (SAM) domain, and one in the cytoplasmatic region of the protein. Functional evaluation of the pathogenic variants using a heterologous expression system and measuring store-operated calcium entry demonstrated their causative role and suggested a link of new variants with the clinical phenotype. Muscle contractures, found in three individuals, showed variability in body distribution and in the number of joints involved. Three patients showed cardiac and respiratory involvement. Short stature, hyposplenism, sensorineural hearing loss, hypothyroidism, and Gilbert syndrome were variably observed among the patients. Laboratory tests revealed hyperCKemia in six patients, thrombocytopenia in two patients, and hypocalcemia in one patient. Muscle biopsy showed the presence of tubular aggregates in three patients, type I fiber atrophy in one patient, and nonspecific myopathic changes in two patients. DISCUSSION: Our clinical, histological, and molecular data expand the genetic and clinical spectrum of STIM1-related diseases.

Anti-MAG IgM: differences in antibody tests and correlation with clinical findings.

OBJECTIVES: Anti-myelin-associated glycoprotein (MAG) antibody is associated with clinically heterogeneous polyneuropathies. Our purpose was to compare neuropathy phenotypes identified by different anti-MAG tests' results. METHODS: Cohort study: Sera from 40 neuropathy anti-MAG EIA positive patients were tested for anti-MAG by Western blot (WB), for anti-peripheral nerve myelin (PNM) on monkey nerve by immunofluorescence assay (IFA), and for anti-HNK1 on rat CNS slices by IFA. Anti-sulfatide antibodies, for comparison, were also tested by EIA. RESULTS: Among 40 anti-MAG EIA positive sera, 85% also had anti-PNM IFA reactivity and 67.5% bind HNK1 on rat CNS. Anti-HNK1 positive patients had the classical predominantly distal acquired demyelinating symmetric (DADS) neuropathy with a benign course, while anti-PNM positive but anti-HNK1 negative patients had predominantly axonal neuropathy with a high frequency of anti-sulfatide reactivity and the worst long-term prognosis. Anti-MAG EIA positive patients without anti-PNM or anti-HNK1 IFA reactivity had a CIDP-like polyneuropathy. CONCLUSION: Different methods to test for anti-MAG antibodies identify different clinical and electrophysiological findings, as well as long-term outcome. HNK1 reactivity is the strongest marker of DADS.

Plasminogen in cerebrospinal fluid originates from circulating blood.

BACKGROUND: Plasminogen activation is a ubiquitous source of fibrinolytic and proteolytic activity. Besides its role in prevention of thrombosis, plasminogen is involved in inflammatory reactions in the central nervous system. Plasminogen has been detected in the cerebrospinal fluid (CSF) of patients with inflammatory diseases; however, its origin remains controversial, as the blood-CSF barrier may restrict its diffusion from blood. METHODS: We investigated the origin of plasminogen in CSF using Alexa Fluor 488-labelled rat plasminogen injected into rats with systemic inflammation and blood-CSF barrier dysfunction provoked by lipopolysaccharide (LPS). Near-infrared fluorescence imaging and immunohistochemistry fluorescence microscopy were used to identify plasminogen in brain structures, its concentration and functionality were determined by Western blotting and a chromogenic substrate assay, respectively. In parallel, plasminogen was investigated in CSF from patients with Guillain-Barré syndrome (n = 15), multiple sclerosis (n = 19) and noninflammatory neurological diseases (n = 8). RESULTS: Endogenous rat plasminogen was detected in higher amounts in the CSF and urine of LPS-treated animals as compared to controls. In LPS-primed rats, circulating Alexa Fluor 488-labelled rat plasminogen was abundantly localized in the choroid plexus, CSF and urine. Plasminogen in human CSF was higher in Guillain-Barré syndrome (median = 1.28 ng/µl (interquartile range (IQR) = 0.66 to 1.59)) as compared to multiple sclerosis (median = 0.3 ng/µl (IQR = 0.16 to 0.61)) and to noninflammatory neurological diseases (median = 0.27 ng/µl (IQR = 0.18 to 0.35)). CONCLUSIONS: Our findings demonstrate that plasminogen is transported from circulating blood into the CSF of rats via the choroid plexus during inflammation. Our data suggest that a similar mechanism may explain the high CSF concentrations of plasminogen detected in patients with inflammation-derived CSF barrier impairment.

Sex influences clinical phenotype in valosin-containing protein mutations: A case family report and systematic literature review.

OBJECTIVE: Mutations in the valosin-containing protein (VCP) gene cause autosomal dominant multisystem proteinopathy 1 (MSP1), characterized by a variable combination of inclusion body myopathy (IBM), Paget's disease of bone (PDB), and frontotemporal dementia (FTD). Here we report a novel VCP missense mutations in an Italian family with FTD as the prevalent manifestation and compare our results with those described in the literature. METHODS: We described the clinical, molecular, and imaging data of the studied family. We also conducted a systematic literature search with the aim of comparing our findings with previously reported VCP-related phenotypes. RESULTS: A novel heterozygous VCP missense mutation (c 0.473 T > C/p.Met158Thr) was found in all the affected family members. The proband is a 69-year-old man affected by progressive muscle weakness since the age of 49. Muscle MRI showed patchy fatty infiltration in most muscles, and STIR sequences revealed an unusual signal increase in distal leg muscles. At age 65, he presented a cognitive disorder suggestive of behavioral variant FTD. A bone scintigraphy also revealed PDB. The patient's mother, his maternal aunt and her daughter had died following a history of cognitive deterioration consistent with FTD; the mother also had PDB. No relatives had any muscular impairments. Reviewing the literature data, we observed a different sex distribution of VCP-related phenotypes, being FTD prevalence higher among women as compared to men (51.2 % vs 31.2 %) and IBM prevalence higher among men as compared to women (92.1 % vs 72.8 %). DISCUSSION: This study broadened our clinical, genetic, and imaging knowledge of VCP-related disorders.

Epidemiology of amyotrophic lateral sclerosis in the north east Tuscany in the 2018-2021 period.

Background: The incidence of Amyotrophic Lateral Sclerosis (ALS) varies among different geographical areas and seems to increase over time. This study aimed to examine the epidemiologic data of ALS in the north-east Tuscany and compare the results with those of similar surveys. Methods: Data from ALS cases diagnosed in Florence and Prato Hospitals were prospectively collected from 1st June 2018 to 31st May 2021. Results: The age- and sex-adjusted incidence rate of ALS in cases per 100,000 population was 2.71 (M/F ratio: 1.21), significantly higher as compared to that reported in the 1967-1976 decade in the same geographical area (0.714). The age- and sex-adjusted incidence rate among resident strangers was similar to that of the general population (2.69). A slightly higher incidence rate (4.36) was observed in the north-east area of Florence province, which includes the Mugello valley. The mean prevalence was of 7.17/100,00. The mean age at diagnosis was 69.7 years, with a peak between 70 and 79 years among men and a smoother age curve among women. Conclusions: ALS epidemiological features in north-east Tuscany are in line with other Italian and European Centers. The dramatic increase of the local disease burden over the last decades probably reflects better ascertainment methods and health system.

Using Cluster Analysis to Overcome the Limits of Traditional Phenotype-Genotype Correlations: The Example of RYR1-Related Myopathies.

Thanks to advances in gene sequencing, RYR1-related myopathy (RYR1-RM) is now known to manifest itself in vastly heterogeneous forms, whose clinical interpretation is, therefore, highly challenging. We set out to develop a novel unsupervised cluster analysis method in a large patient population. The objective was to analyze the main RYR1-related characteristics to identify distinctive features of RYR1-RM and, thus, offer more precise genotype-phenotype correlations in a group of potentially life-threatening disorders. We studied 600 patients presenting with a suspicion of inherited myopathy, who were investigated using next-generation sequencing. Among them, 73 index cases harbored variants in RYR1. In an attempt to group genetic variants and fully exploit information derived from genetic, morphological, and clinical datasets, we performed unsupervised cluster analysis in 64 probands carrying monoallelic variants. Most of the 73 patients with positive molecular diagnoses were clinically asymptomatic or pauci-symptomatic. Multimodal integration of clinical and histological data, performed using a non-metric multi-dimensional scaling analysis with k-means clustering, grouped the 64 patients into 4 clusters with distinctive patterns of clinical and morphological findings. In addressing the need for more specific genotype-phenotype correlations, we found clustering to overcome the limits of the "single-dimension" paradigm traditionally used to describe genotype-phenotype relationships.

Retrospective observational study on the use of acetyl-L-carnitine in ALS.

ALCAR (Acetyl-L-carnitine) is a donor of acetyl groups and increases the intracellular levels of carnitine, the primary transporter of fatty acids across the mitochondrial membranes. In vivo studies showed that ALCAR decrease oxidative stress markers and pro-inflammatory cytokines. In a previous double-blind placebo-controlled phase II trial showed positive effects on self-sufficiency (defined as a score of 3+ on the ALSFRS-R items for swallowing, cutting food and handling utensils, and walking) ALSFRS-R total score and FVC. We conducted an observational, retrospective, multicentre, case-control study to provide additional data on the effects of ALCAR in subjects with ALS in Italy. Subjects treated with ALCAR 1.5 g/day or 3 g/day were included and matched with not treated subjects by sex, age at diagnosis, site of onset, and time from diagnosis to baseline, (45 subjects per group). ALCAR 3 g/day vs not treated: 22 not treated subjects (48.9%) were still alive at 24 months after baseline, compared to 23 (51.1%) treated subjects (adj. OR 1.18, 95% CI 0.46-3.02). No statistically significant differences were detected in ALSFRS nor FVC nor self-sufficiency. ALCAR 1.5 g/day vs not treated: 22 not treated subjects (48.9%) were still alive at 24 months after baseline, compared to 32 (71.1%) treated subjects (adj. OR 0.27, 95% CI 0.10-0.71). For ALSFRS-R, a mean slope of - 1.0 was observed in treated subjects compared to - 1.4 in those not treated (p = 0.0575). No statistically significant difference was detected in the FVC nor self-sufficiency. Additional evidence should be provided to confirm the efficacy of the drug and provide a rationale for the dosage.

Polyneuropathy and monoclonal gammopathy of undetermined significance (MGUS); update of a clinical experience.

BACKGROUND AND PURPOSE: Polyneuropathies associated with monoclonal gammopathy of undetermined significance (MGUS) encompass a group of phenotypically and immunologically heterogeneous neuropathies. While the best characterized is that associated with anti-myelin glycoprotein (MAG) antibodies, there are phenotypical and immunological neuropathy variants that still lack a clear classification. We analyzed a significant number of patients, in order to better evaluate the distribution of neuropathy phenotypes and to look for some common characteristics. METHODS: Clinical, neurophysiological, and laboratory data from 87 consecutive MGUS patients with peripheral neuropathy were analyzed and compared among patient groups with different MGUS classes and autoantibody reactivity. RESULTS: Anti-MAG neuropathy cases account for the most homogeneous group with regard to clinical and neurophysiological findings. Patients with anti-gangliosides or sulfatide (GS) antibodies, despite a marked phenotype heterogeneity, still share several common features, including a younger age at diagnosis, a more severe disease, and a prompt and sustained response to both immunoglobulin and rituximab therapies, mostly requiring chronic administration of immune treatment. CONCLUSIONS: Although heterogeneous, MGUS-associated, anti-GS antibody positive neuropathies have important similar features possibly resulting from a similar biological background.

Neurofilament Light Chain and Intermediate HTT Alleles as Combined Biomarkers in Italian ALS Patients.

OBJECTIVE: To study the possible implication of the two biomarkers, intermediate alleles (IAs) of the Huntingtin (HTT) gene and neurofilament light chain (NfL) levels in plasma, in amyotrophic lateral sclerosis (ALS) patients. METHODS: We analyzed IAs in a cohort of 106 Italian ALS patients and measured the plasma NfL levels in 20% of the patients of the cohort. We correlated the two biomarkers with clinical phenotypes. RESULTS: Intermediate alleles were present in 7.5% of the patients of our cohort, a frequency higher than that reported in general population. Plasma NfL levels increased with age at onset (p < 0.05). Patients with bulbar onset (BO) had higher plasma NfL concentration (CI -0.61 to -0.06, p = 0.02) and a later age at onset of the disease (CI -24.78 to -4.93, p = 0.006) with respect to the spinal onset (SO) form. Additionally, two of the patients, with IAs and plasma NfL concentration lower with respect to normal alleles' carriers, presented an age at onset higher than the mean of the entire cohort. CONCLUSION: According to our findings, plasma NfL and IAs of HTT gene may represent potential biomarkers in ALS, providing evidence of a possible implication in clinical phenotype.

Auditory Training With Synthesized Voice Anchors: Effects on Rater Agreement.

PURPOSE: To investigate the effects of auditory training with synthesized voices on intra- and inter-rater agreement of the auditory-perceptual voice analysis of roughness and breathiness. METHODS: This was an experimental study consisting of four auditory training sessions. The sample consisted of twenty raters, students from a Speech-Language Pathology course, who had previous experience with auditory-perceptual assessment. The raters participated in the four training sessions with a seven-day break in between sessions. Each training consisted of three tasks: 1) Pre-training activity: Participants were asked to rate 20 natural voices, normal and dysphonic, from zero to three, according to the parameters of roughness and breathiness; 2) Training activity: Synthesized voice anchor stimuli were presented, and participants were asked to rate them from zero to three. Four stimuli were related to roughness and four to breathiness. Participants heard 20 voice stimuli and were instructed to pair the natural voice with the synthesized anchor stimulus that most resembled it; and 3) Post-training activity: the 20 voices from the pre-training activity were randomized and participants rated the same voices, without prior knowledge that these were repeated. Statistical analysis of data was performed using the AC2 test, to assess the extent of agreement between raters, and the Friedman test to compare the training sessions. A 5% significance level was considered. RESULTS: For the auditory-perceptual voice analysis of roughness, intra-rater agreement results ranged from 79% to 86% between the first and fourth auditory training session, with improvement in intra-rater agreement from the fourth session forward (P = 0.005). For the analysis of breathiness, results ranged from 88% to 92% between the first and fourth auditory training sessions, with improvement from the fourth session forward (P = 0.036). Inter-rater agreement results for the auditory-perceptual analysis of roughness ranged from 23% to 34%, and from 48% to 61% for breathiness, with no differences regarding training (P = 0.855). CONCLUSION: The auditory-perceptual breathiness parameter had a higher AC2 indicator compared to the roughness parameter, suggesting better agreement. The intra-rater agreement showed improvement starting from the fourth auditory training session for the assessment of roughness and breathiness. The auditory training program did not show a positive inter-rater agreement impact.

AMPA receptor antibodies in limbic encephalitis alter synaptic receptor location.

OBJECTIVE: To report the clinical and immunological features of a novel autoantigen related to limbic encephalitis (LE) and the effect of patients' antibodies on neuronal cultures. METHODS: We conducted clinical analyses of 10 patients with LE. Immunoprecipitation and mass spectrometry were used to identify the antigens. Human embryonic kidney 293 cells expressing the antigens were used in immunocytochemistry and enzyme-linked immunoabsorption assay. The effect of patients' antibodies on cultures of live rat hippocampal neurons was determined with confocal microscopy. RESULTS: Median age was 60 (38-87) years; 9 were women. Seven had tumors of the lung, breast, or thymus. Nine patients responded to immunotherapy or oncological therapy, but neurological relapses, without tumor recurrence, were frequent and influenced the long-term outcome. One untreated patient died of LE. All patients had antibodies against neuronal cell surface antigens that by immunoprecipitation were found to be the glutamate receptor 1 (GluR1) and GluR2 subunits of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR). Human embryonic kidney 293 cells expressing GluR1/2 reacted with all patients' sera or cerebrospinal fluid, providing a diagnostic test for the disorder. Application of antibodies to cultures of neurons significantly decreased the number of GluR2-containing AMPAR clusters at synapses with a smaller decrease in overall AMPAR cluster density; these effects were reversed after antibody removal. INTERPRETATION: Antibodies to GluR1/2 associate with LE that is often paraneoplastic, treatment responsive, and has a tendency to relapse. Our findings support an antibody-mediated pathogenesis in which patients' antibodies alter the synaptic localization and number of AMPARs.