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INTRODUCTION: Myotonic dystrophy type 1 (DM1) is an autosomal dominant disease characterized by myotonia and progressive muscular weakness and atrophy. The aim of this study was to investigate the usefulness of longitudinal muscle MRI in detecting disease activity and progression in DM1, and to better characterize muscle edema, fat replacement and atrophy overtime. MATERIALS AND METHODS: This is a prospective, observational, longitudinal study including 25 DM1 patients that performed at least two muscle MRIs. Demographic and genetic characteristics were recorded. Muscular Impairment Rating Scale (MIRS) and MRC score were performed within 3 months from MRIs at baseline (BL) and at follow-up (FU). We analysed 32 muscles of lower body (LB) and 17 muscles of upper body (UB) by T1 and STIR sequences. T1-, STIR- and atrophy scores and their variations were evaluated. Correlations between MRIs' scores and demographic, clinical and genetic characteristics were analysed. RESULTS: Eighty (80%) of patients showed fat replacement progression at FU. The median T1 score progression (ΔT1-score) was 1.3% per year in LB and 0.5% per year in UB. The rate of fat replacement progression was not homogenous, stratifying patients from non-progressors to fast progressors (> 3% ΔT1-score per year). Half of the STIR-positive muscles at BL showed T1-score progression at FU. Two patients with normal MRI at baseline only showed STIR-positive muscle at FU, marking the disease activity onset. STIR positivity at baseline correlated with fat replacement progression (ΔT1-score; p < 0.0001) and clinical worsening at FU (ΔMRC-score; p < 0.0001). Sixty-five (65%) of patients showed STIR- and fat replacement-independent muscle atrophy progression, more evident in UB. CONCLUSIONS: Muscle MRI represents a sensitive biomarker of disease activity, severity, and progression in DM1. STIR alterations precede fat replacement and identify patients with a higher risk of disease progression, while T1-sequences reveal atrophy and fat replacement progression before clinical worsening.
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INTRODUCTION: Eculizumab, a complement active antibody, and efgartigimod, an Fc fragment that blocks neonatal Fc receptor, are both approved to treat generalized myasthenia gravis (gMG) patients. The objective of this study is to describe the clinical response to both treatments in a real-life setting. METHODS: We collected baseline and follow-up clinical data using the Myasthenia Gravis-Activities of Daily Living (MG-ADL), and Quantitative Myasthenia Gravis (QMG). We included 63 patients, 32 treated with eculizumab and 31 with efgartigimod. Of the efgartigimod-treated patients, 22 were anti-acetylcholine receptor antibody-positive (AChR-Ab +) and 9 were AChR-Ab- (3 MuSK-Ab + and 6 seronegative). RESULTS: Both treatments showed similar efficacy relative to the MG-ADL scale reduction (p = 0.237). Efgartigimod had a similar effect on both AChR-Ab + and AChR-Ab- (p = 0.280). Eculizumab was superior to efgartigimod relative to the QMG score reduction for the entire dataset (p = 0.003) and was more likely to achieve a clinical response at the QMG compared to efgartigimod (OR 1.373; p = 0.016). Steroid-sparing effect was higher for eculizumab than efgartigimod ( - 16.7 vs - 5.2 mg of the baseline daily dose at follow-up; p = 0.001). Mean speed of prednisone reduction was - 13.1 mg of the daily dose for each month of follow-up for eculizumab-treated patients and - 3.2 for efgartigimod (p = 0.001). We found three serious events, all not related to treatment in the investigator's opinion. One eculizumab-treated patient experienced a severe pneumonia and died despite treatment. CONCLUSIONS: Our study provides evidence that eculizumab and efgartigimod can be used in clinical practice to reduce disability in gMG patients. Eculizumab-treated patients had a higher QMG response and steroid sparing effect. Efgartigimod may offer a more flexible schedule due to its cyclical use, no need for vaccination, and efficacy in AChR-Ab- patients.
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BACKGROUND: Recent evidence suggests that both serum neurofilament light chain (sNfL) levels and small fiber related diagnostic variables may be valuable disease biomarkers of hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN). Our study aimed to explore the relations between sNfL and small fiber related skin biopsy and quantitative sensory testing (QST) parameters in a cohort of ATTRv-PN patients and pre-symptomatic carriers. METHODS: We retrospectively analyzed data from 13 ATTRv patients and 21 pre-symptomatic carriers who underwent sNfL dosage, skin biopsy, and QST, and analyzed correlations between sNFL, intraepidermal nerve fiber density (IENFD), and cold (CDT) and warm detection thresholds (WDT). RESULTS: Both sNfL and small fiber related parameters significantly differed between carriers and patients (sNfL: p < 0.0001; IENFD: p = 0.0008; CDT, WDT: < 0.0001). sNFL levels were normal in all carriers, altered in 85% of patients, negatively correlated with distal IENFD (r = -0.47, p = 0.005), and significantly correlated with CDT (r = -0.68; p < 0.0001) and WDT (r = 0.57; p < 0.0001). CONCLUSIONS: Our study showed that sNfL reliably discriminates symptomatic ATTRv-PN patients from pre-symptomatic carriers, and found significant relations between sNfL, skin biopsy, and QST small fiber related parameters, suggesting that sNfL might be a valuable biomarker of peripheral nerve involvement in ATTRv-PN and a supportive criterion for symptomatic disease transition.
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INTRODUCTION: Few studies have pointed to the possible role of infectious diseases in triggering Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). Given the association of Hepatitis E Virus (HEV) with Guillain Barrè syndrome, we conducted a case-control study to determine the possible association of HEV infection with CIDP, analyzing possible risk factors for acquiring HEV infection in both CIDP patients and controls. MATERIALS AND METHODS: 82 CIDP and 260 from the general population have provided some personal information (demographics, anamnestic data and recognized risk factors for HEV infection) and underwent venipuncture blood sampling for virological assays testing for anti-HEV IgG and IgM with ELISA and RNA-HEV performing RT-PCR. RESULTS: Anti-HEV IgG seropositivity resulted in 32 CIDP patients (39.0%) and in 45 controls (17.3%), indicating a significant association between anti-HEV IgG positivity and CIDP (OR 3.04; 95% CI 1.70-5.43, p-value <0.001), but in multivariate logistic regression the only significant associations with anti-HEV positivity were eating pork liver sausages (OR 10.443, 95% CI 2.268-60.12, p-value 0.004) and IVIg/SCIg administration (OR 31.32, 95% CI 7.914-171.7, p-value <0.001). DISCUSSION: The higher prevalence of anti-HEV IgG in CIDP patients than in controls could be justified by chronically administering IVIg/SCIg with a passive acquisition of anti-HEV antibodies. Furthermore, all the 20 CIDP patients who underwent IVIg/SCIg administration reported HEV risk factors, so that they could have acquired the infection. CONCLUSIONS: Further studies in a larger CIDP patient sample in treatment with therapy other than IVIg/SCIg are necessary to rule out the possible confounding effect of IVIg/SCIg.
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Polyradiculoneuropathy, Chronic Inflammatory Demyelinating , Humans , Immunoglobulins, Intravenous , Case-Control Studies , Immunoglobulin G , Risk FactorsABSTRACT
OBJECTIVE: To test the complement inhibitor eculizumab in the treatment of MG exacerbation during therapy with the immune-checkpoint inhibitor (ICI) pembrolizumab, avoiding its discontinuation, which could be detrimental to oncologic course. METHODS: A 76-year-old male with non-thymomatous generalized anti-AchR + MG (MGFA class IVB), during treatment with pembrolizumab for colorectal cancer, developed a severe myasthenic exacerbation, refractory to steroids and IvIg. Eculizumab was started, without pembrolizumab discontinuation. The patient was prospectively followed using MGFA, MG Activities of Daily Living (MG-ADL), Quantitative MG (QMG), MG Composite (MGC), and MG Quality of Life 15 (MG-QOL-15). RESULTS: After an 18-week follow-up, the patient presented a progressive improvement in scores on all scales, achieving a MGFA class IIIB. The percentage improvement was 40% in MG-ADL, 36% in MG Composite, and about 30% in QMG. Bulbar symptoms improved by about 70% in MG-ADL and MG Composite and 40% in QMG. Eculizumab was well tolerated and pembrolizumab regularly continued, with a good control of cancer progression. DISCUSSION: Eculizumab potentially offers a mechanism-based treatment of MG in patients under anti-programmed cell death protein 1 (PD-1) agents, without interfering with their mechanism of action and avoiding their discontinuation. Larger case series deserve to be evaluated.
Subject(s)
Antibodies, Monoclonal, Humanized , Myasthenia Gravis , Male , Humans , Aged , Myasthenia Gravis/drug therapy , Myasthenia Gravis/diagnosis , Immune Checkpoint Inhibitors/therapeutic use , Quality of Life , Activities of Daily LivingABSTRACT
INTRODUCTION: Mitochondrial alterations are a common finding in muscle biopsy of sporadic inclusion body myositis (s-IBM) and polymyositis with mitochondrial pathology (PM-Mito). Both disorders generally have poor treatment response. Nevertheless, mitochondrial myopathology has been rarely reported in dermatomyositis (DM) outside areas of perifascicular atrophy and a relationship with therapeutic outcome is not established. METHODS: We report on clinical, immunological, radiological, and myopathological findings of a case of severe, treatment-refractory anti-Mi-2-positive DM. RESULTS: A 77-year-old woman developed anti-Mi-2 DM with severe diffuse muscle weakness associated with abundant mitochondrial abnormalities at muscle biopsy, beside the typical features of inflammatory myopathy. The patient was poorly responsive to multiple-line therapies and finally anti-JAK (anti-Janus activated kinase) was administered, leading to partial clinical improvement. DISCUSSION: Given the usual satisfactory treatment response and favorable outcome of anti-Mi-2 DM, we suppose that mitochondrial dysfunction on muscle biopsy could represent a marker of disease severity in DM, predicting a worse response to treatment and a poor clinical outcome. JAK-inhibitors could represent a good treatment option in refractory anti-Mi-2 DM with mitochondrial abnormalities.
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Dermatomyositis , Myositis, Inclusion Body , Myositis , Polymyositis , Female , Humans , Aged , Dermatomyositis/complications , Dermatomyositis/drug therapy , Muscle, Skeletal , Polymyositis/drug therapy , Polymyositis/pathology , Myositis, Inclusion Body/pathologyABSTRACT
INTRODUCTION: Hereditary transthyretin amyloidosis polyneuropathy (ATTRv-PN) presymptomatic carriers often show preclinical abnormalities at small fiber-related diagnostic tests. However, no validated biomarker is currently available to use for presymptomatic carriers' follow-up, thus helping therapeutic decision making. Our study aimed at assessing nerve conduction study (NCS), quantitative sensory testing (QST), and skin biopsy parameters in a large cohort of late-onset ATTRv presymptomatic carriers and to evaluate whether they correlated with predicted age of disease onset (PADO). METHODS: Late-onset ATTRv presymptomatic carriers were consecutively enrolled and underwent NCS, QST, and skin biopsy with intraepidermal nerve fiber density (IENFD) evaluation from a distal and a proximal site. Douleur Neuropathique-4 (DN4) and Small Fiber Neuropathy-Symptoms Inventory (SFN-SIQ) were used to assess painful and small fiber neuropathy-related symptoms. PADO and time-to-PADO (delta-PADO) were estimated for each carrier, and correlations with diagnostic test measures were analyzed. RESULTS: Forty presymptomatic ATTRv subjects were enrolled. Twenty carriers (50%) had distal IENFD reduction, with a non-length-dependent distribution in 73% of cases. Eleven subjects (27.5%) had cold and/or warm detection threshold (CDT and/or WDT) abnormalities at QST. Delta-PADO positively correlated with sural sensory nerve action potential (SNAP) amplitude (r = .416, p = .004), and z-values of QST parameters like CDT (r = .314, p = .028), WDT (r = -.294, p = .034), and mechanical detection threshold (MDT; r = -.382, p = .012). Simple linear regression models showed a linear relation between delta-PADO and sural SAP, CDT, and MDT. CONCLUSIONS: Our findings confirm that IENFD reduction and QST abnormalities may occur early in ATTRv presymptomatic carriers, often with a non-length-dependent pattern. However, only sural SAP amplitude and QST parameters correlated with delta-PADO, suggesting that serial combined QST and NCS evaluation could be useful in ATTRv presymptomatic carriers' follow-up.
Subject(s)
Polyneuropathies , Small Fiber Neuropathy , Humans , Small Fiber Neuropathy/diagnosis , Skin/pathology , Pain , Polyneuropathies/pathology , BiopsyABSTRACT
INTRODUCTION: Muscle ultrasound is a fast, non-invasive and cost-effective examination that can identify structural muscular changes by assessing muscle thickness and echointensity (EI) with a quantitative analysis (QMUS). To assess applicability and repeatability of QMUS, we evaluated patients with genetically confirmed facioscapulohumeral muscular dystrophy type 1 (FSHD1), comparing their muscle ultrasound characteristics with healthy controls and with those detected by MRI. We also evaluated relationships between QMUS and demographic and clinical characteristics. MATERIALS AND METHODS: Thirteen patients were included in the study. Clinical assessment included MRC sum score, FSHD score and The Comprehensive Clinical Evaluation Form (CCEF). QMUS was performed with a linear transducer scanning bilaterally pectoralis major, deltoid, rectus femoris, tibialis anterior and semimembranosus muscles in patients and healthy subjects. For each muscle, we acquired three images, which were analysed calculating muscle EI by computer-assisted grey-scale analysis. QMUS analysis was compared with semiquantitative 1.5 T muscle MRI scale. RESULTS: All muscles in FSHD patients showed a significant increased echogenicity compared to the homologous muscles in healthy subjects. Older subjects and patients with higher FSHD score presented increased muscle EI. Tibialis anterior MRC showed a significant inverse correlation with EI. Higher median EI was found in muscles with more severe MRI fat replacement. CONCLUSIONS: QMUS allows quantitative evaluation of muscle echogenicity, displaying a tight correlation with muscular alterations, clinical and MRI data. Although a confirmation on larger sample is needed, our research suggests a possible future application of QMUS in diagnosis and management of muscular disorders.
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OBJECTIVES: Immune-mediated necrotizing myopathy (IMNM) is the most severe idiopathic inflammatory myopathy (IIM) and early aggressive poly-immunotherapy is often required to reduce long-term disability. The aim of this study is to investigate muscle MRI in IMNM as outcome measure for disease activity, severity, progression, response to treatment, and to better characterize the pattern of muscle involvement. METHODS: This is a retrospective, observational, cross-sectional, and longitudinal study including 22 IMNM patients, divided into three groups based on timing of first MRI and if performed before or under treatment. T1 score and percentage of STIR positive muscles (STIR%) were considered and analyzed also in relation to demographic, clinical and laboratory characteristics. RESULTS: STIR% was higher in untreated patients and in those who performed MRI earlier (p = 0.001). Pelvic girdle and thighs were in general more affected than legs. T1 score was higher in patients with MRI performed later in disease course (p = 0.004) with a prevalent involvement of the lumbar paraspinal muscles, gluteus medius and minimus, adductor magnus and hamstrings. 22% of STIR positive muscles showed fat replacement progression at second MRI. Higher STIR% at baseline correlated with higher risk of fat replacement at follow-up (p = 0.003); higher T1 score correlated with clinical disability at follow-up, with late treatment start and delayed treatment with IVIG (p = 0.03). INTERPRETATION: Muscle MRI is a sensitive biomarker for monitoring disease activity and therapy response, especially when performed early in disease course and before treatment start, and could represent a supportive outcome measure and early prognostic index in IMNM.
Subject(s)
Autoimmune Diseases , Myositis , Humans , Longitudinal Studies , Cross-Sectional Studies , Myositis/diagnostic imaging , Myositis/drug therapy , Muscle, Skeletal/diagnostic imaging , Magnetic Resonance ImagingABSTRACT
INTRODUCTION: Myasthenia gravis-inflammatory myopathy (MG-IM) association has been rarely reported as specific clinical entity characterized by variable myositis manifestations, ranging from subclinical to diffuse muscle involvement with characteristic distal upper limb weakness. Although, in view of this, it has been hypothesized that distal muscle weakness in MG-IM could be due to the muscle inflammation instead of a pure neuromuscular transmission impairment, a biopsy-proven myositis process of distal muscles of upper limbs has not yet been provided. METHODS: We report on clinical, immunological, and myopathological characterization of a novel case affected by MG-IM association showing the typical distal upper limb weakness, including muscle biopsy of a weak forearm muscle. RESULTS: Histological and immunohistochemical studies showed a marked inflammatory process on muscle biopsy of extensor digitorum communis. The patient, a 47-year-old man with 10-year history of anti-acetylcholine receptor (AChR) and anti-titin antibody-positive MG with thymoma, developed a progressive, diffuse, and non-fatigable weakness predominant in distal upper limb muscles, unresponsive to acetylcholinesterase inhibitors associated to myalgia and creatine kinase (CK) elevation. DISCUSSION: We provide the histopathological evidence of a prominent inflammatory process responsible of distal upper limb weakness in MG-IM association. Muscle biopsy does not reveal any typical histopathological feature of other nosologically definite inflammatory myopathy, leading MG-IM association to come close to the group of overlap-myositis (OM) with the myopathological features of non-specific myositis (NSM).
Subject(s)
Myositis , Thymus Neoplasms , Male , Humans , Middle Aged , Acetylcholinesterase , Myositis/complications , Myositis/diagnosis , Muscle Weakness/etiology , Muscle, Skeletal/pathology , Upper ExtremityABSTRACT
BACKGROUND: High-resolution nerve ultrasonography (HRUS) could have an emerging importance in diagnosis and follow-up of axonopathic radial palsy associated with humeral shaft fractures due to closed trauma. The aim of our study is to establish the role of HURS in this context through a longitudinal multimodal analysis. METHODS: Clinical, electrodiagnostic (EDX) and HRUS evaluations were prospectively performed at month 1, 3, 6, 12 and 24 from injury, in a continuous series of 19 patients collected in a 5-year study. Clinical severity was scored on MRC of involved muscles, EDX on presence/absence of functional continuity; anatomical continuity and nerve cross sectional area (NCSA) of radial (RN ) and posterior interosseus (PIN) nerves were evaluated through HRUS. RESULTS: All patients showed clinical improvement during follow-up; EDX functional continuity was reached by all patients within 12 months; HRUS revealed RN anatomical continuity in all patients and PIN involvement in 74%. RN NCSA progressively reduced during FU, but it was still significantly higher than contralateral at month 24; PIN NCSA became normal within 24 months. CONCLUSIONS: When anatomical RN continuity is confirmed by HRUS, good functional outcome is reached even in patients with EDX loss of functional continuity. Together with clinical and EDX evaluations, HRUS may provide useful data in the follow-up of radial palsy due to humeral shaft fractures.
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BACKGROUND: Only a few studies have reported muscle imaging data on small cohorts of patients with myotonic dystrophy type 1 (DM1). We aimed to investigate the muscle involvement in a large cohort of patients in order to refine the pattern of muscle involvement, to better understand the pathophysiological mechanisms of muscle weakness, and to identify potential imaging biomarkers for disease activity and severity. METHODS: One hundred and thirty-four DM1 patients underwent a cross-sectional muscle magnetic resonance imaging (MRI) study. Short tau inversion recovery (STIR) and T1 sequences in the lower and upper body were analyzed. Fat replacement, muscle atrophy and STIR positivity were evaluated using three different scales. Correlations between MRI scores, clinical features and genetic background were investigated. RESULTS: The most frequent pattern of muscle involvement in T1 consisted of fat replacement of the tongue, sternocleidomastoideus, paraspinalis, gluteus minimus, distal quadriceps and gastrocnemius medialis. Degree of fat replacement at MRI correlated with clinical severity and disease duration, but not with CTG expansion. Fat replacement was also detected in milder/asymptomatic patients. More than 80% of patients had STIR-positive signals in muscles. Most DM1 patients also showed a variable degree of muscle atrophy regardless of MRI signs of fat replacement. A subset of patients (20%) showed a 'marbled' muscle appearance. CONCLUSIONS: Muscle MRI is a sensitive biomarker of disease severity alsofor the milder spectrum of disease. STIR hyperintensity seems to precede fat replacement in T1. Beyond fat replacement, STIR positivity, muscle atrophy and a 'marbled' appearance suggest further mechanisms of muscle wasting and weakness in DM1, representing additional outcome measures and therapeutic targets for forthcoming clinical trials.
Subject(s)
Myotonic Dystrophy , Cross-Sectional Studies , Humans , Magnetic Resonance Imaging/methods , Muscle Weakness , Muscle, Skeletal/pathology , Myotonic Dystrophy/diagnostic imagingABSTRACT
INTRODUCTION: Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) remains a diagnostic challenge due to clinical, neurophysiological, and laboratory findings suggestive of other diagnoses, particularly chronic inflammatory demyelinating polyneuropathy (CIDP). In this cross-sectional prospective study, we aimed to investigate the utility of high-resolution ultrasonography of peripheral nerves as a diagnostic tool to differentiate ATTRv-PN from CIDP. METHODS: In 11 treatment-naive patients with genetically confirmed late-onset ATTRv-PN and 25 patients with CIDP, we collected clinical, electrodiagnostic, and high-resolution ultrasonography data of the peripheral nerves. In each patient, we used high-resolution ultrasonography to assess 26 nerve sites. RESULTS: Of the 11 patients with ATTRv-PN, two had electrodiagnostic study data compatible with a CIDP diagnosis. High-resolution ultrasonography showed that the cross-sectional area of the brachial plexus, median nerve at the axilla, arm, and forearm, ulnar nerve at the forearm, and peroneal nerve at the popliteal fossa were significantly smaller in the 11 ATTRv-PN patients than in CIDP patients. However, in the two patients with electrodiagnostic study data compatible with a CIDP diagnosis, high-resolution nerve ultrasonography data were comparable to those in patients with CIDP. CONCLUSION: Although high-resolution ultrasonography of peripheral nerves provides reliable information in patients with ATTRv-PN, its usefulness as a standalone diagnostic tool to differentiate ATTRv-PN from CIDP might be limited.
Subject(s)
Polyneuropathies , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating , Amyloid Neuropathies, Familial , Humans , Peripheral Nerves/diagnostic imaging , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/diagnostic imaging , Prospective Studies , UltrasonographyABSTRACT
AIM: Study of intraepidermal nerve fiber density (IENFD) by skin biopsy represents a promising tool in the evaluation of patients with ATTRv polyneuropathy (ATTRv-PN). Herein, we retrospectively analyze intraepidermal innervation and quantitative sensory test (QST) data from an Italian cohort of Italian ATTRv-PN patients and asymptomatic carriers aimed to provide insights into early nerve pathological and functional changes in this disease. METHODS: IENFD and QST data of 14 ATTRv-PN patients and 14 asymptomatic carriers were retrospectively analyzed together with clinical and paraclinical data such as disease stage and severity, neuropathic pain scales, and sural SNAP amplitude. RESULTS: Given an estimated time to the predicted age of onset of symptomatic disease of 20.27 + / - 7.9 years, small nerve fiber loss seems to be unexpectedly early in carriers. Moreover, carriers showed skin denervation at the proximal (thigh) site, suggesting a non-length-dependent neuropathic process. IENFD at ankle correlated with disease severity and other paraclinical variables such as sural nerve potential amplitude and QST parameters. Patients at earlier stages of the disease did not show significant differences in ankle IENFD compared with asymptomatic carriers, but significant differences in terms of QST parameters, small fiber neuropathy symptoms, and neuropathic pain. CONCLUSIONS: Skin biopsy can disclose an early non-length-dependent small fiber loss in ATTRv-PN and, together with QST, could provide a useful insight disease onset and progression.
Subject(s)
Polyneuropathies , Small Fiber Neuropathy , Adolescent , Adult , Biopsy , Child , Denervation , Humans , Retrospective Studies , Skin , Young AdultABSTRACT
OBJECTIVES: To evaluate, in a prospective study, high-resolution ultrasound (HRUS) changes of nerve segments in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and their relationships with clinical and electrodiagnostic (EDX) characteristics. METHODS: Twenty-three consecutive patients with CIDP were included in a 3-year follow-up (FU) study. Each patient underwent neurologic examination, EDX and HRUS study. HRUS was performed on median, ulnar and peroneal nerves, yielding a total of 319 scanned nerve segments. INCAT and MRC-sum scores, motor nerve conduction velocity (NCV), compound muscle action potential (cMAP) amplitude, and nerve cross-sectional area (NCSA) were collected at baseline and at FU end, and were used for statistical analysis. Twenty-two healthy individuals, matched to patients for age and BMI, served as controls. RESULTS: NCSA was higher in patients than in controls (p < 0.0001) and showed significant direct correlation with disease severity, and inverse correlation with NCV and cMAP amplitude, both at baseline and at FU end. Disease duration, clinical scores and EDX were predictors of NCSA enlargement at both time points. During FU, NCSA increased in 51% of nerve segments (p = 0.006), in correlation with INCAT increase and with NCV and cMAP reduction. Considering EDX changes in subgroups that reflect the different types of nerve damage, NCSA significantly increased in those nerve segments that from normal EDX switched to prevalent myelinopathic EDX characteristics. CONCLUSIONS: Peripheral nerve size tends to increase over time in patients with CIDP, in correlation with clinical and EDX changes, in particular in those nerve segments that undergo a predominantly demyelinating damage.
Subject(s)
Polyradiculoneuropathy, Chronic Inflammatory Demyelinating , Follow-Up Studies , Humans , Neural Conduction , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/diagnostic imaging , Prospective Studies , UltrasonographyABSTRACT
ACTA1 gene encodes the skeletal muscle alpha-actin, the core of thin filaments of the sarcomere. ACTA1 mutations are responsible of several muscle disorders including nemaline, cores, actin aggregate myopathies and fiber-type disproportion. We report clinical, muscle imaging, histopatological and genetic data of an Italian family carrying a novel ACTA1 mutation. All affected members showed a late-presenting, diffuse muscle weakness with sternocleidomastoideus and temporalis atrophy. Mild dysmorphic features were also detected. The most affected muscles by muscle MRI were rectus abdominis, gluteus minimus, vastus intermedius and both gastrocnemii. Muscle biopsy showed the presence of nemaline bodies with several unusual dark areas at Gomori Trichrome, corresponding to unstructured cores with abundant electrodense material by electron microscopy. The molecular analysis revealed missense variant c.148G>A; p.(Gly50Ser) in the exon 3 of ACTA1, segregating with affected members in the family. We performed a functional essay of fibre contractility showing a higher pCa50 (a measure of the calcium sensitivity of force) of type 1 fibers compared to control subjects' type 1 muscle fibers. Our findings expand the clinico-pathological spectrum of ACTA1-related congenital myopathies and the genetic spectrum of core-rod myopathies.
Subject(s)
Actins/genetics , Mutation/genetics , Myopathies, Nemaline/genetics , Adult , Aged , Female , Humans , Male , Middle Aged , Muscle Weakness/genetics , Muscle, Skeletal/pathology , Mutation, Missense , Pedigree , Phenotype , Sarcomeres/pathologyABSTRACT
We report the case of a patient with a clinical phenotype characterized by distal lower limb weakness and pes cavus. The electrophysiological study showed slightly reduced or normal amplitude of motor potentials, a decremental response to repetitive nerve stimulation and post-exercise facilitation. Muscle biopsy showed only mild neurogenic features. Genetic analysis included a clinical exome sequencing, followed by Sanger analysis. Three-dimensional (3D) models were generated with a SwissModel (https://swissmodel.expasy.org/) to explain the clinical observations and reinforce the pathogenic nature of the genetic variant identified. Genetic analysis demonstrated a new de novo heterozygous in frame deletion of the SYT2 gene (NM_177402.4: c.1082_1096del), confirmed by Sanger sequencing, which removes five aminoacids in the C2B domain of synaptotagmin-2 protein, that cause a profound effect on the structure and function of this synaptic vesicle protein. We identified a de novo genetic variant in the SYT2 gene, further supporting its association with a highly stereotyped clinical and electrophysiological phenotype. Our case showed electrophysiological features consistent with a presynaptic dysfunction in the neuromuscular junction with normal post-exercise amplitudes, not supporting the presence of predominant axonal damage. Although the analysis of SYT2 gene should be included in genetic analysis of patients presenting with this clinical phenotype that mimics motor neuropathy, clinicians have to consider the study of neuromuscular transmission to early identify this potentially treatable condition.
Subject(s)
Muscle Weakness/physiopathology , Neuromuscular Diseases/diagnosis , Neuromuscular Junction/physiopathology , Peripheral Nervous System Diseases/diagnosis , Synaptotagmin II/genetics , Adult , Electrodiagnosis , Frameshift Mutation , Humans , Lower Extremity/physiopathology , Male , Neuromuscular Diseases/genetics , Neuromuscular Diseases/physiopathology , Pedigree , Peripheral Nervous System Diseases/genetics , Peripheral Nervous System Diseases/physiopathologyABSTRACT
BACKGROUND AND PURPOSE: Cardiac involvement is observed in about 80% of subjects with myotonic dystrophy type 1 (DM1) and is mainly characterized by cardiac conduction and/or rhythm abnormalities (CCRAs), possibly leading to sudden cardiac death (SCD). Our objective was to investigate whether the gender difference may influence the cardiac involvement and SCD in DM1. METHODS: We analyzed prevalence and incidence of cardiological abnormalities in males versus females in 151 consecutive DM1 patients over a 35-year follow-up period. RESULTS: Fifty-five patients, 35 males (62.5%) and 20 females (42.5%), developed some type of CCRA during the follow-up period (mean 7.82 ± 6.21 years). CCRA overall, and specifically cardiac conduction abnormalities (CCAs), were significantly more frequent in males than in females (p = 0.043 and p = 0.031, respectively). CCRAs progressed in 16 males (45.7%) and six females (30%). Twenty-four patients, 14 males (25.0%) and 10 females (21.3%), died during the follow-up. Nine of them, six males (10.7%) and three females (6.4%), had SCD. After correction for Muscular Impairment Rating Scale progression, cytosine thymine-guanine expansion, and follow-up duration, a higher prevalence of CCAs was independently associated with male gender (p = 0.039), but independent association with gender was not detected for CCRAs overall, cardiac rhythm abnormalities, and SCD prevalence, even if prevalence was higher in males than females. CONCLUSIONS: The overall risk of occurrence of CCAs in DM1 is significantly higher in males than females regardless of genetic background and disease severity and progression. Moreover, the data also suggest a similar impact for male gender for CCRAs overall, CCAs, and SCD even if not statistically significant.
Subject(s)
Myotonic Dystrophy , Female , Humans , Incidence , Male , Myotonic Dystrophy/complications , Myotonic Dystrophy/epidemiology , Prevalence , Severity of Illness Index , Sex FactorsABSTRACT
Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is a rare form of treatable severe progressive sensory-motor and autonomic polyneuropathy. Albeit usually axonal, late-onset ATTRv-PN can show clear demyelinating features at electrodiagnostic studies, sometimes fulfilling CIDP diagnostic criteria. High-resolution nerve ultrasonography (HRUS) is an emerging useful supportive tool in the diagnosis of CIDP. Herein, we present a late-onset ATTRv-PN patient in which both clinical-neurophysiological and HRUS features could have led to a CIDP misdiagnosis. Nerve alterations at HRUS and MRI have already been reported in ATTRv-PN, albeit not in ATTRv-PN patients with clinical and electrodiagnostic features of CIDP. Our case shows that ATTRv-PN could present the same morphological nerve alterations pattern of CIDP at ultrasonography, adding HRUS findings as a further source of misdiagnosis late-onset ATTRv-PN.
Subject(s)
Polyneuropathies , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating , Amyloid Neuropathies, Familial , Diagnosis, Differential , Humans , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/diagnostic imaging , UltrasonographyABSTRACT
Myastenia-Inflammatory Myopathy (MG-IM) association has been described in less than 50 cases, as isolated reports or in few case series. In most cases, MG and IM onset occur simultaneously even if the overlapping clinical manifestations could lead to delay the diagnosis in the early stage of disease. In these cases, thymic pathology is present in more than 50% of cases. Pathological findings can be consistent of polymyositis (63%), dermatomyositis (25%) or granulomatosis (12%). Accurate clinical manifestations and severity of IM in MG, including muscle specific antibodies (MSA) and muscle MRI, have not been systematically investigated and focal or mild subclinical myositis have not been reported. We observed that focal myositis or asymptomatic CK elevation can also occur in MG. In this review we have also retrospectively re-analyzed the clinical, serological, pathological and muscle imaging data from 13 patients with MG- IM from our cohort of 441 MG patients (2,9%). Clinical onset occurred simultaneously in 10/13 patients, whereas in 2 patients the IM appeared later in MG disease course (range 10-14 years) and conversely in 1 patient MG symptoms occurred later in IM disease course (4 years). Median age at disease onset was 51 year (range 24-73 years) regardless of clinical onset (MG or IM). Median clinical follow-up was 88 months (range 31-237 months). IM was suspected by CK elevation in all patients (ranging 800-3000 UI/L at first detection) and non-fatigable muscle weakness unresponsive to acetylcholinesterase inhibitors. All the patients presented mild to moderate MG symptoms. Three main categories of muscle involvement, sometimes overlapping, were recognizable: distal, proximal and subclinical myositits, leading to three main clinical groups (A,B,C) and two overlapping subgroups (A/B and B/C). Thymus pathology was present in 10/13 patients. Anti-AChR was detected in al all patients associated with anti-Titin and -RyR1 in those patients with thymoma. No MSA, nor MAA antibodies were detected. Muscle biopsy confirmed IM in all patients. In conclusion we redefined the clinical spectrum of muscle involvement in MG-IM association, which represent a continuum among 3 main clinical groups: distal, proximal and subclinical muscle involvement. Minimal muscle involvement and focal myositis could be underestimated among myasthenic patients and early aggressive immunotherapy could be required in focal group.