Transthyretin amyloid polyneuropathy in France: A cross-sectional study with 413 patients and real-world tafamidis meglumine use (2009-2019).

OBJECTIVE: We aimed to describe characteristics of patients with ATTR variant polyneuropathy (ATTRv-PN) and ATTRv-mixed and assess the real-world use and safety profile of tafamidis meglumine 20mg. METHODS: Thirty-eight French hospitals were invited. Patient files were reviewed to identify clinical manifestations, diagnostic methods, and treatment compliance. RESULTS: Four hundred and thirteen patients (296 ATTRv-PN, 117 ATTRv-mixed) were analyzed. Patients were predominantly male (68.0%) with a mean age of 57.2±17.2 years. Interval between first symptom(s) and diagnosis was 3.4±4.3 years. First symptoms included sensory complaints (85.9%), dysautonomia (38.5%), motor deficits (26.4%), carpal tunnel syndrome (31.5%), shortness of breath (13.3%), and unexplained weight loss (16.0%). Mini-invasive accessory salivary gland or punch skin and nerve biopsies were most common, with a performance of 78.8-100%. TTR genetic sequencing, performed in all patients, revealed 31 TTR variants. Tafamidis meglumine was initiated in 156/214 (72.9%) ATTRv-PN patients at an early disease stage. Median treatment duration was 6.00 years in ATTRv-PN and 3.42 years in ATTRv-mixed patients. Tafamidis was well tolerated, with 20 adverse events likely related to study drug among the 336 patients. CONCLUSION: In France, ATTRv patients are usually identified early thanks to the national network and the help of diagnosis combining genetic testing and mini-invasive biopsies.

[Thymoma and autoimmune diseases]. / Thymomes et maladies auto-immunes.

The association between thymoma and autoimmunity is well known. Besides myasthenia gravis, which is found in 15 to 20% of patients with thymoma, other autoimmune diseases have been reported: erythroblastopenia, systemic lupus erythematosus, inflammatory myopathies, thyroid disorders, Isaac's syndrome or Good's syndrome. More anecdotally, Morvan's syndrome, limbic encephalitis, other autoimmune cytopenias, autoimmune hepatitis, and bullous skin diseases (pemphigus, lichen) have been reported. Autoimmune diseases occur most often before thymectomy, but they can be discovered at the time of surgery or later. Two situations require the systematic investigation of a thymoma: the occurrence of myasthenia gravis or autoimmune erythroblastopenia. Nevertheless, the late onset of systemic lupus erythematosus or the association of several autoimmune manifestations should lead to look for a thymoma. Neither the characteristics of the patients nor the pathological data can predict the occurrence of an autoimmune disease after thymectomy. Thus, thymectomy usefulness in the course of the autoimmune disease, except myasthenia gravis, has not been demonstrated. This seems to indicate the preponderant role of self-reactive T lymphocytes distributed in the peripheral immune system prior to surgery. Given the high infectious morbidity in patients with thymoma, immunoglobulin replacement therapy should be considered in patients with hypogammaglobulinemia who receive immunosuppressive therapy, even in the absence of prior infection.

Focal myositis: A review.

Amongst the heterogeneous group of inflammatory myopathies, focal myositis stands as a rare and benign dysimmune disease. Although it can be associated with root and/or nerve lesions, traumatic muscle lesions and autoimmune diseases, its triggering factors remain poorly understood. Defined as an isolated inflammatory pseudotumour usually restricted to one skeletal muscle, clinical presentation of focal myositis is that of a rapidly growing solitary mass within a single muscle, usually in the lower limbs. Electromyography shows spontaneous activity associated with a myopathic pattern. MRI reveals a contrast enhanced enlarged muscle appearing hyper-intense on FAT-SAT T2 weighted images. Adjacent structures are spared and there are no calcifications. Serum creatine kinase (CK) levels are usually moderately augmented and biological markers of systemic inflammation are absent in most cases. Pathological histological features include marked variation in fibre size, inflammatory infiltrates mostly composed of T CD4+ lymphocytes and macrophages, degenerating/regenerating fibres and interstitial fibrosis. Differential diagnoses are numerous and include myositis of other origin with focal onset. Steroid treatment should be reserved for patients who present with major pain, nerve lesions, associated autoimmune disease, or elevated C reactive protein or CK.

Sporadic inclusion-body myositis: Recent advances and the state of the art in 2016.

Sporadic inclusion-body myositis (sIBM) is the most frequent myopathy after 50 years of age. As the clinical presentation may often be typical, pathological confirmation by muscle biopsy appears necessary, but sometimes difficult. Further delineation of the framework of this particular disease, especially during its early-onset stage, appears to be challenging. New classification of diagnostic criteria as well as the identification of new diagnostic hallmarks appear to be the two main tools towards to achieve this purpose. sIBM pathophysiology has long been discussed and remains yet controversial. Since its initial description, there have been two major pathogenic hypotheses: inflammatory and degenerative. To date, the debate is still ongoing, as recent works support both pathophysiological mechanisms, although the inflammatory process seems to be slightly more preeminent in the recent literature. Treatment remains the most disappointing aspect of the disease as, despite various therapeutic attempts, no significant efficacy has been reported thus far. Nevertheless, advances in our pathophysiological understanding of the disease are paving the way for further therapeutic perspectives that might arise in the years to come. The objective of the present work was to summarize the most significant data published on sIBM during the past 2 years.

Progressive multifocal leukoencephalopathy after liver transplantation can have favorable or unfavorable outcome.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyomavirus (JCPyV) in immunocompromised patients, including solid organ transplant recipients. We report 2 cases of PML late after liver transplantation (144 and 204 months) and review the few other published cases. The clinical course of PML is characterized by a rapid progressive neurological decline coinciding with the presence of white matter lesions on magnetic resonance images. No direct antiviral therapy is available against the JCPyV. The prognosis is therefore extremely poor. Restoration of the immune response achieved by tapering or ending the immunosuppressive therapy is the basis of treatment in transplanted patients. One of our patients is alive 3 years after diagnosis after total withdrawal of immunosuppressive therapy. The other presented severe rejection when tapering immunosuppression and died 26 months after diagnosis.

Thymoma associated with autoimmune diseases: 85 cases and literature review.

OBJECTIVES: To describe the clinical features, treatment, and outcome of autoimmune diseases (AD) in a cohort of patients with thymoma. DESIGN: Pathological records from three university hospitals, between 2005 and 2011, were reviewed to identify patients with thymoma. Patients with thymoma and AD were compared with patients with thymoma without AD. RESULTS: 47/85 (55%) cases of thymoma had AD, including myasthenia gravis (MG) (n=33), Hashimoto's thyroiditis (n=4), Isaac's syndrome (n=3), Morvan syndrome (n=2), pure red cell aplasia (n=2), systemic lupus (n=2), lichen planus (n=2), and one case of each following conditions: aplastic anemia, autoimmune hemolytic anemia, Good's syndrome, pemphigus, autoimmune hepatitis, Graves' disease, limbic encephalitis, and inflammatory myopathy. Six patients (7%) presented at least 2 ADs. The median duration of follow-up after surgery was 60 months (40-78 months). In 32 patients, the diagnosis of AD preceded the diagnosis of thymoma, in 9 patients, thymoma was diagnosed at the same time as the AD and 7 patients had been operated on when they developed an AD. We found a significative difference on the Masaoka stage between the MG patients and the patients who present another AD (p=0.028). No risk factor for developing an AD after thymectomy was identified. CONCLUSIONS: We describe here the long-term follow-up of a large series of AD related to thymoma. Our results confirm previous data concerning AD occurrence in patients with thymoma and suggest that preexisting autoimmunity is not a risk factor for developing autoimmune manifestations after thymectomy.

Significant response to immune therapies in a case of subacute necrotizing myopathy and FKRP mutations.

Necrotizing myopathies can be encountered in various conditions as acquired myopathies (toxic or autoimmune) or muscular dystrophies. We report a twenty-year-old Caucasian woman who presented with clinical findings suggestive of an inflammatory myopathy: subacute onset of lower limb muscle weakness, myalgia, weight loss and absence of family history. The serum creatine kinase level was elevated at 4738 IU/L (normal range, 25-175 IU/L). Muscle biopsy was consistent with necrotizing myopathy. The patient showed significant clinical improvement following corticosteroid, azathioprine and intravenous immunoglobulin treatments. Biological tests revealed no specific autoantibodies associated with necrotizing autoimmune myopathies. Immunohistochemical staining for sarcolemmal proteins in muscle biopsy samples finally led to a diagnosis of limb-girdle muscular dystrophy 2I (fukutin-related protein gene mutations). The response to immune therapies suggested a possible inflammatory component associated with the muscular dystrophy and highlighted the potential benefit of corticosteroid treatment in patients with LGMD2I and subacute onset.

Somatosensory evoked potentials in the assessment of peripheral neuropathies: Commented results of a survey among French-speaking practitioners and recommendations for practice.

BACKGROUND: Somatosensory evoked potentials (SSEPs) are increasingly performed for the assessment of peripheral neuropathies, but no practical guidelines have yet been established in this specific application. STUDY AIM: To determine the relevant indication criteria and optimal technical parameters for SSEP recording in peripheral neuropathy investigation. METHODS: A survey was conducted among the French-speaking practitioners with experience of SSEP recording in the context of peripheral neuropathies. The results of the survey were analyzed and discussed to provide recommendations for practice. RESULTS: SSEPs appear to be a second-line test when electroneuromyographic investigation is not sufficiently conclusive, providing complementary and valuable information on central and proximal peripheral conduction in the somatosensory pathways. CONCLUSIONS: Guidelines for a standardized recording protocol, including the various parameters to be measured, are proposed. CLINICAL RELEVANCE: We hope that these proposals will help to recognize the value of this technique in peripheral neuropathy assessment in clinical practice.

Antibodies to clustered acetylcholine receptor: expanding the phenotype.

BACKGROUND AND PURPOSE: To provide a detailed phenotypical description of seronegative patients with generalized myasthenia gravis and antibodies to clustered acetylcholine receptors (AChRs) and to assess their frequency amongst a French seronegative generalized myasthenia gravis (SNMG) population. METHODS: A French SNMG database was created and the sera from the 37 patients included in it were analysed by immunofluorescence of cell-based assays using cotransfection of AChR subunit genes together with rapsyn to densely cluster the AChRs. RESULTS: Sixteen per cent (n = 6) of the SNMG patients were found to have antibodies to clustered AChR. They presented either with early onset MG and thymic hyperplasia, late onset MG and thymic involution, or thymoma associated MG. They responded well to cholinesterase inhibitors and immunosuppressants. CONCLUSIONS: Patients with antibodies to clustered AChR account for a significant proportion of SNMG patients and resemble patients with AChR antibodies detected by standard radio-immunoprecipitation.

[Necrotizing autoimmune myopathies]. / Les myopathies nécrosantes auto-immunes.

Necrotizing autoimmune myopathies are included in the spectrum of inflammatory myopathies, together with polymyosis, dermatopolymyosis and inclusion body myositis, despite the characteristic feature of marked muscular necrosis without inflammatory infiltrates. The clinical presentation is highly variable, often similar to the other inflammatory myopathies. The most common finding is nevertheless the severe form with rhabdomyolysis. The creatine kinase level is elevated (around 10,000IU/l) and electromyography shows myopathic changes with increased spontaneous activities reflecting the importance of the muscular necrosis. Muscle biopsy is required for diagnosis, revealing active necrosis of the muscle fibers without inflammatory invasion by CDA+ or CD8+ T-cells. Deposition of a microvascular membrane attack complex (C5b9) is often noted, whereas the upregulation of MHC class 1 is rarely detected. Signs of endomysial microangiopathy are frequently reported. Necrotizing autoimmune myopathies can be associated with antisignal recognition particle (SRP) antibodies or more rarely with the usual inflammatory myopathy antibodies. Paraneoplasic forms are described but remain exceptional. Lastly, necrotizing autoimmune myopathies, sometimes associated with statin therapy, have been recently described. They are linked with an antibody directed against 3-hydroxy-3-methyglutaryl-coenzyme A. Treatment is based on corticosteroid therapy, immunosuppressive drugs or intravenous immunoglobulins. Response is variable, depending on the clinical form.

[Distal hereditary motor neuropathy]. / Les amyotrophies spinales distales.

INTRODUCTION: Distal hereditary motor neuropathy (dHMN), also known as spinal muscular atrophy, represents a group of clinically and genetically heterogeneous diseases caused by degenerations of spinal motor neurons and leading to distal muscle weakness and wasting. Nerve conduction studies reveal a pure motor axonopathy and needle examination shows chronic denervation. STATE OF ART: dHMN were initially subdivided into seven subtypes according to mode of inheritance, age at onset, and clinical evolution. Recent studies have shown that these subtypes are still heterogeneous at the molecular genetic level and novel clinical and genetic entities have been characterized. To date, mutations in 11 different genes have been identified for autosomal-dominant, autosomal-recessive, and X-linked recessive dHMN. Most of the genes encode protein involved in housekeeping functions, endosomal trafficking, axonal transport, translation synthesis, RNA processing, oxidative stress response and apoptosis. PERSPECTIVES: The pathophysiological mechanisms underlying dHMN seem to be related to the "length-dependent" death of motor neurons of the anterior horn of the spinal cord, likely because their large axons have higher metabolic requirements for maintenance. CONCLUSION: dHMN remain heterogeneous at the clinical and molecular genetic level. The molecular pathomechanisms explaining why mutations in these ubiquitously expressed housekeeping genes result in the selective involvement of spinal motor neurons remain to be unravelled.

Respiratory onset in an ALS family with L144F SOD1 mutation.

Familial amyotrophic lateral sclerosis (FALS) cases linked to SOD1 mutations may sometimes present with unusual clinical features such as pure lower motor neuron involvement or sensory signs. The authors describe a FALS pedigree with the L144F SOD1 mutation in which all cases had respiratory involvement as a first symptom. Although atypical clinical features are not rare in ALS families, this is the first pedigree with respiratory-onset in three affected members. This unusual presentation led to delayed diagnosis in the proband and highlights the fact that respiratory-onset can occur in familial ALS cases carrying SOD1 mutation.

[Diagnostic pitfalls in carpal tunnel syndrome]. / Pièges diagnostiques du syndrome du canal carpien.

BACKGROUND: This review focuses on the main aspects of positive and differential diagnosis of carpal tunnel syndrome (CTS) in different clinical situations encountered in daily practice. STATE OF THE ART: Authentic CTS can be discovered in situations, which alter the usual presentation or therapeutic management. This is the case for instance in pregnant women or in the elderly subject or with acute motor forms where CTS discloses a focal intratunnel disorder (neuroma, lipoma, arterial condition, bone disorder) or a general disease (hereditary neuropathy, amylosis). In certain situations, the clinical manifestations suggest a more proximal compression of the medial nerve (round pronator, Struthers arcade, or superficial flexor) or an inflammatory condition (mononeuritis, inflammatory demyelinising neuropathy). Locoregional disease may also be involved, for instance a plexus (thoracobrachial outlet syndrome, post-radiation plexitis) or radicular condition. The clinical presentation of diffuse polyneuropathy with initial manifestations involving the upper limb (ganglioneuropathies, polyradiculoneuritis, small-fiber neuropathies) may also be misleading. Finally central conditions can sometimes be confused with CTS. CONCLUSION: A rigorous physical examination and an electroneuromyogram are determining to avoid diagnostic pitfalls.

Phenotype genotype analysis in 15 patients presenting a congenital myasthenic syndrome due to mutations in DOK7.

Congenital myasthenic syndromes (CMSs) are a heterogeneous group of diseases caused by genetic defects affecting neuromuscular transmission. Mutations of DOK7 have recently been described in recessive forms of CMS. Dok-7 is a cytoplasmic post-synaptic protein co-activator of the muscle-specific receptor-tyrosine kinase (MuSK) involved in neuromuscular synaptogenesis and maintenance. We report clinical, morphological and molecular data on 15 patients with mutations in DOK7. Eleven different mutations (5 novel) were identified and all patients but one were found to carry at least the common c.1124_1127dupTGCC mutation. Patients with DOK7 mutations have a particular limb-girdle pattern, without tubular aggregates but a frequent lipidosis on the muscle biopsy. Changes in pre- and post-synaptic compartments of the neuromuscular junction were also observed in muscle biopsies: terminal axons showed defective branching which resulted in a unique terminal axon contacting en passant postsynaptic cups. Clinical features, muscle biopsy findings or response to therapy were confusing in several patients. Characterization of this distinct phenotype is essential to provide clues for targeted genetic screening and to predict the therapeutic response to anticholinesterase treatments or ephedrine as has been suggested.

[Multiple phenotypic manifestations of X-linked spinobulbar muscular atrophy]. / L'amyotrophie bulbospinale liée à l'X ou maladie de Kennedy: variations phénotypiques.

Recessive X-linked amyotrophic spinobulbar muscular atrophy (SBMA) or Kennedy disease is a neuroendocrine disorder with a slowly progressive phenotype, caused by an expansion of a polymorphic tandem CAG repeat of the androgen receptor gene. Classical clinical hallmarks include onset in the third decade of life, weakness and wasting predominantly in proximal extremity muscles, variable weakness of bulbar muscles, abundant muscle fasciculations, sensory nerve action potential abnormalities and signs of androgen insensitivity such as gynecomastia and testicular atrophy. The diagnosis has been recently made easier by the availability of genetic testing but Kennedy disease is probably still underdiagnosed because of phenotypic variability. We report 11 new cases, of which seven had atypical initial manifestations presenting respectively with myasthenia, cramps and fasciculation syndrome, polyneuropathy, post-trauma monomelic neuronopathy, effort-dependent muscle intolerance and/or muscular dystrophy, with the aim to enlarge the phenotypic spectrum of the published series.

Dilative arteriopathy and basilar artery dolichoectasia complicating late-onset Pompe disease.

BACKGROUND: Strokes related to intracranial aneurysm or arteriopathy have been reported in a few patients with late-onset Pompe disease. These reports suggested that cerebral vessel involvement could be an underrecognized complication of this disease. METHODS: We report cerebral artery involvement in three French patients with late-onset Pompe disease. RESULTS: The first patient died at age 35 years from complications of a giant fusiform aneurysm of the basilar artery, and her 34-year-old sister showed evidence of dolichoectatic basilar artery on magnetic resonance angiography. A dilative arteriopathy complicated with carotid artery dissection was diagnosed in the third patient, aged 50 years. Two patients are currently being treated with enzyme replacement therapy (alglucosidase alfa), and regular angiographic follow-up showed the absence of progression of vascular abnormalities in one of them. CONCLUSION: These observations, combined with previously reported cases, confirm that Pompe disease should be recognized as a predisposing condition to dilative arteriopathy and cerebral aneurysm formation, although the real incidence of these vascular complications remains unknown.