Nonamyloidogenic TTR gene variants c.76G>A and c.337-18G>C are not associated with idiopathic small-fiber neuropathy.

Background And Purpose: Small-fiber neuropathy (SFN) affects only unmyelinated and thin myelinated fibers. It may be caused by amyloidogenic mutations of the transthyretin (TTR) gene, but not all TTR gene variants are pathogenic. The nonamyloidogenic c.

Detailed clinical, physiological and pathological phenotyping can impact access to disease-modifying treatments in ATTR carriers.

Background: Hereditary transthyretin amyloidosis is a life-threatening autosomal dominant systemic disease due to pathogenic variants (ATTRv), mostly affecting the peripheral nerves and heart. The disease is characterised by a combination of symptoms, organ involvement and histological amyloid deposition. The available disease-modifying ATTRv treatments (DMTs) are more effective if initiated early.

Red Flags for Chronic Inflammatory Demyelinating Polyradiculoneuropathy Associated with Sarcoidosis or Connective Tissue Diseases.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare autoimmune disorder of the peripheral nervous system. Diagnosis relies on clinical and electrophysiological criteria. Various disorders requiring specific treatment regimens may be associated with CIDP, including sarcoidosis (SAR-CIDP) and connective tissue disease (CTD-CIDP).

Skin amyloid deposits and nerve fiber loss as markers of neuropathy onset and progression in hereditary transthyretin amyloidosis.

Background And Purpose: This study was undertaken to assess skin biopsy as a marker of disease onset and severity in hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN), a treatable disease.

Methods: In this single center retrospective study, skin Congo red staining and intraepidermal nerve fiber density (IENFD) were evaluated in symptomatic ATTRv-PN patients and asymptomatic TTR gene mutation carriers between 2012 and 2019. Non-ATTRv subjects with suspected small fiber neuropathy who underwent skin biopsy during the same timespan were used as controls.

A multicenter cross-sectional French study of the impact of COVID-19 on neuromuscular diseases.

Background: Due to their health condition, patients with neuromuscular diseases (NMD) are at greater risk of developing serious complications with COVID-19. The objective of this study was to analyze the prevalence of COVID-19 among NMD patients and the risk factors for its impact and severity during the first wave of the pandemic. Clinical data were collected from NMD-COVID-19 patients, between March 25, 2020 and May 11, 2020 in an anonymous survey carried out by expert physicians from the French Health Care Network Filnemus.

Neurological complications induced by immune checkpoint inhibitors: a comprehensive descriptive case-series unravelling high risk of long-term sequelae.

Neurological immune-related adverse events are complications of programmed-cell death 1 or programmed-cell death 1 ligand immunotherapies that can be life threatening and often lead to anticancer immunotherapy withdrawal. Scant clinical data are available that integrate the clinical presentation, therapeutic management and long-term outcome. All consecutive adult patients treated by programmed-cell death 1 or programmed-cell death 1 ligand immunotherapies, given alone or in combination with other treatment, who experienced a neurological immune-related adverse event with a severity grade ≥2 in Paris Saclay-University hospitals were investigated from June 2014 to February 2019.

Motor unit number index as an individual biomarker: Reference limits of intra-individual variability over time in healthy subjects.

Objective: Motor unit number index (MUNIX) is proposed to monitor neuromuscular disorders. Our objective is to determine the intra-individual variability over time of the MUNIX.

Methods: In 11 different hospital centres, MUNIX was assessed twice, at least 3 months apart (range 90-360 days), in tibialis anterior (TA), abductor pollicis brevis (APB), abductor digiti minimi (ADM) and deltoid muscles in 118 healthy subjects.

Transthyretin amyloid polyneuropathies mimicking a demyelinating polyneuropathy.

Objective: To clearly define transthyretin familial amyloid polyneuropathies (TTR-FAPs) fulfilling definite clinical and electrophysiologic European Federation of Neurological Societies/Peripheral Nerve Society criteria for chronic inflammatory demyelinating polyneuropathy (CIDP).

Methods: From a cohort of 194 patients with FAP, 13 of 84 patients (15%) of French ancestry had late-onset demyelinating TTR-FAP. We compared clinical presentation and electrophysiology to a cohort with CIDP and POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes) syndrome.

Motor neuron disease of paraneoplastic origin: a rare but treatable condition.

Paraneoplastic motor neuron disorders (MND) are rare conditions; their exact clinical and electrophysiological phenotype have not been exhaustively described yet. The purpose of this study is to depict the main characteristics of paraneoplastic MND to highlight the features that may allow its diagnosis. Based on the description of eight original cases, and on the revision of 21 patients identified from a systematic review of the literature, the main features of paraneoplastic MND can be summarized as follows: (1) subacute; (2) lower motor neuron syndrome, associated or not with upper motor neuron involvement; (3) predominant asymmetric upper limb involvement; (4) presence of other non-motor neurological manifestations, including sensory neuronopathy; (5) signs of inflammation in the cerebrospinal fluid (CSF); (6) neurological improvement or stabilization after immunotherapy and tumor treatment.

TTR kinetic stabilizers and TTR gene silencing: a new era in therapy for familial amyloidotic polyneuropathies.

Introduction: Transthyretin Familial Amyloid Polyneuropathy (TTR-FAP) is a rare disease with autosomal dominant transmission due to a point mutation of the TTR gene. By removing the main source of systemic mutant TTR, liver transplantation (LT) has become the reference therapy of this severe and fatal polyneuropathy of adult-onset, stopping disease progression in subgroup of patients. Recently, new therapeutic strategies have emerged, which intend to stabilize TTR or to silence the TTR gene.