Heterogenous electrophysiological features in early stage of hereditary transthyretin amyloidosis neuropathy

INTRODUCTION

Hereditary transthyretin-mediated amyloidosis (ATTRv, v for variant) is a progressive disease caused by mutations in the TTR gene, leading to sensory-motor, axonal and length-dependent neuropathy. However, some patients may show variable electrophysiological pattern. The aim of this study was to evaluate the electrophysiological features of TTR amyloid neuropathy at the time of the first nerve conduction study (NCS) to assess whether there were distinguishing features useful for early diagnosis.

METHODS

We retrospectively revised the first electrophysiological findings of ATTRv patients, and we categorized the neuropathy based on nerve conduction slowing, type of involved fibres and distribution pattern of PNS involvement. Cluster analysis was performed to evaluate the prevalence of neuropathy features between the early and late stage of disease, based on disease duration and disability burden assessed by NIS.

RESULTS

We recruited 33 patients (27 males) with mean age 63.9 ± 10.8 years, mean disease duration 2.8 ± 2.4 years and mean NIS 47.6 ± 41.8. Overall, the frequency analysis showed that the most common features of ATTRv neuropathy included the categories of axonal, sensory-motor and neuronopathic-like pattern. This electrophysiological pattern of PNS involvement was constant in patients in late stage of disease, whereas ATTRv patients in early stage of disease displayed variable electrophysiological pattern of PNS involvement.

DISCUSSION

Our findings demonstrated that ATTRv neuropathy may present at first NCS in a variable way, and it changes over the course of disease. Such heterogeneity makes the suspicion of ATTRv even more challenging at the time of first electrophysiological examination.

Proximal weakness involvement in the first Italian case of Charcot-Marie-Tooth 2CC harboring a novel frameshift variant in NEFH

Charcot-Marie-Tooth (CMT) diseases are a clinically and genetically heterogeneous group of disorders. Different variants in the neurofilament heavy chain (NEFH) gene have been described to cause the CMT2CC subtype. Here we report the first Italian patient affected by CMT2CC, harboring a novel variant in NEFH. In describing our patient, we also reviewed previously CMT2CC individuals, and suggested to consider NEFH variant if patients have an axonal sensory-motor neuropathy with a prominent proximal muscles involvement with early requirement of walking aids or wheelchair, remembering a motor neuron disorder.

The neuropathy in hereditary transthyretin amyloidosis: A narrative review

Hereditary transthyretin amyloidosis (ATTRv) is a condition with adult onset, caused by mutation of the transthyretin (TTR) gene and characterized by extracellular deposition of amyloid fibrils in tissue, especially in the peripheral nervous system (PNS) and heart. PNS involvement leads to a rapidly progressive and disabling sensory‐motor axonal neuropathy. Although awareness among neurologists increased in recent years thanks to new treatment options, ATTRv is frequently misdiagnosed, and thus a correct diagnosis can be delayed by several years. This review aims to draw the history and features of polyneuropathy in ATTRv based on pathological and electrophysiological correlates. We assessed original articles and case reports based on their relevance to ATTRv neuropathy and we included those appropriate for the scheme of this narrative review. Amyloid fibrils initially deposit in ganglia, causing an axonal neuropathy without amyloid deposits in distal segments (eg, sural nerve biopsy). Over time, amyloid fibrils spread along the nerves, leading to some demyelinating features in the context of severe axonal loss. This review highlights how the features of neuropathy change based on type of ATTRv (early vs late onset) and stage of disease.

The impact of symptoms on daily life as perceived by patients with Charcot-Marie-Tooth type 1A disease

Introduction

In Charcot-Marie-Tooth type 1A (CMT1A) patients, daily life is mainly influenced by mobility and ambulation dysfunctions. The aim of our work was to evaluate the perception of disturbances that mostly impact on daily life in CMT1A patients and its difference on the basis of age, gender, disability, and quality of life.

Methods

Forty-one CMT1A patients underwent neurological assessment focused on establishing clinical disability through the Charcot-Marie-Tooth Neuropathy Score (CMTNS) and quality of life through the Short Form-36 (SF-36) questionnaire. We identified from CMT disturbances 5 categories [weakness in lower limbs (WLL), weakness in upper limbs (WUL), skeletal deformities (SD), sensory symptoms (SS), balance (B)] and patients classified the categories from the highest to the lowest impact on daily life (1: highest; 5: lowest). Ranking of the 5 categories, in the overall sample and in the different subgroups (dividing by gender, median of age and disease duration, CMTNS, domains of SF-36), was obtained and differences among subgroups were assessed using a bootstrap approach.

Results

Rank analysis showed that WLL was the most important disturbance on daily life whereas WUL had the lowest impact. In the older CMT1A group, the most important disturbance on daily life was B that was also the most relevant disturbance in patients with a greater disability. SD influenced daily life in younger patients. SS had less impact on daily life, with the exception of patients with a milder disability.

Discussion

Our findings demonstrated that the perception of disturbances that mostly impact on CMT1A patients’ daily life changes over the lifetime and with degree of disability.

Primary Progressive Multiple Sclerosis Under Anti-TNFα Treatment: A Case Report

Antagonists of tumour necrosis factor α (TNFα) are a common therapeutic choice for autoimmune diseases. Although they are effective and relatively safe, an increasing number of immune-mediated adverse events have been reported. Among these, neurological adverse effectsm such as consisting of demyelinating events in the central and peripheral nervous system were described. Demyelination of the central nervous system is a rare complication after treatment with TNFα antagonists. Here, we report a case of multiple sclerosis under treatment with TNFα antagonists and discuss its etiopathogenesis. This 45-year-old female patient developed signs and symptoms suggestive of primary progressive multiple sclerosis during treatment with adalinumab for nodular cystic acne, and magnetic resonance imaging of the patient showed typical lesions of demyelinating disease.

CLIPPERS

We present the clinical case of a woman suffering from CLIPPERS syndrome (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids). The images obtained from the brain magnetic resonance show the lesions typical of the disease.

Multimodal evaluation of an Italian family with a hereditary spastic paraplegia and POLR3A mutations

We describe an Italian family with adult‐onset pure hereditary spastic paraplegia due to biallelic variants in POLR3A gene [c.1909 + 22G > A and c.3839dupT (p.M1280fs*20]. MRI showed a mild hyperintensity of superior cerebellar peduncles and cervical spinal cord atrophy. The neurophysiological metrics about intracortical excitability showed higher values of motor thresholds and a significant reduction of short interval intracortical inhibition (SICI) in the patient with a more severe phenotype. Our multimodal evaluation further expands the wide phenotypic spectrum associated with mutations in the POLR3A gene. An extensive genotype–phenotype correlation study is necessary to explain the role of the many new mutations on the function of protein.

Facioscapulohumeral muscular dystrophy (FSHD) and multiple sclerosis: a case report

Facioscapulohumeral muscular dystrophy 1 (FSHD1) is an autosomal dominant neuromuscular disorder, associated with reduction of tandemly arrayed repetitive DNA elements D4Z4 (DRA), at 4q35. Few cases, especially carriers of 1-3 DRA show a syndromic form. Anecdotally the association of FSHD with multiple sclerosis (MS) is reported. Herein we report a 33 years old Caucasian with a molecular diagnosis of FSHD1 with classical phenotype (clinical category A2) and concomitant white matter lesions suggestive of MS. White matter lesions in patients with FSHD have often been described but rarely investigated in order to evaluate a possible diagnosis of MS. We think that MS and FSHD remain clearly distinct diseases, but growing evidences show a widespread and variable activation of the immune system in patients suffering from FSHD probably an hypotheses on a potential common pathogenetic mechanism between these two disorders could should be better investigated.

Lichenoid rash: A new side effect of oral Cladribine

Cladribine is an approved drug for the treatment of highly active multiple sclerosis. We report a 28-years-old man with a poor response to previous treatments, elected to treatment with Cladribine. He developed a lichenoid rash two weeks after taking the first and second treatment cycles. This symptom regressed with specific therapy. A lichenoid drug eruption is a rare side effect which can occur following the administration of several different medications, but it has never been described after treatment with oral Cladribine.

Different cortical excitability profiles in hereditary brain iron and copper accumulation

BACKGROUND AND AIM

Neurodegeneration with brain iron accumulation (NBIA) and Wilson's disease (WD) is considered the prototype of neurodegenerative disorders characterised by the overloading of iron and copper in the central nervous system. Growing evidence has unveiled the involvement of these metals in brain cortical neurotransmission. Aim of this study was to assess cortical excitability profile due to copper and iron overload.

METHODS

Three patients affected by NBIA, namely two patients with a recessive hereditary parkinsonism (PARK9) and one patient with aceruloplasminemia and 7 patients with neurological WD underwent transcranial magnetic stimulation (TMS) protocols to assess cortical excitability. Specifically, we evaluated the motor thresholds that reflect membrane excitability related to the voltage-gated sodium channels in the neurons of the motor system and the ease of activation of motor cortex via glutamatergic networks, and ad hoc TMS protocols to probe inhibitory-GABAergic (short interval intracortical inhibition, SICI; short-latency afferent inhibition, SAI; cortical silent period, CSP) and excitatory intracortical circuitry (intracortical facilitation, ICF).

RESULTS

Patients with NBIA exhibited an abnormal prolongation of CSP respect to HC and WD patients. On the contrary, neurological WD displayed higher motor thresholds and reduced CSP and SICI.

CONCLUSION

Hereditary conditions due to overload of copper and iron exhibited peculiar cortical excitability profiles that can help during differential diagnosis between these conditions. Moreover, such results can give us more clues about the role of metals in acquired neurodegenerative disorders, such as Parkinson disease, Alzheimer disease, and multiple sclerosis.