Lipid Myopathies Pennisi, Elena Maria; Garibaldi, Matteo; Antonini, Giovanni
Journal of clinical medicine,
11/2018, Letnik:
7, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Disorders of lipid metabolism affect several tissues, including skeletal and cardiac muscle tissues. Lipid myopathies (LM) are rare multi-systemic diseases, which most often are due to genetic ...defects. Clinically, LM can have acute or chronic clinical presentation. Disease onset can occur in all ages, from early stages of life to late-adult onset, showing with a wide spectrum of clinical symptoms. Muscular involvement can be fluctuant or stable and can manifest as fatigue, exercise intolerance and muscular weakness. Muscular atrophy is rarely present. Acute muscular exacerbations, resulting in rhabdomyolysis crisis are triggered by several factors. Several classifications of lipid myopathies have been proposed, based on clinical involvement, biochemical defect or histopathological findings. Herein, we propose a full revision of all the main clinical entities of lipid metabolism disorders with a muscle involvement, also including some those disorders of fatty acid oxidation (FAO) with muscular symptoms not included among previous lipid myopathies classifications.
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.
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•Inflammatory myopathy occurs in less than 3% of myasthenic patients.•All myasthenia-myositis patients have AChR antibodies and most of them has thymoma.•Three main clinical groups of muscle involvement: distal, proximal and subclinical.•Distal and subclinical involvement could be underestimated.•Distal myositis has poor clinical outcome and could require early aggressive therapy.
Only few studies have reported muscle involvement in spinal muscular atrophy using muscle MRI but this has not been systematically investigated in a large cohort of both pediatric and adult patients ...with type 2 and type 3 spinal muscular atrophy. The aim of the present study was to define possible patterns of muscle involvement on MRI, assessing both fatty replacement and muscle atrophy, in a cohort of type 2 and type 3 spinal muscular atrophy children and adults (age range 2–45 years), including both ambulant and non-ambulant patients. Muscle MRI protocol consisted in T1-weighted sequences acquired on axial plane covering the pelvis, the thigh, and the leg with contiguous slices. Each muscle was examined through its whole extension using a grading system that allows a semiquantitative evaluation of fatty infiltration. Thigh muscles were also grouped in anterior, posterior, and medial compartment for classification of global atrophy. The results showed a large variability in both type 2 and type 3 spinal muscular atrophy, with a various degree of proximal to distal gradient. Some muscles, such us the adductor longus and gracilis were always selectively spared. In all patients, the involvement was a combination of muscle atrophy and muscle infiltration. The variability observed may help to better understand both natural history and response to new treatments.
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.
Inherited peripheral neuropathies (IPNs) represent a broad group of genetically and clinically heterogeneous disorders, including axonal Charcot-Marie-Tooth type 2 (CMT2) and hereditary motor ...neuropathy (HMN). Approximately 60%-70% of cases with HMN/CMT2 still remain without a genetic diagnosis. Interestingly, mutations in HMN/CMT2 genes may also be responsible for motor neuron disorders or other neuromuscular diseases, suggesting a broad phenotypic spectrum of clinically and genetically related conditions. Thus, it is of paramount importance to identify novel causative variants in HMN/CMT2 patients to better predict clinical outcome and progression.
We designed a collaborative study for the identification of variants responsible for HMN/CMT2. We collected 15 HMN/CMT2 families with evidence for autosomal recessive inheritance, who had tested negative for mutations in 94 known IPN genes, who underwent whole-exome sequencing (WES) analyses. Candidate genes identified by WES were sequenced in an additional cohort of 167 familial or sporadic HMN/CMT2 patients using next-generation sequencing (NGS) panel analysis.
Bioinformatic analyses led to the identification of novel or very rare variants in genes, which have not been previously associated with HMN/CMT2 (
,
,
and
); in genes previously associated with HMN/CMT2 but in combination with different clinical phenotypes (
and
), and in the
gene, which has been linked to HMN/CMT2 in only a few cases. These findings were further validated by Sanger sequencing, segregation analyses and functional studies.
These results demonstrate the broad spectrum of clinical phenotypes that can be associated with a specific disease gene, as well as the complexity of the pathogenesis of neuromuscular disorders.
Many different trials were assessed for rehabilitation of patients with amyotrophic lateral sclerosis (ALS), with non-unique results. Beside the effects on muscle trophism, some of the encouraging ...results of physical training could be ascribed to the modulation of cortical excitability, which was found hyperexcited in ALS.
The effects of tactile skin stimulation in the modulation of the sensory-motor integrative networks in healthy subjects were assayed through the paired associative stimulation (PAS) protocol.
In total, 15 healthy subjects were enrolled. In the
, the average amplitude of the motor evoked potential (MEP) after 10 stimuli of transcranial magnetic stimulation (TMS) was measured at the baseline and after the PAS protocol (0, 10, 20, 30, and 60 min). In the
, the average amplitude of the MEP was measured before and after 10 min of skin stimulation over the hand. Subsequently, each subject underwent the PAS stimulation and the measure of the average amplitude of the MEP (0, 10, 20, 30, and 60 min).
The tactile skin stimulation on healthy subjects increases the PAS-induced sensory-motor network hyperexcitability in healthy subjects.
Skin stimulation should be avoided in the physiotherapeutic approaches for patients with ALS, given the possible hyperexciting effects on the already upmodulated sensory-motor networks. They can be taken into account for diseases characterized by downregulation of cortical and transcortical networks.
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.
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.
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