Phenotype of a second Irish variant causing hereditary amyloidogenic transthyretin amyloidosis.

INTRODUCTION: Hereditary amyloidogenic transthyretin (ATTR) amyloidosis is an autosomal dominant, multi-systemic and progressive disorder characterised by polyneuropathy, cardiomyopathy and dysautonomia to varying degrees. In Ireland, the p.Thr80Ala mutation has been well documented, but little has been reported about a second variant, the p.His110Asp mutation first discovered in a family native to county Cork. Here we elaborate on the phenotype of this recently identified mutation using an extended pedigree of the original kindred and include for the first time a second affected family. MATERIALS AND METHODS: Patients attending our centre with confirmed or suspected ATTR amyloidosis as a result of a p.His110Asp mutation were identified. Detailed chart reviews and patient interviews were completed. Data on symptoms, examination findings, neurophysiology, histology, biochemistry, and cardiac investigations were gathered. A large extended pedigree was plotted. RESULTS: A total of 17 members across four generations of one kindred, and 2 members of a previously unreported family were identified. A phenotype of progressive late-onset polyneuropathy with cardiac involvement was common to both families. An early manifestation was carpal tunnel syndrome, preceededing neuropathy by many years. Gastrointestinal and urinary symptoms were common. DISCUSSION: We describe a wider phenotype of the p.His110Asp mutation of transthyretin in two Irish families. Importantly, we describe cardiac involvement which was not previously emphasised. The discovery of a new unrelated family highlights the importance of clinical suspicion even in those without known family history. We suggest that this second important transthyretin mutation should be considered in patients of Irish origin.

Use of non-invasive ventilation in motor neuron disease - a retrospective cohort analysis.

Motor neuron disease (MND) is a neurodegenerative disorder which leads to progressive muscle weakness including respiratory muscle decline. The introduction of non-invasive ventilation (NIV) has been shown to improve quality of life, survival and slow the rate of pulmonary function decline. A retrospective chart analysis of patients who attended the MND clinic from 2014 to 2019 at a tertiary-referral, academic, teaching hospital was carried out to evaluate if NIV and greater compliance with NIV was associated with improved survival. 111 patients were included. The mean age at diagnosis was 63.8 years and 61.3% were males. 66.7% of our cohort used NIV and of this 66.7%, 44.1% were compliant. There was a significantly longer survival in those who used NIV (p = 0.002) and in those who used NIV optimally (p = 0.02) when both groups were compared to those who did not use NIV. In the bulbar MND group those who were compliant with NIV survived longer than who those who did not use NIV (p = 0.001). We found a significantly longer survival with the use of NIV, the use of NIV optimally and with use of NIV in those with bulbar onset MND compared to those who did not use NIV.

The Diagnostic Yield of Electromyography at Detecting Abnormalities on Muscle Biopsy: A Single Center Experience.

Historically, electromyography (EMG) is utilized early in the diagnostic evaluation of neuromuscular disorders, but its importance may be diminishing with more sophisticated genetic, imaging and immunohistochemistry investigations now available. In the present study, the diagnostic yield of EMG at predicting pathological abnormalities confirmed by muscle biopsy was determined at our neuroscience center. A retrospective study of consecutive cases reviewed at neuromuscular multidisciplinary meetings between 2007 and 2016 identified patients who had EMG and muscle biopsy as part of their diagnostic evaluation. EMG and biopsy findings were categorized as myopathic, neurogenic or normal. The diagnostic accuracy was determined by calculating the concordance between EMG and pathological findings. Of the 175 cases included in the analysis, there was definite concordance between EMG and muscle biopsy findings in 134 cases (76.6%). Abnormal EMG produced sensitivity of 87% and specificity of 65% for abnormal muscle biopsy. Seventeen patients had a normal EMG and an abnormal muscle biopsy, of which 6 had histopathological findings consistent with mitochondrial myopathy, central core myopathy or glycogen storage disorder. Conflicting EMG and muscle biopsy findings were observed in 10 cases. Inclusion body myositis, chronic neuromuscular disorders and dual pathologies were associated with discordant findings. This study demonstrates that EMG has accurate predictive value in diagnosing neuromuscular disorders at our neuroscience center. EMG retains a vital role, particularly in initial diagnostic evaluations of neuromuscular disorders.

Late-Onset Tay-Sachs Disease in an Irish Family.

BACKGROUND: Late-onset Tay-Sachs disease (LOTS) is an autosomal-recessive lysosomal storage disease caused by deficient ß-hexosaminidase A activity. LOTS is rare in the Ashkenazi Jews, but even rarer in the non-Jewish population. CASES: We report an Irish family expanding the LOTS phenotype (ataxia, diffuse muscle wasting, dystonia, chorea, belly dancer's dyskinesia, and neuropsychiatric features) associated with the known HEXA variant 1073 + 1G > A and a novel variant c.459 + 24G > C. CONCLUSIONS: LOTS should be considered in patients with similar symptoms and cerebellar atrophy on brain imaging.

Cycle ergometer training enhances plasma interleukin-10 in multiple sclerosis.

The objective was to determine plasma levels of pro- (IL-12p70/IL-6) and anti-inflammatory (IL-10) cytokines before and after cycle ergometer training in healthy control (HC) and people with multiple sclerosis (pwMS), and to correlate plasma cytokines with physical/mental health. Study participants cycled for 30 min at 65-75% age-predicted maximal heart rate, twice a week for 8 weeks during supervised sessions. We determined that plasma IL-10 expression was lower in pwMS, compared to HCs, and that exercise augmented IL-10 in pwMS to baseline levels in HCs. Furthermore, plasma isolated from pwMS displayed enhanced expression of the pro-inflammatory cytokines IL-12p70/IL-6. Plasma cytokine signatures correlated with physical/mental health. Overall, this study highlights the potential of a short-term exercise programme to regulate circulating cytokine profiles with relevance to pwMS.

Correction to: Cycle ergometer training enhances plasma interleukin-10 in multiple sclerosis.

Following publication the authors informed the Journal that the published version of this article contained a mistake. All occurrences of pg/µl found in the original article should be changed to pg/L. The original article has been corrected. The correction has no impact on the conclusions drawn in the manuscript.

Familial Hemiplegic Migraine With Asymmetric Encephalopathy Secondary to ATP1A2 Mutation: A Case Series.

INTRODUCTION: Familial hemiplegic migraine (FHM) is a genetic disease with a variable clinical phenotype. The imaging and electroencephalogram (EEG) correlates of FHM are not well described. CASE SERIES: We describe a case series of five young women aged 12 to 32 years. Each case presented with headache, encephalopathy, and hemiparesis of varying severity. One patient developed seizures. All patients improved spontaneously. INVESTIGATIONS: Asymmetric slow-wave activity was seen on electroencephalogram in each case. One patient developed marked unilateral cortical edema on MR imaging. Cerebro-spinal fluid (CSF) studies were normal for all patients. Genetic testing in each case showed a mutation of the ATP1A2 gene. One of the mutations identified is a novel mutation. DISCUSSION: Genetic mutation of the ATP1A2 gene results in a channelopathy which is thought to predispose to spreading depolarization, the probable physiologic correlate of migraine aura. We hypothesize that widespread prolonged depolarization accounts for the characteristic electroencephalogram findings in these cases. Familial hemiplegic migraine should be considered in the differential diagnosis of an asymmetric encephalopathy, particularly when CSF and imaging studies are normal.

Impact of short-term cycle ergometer training on quality of life, cognition and depressive symptomatology in multiple sclerosis patients: a pilot study.

In this pilot study, we investigate whether a routine cycle ergometry training programme has therapeutic potential in individuals with multiple sclerosis (MS) by improving quality of life (QOL) and depressive symptomatology, while ameliorating cognitive disturbances. Healthy volunteers and MS patients cycled for 30 min at 65-75% age-predicted maximal heart rate on a recumbent ergometer, with this session repeated twice a week for 8 weeks. QOL, depressive symptomatology and cognitive function were assessed pre- and post-exercise using the MS Quality of Life-54 (MSQOL-54) questionnaire, 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR16) questionnaire and the Cambridge Neuropsychological Test Automated Battery (CANTAB), respectively. We determined that QOL was lower in MS patients, compared to healthy subjects, with a reduction in physical and mental health summary scores observed. Exercise improved both physical and mental health scores in MS patients. In support of this, exercise was shown to reduce depressive symptomatology in MS patients. Exercise was also associated with an improvement in visual sustained attention, executive function/cognitive flexibility and hippocampal-dependent visuospatial memory in patients. Overall, this study identifies a short-term exercise programme that improves physical and mental health, while reducing depressive symptomatology and cognitive dysfunction in MS.

Investigating Idiopathic Inflammatory Myopathy; Initial Cross Speciality Experience with Use of the Extended Myositis Antibody Panel.

The discovery of unique autoantibodies has informed and altered our approach to the diagnosis and management of the inflammatory myopathies. This study reports the initial clinical experience of use of the Extended Myositis Antibody (EMA) panel in the largest university teaching hospital in Ireland. We conducted a retrospective review of all patients who had serum samples tested for myositis specific antibodies and myositis associated antibodies from April 2014 to March 2015. A positive EMA panel was of significant clinical utility in facilitating decisions on appropriate investigations, and need for onward referral to other physicians. Furthermore, this paper highlights the diversity of possible presentations of idiopathic inflammatory myopathy with subsequent need for multi-speciality involvement, and serves to heighten awareness among clinicians of the diagnostic use of extended myositis antibody testing in these cases.

A population-based epidemiologic study of adult neuromuscular disease in the Republic of Ireland.

OBJECTIVE: To estimate the prevalence rates (PRs) of acquired and inherited neuromuscular diseases (NMD) in the adult Irish population, reflecting the burden of these conditions in a single country. METHODS: This population-based study was performed in the Republic of Ireland (RoI), with a PR estimated for December 2013. Multiple case ascertainment sources were utilized. Demographic and clinical information and relevant diagnostic results were registered. RESULTS: A total of 2,641 adults were identified, giving a PR of 62.6/100,000 (95% confidence interval [CI] 59.95-65.24) for all NMD in RoI. Disease-specific PR include chronic inflammatory demyelinating polyradiculoneuropathy 5.87/100,000 (95% CI 5.06-6.68), Charcot-Marie-Tooth 10.52/100,000 (95% CI 9.44-11.61), hereditary neuropathy with liability to pressure palsies 0.84/100,000 (95% CI 0.54-1.15), myotonic dystrophy type I 6.75/100,000 (95% CI 5.88-7.61), Duchenne muscular dystrophy 3.0/100,000 (95% CI 2.33-3.70), Becker muscular dystrophy 2.2/100,000 (95% CI 1.64-2.88), facioscapulohumeral dystrophy 2.59/100,000 (95% CI 2.05-3.13), limb-girdle muscular dystrophy 2.88/100,000 (95% CI 2.31-3.45), periodic paralysis 1.72/100,000 (95% CI 1.28-2.15), myotonia congenita 0.32/100,000 (95% CI 0.18-0.56), paramyotonia congenita 0.15/100,000 (95% CI 0.06-0.34), Kennedy disease 0.83/100,000 (95% CI 0.40-1.27), Lambert-Eaton myasthenic syndrome 0.29/100,000 (95% CI 0.11-0.47), myasthenia gravis 15.12/100,000 (95% CI 13.82-16.42), and sporadic inclusion body myositis 11.7/100,000 (95% CI 9.82-13.58). PR for amyotrophic lateral sclerosis was established from an existing Register as 7.20/100,000 (95% CI 6.34-8.15). CONCLUSIONS: The PR of all adult NMD in RoI is relatively high when compared with other chronic neurologic disorders, although some figures may be an underestimate of the true prevalence. The data provide a framework for international comparison and service planning.

Impact of Exercise on Innate Immunity in Multiple Sclerosis Progression and Symptomatology.

Multiple Sclerosis (MS), an idiopathic progressive immune-mediated neurological disorder of the central nervous system (CNS), is characterized by recurrent episodes of inflammatory demyelination and consequent axonal deterioration. It accounts for functional deterioration and lasting disability among young adults. A body of literature demonstrates that physical activity counteracts fatigue and depression and may improve overall quality of life in MS patients. Furthermore, much data indicates that exercise ameliorates chronic neuroinflammation and its related pathologies by tipping cytokine profiles toward an anti-inflammatory signature. Recent data has focused on the direct impact of exercise training on the innate immune system by targeting toll-like receptors (TLRs), signaling pattern recognition receptors that govern the innate immune response, shedding light on the physiological role of TLRs in health and disease. Indeed, TLRs continue to emerge as players in the neuroinflammatory processes underpinning MS. This review will highlight evidence that physical activity and exercise are potential immunomodulatory therapies, targeting innate signaling mechanism(s) to modulate MS symptom development and progression.

A novel MYH7 Leu1453pro mutation resulting in Laing distal myopathy in an Irish family.

Authors describe clinical, pathological, imaging and genetic findings in the first Irish family with Laing distal myopathy in whom a novel mutation in the human slow ß-myosin heavy chain (MYH7) gene has been identified. A kindred of 14 over 6 generations included 6 individuals with childhood onset distal lower limb weakness in a scapula-peroneal distribution with subsequent proximal upper and lower limb weakness. Finger extensor weakness especially in the 3rd-5th fingers was present in each and two patients had "hanging big toe" sign. Three patients were non-ambulatory by middle-age. One patient developed cardiomyopathy and two patients had respiratory muscle impairment. Intriguingly, brain white matter lesions and epilepsy were present in three patients. Muscle biopsy revealed fibre-size variation, rimmed vacuoles, mild-extensive central nucleation, redundant and folded sarcolemmal membrane and Z band streaming. Genetic analysis revealed a novel heterozygous mutation in the MYH7 gene in one patient which co-segregated perfectly in the remaining 5 affected members and was absent in six unaffected members.

Methodology and design of a national epidemiological study on adult neuromuscular disease.

BACKGROUND: There have been no previous population-based studies of adult neuromuscular disease (NMD) in the Republic of Ireland (RoI). This article describes methods and case-ascertainment strategies used to identify patients with inherited and acquired NMD for the purpose of obtaining the prevalence of these disorders in the RoI. METHODS: This epidemiological study was conducted between January 2012 and January 2014. Prospective and retrospective (until 1990) case identification of adults with inherited and acquired NMD have been carried out. Multiple countrywide patient identification sources including neuromuscular clinics, hospital neurology databases, the hospital in-patient enquiry (HIPE) system of each hospital and the records of Muscular Dystrophy Ireland, a nonprofit organisation, were used. RESULTS: In total, 3,724 potential cases were identified. Of these, 1,083 were excluded because 869 cases represented duplicates or triplicates, 133 were coded incorrectly in HIPE, 74 patients were deceased and 7 patients had moved out of the country. The highest number of cases was identified in neurology databases and HIPE (1,724 and 884, respectively). A total of 2,641 individuals fulfilled the inclusion criteria and were included in the study. CONCLUSION: Detailed epidemiological data of this nature is difficult to acquire in the current structure of the Irish health service, requiring multiple sources including input from voluntary patient organisations. The development of a national patient registry for some or all of these conditions would greatly facilitate standardised data recording, giving a true picture of the burden of neuromuscular diseases in a population.

Andersen-Tawil syndrome with early fixed myopathy.

Andersen-Tawil syndrome (ATS) is a rare autosomal dominant potassium channelopathy characterized by a triad of periodic paralysis, ventricular arrhythmias, and distinctive dysmorphic abnormalities. We present a 19-year-old man with characteristic skeletal dysmorphic features of ATS, early nonfluctuating proximal lower limb weakness from childhood, and neonatal focal seizures. He later developed fluctuating weakness in addition to a fixed proximal myopathy. A 12-lead electrocardiogram showed prominent "U" waves, and McManis protocol prolonged exercise test showed an unusually early decline in the compound motor action potential amplitude by 51%. Genetic testing revealed a de novo heterozygous mutation (R218W) in KCNJ2 associated with ATS. This is the first reported case of ATS in an Irish population with an unusual fixed myopathy from early childhood.

The use of cytokine signature patterns: separating drug naïve, interferon and natalizumab-treated multiple sclerosis patients.

Multiple sclerosis (MS) is an inflammatory illness characterized by demyelination and axonal neurodegeneration. Here, we used serum samples from MS patients to demonstrate if "cytokine signature" patterns can separate different patient groups better than using single cytokines. In this case, we used cytokine profiling to demonstrate if "cytokine signature" patterns can separate MS patients treated with interferon or natalizumab from drug naïve patients. Serum levels of eight individual cytokines (TNFα, IFNγ, S100B, IL-1ß, IL-6, IL-8, IL-17 and IL-23) in MS patients treated with interferons (n = 11) and natalizumab (n = 14) were measured and, in general, showed reduced levels compared to drug naïve MS patients (n = 12). More evident changes were seen when analyzing "cytokine signatures" (i.e. summed value of all eight cytokines), which showed that patients treated with natalizumab and interferons showed significantly reduced cytokine signature levels than drug naïve MS patients. Moreover, patients treated with natalizumab were separated from drug naïve patients by almost 100% fidelity and that patients treated with natalizumab also had reduced levels of pro-inflammatory cytokines compared to patients treated with interferon. Overall, this study provides an example showing that the use of "cytokine signatures" may provide benefits over the analysis of single cytokines for the development of potential biomarkers.

The phenomenon of disproportionate antecollis in Parkinson's disease and multiple system atrophy.

We sought to explore the phenomenon of disproportionate antecollis in multiple system atrophy (MSA) and Parkinson's disease (PD). The etiology is much debated and the main issue is whether it represents a primary myopathy or is secondary to the underlying motor disorder. The clinical, electrophysiological, and biopsy data of MSA or PD patients with antecollis were reviewed. We reviewed 16 patients (7 MSA and 9 PD) who developed antecollis during the course of their disease. The interval between onset of motor symptoms and of antecollis was shorter in the MSA group (4.6 +/- 1.7 years vs. 10.5 +/- 7.0 years). In 6 patients, the antecollis developed subacutely, and in 2 the abnormal neck flexion was initially an off-period phenomenon. Two additional patients also showed some dopa-responsiveness. Clinically, the antecollis was characterized by a forward flexion and anterior shift of the neck, with prominent cervical paraspinal and levator scapulae muscles, usually without weakness of residual neck extension. Electromyography of cervical paraspinal muscles showed mixed myopathic, normal, and neurogenic units, without early recruitment. Cervical paraspinal muscle biopsy in 2 patients disclosed fibrosis and nonspecific myopathic changes. We suggest that, in the context of MSA or PD, the initiating event in antecollis could be a disproportionately increased tone in anterior neck muscles that leads to secondary fibrotic and myopathic changes. However, a primary but yet unexplained neck extensor myopathy still remains the alternative possibility and longitudinal studies are necessary to settle this issue.

Skeletal-muscle channelopathies: periodic paralysis and nondystrophic myotonias.

PURPOSE OF REVIEW: To provide a current review of clinical phenotypes, genetics, molecular pathophysiology, and electro-diagnostic testing strategies of periodic paralysis and nondystrophic myotonias. RECENT FINDINGS: The number of pathogenic mutations causing periodic paralysis and nondystrophic myotonias continues to increase. Important insight into the molecular pathogenesis of muscle sodium channelopathies has been revealed by the finding of 'leaky' closed sodium channels. Previously, alterations in sodium-channel activation or inactivation have been identified as important disease mechanisms. The recent discovery that substitutions of key arginine residues in the voltage-sensing segment of the channel may lead to a 'pore leak' when the channel is closed suggests a new mechanism. Since similar mutations exist in corresponding positions of other channels, this mechanism may apply to other channel diseases. The recognition of different electrophysiological patterns that are specific to muscle ion-channel genotypes will be useful in diagnosis and in guiding genetic testing. Recent studies demonstrate that magnetic resonance imaging may be used to detect intramuscular accumulation of sodium during episodes of weakness. SUMMARY: Recent advances have refined our ability to make a precise molecular diagnosis in muscle channelopathies. The description of a pore leak with voltage-sensor mutations may represent a new disease mechanism.