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Kaji R, Izumi Y, Oki R. Ultra-high dose methylcobalamin and other emerging therapies for amyotrophic lateral sclerosis. Curr Opin Neurol 2024; 37:593-602. [PMID: 39083229 DOI: 10.1097/wco.0000000000001311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
PURPOSE OF REVIEW Recent development in understanding the pathophysiology of amyotrophic lateral sclerosis (ALS) has led to increasing number of promising test drugs in the pipeline along with the existing ones. We will review these agents focusing on ultra-high dose methylcobalamin, which is pending approval in Japan. Clinical trial design best suited for ALS will also be discussed. RECENT FINDINGS The most recent phase 3 trial (JETALS) of ultra-high dose methylcobalamin demonstrated significant slowing of ALSFRSR changes (0.5/month), with marked reduction of serum homocysteine levels in the initial double-blind period. The post hoc analysis of the previous phase 2/3 study (E761 trial; Eisai) showed that it prolonged survival of ALS patients, if started within 1 year of onset, but the previous studies suggested its efficacy even in later stages, depending upon the rate of progression. Phase 3 trial of AMX0035 or Relyvrio on the other hand showed negative results despite the promising phase 2 data. The latter did not adjust the disease progression rate before entry. SUMMARY Ultra-high dose methylcobalamin is not a vitamin supplement but a novel disease-modifying therapy for ALS, and it emphasizes homocysteine as a key factor in the disease process. Clinical trial design must include entering patients early and with similar rates of progression using pretrial observation periods for meaningful results, since ALS is a chronologically heterogenous condition with similar phenotypes.
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Affiliation(s)
- Ryuji Kaji
- Department of Neurology, Tokushima University, Tokushima, Japan
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Stikvoort García DJL, Goedee HS, van Eijk RPA, van Schelven LJ, van den Berg LH, Sleutjes BTHM. Revisiting distinct nerve excitability patterns in patients with amyotrophic lateral sclerosis. Brain 2024; 147:2842-2853. [PMID: 38662766 DOI: 10.1093/brain/awae131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/29/2024] [Accepted: 04/08/2024] [Indexed: 08/02/2024] Open
Abstract
Amyotrophic lateral sclerosis is a devastating neurodegenerative disease, characterized by loss of central and peripheral motor neurons. Although the disease is clinically and genetically heterogeneous, axonal hyperexcitability is a commonly observed feature that has been suggested to reflect an early pathophysiological step linked to the neurodegenerative cascade. Therefore, it is important to clarify the mechanisms causing axonal hyperexcitability and how these relate to the clinical characteristics of patients. Measures derived directly from a nerve excitability recording are frequently used as study end points, although their biophysical basis is difficult to deduce. Mathematical models can aid in the interpretation but are reliable only when applied to group-averaged recordings. Consequently, model estimates of membrane properties cannot be compared with clinical characteristics or treatment effects in individual patients, posing a considerable limitation in heterogeneous diseases, such as amyotrophic lateral sclerosis. To address these challenges, we revisited nerve excitability using a new pattern analysis-based approach (principal component analysis). We evaluated disease-specific patterns of excitability changes and established their biophysical origins. Based on the observed patterns, we developed new compound measures of excitability that facilitate the implementation of this approach in clinical settings. We found that excitability changes in amyotrophic lateral sclerosis patients (n = 161, median disease duration = 11 months) were characterized by four unique patterns compared with controls (n = 50, age and sex matched). These four patterns were best explained by changes in resting membrane potential (modulated by Na+/K+ currents), slow potassium and sodium currents (modulated by their gating kinetics) and refractory properties of the nerve. Consequently, we were able to show that altered gating of slow potassium channels was associated with, and predictive of, the rate of progression of the disease on the amyotrophic lateral sclerosis functional rating scale. Based on these findings, we designed four composite measures that capture these properties to facilitate implementation outside this study. Our findings demonstrate that changes in nerve excitability in patients with amyotrophic lateral sclerosis are dominated by four distinct patterns, each with a distinct biophysical origin. Based on this new approach, we provide evidence that altered slow potassium-channel function might play a role in the rate of disease progression. The magnitudes of these patterns, quantified using a similar approach or our new composite measures, have potential as efficient measures to study membrane properties directly in amyotrophic lateral sclerosis patients, and thus aid prognostic stratification and trial design.
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Affiliation(s)
| | - H Stephan Goedee
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, 3584CX, The Netherlands
| | - Ruben P A van Eijk
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, 3584CX, The Netherlands
- Biostatistics and Research Support, Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Universiteitsweg 100, 3584CX, Utrecht, The Netherlands
| | - Leonard J van Schelven
- Department of Medical Technology and Clinical Physics, University Medical Centre Utrecht, 3584CX, Utrecht, The Netherlands
| | - Leonard H van den Berg
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, 3584CX, The Netherlands
| | - Boudewijn T H M Sleutjes
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, 3584CX, The Netherlands
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Shin-Yi Lin C, Howells J, Rutkove S, Nandedkar S, Neuwirth C, Noto YI, Shahrizaila N, Whittaker RG, Bostock H, Burke D, Tankisi H. Neurophysiological and imaging biomarkers of lower motor neuron dysfunction in motor neuron diseases/amyotrophic lateral sclerosis: IFCN handbook chapter. Clin Neurophysiol 2024; 162:91-120. [PMID: 38603949 DOI: 10.1016/j.clinph.2024.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 02/07/2024] [Accepted: 03/12/2024] [Indexed: 04/13/2024]
Abstract
This chapter discusses comprehensive neurophysiological biomarkers utilised in motor neuron disease (MND) and, in particular, its commonest form, amyotrophic lateral sclerosis (ALS). These encompass the conventional techniques including nerve conduction studies (NCS), needle and high-density surface electromyography (EMG) and H-reflex studies as well as novel techniques. In the last two decades, new methods of assessing the loss of motor units in a muscle have been developed, that are more convenient than earlier methods of motor unit number estimation (MUNE),and may use either electrical stimulation (e.g. MScanFit MUNE) or voluntary activation (MUNIX). Electrical impedance myography (EIM) is another novel approach for the evaluation that relies upon the application and measurement of high-frequency, low-intensity electrical current. Nerve excitability techniques (NET) also provide insights into the function of an axon and reflect the changes in resting membrane potential, ion channel dysfunction and the structural integrity of the axon and myelin sheath. Furthermore, imaging ultrasound techniques as well as magnetic resonance imaging are capable of detecting the constituents of morphological changes in the nerve and muscle. The chapter provides a critical description of the ability of each technique to provide neurophysiological insight into the complex pathophysiology of MND/ALS. However, it is important to recognise the strengths and limitations of each approach in order to clarify utility. These neurophysiological biomarkers have demonstrated reliability, specificity and provide additional information to validate and assess lower motor neuron dysfunction. Their use has expanded the knowledge about MND/ALS and enhanced our understanding of the relationship between motor units, axons, reflexes and other neural circuits in relation to clinical features of patients with MND/ALS at different stages of the disease. Taken together, the ultimate goal is to aid early diagnosis, distinguish potential disease mimics, monitor and stage disease progression, quantify response to treatment and develop potential therapeutic interventions.
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Affiliation(s)
- Cindy Shin-Yi Lin
- Faculty of Medicine and Health, Central Clinical School, Brain and Mind Centre, University of Sydney, Sydney 2006, Australia.
| | - James Howells
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Seward Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Sanjeev Nandedkar
- Natus Medical Inc, Middleton, Wisconsin, USA and Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christoph Neuwirth
- Neuromuscular Diseases Unit/ALS Clinic, Kantonsspital, St. Gallen, Switzerland
| | - Yu-Ichi Noto
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Nortina Shahrizaila
- Division of Neurology, Department of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Roger G Whittaker
- Newcastle University Translational and Clinical Research Institute (NUTCRI), Newcastle University., Newcastle Upon Tyne, United Kingdom
| | - Hugh Bostock
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, WC1N 3BG, London, United Kingdom
| | - David Burke
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
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Lugg A, Schindle M, Sivak A, Tankisi H, Jones KE. Nerve excitability measured with the TROND protocol in amyotrophic lateral sclerosis: a systematic review and meta-analysis. J Neurophysiol 2023; 130:1480-1491. [PMID: 37910562 DOI: 10.1152/jn.00174.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 11/03/2023] Open
Abstract
This meta-analysis assessed the 30+ nerve excitability indices generated by the TROND protocol to identify potential biomarkers for amyotrophic lateral sclerosis (ALS). A comprehensive search was conducted in multiple databases to identify human studies that tested median motor axons. Forest plot analyses were performed using a random-effects model to determine the pooled effect (Z-score), heterogeneity (I2), and Cohen's d for potential biomarker identification. Out of 2,866 studies, 23 studies met the inclusion criteria, incorporating data from 719 controls and 942 patients with ALS. Seven indices emerged as potential biomarkers: depolarizing threshold electrotonus (TEd) 90-100 ms, strength-duration time constant (SDTC), superexcitability, TEd 40-60 ms, resting I/V slope, 50% depolarizing I/V, and subexcitability (ranked by the magnitude of the difference between patients and controls from largest to smallest). In a sensitivity analysis focusing on patients with larger compound muscle action potentials (CMAPs), only four indices were potential biomarkers: TEd 10-20 ms, TEd 90-100 ms, superexcitability, and SDTC. Among the extensive range of 30+ excitability indices generated by the TROND protocol, we have identified seven indices that effectively differentiate patients with ALS from healthy controls. Furthermore, a smaller subset of four indices shows promise as potential biomarkers when the CMAP remains relatively large. However, most studies were considered to be at moderate risk of bias due to case-control designs and absence of sensitivity and specificity calculations, underscoring the need for more prospective diagnostic test-accuracy studies with appropriate disease controls.NEW & NOTEWORTHY This meta-analysis uncovers seven potential axonal excitability biomarkers for lower motor neuron pathology in ALS, shedding light on ion channel dysfunction. The identified dysfunction aligns with the primary pathology-protein homeostasis disruption. These biomarkers could fill a gap to detect presymptomatic spread of the disease in the spinal cord and monitor treatments targeting protein homeostasis and limiting spread, toward enhancing patient care.
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Affiliation(s)
- Anna Lugg
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Mason Schindle
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Allison Sivak
- University of Alberta Library, Edmonton, Alberta, Canada
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - Kelvin E Jones
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, Edmonton, Alberta, Canada
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Sleutjes BTHM, Ruisch J, Nassi TE, Buitenweg JR, van Schelven LJ, van den Berg LH, Franssen H, Stephan Goedee H. Impact of stimulus duration on motor unit thresholds and alternation in compound muscle action potential scans. Clin Neurophysiol 2021; 132:323-331. [PMID: 33450554 DOI: 10.1016/j.clinph.2020.10.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/30/2020] [Accepted: 10/26/2020] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To investigate the impact of stimulus duration on motor unit (MU) thresholds and alternation within compound muscle action potential (CMAP) scans. METHODS The stimulus duration (0.1, 0.2, 0.6, and 1.0 ms) in thenar CMAP scans and individual MUs of 14 healthy subjects was systematically varied. We quantified variability of individual MU's thresholds by relative spread (RS), MU thresholds by stimulus currents required to elicit target CMAPs of 5% (S5), 50% (S50) and 95% (S95) of the maximum CMAP, and relative range (RR) by 100*[S95-S5]/S50. We further assessed the strength-duration time constant (SDTC). Experimental observations were subsequently simulated to quantify alternation. RESULTS RS, unaffected by stimulus duration, was 1.65% averaged over all recordings. RR increased for longer stimulus duration (11.4% per ms, p < 0.001). SDTC shortened with higher target CMAPs (0.007 ms per 10% CMAP, p < 0.001). Experiments and simulations supported that this may underlie the increased RR. A short compared to long stimulus duration recruited relative more MUs at S50 (more alternation) than at the tails (less alternation). CONCLUSIONS The stimulus duration significantly affects MU threshold distribution and alternation within CMAP scans. SIGNIFICANCE Stimulation settings can be further optimized and their standardization is preferred when using CMAP scans for monitoring neuromuscular diseases.
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Affiliation(s)
- Boudewijn T H M Sleutjes
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, the Netherlands.
| | - Janna Ruisch
- Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, the Netherlands
| | - Thijs E Nassi
- Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, the Netherlands
| | - Jan R Buitenweg
- Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, the Netherlands
| | - Leonard J van Schelven
- Department of Medical Technology and Clinical Physics, University Medical Center Utrecht, the Netherlands
| | - Leonard H van den Berg
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Hessel Franssen
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - H Stephan Goedee
- Department of Neurology, Brain Centre Utrecht, University Medical Centre Utrecht, Utrecht, the Netherlands
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Verber NS, Shepheard SR, Sassani M, McDonough HE, Moore SA, Alix JJP, Wilkinson ID, Jenkins TM, Shaw PJ. Biomarkers in Motor Neuron Disease: A State of the Art Review. Front Neurol 2019; 10:291. [PMID: 31001186 PMCID: PMC6456669 DOI: 10.3389/fneur.2019.00291] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 03/06/2019] [Indexed: 12/17/2022] Open
Abstract
Motor neuron disease can be viewed as an umbrella term describing a heterogeneous group of conditions, all of which are relentlessly progressive and ultimately fatal. The average life expectancy is 2 years, but with a broad range of months to decades. Biomarker research deepens disease understanding through exploration of pathophysiological mechanisms which, in turn, highlights targets for novel therapies. It also allows differentiation of the disease population into sub-groups, which serves two general purposes: (a) provides clinicians with information to better guide their patients in terms of disease progression, and (b) guides clinical trial design so that an intervention may be shown to be effective if population variation is controlled for. Biomarkers also have the potential to provide monitoring during clinical trials to ensure target engagement. This review highlights biomarkers that have emerged from the fields of systemic measurements including biochemistry (blood, cerebrospinal fluid, and urine analysis); imaging and electrophysiology, and gives examples of how a combinatorial approach may yield the best results. We emphasize the importance of systematic sample collection and analysis, and the need to correlate biomarker findings with detailed phenotype and genotype data.
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Affiliation(s)
- Nick S Verber
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Stephanie R Shepheard
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Matilde Sassani
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Harry E McDonough
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Sophie A Moore
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - James J P Alix
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Iain D Wilkinson
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Tom M Jenkins
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Pamela J Shaw
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
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Banzrai C, Nodera H, Okada R, Higashi S, Osaki Y, Kaji R. Modification of multiple ion channel functions in vivo by pharmacological inhibition: observation by threshold tracking and modeling. THE JOURNAL OF MEDICAL INVESTIGATION 2017; 64:30-38. [PMID: 28373625 DOI: 10.2152/jmi.64.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Maintenance of axonal excitability relies on complex balance by multiple ion currents, but its evaluation is limited by in vitro single channel neurophysiological study on overall behavior. We sought to evaluate behaviors of multiple ion currents by pharmacological blockade. The threshold tracking technique was used to measure multiple excitability indices on tail sensory nerve of normal male mice before and after administration of either BaCl2 or ivabradine. Mathematical modeling was used to identify the interval changes of the channel parameters. After administration of BaCl2 and ivabradine, the following changes were present: greater threshold changes of both depolarizing and hyperpolarizing threshold electrotonus by both; additionally, reduced S2 accommodation, reduced late subexcitability and increased superexcitability by BaCl2, increased S3 accommodation by ivabradine. Mathematical modelling implied reduction of slow K+ conductance, along with reduction of H conductance (Ih) by BaCl2; and reduction of Ih while augmentation of K+ conductances by ivabradine. Pharmacological blockade of a selective ion channel may be compensated by other ion channels. Unintended effects by ion channel modification could be caused by secondary current alteration by multiple ion channels. J. Med. Invest. 64: 30-38, February, 2017.
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Park SB, Kiernan MC, Vucic S. Axonal Excitability in Amyotrophic Lateral Sclerosis : Axonal Excitability in ALS. Neurotherapeutics 2017; 14:78-90. [PMID: 27878516 PMCID: PMC5233634 DOI: 10.1007/s13311-016-0492-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Axonal excitability testing provides in vivo assessment of axonal ion channel function and membrane potential. Excitability techniques have provided insights into the pathophysiological mechanisms underlying the development of neurodegeneration and clinical features of amyotrophic lateral sclerosis (ALS) and related neuromuscular disorders. Specifically, abnormalities of Na+ and K+ conductances contribute to development of membrane hyperexcitability in ALS, thereby leading to symptom generation of muscle cramps and fasciculations, in addition to promoting a neurodegenerative cascade via Ca2+-mediated processes. Modulation of axonal ion channel function in ALS has resulted in significant symptomatic improvement that has been accompanied by stabilization of axonal excitability parameters. Separately, axonal ion channel dysfunction evolves with disease progression and correlates with survival, thereby serving as a potential therapeutic biomarker in ALS. The present review provides an overview of axonal excitability techniques and the physiological mechanisms underlying membrane excitability, with a focus on the role of axonal ion channel dysfunction in motor neuron disease and related neuromuscular diseases.
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Affiliation(s)
- Susanna B Park
- Brain and Mind Centre, University of Sydney, Sydney, Australia
| | | | - Steve Vucic
- Westmead Clinical School, University of Sydney, Sydney, Australia.
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de Carvalho M, Swash M. Lower motor neuron dysfunction in ALS. Clin Neurophysiol 2016; 127:2670-81. [DOI: 10.1016/j.clinph.2016.03.024] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 02/08/2016] [Accepted: 03/01/2016] [Indexed: 12/11/2022]
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Kaji S, Kawarai T, Miyamoto R, Nodera H, Pedace L, Orlacchio A, Izumi Y, Takahashi R, Kaji R. Late-onset spastic paraplegia type 10 (SPG10) family presenting with bulbar symptoms and fasciculations mimicking amyotrophic lateral sclerosis. J Neurol Sci 2016; 364:45-9. [PMID: 27084214 DOI: 10.1016/j.jns.2016.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/02/2016] [Accepted: 03/01/2016] [Indexed: 12/12/2022]
Abstract
Pathogenic mutations in the KIF5A-SPG10 gene, encoding the kinesin HC5A, can be associated with autosomal dominant hereditary spastic paraplegia (ADHSP). It accounts for about 10% of the complicated forms of ADHSP. Peripheral neuropathy, distal upper limb amyotrophy, and cognitive decline are the most common additional clinical features. We examined a 66-year-old Japanese woman manifesting gait disturbance and spastic dysarthria for 6years with positive family history. She showed evidence of upper and lower motor neuron involvement and fasciculations, thus mimicking amyotrophic lateral sclerosis (ALS). Genetic analysis revealed a heterozygous variant in KIF5A (c.484C>T, p.Arg162Trp) in 2 symptomatic members. The mutation was also identified in 4 asymptomatic members, including 2 elderly members aged over 78years. Electromyography in the 2 symptomatic members revealed evidence of lower motor neuron involvement and fasciculation potentials in distal muscles. This report describes the first known Asian family with a KIF5A mutation and broadens the clinical and electrophysiological spectrum associated with KIF5A-SPG10 mutations. Given that our cases showed pseudobulbar palsy, fasciculation and altered penetrance, KIF5A-SPG10 might well be considered as a differential diagnosis of sporadic ALS.
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Affiliation(s)
- Seiji Kaji
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan; Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
| | - Toshitaka Kawarai
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan.
| | - Ryosuke Miyamoto
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan.
| | - Hiroyuki Nodera
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan.
| | - Lucia Pedace
- Laboratorio di Neurogenetica, CERC-IRCCS Santa Lucia, Rome, Italy.
| | - Antonio Orlacchio
- Laboratorio di Neurogenetica, CERC-IRCCS Santa Lucia, Rome, Italy; Dipartimento di Scienze Chirurgiche e Biomolecolari, Università di Perugia, Perugia, Italy.
| | - Yuishin Izumi
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan.
| | - Ryosuke Takahashi
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan.
| | - Ryuji Kaji
- Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan.
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Focal nerve enlargement is not the cause for increased distal motor latency in ALS: Sonographic evaluation. Clin Neurophysiol 2015; 126:1632-7. [DOI: 10.1016/j.clinph.2014.10.152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/23/2014] [Accepted: 10/26/2014] [Indexed: 11/19/2022]
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de Carvalho M. Nerve excitabitability and fasciculations. Clin Neurophysiol 2013; 124:1925. [PMID: 23643312 DOI: 10.1016/j.clinph.2013.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Revised: 03/08/2013] [Accepted: 03/13/2013] [Indexed: 10/26/2022]
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