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Barkhaus PE, Nandedkar SD, de Carvalho M, Swash M, Stålberg EV. Revisiting the compound muscle action potential (CMAP). Clin Neurophysiol Pract 2024; 9:176-200. [PMID: 38807704 PMCID: PMC11131082 DOI: 10.1016/j.cnp.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/15/2024] [Accepted: 04/21/2024] [Indexed: 05/30/2024] Open
Abstract
The compound muscle action potential (CMAP) is among the first recorded waveforms in clinical neurography and one of the most common in clinical use. It is derived from the summated muscle fiber action potentials recorded from a surface electrode overlying the studied muscle following stimulation of the relevant motor nerve fibres innervating the muscle. Surface recorded motor unit potentials (SMUPs) are the fundamental units comprising the CMAP. Because it is considered a basic, if not banal signal, what it represents is often underappreciated. In this review we discuss current concepts in the anatomy and physiology of the CMAP. These have evolved with advances in instrumentation and digitization of signals, affecting its quantitation and measurement. It is important to understand the basic technical and biological factors influencing the CMAP. If these influences are not recognized, then a suboptimal recording may result. The object is to obtain a high quality CMAP recording that is reproducible, whether the study is done for clinical or research purposes. The initial sections cover the relevant CMAP anatomy and physiology, followed by how these principles are applied to CMAP changes in neuromuscular disorders. The concluding section is a brief overview of CMAP research where advances in recording systems and computer-based analysis programs have opened new research applications. One such example is motor unit number estimation (MUNE) that is now being used as a surrogate marker in monitoring chronic neurogenic processes such as motor neuron diseases.
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Affiliation(s)
- Paul E. Barkhaus
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI USA
| | - Sanjeev D. Nandedkar
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI USA
- Natus Medical Inc., Hopewell Junction, NY, USA
| | - Mamede de Carvalho
- Instituto de Medicina Molecular and Institute of Physiology, Centro de Estudos Egas Moniz, Faculty of Medicine, University of Lisbon, Portugal
- Department of Neurosciences and Mental Health, CHULN-Hospital de Santa Maria, Lisbon, Portugal
| | - Michael Swash
- Barts and the London School of Medicine, Queen Mary University of London, London UK
| | - Erik V. Stålberg
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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Santos Silva C, Swash M, de Carvalho M. Exploring the split hand phenomenon with the neurophysiological index. Neurophysiol Clin 2023; 53:102864. [PMID: 37224600 DOI: 10.1016/j.neucli.2023.102864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 05/26/2023] Open
Abstract
In 164 subjects of different age groups, we studied the neurophysiological index (NI) ([CMAP amplitude/Distal motor latency] *[F-wave frequency]; CMAP=compound muscle action potential) for three hand muscles (APB= abductor pollicis brevis; FDI= first dorsal interosseous; ADM= abductor digiti minimi). A split hand index based on CMAP amplitude (SHI_CMAP) and NI (SHI_NI) were calculated ([APB CMAP amplitude or NI * FDI CMAP amplitude or NI]/[ADM CMAP amplitude or NI]). All these neurophysiological measurements differed between age groups (p<0.001). Hand muscle NIs, as well as SHI_NI and SHI_CMAP were age dependent. This may be relevant for diagnostic purposes in motor neuron diseases.
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Affiliation(s)
- Cláudia Santos Silva
- Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa-Norte, Lisbon, Portugal; Faculdade de Medicina- Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal.
| | - Michael Swash
- Faculdade de Medicina- Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal; Departments of Neurology and Neuroscience, Barts and the London School of Medicine, Queen Mary University of London and Royal London Hospital, UK
| | - Mamede de Carvalho
- Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa-Norte, Lisbon, Portugal; Faculdade de Medicina- Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
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Vucic S, Menon P, Huynh W, Mahoney C, Ho KS, Hartford A, Rynders A, Evan J, Evan J, Ligozio S, Glanzman R, Hotchkin MT, Kiernan MC. Efficacy and safety of CNM-Au8 in amyotrophic lateral sclerosis (RESCUE-ALS study): a phase 2, randomised, double-blind, placebo-controlled trial and open label extension. EClinicalMedicine 2023; 60:102036. [PMID: 37396808 PMCID: PMC10314176 DOI: 10.1016/j.eclinm.2023.102036] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 07/04/2023] Open
Abstract
Background CNM-Au8® is a catalytically-active gold nanocrystal neuroprotective agent that enhances intracellular energy metabolism and reduces oxidative stress. The phase 2, randomised, double-blind, placebo-controlled trial and open label extension RESCUE-ALS trial evaluated the efficacy and safety of CNM-Au8 for treatment of amyotrophic lateral sclerosis (ALS). Methods RESCUE-ALS and its long-term open label extension (OLE) were conducted at two multidisciplinary ALS clinics located in Sydney, Australia: (i) the Brain and Mind Centre and (ii) Westmead Hospital. The double-blind portion of RESCUE-ALS was conducted from January 16, 2020 (baseline visit, first-patient first-visit (FPFV)) through July 13, 2021 (double-blind period, last-patient last-visit (LPLV)). Participants (N = 45) were randomised 1:1 to receive 30 mg of CNM-Au8 or matching placebo daily over 36 weeks in addition to background standard of care, riluzole. The primary outcome was mean percent change in summed motor unit number index (MUNIX), a sensitive neurophysiological biomarker of lower motor neuron function. Change in total (or summated) MUNIX score and change in forced vital capacity (FVC) were secondary outcome measures. ALS disease progression events, ALS Functional Rating Scale (ALSFRS-R) change, change in quality of life (ALSSQOL-SF) were assessed as exploratory outcome measures. Long-term survival evaluated vital status of original active versus placebo randomisation for all participants through at least 12 months following last-patient last-visit (LPLV) of the double-blind period. RESCUE-ALS and the open label study are registered in clinicaltrials.gov with registration numbers NCT04098406 and NCT05299658, respectively. Findings In the intention-to-treat (ITT) population, there was no significant difference in the summated MUNIX score percent change (LS mean difference: 7.7%, 95% CI: -11.9 to 27.3%, p = 0.43), total MUNIX score change (18.8, 95% CI: -56.4 to 94.0), or FVC change (LS mean difference: 3.6, 95% CI: -12.4 to 19.7) between the active and placebo treated groups at week 36. In contrast, survival analyses through 12-month LPLV demonstrated a 60% reduction in all-cause mortality with CNM-Au8 treatment [hazard ratio = 0.408 (95% Wald CI: 0.166 to 1.001, log-rank p = 0.0429). 36 participants entered the open label extension (OLE), and those initially randomised to CNM-Au8 exhibited a slower rate of disease progression, as measured by time to the occurrence of death, tracheostomy, initiation of non-invasive ventilatory support, or gastrostomy tube placement. CNM-Au8 was well-tolerated, and no safety signals were observed. Interpretation CNM-Au8, in combination with riluzole, was well-tolerated in ALS with no identified safety signals. While the primary and secondary outcomes of this trial were not significant, the clinically meaningful exploratory results support further investigation of CNM-Au8 in ALS. Funding The RESCUE-ALS was substantially funded by a grant from FightMND. Additional funding was provided by Clene Australia Pty Ltd.
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Affiliation(s)
- Steve Vucic
- Brain and Nerve Research Centre, Concord Clinical School and Department of Neurology, Concord Repatriation General Hospital, The University of Sydney, Sydney, Australia
| | - Parvathi Menon
- Brain and Nerve Research Centre, Concord Clinical School and Department of Neurology, Concord Repatriation General Hospital, The University of Sydney, Sydney, Australia
| | - William Huynh
- Brain and Mind Centre, University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Colin Mahoney
- Brain and Mind Centre, University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Karen S. Ho
- Clene Nanomedicine, Inc., Salt Lake City, UT, USA
| | | | | | - Jacob Evan
- Clene Nanomedicine, Inc., Salt Lake City, UT, USA
| | - Jeremy Evan
- Clene Nanomedicine, Inc., Salt Lake City, UT, USA
| | | | | | | | - Matthew C. Kiernan
- Brain and Mind Centre, University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Sydney, Australia
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Abstract
While the traditional lung function tests are used to assess lung capacity and pulmonary function, they cannot evaluate respiratory driving function and the integrity of the conduction pathway from the central nervous system to the respiratory motor neuron in the spinal cord and to the diaphragm. The inspiratory trigger is sent from the central nervous system through the phrenic nerve and drives the diaphragm to generate inspiratory movement. Therefore, phrenic nerve stimulation and diaphragmatic electromyography are two fundamental methods to assess respiratory function. There are several useful tools to assess respiratory motor system including electrical or magnetic phrenic nerve stimulation, diaphragmatic needle electromyography, and diaphragmatic ultrasound. By these means, physicians can assess current respiratory status in different neurological diseases that affect respiratory muscles, follow-up of the severity of respiratory impairment, help to predict the chance of successfully weaning from ventilatory support, and confirm clinical diagnoses such as diaphragmatic myoclonus. Although some of these tests require special training, applying these neurophysiological assessments in clinical practice is highly recommended.
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Affiliation(s)
- Yih-Chih Jacinta Kuo
- Department of Neurology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Kai-Hsiang Stanley Chen
- Department of Neurology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan.
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Barp A, Lizio A, Gerardi F, Tarlarini C, Mauro L, Sansone VA, Lunetta C. Neurophysiological indices in amyotrophic lateral sclerosis correlate with functional outcome measures, staging and disease progression. Clin Neurophysiol 2021; 132:1564-1571. [PMID: 34023632 DOI: 10.1016/j.clinph.2021.02.394] [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: 12/14/2020] [Revised: 01/19/2021] [Accepted: 02/01/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVE This study examined neurophysiological (NI), split-hand (SI) and split-leg (SLI) index in patients with amyotrophic lateral sclerosis (ALS), and their correlation with functional status, disease duration, staging and survival. METHODS Eighty-two patients underwent nerve conduction study to analyze NI, SI and SLI. Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R), disease progression rate (ΔFS), Milano-Torino (MiToS) and King's staging systems, Forced Vital Capacity (FVC), and survival data were collected. RESULTS Both NI and SI indices were significantly associated with ALSFRS-R, MiToS, King's and FVC. Slow progressor patients (ΔFS < 0.5) reported a significantly higher NI and SI values compared to both normal (0.5 ≤ ΔFS < 1.00) and fast progressors (ΔFS ≥ 1.0). After dichotomizing patients in slow progressors (ΔFS < 0.5) and not-slow progressors (ΔFS ≥ 0.5), a combination of SI index and disease duration revealed to be the best prediction model to discriminate patients in accordance with their disease progression (c-index: 0.92), leading to a new prognostic index: the 'Split-Hand prognostic index' (SHpi). CONCLUSION SI and NI are correlated with functional status and FVC. SHpi index could represent an useful tool to discriminate patients in accordance with their disease progression. SIGNIFICANCE These data provide novel evidence of neurophysiological indices as promising biomarkers in ALS.
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Affiliation(s)
- Andrea Barp
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy; Neurorehabilitation Unit, University of Milan, Italy.
| | - Andrea Lizio
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy.
| | - Francesca Gerardi
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy.
| | - Claudia Tarlarini
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy.
| | - Luca Mauro
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy.
| | - Valeria Ada Sansone
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy.
| | - Christian Lunetta
- NEuroMuscular Omnicentre, Fondazione Serena Onlus, Piazza Ospedale Maggiore 3, 20162 Milano, Italy; NeMO LAB S.r.l., Milan Italy.
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Yu H, Chen L, Zhang S, He J, Fan D. Early Axonal Dysfunction of the Peripheral Nervous System Influences Disease Progression of ALS: Evidence From Clinical Neuroelectrophysiology. Front Neurol 2021; 12:574919. [PMID: 33643181 PMCID: PMC7905229 DOI: 10.3389/fneur.2021.574919] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 01/20/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: To assess the prognostic value of the decrement in compound muscle action potential amplitude within 12 months of symptom onset (CMAP-12 amplitude) for the survival of patients with amyotrophic lateral sclerosis (ALS). Methods: Patients were stratified into 4 groups according to the decrement of the CMAP-12 amplitudes: normal (≥the lower limit of normal, LLN), mild (<LLN but ≥50% of LLN), moderate (<50% but ≥30% of LLN) and severe (<30% of LLN). All patients were followed up every 3 months. Survival was analyzed using the Kaplan-Meier method and Cox proportional hazards regression. Results: A total of 149 patients were included in the analysis [90 males (60.4%); mean age at onset, 50.7 years]. The decrement of CMAP-12 amplitudes was normal in 24.2% of patients, mild in 22.1%, moderate in 15.4% and severe in 38.3%. Kaplan–Meier analysis showed there was a significant difference in the overall survival across the 4 groups (p < 0.05). Further pairwise comparisons identified significant differences in survival between the normal vs. the moderate group (p < 0.05) and the normal vs. the severe group (p < 0.01). There was a significant inverse correlation between the CMAP-12 amplitude and overall survival. Compared to that in the normal group, survival in the moderately and severely decreased groups was significantly shorter (HR 3.394, 95% CI 1.292–8.917, p = 0.013; and HR 4.732, 95% CI 2.032–11.017; p = 0.000, respectively). Conclusions: Our results suggest that CMAP-12 amplitude could be a prognostic indicator of disease progression in ALS. More importantly, our findings provide clinical evidence for the viewpoint that early axonal dysfunction of the peripheral nervous system accelerates disease progression of ALS.
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Affiliation(s)
- Huiyan Yu
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Department of Neurology, National Center of Gerontology, Beijing Hospital, Beijing, China
| | - Lu Chen
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China
| | - Shuo Zhang
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China
| | - Jing He
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Department of Neurology, National Center of Gerontology, Beijing Hospital, Beijing, China
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing, China.,Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China.,Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
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Ranieri F, Mariotto S, Dubbioso R, Di Lazzaro V. Brain Stimulation as a Therapeutic Tool in Amyotrophic Lateral Sclerosis: Current Status and Interaction With Mechanisms of Altered Cortical Excitability. Front Neurol 2021; 11:605335. [PMID: 33613416 PMCID: PMC7892772 DOI: 10.3389/fneur.2020.605335] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 12/22/2020] [Indexed: 12/14/2022] Open
Abstract
In the last 20 years, several modalities of neuromodulation, mainly based on non-invasive brain stimulation (NIBS) techniques, have been tested as a non-pharmacological therapeutic approach to slow disease progression in amyotrophic lateral sclerosis (ALS). In both sporadic and familial ALS cases, neurophysiological studies point to motor cortical hyperexcitability as a possible priming factor in neurodegeneration, likely related to dysfunction of both excitatory and inhibitory mechanisms. A trans-synaptic anterograde mechanism of excitotoxicity is thus postulated, causing upper and lower motor neuron degeneration. Specifically, motor neuron hyperexcitability and hyperactivity are attributed to intrinsic cell abnormalities related to altered ion homeostasis and to impaired glutamate and gamma aminobutyric acid gamma-aminobutyric acid (GABA) signaling. Several neuropathological mechanisms support excitatory and synaptic dysfunction in ALS; additionally, hyperexcitability seems to drive DNA-binding protein 43-kDA (TDP-43) pathology, through the upregulation of unusual isoforms directly contributing to ASL pathophysiology. Corticospinal excitability can be suppressed or enhanced using NIBS techniques, namely, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), as well as invasive brain and spinal stimulation. Experimental evidence supports the hypothesis that the after-effects of NIBS are mediated by long-term potentiation (LTP)-/long-term depression (LTD)-like mechanisms of modulation of synaptic activity, with different biological and physiological mechanisms underlying the effects of tDCS and rTMS and, possibly, of different rTMS protocols. This potential has led to several small trials testing different stimulation interventions to antagonize excitotoxicity in ALS. Overall, these studies suggest a possible efficacy of neuromodulation in determining a slight reduction of disease progression, related to the type, duration, and frequency of treatment, but current evidence remains preliminary. Main limitations are the small number and heterogeneity of recruited patients, the limited "dosage" of brain stimulation that can be delivered in the hospital setting, the lack of a sufficient knowledge on the excitatory and inhibitory mechanisms targeted by specific stimulation interventions, and the persistent uncertainty on the key pathophysiological processes leading to motor neuron loss. The present review article provides an update on the state of the art of neuromodulation in ALS and a critical appraisal of the rationale for the application/optimization of brain stimulation interventions, in the light of their interaction with ALS pathophysiological mechanisms.
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Affiliation(s)
- Federico Ranieri
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Sara Mariotto
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples “Federico II”, Naples, Italy
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University, Rome, Italy
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Vucic S, Kiernan MC, Menon P, Huynh W, Rynders A, Ho KS, Glanzman R, Hotchkin MT. Study protocol of RESCUE-ALS: A Phase 2, randomised, double-blind, placebo-controlled study in early symptomatic amyotrophic lateral sclerosis patients to assess bioenergetic catalysis with CNM-A u8 as a mechanism to slow diseas e progression. BMJ Open 2021; 11:e041479. [PMID: 33431491 PMCID: PMC7802642 DOI: 10.1136/bmjopen-2020-041479] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is an adult-onset, progressive and universally fatal neurodegenerative disorder. In Europe, Australia and Canada, riluzole is the only approved therapeutic agent for the treatment of ALS, while in the USA, riluzole and edaravone have been approved by the Food and Drug Administration (FDA) . Neither riluzole nor edaravone treatment has resulted in substantial disease-modifying effects. There is, therefore, an urgent need for drugs that result in safe and effective treatment. Here, we present the design and rationale for the phase 2 RESCUE-ALS study, investigating the novel nanocatalytic drug, CNM-Au8, as a therapeutic intervention that enhances the metabolic and energetic capacity of motor neurones. CNM-Au8 is an aqueous suspension of clean-surfaced, faceted gold nanocrystals that have extraordinary catalytic capabilities, that enhance efficiencies of key metabolic reactions, while simultaneously reducing levels of reactive oxygen species. This trial utilises a novel design by employing motor unit number index (MUNIX), measured by electromyography, as a quantitative measure of lower motor neurone loss and as an early marker of ALS disease progression. METHODS AND ANALYSIS This is a multicentre, randomised, double-blind, parallel group, placebo-controlled study of the efficacy, safety, pharmacokinetics and pharmacodynamics of CNM-Au8 in ALS patients. Patients will be randomised 1:1 to either receive 30 mg of CNM-Au8 once daily or matching placebo over a 36-week double-blind treatment period. Efficacy will be assessed as the change in motor neurone loss as measured by electromyography (eg, MUNIX, the primary endpoint; and secondary endpoints including MScanFit, motor unit size index, Split Hand Index, Neurophysiology Index). Exploratory endpoints include standard clinical and quality of life assessments. ETHICS AND DISSEMINATION RESCUE-ALS was approved by the Western Sydney Local Health District Human Research Ethics Committee (Ethics Ref: 2019/ETH12107). Results of the study will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER NCT04098406.
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Affiliation(s)
- Steve Vucic
- Department of Neurology, Westmead Hospital and Western Clinical School, University of Sydney, Sydney, New South Wales, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Parvathi Menon
- Department of Neurology, Westmead Hospital and Western Clinical School, University of Sydney, Sydney, New South Wales, Australia
| | - William Huynh
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia
- Prince of Wales Clinical School, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Karen S Ho
- Clene Nanomedicine, Salt Lake City, Utah, USA
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Fileccia E, De Pasqua S, Rizzo G, Di Stasi V, Vacchiano V, Avoni P, Bartolomei I, Pastorelli F, Plasmati R, Donadio V, Salvi F, Liguori R. Denervation findings on EMG in amyotrophic lateral sclerosis and correlation with prognostic milestones: Data from a retrospective study. Clin Neurophysiol 2020; 131:2017-2022. [DOI: 10.1016/j.clinph.2020.04.161] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/03/2020] [Accepted: 04/03/2020] [Indexed: 10/24/2022]
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Bashford J, Mills K, Shaw C. The evolving role of surface electromyography in amyotrophic lateral sclerosis: A systematic review. Clin Neurophysiol 2020; 131:942-950. [PMID: 32044239 PMCID: PMC7083223 DOI: 10.1016/j.clinph.2019.12.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/23/2019] [Accepted: 12/14/2019] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that leads to inexorable motor decline and a median survival of three years from symptom onset. Surface EMG represents a major technological advance that has been harnessed in the development of novel neurophysiological biomarkers. We have systematically reviewed the current application of surface EMG techniques in ALS. METHODS We searched PubMed to identify 42 studies focusing on surface EMG and its associated analytical methods in the diagnosis, prognosis and monitoring of ALS patients. RESULTS A wide variety of analytical techniques were identified, involving motor unit decomposition from high-density grids, motor unit number estimation and measurements of neuronal hyperexcitability or neuromuscular architecture. Some studies have proposed specific diagnostic and prognostic criteria however clinical calibration in large ALS cohorts is currently lacking. The most validated method to monitor disease is the motor unit number index (MUNIX), which has been implemented as an outcome measure in two ALS clinical trials. CONCLUSION Surface EMG offers significant practical and analytical flexibility compared to invasive techniques. To capitalise on this fully, emphasis must be placed upon the multi-disciplinary collaboration of clinicians, bioengineers, mathematicians and biostatisticians. SIGNIFICANCE Surface EMG techniques can enrich effective biomarker development in ALS.
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Affiliation(s)
- J. Bashford
- UK Dementia Research Institute, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College, London, UK
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Pyun SY, Kim Y, Oh SI, Bae JS. Differences in nerve excitability properties between isolated bulbar palsy and bulbar-dominant amyotrophic lateral sclerosis. Neurol Res 2020; 42:133-140. [PMID: 31928339 DOI: 10.1080/01616412.2019.1710407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Objectives: Isolated bulbar palsy (IBP) is a rare variant that can show a benign course, while progressive bulbar palsy (PBP) has been regarded as a bulbar-dominant type of classical amyotrophic lateral sclerosis (cALS). This study aimed to identify differences in the excitability properties between them.Methods: We consecutively collected data on 22 ALS patients: 13 with cALS, 5 with PBP, and 4 with IBP. An automated nerve excitability test (NET) was applied to measure the strength-duration time constant, threshold electrotonus (TE), current-threshold relationship, and recovery cycle. The axonal excitability properties were compared between the ALS groups and 25 controls.Results: Compared to controls, the cALS group showed a greater change in the depolarizing phase of TE of 90-100 ms after depolarizing current [TEd(90-100)] (53.3±1.3 [mean±SEM] for cALS and 49.0±0.7 for control, P<0.01) and lower S2 accommodation (19.6±0.8 and 22.6±0.7, respectively; P=0.01). There was a nonsignificant tendency for a high TEd(90-100) pattern to be less prominent in the IBP group than in the PBP group (51.5±4.22 and 48.8±1.5, respectively). In addition, all of the parameters of nerve excitability other than S2 accommodation in the PBP and IBP groups did not differ significantly from those in the controls.Conclusions: The excitability properties of IBP and PBP differ from those of cALS. The pattern of NET in PBP was more similar to that in cALS than that in IBP. These findings suggest that IBP is a different entity from bulbar-dominant ALS and PBP.
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Affiliation(s)
- So Young Pyun
- Department of Neurology, National Police Hospital, Seoul, Korea
| | - Yerim Kim
- Department of Neurology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Seong-Il Oh
- Department of Neurology, Inje University College of Medicine, Busan, Korea
| | - Jong Seok Bae
- Department of Neurology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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Bashford JA, Wickham A, Iniesta R, Drakakis EM, Boutelle MG, Mills KR, Shaw CE. The rise and fall of fasciculations in amyotrophic lateral sclerosis. Brain Commun 2020; 2:fcaa018. [PMID: 32901231 PMCID: PMC7425399 DOI: 10.1093/braincomms/fcaa018] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Amyotrophic lateral sclerosis is a devastating neurodegenerative disease with a median survival of 3 years from symptom onset. Accessible and reliable biomarkers of motor neuron decline are urgently needed to quicken the pace of drug discovery. Fasciculations represent an early pathophysiological hallmark of amyotrophic lateral sclerosis and can be reliably detected by high-density surface electromyography. We set out to quantify fasciculation potentials prospectively over 14 months, seeking comparisons with established markers of disease progression. Twenty patients with amyotrophic lateral sclerosis and five patients with benign fasciculation syndrome underwent up to seven assessments each. At each assessment, we performed the amyotrophic lateral sclerosis-functional rating scale, sum power score, slow vital capacity, 30-min high-density surface electromyography recordings from biceps and gastrocnemius and the motor unit number index. We employed the Surface Potential Quantification Engine, which is an automated analytical tool to detect and characterize fasciculations. Linear mixed-effect models were employed to account for the pseudoreplication of serial measurements. The amyotrophic lateral sclerosis-functional rating scale declined by 0.65 points per month (P < 0.0001), 35% slower than average. A total of 526 recordings were analysed. Compared with benign fasciculation syndrome, biceps fasciculation frequency in amyotrophic lateral sclerosis was 10 times greater in strong muscles and 40 times greater in weak muscles. This was coupled with a decline in fasciculation frequency among weak muscles of -7.6/min per month (P = 0.003), demonstrating the rise and fall of fasciculation frequency in biceps muscles. Gastrocnemius behaved differently, whereby strong muscles in amyotrophic lateral sclerosis had fasciculation frequencies five times greater than patients with benign fasciculation syndrome while weak muscles were increased by only 1.5 times. Gastrocnemius demonstrated a significant decline in fasciculation frequency in strong muscles (2.4/min per month, P < 0.0001), which levelled off in weak muscles. Fasciculation amplitude, an easily quantifiable surrogate of the reinnervation process, was highest in the biceps muscles that transitioned from strong to weak during the study. Pooled analysis of >900 000 fasciculations revealed inter-fasciculation intervals <100 ms in the biceps of patients with amyotrophic lateral sclerosis, particularly in strong muscles, consistent with the occurrence of doublets. We hereby present the most comprehensive longitudinal quantification of fasciculation parameters in amyotrophic lateral sclerosis, proposing a unifying model of the interactions between motor unit loss, muscle power and fasciculation frequency. The latter showed promise as a disease biomarker with linear rates of decline in strong gastrocnemius and weak biceps muscles, reflecting the motor unit loss that drives clinical progression.
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Affiliation(s)
- James A Bashford
- UK Dementia Research Institute, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Correspondence to: James A. Bashford, MRCP, PhD UK Dementia Research Institute, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, 5 Cutcombe Road, King’s College London, London SE5 9RT, UK E-mail:
| | - Aidan Wickham
- Department of Bioengineering, Imperial College London, London, UK
| | - Raquel Iniesta
- Department of Biostatistics and Health Informatics, King’s College London, London, UK
| | | | | | - Kerry R Mills
- UK Dementia Research Institute, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Chris E Shaw
- UK Dementia Research Institute, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
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Civardi C, Collini A, Mazzini L, Monaco F, Geda C. Single-pulse transcranial magnetic stimulation in amyotrophic lateral sclerosis. Muscle Nerve 2019; 61:330-337. [PMID: 31837153 DOI: 10.1002/mus.26780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 12/04/2019] [Accepted: 12/07/2019] [Indexed: 11/07/2022]
Abstract
INTRODUCTION Transcranial magnetic stimulation (TMS) is one of the best methods to identify changes in the corticospinal tract. We used single-pulse TMS at the beginning of the disease and in the follow-up in a group of patients with amyotrophic lateral sclerosis (ALS). METHODS We evaluated the corticospinal tract in the bulbar, upper, and lower regions in 55 patients with ALS, and we monitored them for a period of 24 months. Data were correlated with clinical scales. RESULTS An increase of central motor conduction time (CMCT) was the most sensitive marker of upper motor neuron involvement. The resting motor threshold, CMCT, and the central silent period increased linearly with disease duration and upper/lower motor neuron involvement. DISCUSSION Transcranial magnetic stimulation could be an essential neurophysiological technique in the early phase of ALS because it has been shown to be useful in detecting subclinical upper motor neuron involvement. Multiple evaluations of several regions increase TMS sensitivity.
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Affiliation(s)
| | | | - Letizia Mazzini
- ALS Centre Department of Neurology Maggiore della Carità University Hospital, Novara, Italy
| | - Francesco Monaco
- Department of Neurology Maggiore della Carità University Hospital, Novara, Italy
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Oguz Akarsu E, Sirin NG, Kocasoy Orhan E, Erbas B, Dede HO, Baslo MB, Idrisoglu HA, Oge AE. Repeater F-waves in amyotrophic lateral sclerosis: Electrophysiologic indicators of upper or lower motor neuron involvement? Clin Neurophysiol 2019; 131:96-105. [PMID: 31760213 DOI: 10.1016/j.clinph.2019.09.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/08/2019] [Accepted: 09/25/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To extract insight about the mechanism of repeater F-waves (Frep) by exploring their correlation with electrophysiologic markers of upper and lower motor neuron dysfunction in amyotrophic lateral sclerosis (ALS). METHODS The correlations of Frep parameters with clinical scores and the results of neurophysiological index (NI), MScanfit MUNE, F/M amplitude ratio (F/M%), single and paired-pulse transcranial magnetic stimulation (TMS), and triple stimulation technique (TST) studies, recorded from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 35 patients with ALS were investigated. RESULTS Frep parameters were correlated with NI and MScanfit MUNE in ADM muscle and F/M% in both muscles. None of the Frep parameters were correlated with clinical scores or TST and TMS measures. While the CMAP amplitudes were similar in the two recording muscles, there was a more pronounced decrease of F-wave persistence in APB, probably heralding the subsequent split hand phenomenon. CONCLUSION Our findings suggest that the presence and density of Freps are primarily related to the degree of lower motor neuron loss and show no correlation with any of the relatively extensive set of parameters for upper motor neuron dysfunction. SIGNIFICANCE Freps are primarily related to lower motor neuron loss in ALS.
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Affiliation(s)
- Emel Oguz Akarsu
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey.
| | - Nermin Gorkem Sirin
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
| | - Elif Kocasoy Orhan
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
| | - Bahar Erbas
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey; Demiroglu Bilim University, Faculty of Medicine, Department of Pharmacology, Istanbul, Turkey
| | - Hava Ozlem Dede
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
| | - Mehmet Baris Baslo
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
| | - Halil Atilla Idrisoglu
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
| | - Ali Emre Oge
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
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15
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The ‘neurophysiological index’ predicts survival in amyotrophic lateral sclerosis. Clin Neurophysiol 2019; 130:1684-1685. [DOI: 10.1016/j.clinph.2019.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 05/27/2019] [Indexed: 12/13/2022]
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16
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Sirin NG, Oguz Akarsu E, Kocasoy Orhan E, Erbas B, Artug T, Dede HO, Baslo MB, Idrisoglu HA, Oge AE. Parameters derived from compound muscle action potential scan for discriminating amyotrophic lateral sclerosis‐related denervation. Muscle Nerve 2019; 60:400-408. [DOI: 10.1002/mus.26644] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 07/13/2019] [Accepted: 07/16/2019] [Indexed: 12/11/2022]
Affiliation(s)
- N. Gorkem Sirin
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - Emel Oguz Akarsu
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - Elif Kocasoy Orhan
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - Bahar Erbas
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - Tugrul Artug
- Electrical and Electronics EngineeringIstanbul Arel University Istanbul Turkey
| | - H. Ozlem Dede
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - M. Baris Baslo
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - Halil A. Idrisoglu
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
| | - A. Emre Oge
- Department of Neurology, Istanbul Faculty of MedicineIstanbul University Istanbul Turkey
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Abstract
PURPOSE OF REVIEW Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the motor neurons, characterized by upper motor neuron (UMN) and lower motor neuron (LMN) dysfunction. There have been significant technological advances in the development of neurophysiological biomarkers of UMN and LMN dysfunction in ALS. In this review, we discuss major advances in development of neurophysiological biomarkers in ALS, critiquing their potential in diagnosis and prognosis of ALS, as well as utility in monitoring treatment effects. RECENT FINDINGS The threshold tracking transcranial magnetic stimulation (TMS) technique has established cortical hyperexcitability as an early and specific biomarker of UMN dysfunction in ALS, and associated with neurodegeneration. In addition to establishing cortical hyperexcitability as a pathophysiological mechanism, threshold tracking TMS has enabled an earlier diagnosis of ALS and provided a means of monitoring effects of therapeutic agents. Biomarkers of LMN dysfunction, including motor unit number estimation, the neurophysiological index, electrical impedance myography and axonal excitability techniques, have all exhibited utility in monitoring disease progression. SUMMARY In addition to enhancing ALS diagnosis, the development of novel neurophysiological biomarkers has implications for clinical trials research and drug development, enabling the assessment of biological efficacy of agents in early stages of drug development.
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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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19
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Chipika RH, Finegan E, Li Hi Shing S, Hardiman O, Bede P. Tracking a Fast-Moving Disease: Longitudinal Markers, Monitoring, and Clinical Trial Endpoints in ALS. Front Neurol 2019; 10:229. [PMID: 30941088 PMCID: PMC6433752 DOI: 10.3389/fneur.2019.00229] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 02/22/2019] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) encompasses a heterogeneous group of phenotypes with different progression rates, varying degree of extra-motor involvement and divergent progression patterns. The natural history of ALS is increasingly evaluated by large, multi-time point longitudinal studies, many of which now incorporate presymptomatic and post-mortem assessments. These studies not only have the potential to characterize patterns of anatomical propagation, molecular mechanisms of disease spread, but also to identify pragmatic monitoring markers. Sensitive markers of progressive neurodegenerative change are indispensable for clinical trials and individualized patient care. Biofluid markers, neuroimaging indices, electrophysiological markers, rating scales, questionnaires, and other disease-specific instruments have divergent sensitivity profiles. The discussion of candidate monitoring markers in ALS has a dual academic and clinical relevance, and is particularly timely given the increasing number of pharmacological trials. The objective of this paper is to provide a comprehensive and critical review of longitudinal studies in ALS, focusing on the sensitivity profile of established and emerging monitoring markers.
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Affiliation(s)
| | - Eoin Finegan
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Stacey Li Hi Shing
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Orla Hardiman
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Peter Bede
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
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20
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Huynh W, Dharmadasa T, Vucic S, Kiernan MC. Functional Biomarkers for Amyotrophic Lateral Sclerosis. Front Neurol 2019; 9:1141. [PMID: 30662429 PMCID: PMC6328463 DOI: 10.3389/fneur.2018.01141] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/10/2018] [Indexed: 01/06/2023] Open
Abstract
The clinical diagnosis of amyotrophic lateral sclerosis (ALS) relies on determination of progressive dysfunction of both cortical as well as spinal and bulbar motor neurons. However, the variable mix of upper and lower motor neuron signs result in the clinical heterogeneity of patients with ALS, resulting frequently in delay of diagnosis as well as difficulty in monitoring disease progression and treatment outcomes particularly in a clinical trial setting. As such, the present review provides an overview of recently developed novel non-invasive electrophysiological techniques that may serve as biomarkers to assess UMN and LMN dysfunction in ALS patients.
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Affiliation(s)
- William Huynh
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia.,Prince of Wales Clinical School, University of New South Wales, Sydney, NSW, Australia
| | | | - Steve Vucic
- Western Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia.,Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, NSW, Australia
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21
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Taga A, Maragakis NJ. Current and emerging ALS biomarkers: utility and potential in clinical trials. Expert Rev Neurother 2018; 18:871-886. [DOI: 10.1080/14737175.2018.1530987] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Arens Taga
- School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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22
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Escorcio‐Bezerra ML, Abrahao A, Nunes KF, De Oliveira Braga NI, Oliveira ASB, Zinman L, Manzano GM. Motor unit number index and neurophysiological index as candidate biomarkers of presymptomatic motor neuron loss in amyotrophic lateral sclerosis. Muscle Nerve 2018; 58:204-212. [DOI: 10.1002/mus.26087] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 01/23/2018] [Accepted: 01/24/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Marcio Luiz Escorcio‐Bezerra
- Department of Neurology and NeurosurgeryEscola Paulista de Medicina, Universidade Federal de São Paulo, Rua Pedro de Toledo, 65004039‐002São Paulo SP Brazil
| | - Agessandro Abrahao
- Department of Neurology and NeurosurgeryEscola Paulista de Medicina, Universidade Federal de São Paulo, Rua Pedro de Toledo, 65004039‐002São Paulo SP Brazil
- Sunnybrook Health Sciences Centre, Division of Neurology, Department of MedicineUniversity of TorontoToronto Ontario Canada
| | - Karlo Faria Nunes
- Department of Neurology and NeurosurgeryEscola Paulista de Medicina, Universidade Federal de São Paulo, Rua Pedro de Toledo, 65004039‐002São Paulo SP Brazil
| | - Nadia Iandoli De Oliveira Braga
- Department of Neurology and NeurosurgeryEscola Paulista de Medicina, Universidade Federal de São Paulo, Rua Pedro de Toledo, 65004039‐002São Paulo SP Brazil
| | - Acary Souza Bulle Oliveira
- Department of Neurology and NeurosurgeryEscola Paulista de Medicina, Universidade Federal de São Paulo, Rua Pedro de Toledo, 65004039‐002São Paulo SP Brazil
| | - Lorne Zinman
- Sunnybrook Health Sciences Centre, Division of Neurology, Department of MedicineUniversity of TorontoToronto Ontario Canada
| | - Gilberto Mastrocola Manzano
- Department of Neurology and NeurosurgeryEscola Paulista de Medicina, Universidade Federal de São Paulo, Rua Pedro de Toledo, 65004039‐002São Paulo SP Brazil
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Shibuya K, Simon NG, Geevasinga N, Menon P, Howells J, Park SB, Huynh W, Noto YI, Vucic S, Kiernan MC. The evolution of motor cortical dysfunction in amyotrophic lateral sclerosis. Clin Neurophysiol 2017; 128:1075-1082. [PMID: 28400096 DOI: 10.1016/j.clinph.2017.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/18/2017] [Accepted: 03/01/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The present study aimed to investigate alterations in cortical function in amyotrophic lateral sclerosis (ALS) related to disease progression. METHODS In total, clinical assessments were evaluated in 189 ALS patients, combined with assessment of cortical function utilising threshold tracking transcranial magnetic stimulation. Results were compared with disease stage. Disease stage was defined in three ways: (1) as a proportion of disease duration in deceased patients; (2) from the time of ALS onset; and (3) using the ALS rating scale-revised (ALSFRS-R). RESULTS Prospective studies in ALS patients demonstrated decreased neurophysiological index (p<0.0001) and decreased compound muscle action potential (CMAP) (p<0.0001), combined with abnormalities of central function including prolonged central motor conduction time (CMCT) (p<0.05), increased motor evoked potential/CMAP amplitude ratio (p<0.0001) and decreased short interval intracortical inhibition (SICI) (p<0.001). SICI at 3ms (p<0.05, β=-0.21) and averaged SICI (p<0.05, β=-0.21) decreased with disease progression, measured using proportion of disease duration. Alternatively, using time from disease onset, CMCT prolonged with disease progression (p<0.01, β=0.25), while ALSFRS-R decline correlated with decreased SICI at 3ms (p<0.01, β=0.20). CONCLUSIONS Clinical measures combined with assessment of cortical function established that SICI decreased with disease progression. SIGNIFICANCE These findings may suggest dysfunction of inhibitory interneurons with disease progression.
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Affiliation(s)
| | - Neil G Simon
- St. Vincent's Clinical School, University of Sydney, Australia
| | | | - Parvathi Menon
- Western Clinical School, University of Sydney, Australia
| | - James Howells
- Brain and Mind Centre, University of Sydney, Australia
| | | | - William Huynh
- Brain and Mind Centre, University of Sydney, Australia; Prince of Wales Clinical School, University of New South Wales, Australia
| | - Yu-Ichi Noto
- Brain and Mind Centre, University of Sydney, Australia
| | - Steve Vucic
- Western Clinical School, University of Sydney, Australia
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Iwai Y, Shibuya K, Misawa S, Sekiguchi Y, Watanabe K, Amino H, Kuwabara S. Axonal Dysfunction Precedes Motor Neuronal Death in Amyotrophic Lateral Sclerosis. PLoS One 2016; 11:e0158596. [PMID: 27383069 PMCID: PMC4934877 DOI: 10.1371/journal.pone.0158596] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 06/18/2016] [Indexed: 12/20/2022] Open
Abstract
Wide-spread fasciculations are a characteristic feature in amyotrophic lateral sclerosis (ALS), suggesting motor axonal hyperexcitability. Previous excitability studies have shown increased nodal persistent sodium conductances and decreased potassium currents in motor axons of ALS patients, both of the changes inducing hyperexcitability. Altered axonal excitability potentially contributes to motor neuron death in ALS, but the relationship of the extent of motor neuronal death and abnormal excitability has not been fully elucidated. We performed multiple nerve excitability measurements in the median nerve at the wrist of 140 ALS patients and analyzed the relationship of compound muscle action potential (CMAP) amplitude (index of motor neuronal loss) and excitability indices, such as strength-duration time constant, threshold electrotonus, recovery cycle and current-threshold relationships. Compared to age-matched normal controls (n = 44), ALS patients (n = 140) had longer strength-duration time constant (SDTC: a measure of nodal persistent sodium current; p < 0.05), greater threshold changes in depolarizing threshold electrotonus (p < 0.05) and depolarizing current threshold relationship (i.e. less accommodation; (p < 0.05), greater superexcitability (a measure of fast potassium current; p < 0.05) and reduced late subexcitability (a measure of slow potassium current; p < 0.05), suggesting increased persistent sodium currents and decreased potassium currents. The reduced potassium currents were found even in the patient subgroups with normal CMAP (> 5mV). Regression analyses showed that SDTC (R = -0.22) and depolarizing threshold electrotonus (R = -0.22) increased with CMAP decline. These findings suggest that motor nerve hyperexcitability occurs in the early stage of the disease, and precedes motor neuronal loss in ALS. Modulation of altered ion channel function could be a treatment option for ALS.
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Affiliation(s)
- Yuta Iwai
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Kazumoto Shibuya
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Sonoko Misawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yukari Sekiguchi
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Keisuke Watanabe
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hiroshi Amino
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
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25
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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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26
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New insights into the clinical neurophysiological assessment of ALS. Neurophysiol Clin 2016; 46:157-63. [PMID: 27364772 DOI: 10.1016/j.neucli.2016.05.070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 05/25/2016] [Accepted: 05/25/2016] [Indexed: 12/11/2022] Open
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27
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Shibuya K, Park SB, Geevasinga N, Huynh W, Simon NG, Menon P, Howells J, Vucic S, Kiernan MC. Threshold tracking transcranial magnetic stimulation: Effects of age and gender on motor cortical function. Clin Neurophysiol 2016; 127:2355-61. [DOI: 10.1016/j.clinph.2016.03.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 03/05/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
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28
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de Carvalho M, Swash M. Fasciculation discharge frequency in amyotrophic lateral sclerosis and related disorders. Clin Neurophysiol 2016; 127:2257-62. [DOI: 10.1016/j.clinph.2016.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/17/2016] [Accepted: 02/18/2016] [Indexed: 10/22/2022]
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30
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Benatar M, Boylan K, Jeromin A, Rutkove SB, Berry J, Atassi N, Bruijn L. ALS biomarkers for therapy development: State of the field and future directions. Muscle Nerve 2015; 53:169-82. [PMID: 26574709 DOI: 10.1002/mus.24979] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2015] [Indexed: 12/11/2022]
Abstract
Biomarkers have become the focus of intense research in the field of amyotrophic lateral sclerosis (ALS), with the hope that they might aid therapy development efforts. Notwithstanding the discovery of many candidate biomarkers, none have yet emerged as validated tools for drug development. In this review we present a nuanced view of biomarkers based on the perspective of the Food and Drug Administration; highlight the distinction between discovery and validation; describe existing and emerging resources; review leading biological fluid-based, electrophysiological, and neuroimaging candidates relevant to therapy development efforts; discuss lessons learned from biomarker initiatives in related neurodegenerative diseases; and outline specific steps that we, as a field, might take to hasten the development and validation of biomarkers that will prove useful in enhancing efforts to develop effective treatments for ALS patients. Most important among these is the proposal to establish a federated ALS Biomarker Consortium in which all interested and willing stakeholders may participate with equal opportunity to contribute to the broader mission of biomarker development and validation.
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Affiliation(s)
- Michael Benatar
- Department of Neurology, University of Miami, Miami, Florida, USA, 33136
| | - Kevin Boylan
- Department of Neurology, Mayo Clinic Jacksonville, Jacksonville, Florida, USA
| | | | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - James Berry
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Nazem Atassi
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
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Flecainide in Amyotrophic Lateral Sclerosis as a Neuroprotective Strategy (FANS): A Randomized Placebo-Controlled Trial. EBioMedicine 2015; 2:1916-22. [PMID: 26844270 PMCID: PMC4703720 DOI: 10.1016/j.ebiom.2015.11.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/09/2015] [Accepted: 11/11/2015] [Indexed: 12/03/2022] Open
Abstract
Background Abnormalities in membrane excitability and Na+ channel function are characteristic of amyotrophic lateral sclerosis (ALS). We aimed to examine the neuroprotective potential, safety and tolerability of the Na+ channel blocker and membrane stabiliser flecainide in ALS. Methods A double-blind, placebo-controlled, randomised clinical trial of flecainide (200 mg/day) for 32-weeks with a 12-week lead-in phase was conducted in participants with probable or definite ALS recruited from multiple Australian centres (ANZCT Registry number ACTRN12608000338369). Patients were reviewed by a cardiologist to rule out cardiac contraindications. Participants were randomly assigned (1:1) to flecainide or placebo using stratified permuted blocks by a central pharmacy. The primary outcome measure was the slope of decline of the ALS Functional Rating Scale-revised (ALS FRS-r) during the treatment period. Findings Between March 11, 2008 and July 1, 2010, 67 patients were screened, 54 of whom were randomly assigned to receive flecainide (26 patients) or placebo (28 patients). Four patients in the flecainide group and three patients in the placebo group withdrew from the study. One patient in the flecainide group died during the study, attributed to disease progression. Flecainide was generally well tolerated, with no serious adverse events reported in either group. There was no significant difference in the rate of decline in the primary outcome measure ALS-FRS-r between placebo and flecainide treated patients (Flecainide 0.65 [95% CI 0.49 to 0.98]; Placebo 0.81 [0.49 to 2.12] P = 0.50). However, the rate of decline of the neurophysiological index was significantly reduced in the flecainide group (Flecainide 0.06 [0.01 to 0.11]; Placebo 0.14 [0.09 to 0.19], P = 0.02). Placebo-treated patients demonstrated greater CMAP amplitude reduction during the course of the study in the subset of patients with a reduced baseline CMAP amplitude (Flecainide: − 15 ± 12%; Placebo − 59 ± 12%; P = 0.03). Flecainide-treated patients maintained stabilized peripheral axonal excitability over the study compared to placebo. Interpretation This pilot study indicated that flecainide was safe and potentially biologically effective in ALS. There was evidence that flecainide stabilized peripheral axonal membrane function in ALS. While the study was not powered to detect evidence of benefit of flecainide on ALS-FRS-r decline, further studies may demonstrate clinical efficacy of flecainide in ALS. To determine safety and neuroprotective potential, a double-blind, placebo-controlled, randomised trial of the Na+ channel blocking agent flecainide was conducted in ALS. Flecainide was well tolerated, with no serious adverse events. Although there was some evidence that flecainide stabilised peripheral axonal membrane function, the study was not powered to provide evidence of benefit on functional decline.
Changes in nerve excitability function occur in patients with amyotrophic lateral sclerosis (ALS). We conducted a double-blind, placebo-controlled, randomised clinical trial to examine the impact of a membrane/nerve stabilizer (flecainide) in ALS patients. Although there was some evidence that flecainide stabilised peripheral axonal membrane function in ALS, the study was not powered to find evidence that flecainide benefited patient function.
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Abstract
Progressive weakness remains the clinical hallmark of amyotrophic lateral sclerosis (ALS). Accordingly, a variety of tools has been developed to capture this disease feature, including questionnaires, such as the ALS-functional rating scale, strength testing, pulmonary function tests, electrophysiologic measures, including motor unit number estimation, and imaging techniques. Despite this plethora of approaches, there is little agreement as to what measures to use in a given clinical trial or in the clinic during routine patient care. Part of the reason for this uncertainty is that ALS is a remarkably protean disease. Some individuals progress rapidly, others slowly; some patients have considerable upper motor neuron dysfunction, whereas others have little; and there is considerable variation in the sequence of body regions affected, in some the disease beginning in the bulbar musculature and in others in one arm or one leg. Here, I present a variety of basic and more complex clinical measures for potential use in therapeutic trials with the aim of offering a balanced and practical set of recommendations, as well as considerations for future studies.
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Affiliation(s)
- Seward B Rutkove
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA,
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Rosenfeld J, Strong MJ. Challenges in the Understanding and Treatment of Amyotrophic Lateral Sclerosis/Motor Neuron Disease. Neurotherapeutics 2015; 12:317-25. [PMID: 25572957 PMCID: PMC4404444 DOI: 10.1007/s13311-014-0332-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
With the acceleration in our understanding of ALS and the related motor neuron disease has come even greater challenges in reconciling all of the proposed pathogenic mechanisms and how this will translate into impactful treatments. Fundamental issues such as diagnostic definition(s) of the disease spectrum, relevant biomarkers, the impact of multiple novel genetic mutations and the significant effect of symptomatic treatments on disease progression are all areas of active investigation. In this review, we will focus on these key issues and highlight the challenges that confront both clinicians and basic science researchers.
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Affiliation(s)
- Jeffrey Rosenfeld
- Central California Neuroscience Institute, UCSF Fresno, Division of Neurology, Fresno, CA, USA,
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Simon NG, Turner MR, Vucic S, Al-Chalabi A, Shefner J, Lomen-Hoerth C, Kiernan MC. Quantifying disease progression in amyotrophic lateral sclerosis. Ann Neurol 2014; 76:643-57. [PMID: 25223628 PMCID: PMC4305209 DOI: 10.1002/ana.24273] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 09/12/2014] [Accepted: 09/12/2014] [Indexed: 12/28/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) exhibits characteristic variability of onset and rate of disease progression, with inherent clinical heterogeneity making disease quantitation difficult. Recent advances in understanding pathogenic mechanisms linked to the development of ALS impose an increasing need to develop strategies to predict and more objectively measure disease progression. This review explores phenotypic and genetic determinants of disease progression in ALS, and examines established and evolving biomarkers that may contribute to robust measurement in longitudinal clinical studies. With targeted neuroprotective strategies on the horizon, developing efficiencies in clinical trial design may facilitate timely entry of novel treatments into the clinic.
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Affiliation(s)
- Neil G Simon
- Department of Neurology, University of California, San Francisco, San Francisco, CA; Prince of Wales Clinical School, University of New South Wales, Randwick, Australia; Neuroscience Research Australia, Barker St, Randwick, Australia
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Decreased movement-related beta desynchronization and impaired post-movement beta rebound in amyotrophic lateral sclerosis. Clin Neurophysiol 2014; 125:1689-99. [PMID: 24457137 DOI: 10.1016/j.clinph.2013.12.108] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/21/2013] [Accepted: 12/25/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVE This study explored event-related desynchronization (ERD) and synchronization (ERS) in amyotrophic lateral sclerosis (ALS) to quantify cortical sensorimotor processes during volitional movements. We furthermore compared ERD/ERS measures with clinical scores and movement-related cortical potential (MRCP) amplitudes. METHODS Electroencephalograms were recorded while 21 ALS patients and 19 controls performed two self-paced motor tasks: sniffing and right index finger flexion. Based on Wavelet analysis the alpha and beta frequency bands were selected for subsequent evaluation. RESULTS Patients generated significantly smaller resting alpha spectral power density (SPD) and smaller beta ERD compared to controls. Additionally patients exhibited merely unilateral post-movement ERS (beta rebound) whereas this phenomenon was bilateral in controls. ERD/ERS amplitudes did not correlate with corresponding MRCPs for either patients or controls. CONCLUSIONS The smaller resting alpha SPD and beta ERD and asymmetrical appearance of beta ERS in patients compared to controls could be the result of pyramidal cell degeneration and/or corpus callosum involvement in ALS. SIGNIFICANCE These results support the notion of reduced movement preparation in ALS involving also areas outside the motor cortex. Furthermore post-movement cortical inhibition seems to be impaired in ALS. ERD/ERS and MRCP are found to be independent measures of cortical motor functions in ALS.
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Paganoni S, Cudkowicz M, Berry JD. Outcome measures in amyotrophic lateral sclerosis clinical trials. CLINICAL INVESTIGATION 2014; 4:605-618. [PMID: 28203356 PMCID: PMC5305182 DOI: 10.4155/cli.14.52] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with an average survival of 3-5 years. While therapies for ALS remain limited, basic and translational ALS research has been host to numerous influential discoveries in recent years. These discoveries have led to a large pipeline of potential therapies that await testing in clinical trials. Until recently, ALS clinical trials have relied on a limited cadre of 'traditional' outcome measures, including survival and measures of function. These measures have proven useful, although imperfect, in Phase III ALS trials. However, their utility in early-phase ALS trials is limited. For these early trials, outcome measures focused on target engagement or biological pathway analysis might improve trial outcomes and better support the drug development process.
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Affiliation(s)
- Sabrina Paganoni
- Harvard Medical School, Department of Neurology, Neurological Clinical Research Institute (NCRI), Massachusetts Genera Hospital, MA, USA
- Harvard Medical School, Department of Physical Medicine & Rehabilitation, Spaulding Rehabilitation Hospital, Boston, MA, USA
| | - Merit Cudkowicz
- Harvard Medical School, Department of Neurology, Neurological Clinical Research Institute (NCRI), Massachusetts Genera Hospital, MA, USA
| | - James D Berry
- Harvard Medical School, Department of Neurology, Neurological Clinical Research Institute (NCRI), Massachusetts Genera Hospital, MA, USA
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Antisense therapy in neurology. J Pers Med 2013; 3:144-76. [PMID: 25562650 PMCID: PMC4251390 DOI: 10.3390/jpm3030144] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 07/26/2013] [Accepted: 07/29/2013] [Indexed: 12/12/2022] Open
Abstract
Antisense therapy is an approach to fighting diseases using short DNA-like molecules called antisense oligonucleotides. Recently, antisense therapy has emerged as an exciting and promising strategy for the treatment of various neurodegenerative and neuromuscular disorders. Previous and ongoing pre-clinical and clinical trials have provided encouraging early results. Spinal muscular atrophy (SMA), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), Fukuyama congenital muscular dystrophy (FCMD), dysferlinopathy (including limb-girdle muscular dystrophy 2B; LGMD2B, Miyoshi myopathy; MM, and distal myopathy with anterior tibial onset; DMAT), and myotonic dystrophy (DM) are all reported to be promising targets for antisense therapy. This paper focuses on the current progress of antisense therapies in neurology.
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Vucic S, Lin CSY, Cheah BC, Murray J, Menon P, Krishnan AV, Kiernan MC. Riluzole exerts central and peripheral modulating effects in amyotrophic lateral sclerosis. ACTA ACUST UNITED AC 2013; 136:1361-70. [PMID: 23616585 DOI: 10.1093/brain/awt085] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Riluzole, a benzothiazole derivative, has been shown to be effective in prolonging survival in amyotrophic lateral sclerosis. The mechanisms by which riluzole exerts neuroprotective effects in amyotrophic lateral sclerosis remains to be fully elucidated, although inhibition of glutamatergic transmission and modulation of Na+ channel function have been proposed. In an attempt to determine the mechanisms by which riluzole exerts neuroprotective effects, in particular to dissect the relative contributions of inhibition of glutamatergic transmission and Na+ channel modulation, the present study utilized a combination of cortical and peripheral axonal excitability approaches to monitor changes in excitability and function in patients with amyotrophic lateral sclerosis. Cortical assessment was undertaken by utilising the threshold tracking transcranial magnetic stimulation (TMS) technique and combined with peripheral axonal excitability studies in 25 patients with amyotrophic lateral sclerosis. Studies were performed at baseline and repeated when patients were receiving riluzole 100 mg/day. At the time of second testing all patients were tolerating the medication well. Motor evoked potential and compound muscle action potential responses were recorded over the abductor pollicis brevis muscle. At baseline, features of cortical hyperexcitability were evident in patients with amyotrophic lateral sclerosis, indicated by marked reduction in short interval intracortical inhibition (P < 0.001) and cortical silent period duration (P < 0.001), as well as an increase in the motor evoked potential amplitude (P < 0.01). Riluzole therapy partially normalized cortical excitability by significantly increasing short interval intracortical inhibition (short interval intracortical inhibitionbaseline 0.5 ± 1.8%; short interval intracortical inhibitionON riluzole 7.9 ± 1.7%, P < 0.01). In contrast, riluzole did not exert any modulating effect on cortical silent period duration (P = 0.45) or motor evoked potential amplitude (P = 0.31). In terms of peripheral nerve function, axonal excitability studies established that, relative to control subjects, patients with amyotrophic lateral sclerosis had significant increases in depolarizing threshold electrotonus [amyotrophic lateral sclerosisbaseline TEd (90-100 ms) 49.1 ± 1.8%; controlsTEd (90-100 ms) 45.2 ± 0.6%, P < 0.01] and superexcitability (amyotrophic lateral sclerosisbaseline 30.1 ± 2.3%; control subjects 23.4 ± 1.0%, P < 0.01) at baseline. Following institution of riluzole therapy there was a significant reduction in superexcitability (amyotrophic lateral sclerosisbaseline 30.1 ± 2.3%; amyotrophic lateral sclerosisON riluzole 27.3 ± 2.3%, P < 0.05) and refractoriness at 2 ms (amyotrophic lateral sclerosisbaseline 98.7 ± 10.7%; amyotrophic lateral sclerosisON riluzole 67.8 ± 9.3%, P < 0.001). In conclusion, the present study has established that riluzole exerts effects on both central and peripheral nerve function, interpreted as partial normalization of cortical hyperexcitability and reduction of transient Na+ conductances. Taken together, these findings suggest that the neuroprotective effects of riluzole in amyotrophic lateral sclerosis are complex, with evidence of independent effects across both compartments of the nervous system.
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Affiliation(s)
- Steve Vucic
- Neuroscience Research Australia, Barker Street, Randwick, Sydney, NSW 2031, Australia
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Gladman M, Cudkowicz M, Zinman L. Enhancing clinical trials in neurodegenerative disorders: lessons from amyotrophic lateral sclerosis. Curr Opin Neurol 2013; 25:735-42. [PMID: 23160423 DOI: 10.1097/wco.0b013e32835a309d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW This review article is focused on strategies that may enhance clinical trial efficiency in neurodegenerative disorders, as demonstrated within the research field of amyotrophic lateral sclerosis (ALS). RECENT FINDINGS Unravelling ALS pathophysiology will result in an increased number of candidate therapeutics. Recent ALS clinical trials have employed novel study designs that expedite the drug development process and limit sample size, including futility, lead-in, selection, adaptive and sequential designs. The search for sensitive and specific biomarkers in ALS continues to develop, and they are essential in accelerating the drug discovery process. Several candidate cerebrospinal fluid (CSF), neuroimaging and electrophysiological biomarkers have been recently described in ALS, and some have been successfully employed as secondary outcome measures in clinical trials. The advent of web-based technologies has provided a complementary platform to expedite clinical trials, through electronic data capture, teleconferencing and online registries. In addition, the formation of ALS consortia has enhanced collaborative multicentre studies. SUMMARY ALS research studies have employed novel strategies to accelerate the efficiency and pace of drug discovery. The importance of adapting to novel measures that enhance study efficiency is not unique to ALS and can be applied to other neurodegenerative diseases in search of effective treatments.
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Affiliation(s)
- Matthew Gladman
- Department of Medicine, University of Toronto Medical School, Toronto, Ontario, Canada
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Turner MR, Hardiman O, Benatar M, Brooks BR, Chio A, de Carvalho M, Ince PG, Lin C, Miller RG, Mitsumoto H, Nicholson G, Ravits J, Shaw PJ, Swash M, Talbot K, Traynor BJ, Van den Berg LH, Veldink JH, Vucic S, Kiernan MC. Controversies and priorities in amyotrophic lateral sclerosis. Lancet Neurol 2013; 12:310-22. [PMID: 23415570 DOI: 10.1016/s1474-4422(13)70036-x] [Citation(s) in RCA: 383] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Two decades after the discovery that 20% of familial amyotrophic lateral sclerosis (ALS) cases were linked to mutations in the superoxide dismutase-1 (SOD1) gene, a substantial proportion of the remainder of cases of familial ALS have now been traced to an expansion of the intronic hexanucleotide repeat sequence in C9orf72. This breakthrough provides an opportunity to re-evaluate longstanding concepts regarding the cause and natural history of ALS, coming soon after the pathological unification of ALS with frontotemporal dementia through a shared pathological signature of cytoplasmic inclusions of the ubiquitinated protein TDP-43. However, with profound clinical, prognostic, neuropathological, and now genetic heterogeneity, the concept of ALS as one disease appears increasingly untenable. This background calls for the development of a more sophisticated taxonomy, and an appreciation of ALS as the breakdown of a wider network rather than a discrete vulnerable population of specialised motor neurons. Identification of C9orf72 repeat expansions in patients without a family history of ALS challenges the traditional division between familial and sporadic disease. By contrast, the 90% of apparently sporadic cases and incomplete penetrance of several genes linked to familial cases suggest that at least some forms of ALS arise from the interplay of multiple genes, poorly understood developmental, environmental, and age-related factors, as well as stochastic events.
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Affiliation(s)
- Martin R Turner
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Garway-Heath DF, Lascaratos G, Bunce C, Crabb DP, Russell RA, Shah A. The United Kingdom Glaucoma Treatment Study: a multicenter, randomized, placebo-controlled clinical trial: design and methodology. Ophthalmology 2012; 120:68-76. [PMID: 22986112 DOI: 10.1016/j.ophtha.2012.07.028] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 07/08/2012] [Accepted: 07/10/2012] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Elevated intraocular pressure (IOP) is a major risk factor for the deterioration of open-angle glaucoma (OAG); medical IOP reduction is the standard treatment, yet no randomized placebo-controlled study of medical IOP reduction has been undertaken previously. The United Kingdom Glaucoma Treatment Study (UKGTS) tests the hypothesis that treatment with a topical prostaglandin analog, compared with placebo, reduces the frequency of visual field (VF) deterioration events in OAG patients by 50% over a 2-year period. DESIGN The UKGTS is a randomized, double-masked, placebo-controlled, multicenter treatment trial for OAG. PARTICIPANTS Five hundred sixteen newly diagnosed (previously untreated) patients with OAG were recruited prospectively at 10 centers between 2007 and 2010. METHODS Patients were assigned by concealed telephone allocation to treatment with a prostaglandin analog (latanoprost 0.005%) or placebo. The observation period was 2 years, with subjects monitored by VF testing, quantitative imaging, optic disc photography, and tonometry at 11 visits. Data were acquired according to novel protocols optimized for the analysis of deterioration velocity. The sample size was determined for a 2-sided error of α=0.05 to detect the difference between 24% and 11% in incident deterioration over a 24-month follow-up at 90% power and assuming a 25% attrition rate. MAIN OUTCOME MEASURES The primary outcome was time to VF deterioration within 24 months. Secondary outcomes included the deterioration velocity of VF and quantitative imaging measures and the relationship between these velocities and risk factors for deterioration. RESULTS The study design enabled a short trial with a 2-year observation period and provided data that can be used to assess the feasibility of further shortening trial duration with the progression velocity of VF and structural imaging measurements as outcomes. CONCLUSIONS The UKGTS is the first randomized, placebo-controlled trial to evaluate the efficacy of medical treatment in reducing VF deterioration in OAG. The measurement of deterioration velocity and inclusion of quantitative imaging has the potential to reduce the number of patients and duration required for subsequent clinical trials. This trial also will quantify risk factors for deterioration, enabling more precise risk profiling of patients and the development of patient management protocols. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
- David F Garway-Heath
- National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom.
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Moore DH, Katz JS, Miller RG. A review of clinical trial designs in amyotrophic lateral sclerosis. Neurodegener Dis Manag 2011. [DOI: 10.2217/nmt.11.70] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SUMMARY Amyotrophic lateral sclerosis is a serious disease characterized by a rapid decline in the ability to carry out daily activities, which leads to death within 2–5 years of diagnosis. Numerous agents for slowing disease progression have been tested but only one (riluzole) has proven to be moderately successful. Here we review clinical trial designs with a focus on novel Phase II designs developed since 2005, that attempt to speed up the process of testing new agents. The review is organized by four features that are critical in defining a clinical trial: the comparison group, the end point, the method of analysis and the type of trial. We note continuing trends over the past 5 years toward more efficient designs with shorter duration trials, increased interest in biomarkers and use of well-characterized historical controls.
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