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Calma AD, van den Bos M, Pavey N, Santos Silva C, Menon P, Vucic S. Physiological Biomarkers of Upper Motor Neuron Dysfunction in ALS. Brain Sci 2024; 14:760. [PMID: 39199454 PMCID: PMC11352893 DOI: 10.3390/brainsci14080760] [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: 06/03/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 09/01/2024] Open
Abstract
Upper motor neuron (UMN) dysfunction is an important feature of amyotrophic lateral sclerosis (ALS) for the diagnosis and understanding of pathogenesis. The identification of UMN signs forms the basis of ALS diagnosis, although may be difficult to discern, especially in the setting of severe muscle weakness. Transcranial magnetic stimulation (TMS) techniques have yielded objective physiological biomarkers of UMN dysfunction in ALS, enabling the interrogation of cortical and subcortical neuronal networks with diagnostic, pathophysiological, and prognostic implications. Transcranial magnetic stimulation techniques have provided pertinent pathogenic insights and yielded novel diagnostic and prognostic biomarkers. Cortical hyperexcitability, as heralded by a reduction in short interval intracortical inhibition (SICI) and an increase in short interval intracortical facilitation (SICF), has been associated with lower motor neuron degeneration, patterns of disease evolution, as well as the development of specific ALS clinical features including the split hand phenomenon. Reduction in SICI has also emerged as a potential diagnostic aid in ALS. More recently, physiological distinct inhibitory and facilitatory cortical interneuronal circuits have been identified, which have been shown to contribute to ALS pathogenesis. The triple stimulation technique (TST) was shown to enhance the diagnostic utility of conventional TMS measures in detecting UMN dysfunction. Resting-state EEG is a novel neurophysiological technique developed for directly interrogating cortical neuronal networks in ALS, that have yielded potentially useful physiological biomarkers of UMN dysfunction. The present review discusses physiological biomarkers of UMN dysfunction in ALS, encompassing conventional and novel TMS techniques developed to interrogate the functional integrity of the corticomotoneuronal system, focusing on pathogenic, diagnostic, and prognostic utility.
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Affiliation(s)
- Aicee Dawn Calma
- Brain and Nerve Research Center, The University of Sydney, Sydney 2139, Australia (C.S.S.)
| | - Mehdi van den Bos
- Brain and Nerve Research Center, The University of Sydney, Sydney 2139, Australia (C.S.S.)
| | - Nathan Pavey
- Brain and Nerve Research Center, The University of Sydney, Sydney 2139, Australia (C.S.S.)
| | - Cláudia Santos Silva
- Brain and Nerve Research Center, The University of Sydney, Sydney 2139, Australia (C.S.S.)
- Department of Neurosciences and Mental Health, Unidade Local de Saúde de Santa Maria, 1649-028 Lisbon, Portugal
- Faculdade de Medicina-Instituto de Medicina Molecular, Centro de Estudos Egas Moniz, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Parvathi Menon
- Brain and Nerve Research Center, The University of Sydney, Sydney 2139, Australia (C.S.S.)
| | - Steve Vucic
- Brain and Nerve Research Center, The University of Sydney, Sydney 2139, Australia (C.S.S.)
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Salzinger A, Ramesh V, Das Sharma S, Chandran S, Thangaraj Selvaraj B. Neuronal Circuit Dysfunction in Amyotrophic Lateral Sclerosis. Cells 2024; 13:792. [PMID: 38786016 PMCID: PMC11120636 DOI: 10.3390/cells13100792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/27/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024] Open
Abstract
The primary neural circuit affected in Amyotrophic Lateral Sclerosis (ALS) patients is the corticospinal motor circuit, originating in upper motor neurons (UMNs) in the cerebral motor cortex which descend to synapse with the lower motor neurons (LMNs) in the spinal cord to ultimately innervate the skeletal muscle. Perturbation of these neural circuits and consequent loss of both UMNs and LMNs, leading to muscle wastage and impaired movement, is the key pathophysiology observed. Despite decades of research, we are still lacking in ALS disease-modifying treatments. In this review, we document the current research from patient studies, rodent models, and human stem cell models in understanding the mechanisms of corticomotor circuit dysfunction and its implication in ALS. We summarize the current knowledge about cortical UMN dysfunction and degeneration, altered excitability in LMNs, neuromuscular junction degeneration, and the non-cell autonomous role of glial cells in motor circuit dysfunction in relation to ALS. We further highlight the advances in human stem cell technology to model the complex neural circuitry and how these can aid in future studies to better understand the mechanisms of neural circuit dysfunction underpinning ALS.
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Affiliation(s)
- Andrea Salzinger
- UK Dementia Research Institute, University of Edinburgh, Edinburgh EH16 4SB, UK; (A.S.); (V.R.); (S.D.S.); (S.C.)
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Vidya Ramesh
- UK Dementia Research Institute, University of Edinburgh, Edinburgh EH16 4SB, UK; (A.S.); (V.R.); (S.D.S.); (S.C.)
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Shreya Das Sharma
- UK Dementia Research Institute, University of Edinburgh, Edinburgh EH16 4SB, UK; (A.S.); (V.R.); (S.D.S.); (S.C.)
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Siddharthan Chandran
- UK Dementia Research Institute, University of Edinburgh, Edinburgh EH16 4SB, UK; (A.S.); (V.R.); (S.D.S.); (S.C.)
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Anne Rowling Regenerative Neurology Clinic (ARRNC), University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Bhuvaneish Thangaraj Selvaraj
- UK Dementia Research Institute, University of Edinburgh, Edinburgh EH16 4SB, UK; (A.S.); (V.R.); (S.D.S.); (S.C.)
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
- Anne Rowling Regenerative Neurology Clinic (ARRNC), University of Edinburgh, Edinburgh EH16 4SB, UK
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Xie M, Pallegar PN, Parusel S, Nguyen AT, Wu LJ. Regulation of cortical hyperexcitability in amyotrophic lateral sclerosis: focusing on glial mechanisms. Mol Neurodegener 2023; 18:75. [PMID: 37858176 PMCID: PMC10585818 DOI: 10.1186/s13024-023-00665-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 10/05/2023] [Indexed: 10/21/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the loss of both upper and lower motor neurons, resulting in muscle weakness, atrophy, paralysis, and eventually death. Motor cortical hyperexcitability is a common phenomenon observed at the presymptomatic stage of ALS. Both cell-autonomous (the intrinsic properties of motor neurons) and non-cell-autonomous mechanisms (cells other than motor neurons) are believed to contribute to cortical hyperexcitability. Decoding the pathological relevance of these dynamic changes in motor neurons and glial cells has remained a major challenge. This review summarizes the evidence of cortical hyperexcitability from both clinical and preclinical research, as well as the underlying mechanisms. We discuss the potential role of glial cells, particularly microglia, in regulating abnormal neuronal activity during the disease progression. Identifying early changes such as neuronal hyperexcitability in the motor system may provide new insights for earlier diagnosis of ALS and reveal novel targets to halt the disease progression.
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Affiliation(s)
- Manling Xie
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Praveen N Pallegar
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Sebastian Parusel
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Aivi T Nguyen
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
- Department of Immunology, Mayo Clinic, Rochester, MN, USA.
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Milella G, Zoccolella S, Giugno A, Filardi M, Urso D, Nigro S, Tafuri B, Tamburrino L, Gnoni V, Logroscino G. The impact of upper and lower motor neuron burden on diagnostic certainty, and clinical course of spinal-onset amyotrophic lateral sclerosis: a cluster-based approach. J Neurol 2023; 270:4868-4875. [PMID: 37338613 DOI: 10.1007/s00415-023-11827-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/10/2023] [Accepted: 06/13/2023] [Indexed: 06/21/2023]
Abstract
BACKGROUND Upper motor neuron (UMN) and lower motor neuron (LMN) involvement represent the core clinical features of amyotrophic lateral sclerosis (ALS). Several studies divided patients into prevalent UMN and LMN impairment phenotypes to investigate the association between motor systems impairments and ALS clinical course. However, this distinction was somehow heterogeneous and significantly affected the comparability across studies. AIMS This study aimed to investigate whether patients spontaneously segregate based on the extent of UMN and LMN involvement without a-priori categorization and to identify potential clinical and prognostic features of different clusters. METHODS Eighty-eight consecutive spinal-onset ALS patients were referred to an ALS tertiary center between 2015 and 2022. UMN and LMN burden was assessed with the Penn Upper Motor Neuron scale (PUMNS) and the Devine score, respectively. PUMNS and LMN scores were normalized into 0-1 and analyzed using a two-step cluster analysis and the Euclidean distance measure. The Bayesian Information Criterion was used to determine the cluster number. Demographic and clinical variables were tested for differences among the clusters. RESULTS Three distinct clusters emerged at cluster analysis. Patients in "cluster-1" showed moderate UMN and severe LMN involvement, corresponding to the typical ALS phenotype. Patients in "cluster-2" showed mild LMN and severe UMN damage, corresponding to a predominant UMN phenotype, while "cluster-3" patients showed mild UMN and moderate LMN damage, corresponding to a predominant LMN phenotype. Patients in "cluster-1" and "cluster-2" showed a higher prevalence of definite ALS than those in "cluster-3" (61% and 46 vs 9%, p < 0.001). "Cluster-1" patients had a lower median ALSFRS-r score compared to both "cluster-2" and 3 patients (27 vs 40 and 35, < 0.001). "Cluster-1" (HR: 8.5; 95% CI 2.1-35.1 and p = 0.003) and 3 (HR: 3.2; 95% CI 1.1-9.1; p = 0.03) were associated with shorter survival than those in "cluster-2". CONCLUSIONS Spinal-onset ALS can be categorized into three groups according to LMN and UMN burden. The UMN burden is related to higher diagnostic certainty and broader disease spread, while LMN involvement is associated with higher disease severity and shorter survival.
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Affiliation(s)
- Giammarco Milella
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
| | - Stefano Zoccolella
- Neurology Unit, ASL Bari, San Paolo Hospital, Bari, Italy.
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy.
| | - Alessia Giugno
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Marco Filardi
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Daniele Urso
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Salvatore Nigro
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Benedetta Tafuri
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Ludovica Tamburrino
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Valentina Gnoni
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
| | - Giancarlo Logroscino
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
- Center for Neurodegenerative Diseases and the Aging Brain at Pia Fondazione "Card. G. Panico", University of Bari, Tricase (Lecce), Italy
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Toh C, Keslake A, Payne T, Onwuegbuzie A, Harding J, Baster K, Hoggard N, Shaw PJ, Wilkinson ID, Jenkins TM. Analysis of brain and spinal MRI measures in a common domain to investigate directional neurodegeneration in motor neuron disease. J Neurol 2023; 270:1682-1690. [PMID: 36509983 PMCID: PMC9971079 DOI: 10.1007/s00415-022-11520-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/26/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) of the brain and cervical spinal cord is often performed in diagnostic evaluation of suspected motor neuron disease/amyotrophic lateral sclerosis (MND/ALS). Analysis of MRI-derived tissue damage metrics in a common domain facilitates group-level inferences on pathophysiology. This approach was applied to address competing hypotheses of directionality of neurodegeneration, whether anterograde, cranio-caudal dying-forward from precentral gyrus or retrograde, dying-back. METHODS In this cross-sectional study, MRI was performed on 75 MND patients and 13 healthy controls. Precentral gyral thickness was estimated from volumetric T1-weighted images using FreeSurfer, corticospinal tract fractional anisotropy (FA) from diffusion tensor imaging using FSL, and cross-sectional cervical cord area between C1-C8 levels using Spinal Cord Toolbox. To analyse these multimodal data within a common domain, individual parameter estimates representing tissue damage at each corticospinal tract level were first converted to z-scores, referenced to healthy control norms. Mixed-effects linear regression models were then fitted to these z-scores, with gradients hypothesised to represent directionality of neurodegeneration. RESULTS At group-level, z-scores did not differ significantly between precentral gyral and intracranial corticospinal tract tissue damage estimates (regression coefficient - 0.24, [95% CI - 0.62, 0.14], p = 0.222), but step-changes were evident between intracranial corticospinal tract and C1 (1.14, [95% CI 0.74, 1.53], p < 0.001), and between C5 and C6 cord levels (0.98, [95% CI 0.58, 1.38], p < 0.001). DISCUSSION Analysis of brain and cervical spinal MRI data in a common domain enabled investigation of pathophysiological hypotheses in vivo. A cranio-caudal step-change in MND patients was observed, and requires further investigation in larger cohorts.
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Affiliation(s)
- C Toh
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - A Keslake
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - T Payne
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - A Onwuegbuzie
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - J Harding
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - K Baster
- School of Mathematics and Statistics, University of Sheffield, Sheffield, UK
| | - N Hoggard
- Academic Unit of Radiology, University of Sheffield, Sheffield, UK
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - P J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - I D Wilkinson
- Academic Unit of Radiology, University of Sheffield, Sheffield, UK
| | - T M Jenkins
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK.
- Royal Perth Hospital, Victoria Square, Perth, WA, 6000, Australia.
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Functional alterations in large-scale resting-state networks of amyotrophic lateral sclerosis: A multi-site study across Canada and the United States. PLoS One 2022; 17:e0269154. [PMID: 35709100 PMCID: PMC9202847 DOI: 10.1371/journal.pone.0269154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 05/16/2022] [Indexed: 11/19/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a multisystem neurodegenerative disorder characterized by progressive degeneration of upper motor neurons and lower motor neurons, and frontotemporal regions resulting in impaired bulbar, limb, and cognitive function. Magnetic resonance imaging studies have reported cortical and subcortical brain involvement in the pathophysiology of ALS. The present study investigates the functional integrity of resting-state networks (RSNs) and their importance in ALS. Intra- and inter-network resting-state functional connectivity (Rs-FC) was examined using an independent component analysis approach in a large multi-center cohort. A total of 235 subjects (120 ALS patients; 115 healthy controls (HC) were recruited across North America through the Canadian ALS Neuroimaging Consortium (CALSNIC). Intra-network and inter-network Rs-FC was evaluated by the FSL-MELODIC and FSLNets software packages. As compared to HC, ALS patients displayed higher intra-network Rs-FC in the sensorimotor, default mode, right and left fronto-parietal, and orbitofrontal RSNs, and in previously undescribed networks including auditory, dorsal attention, basal ganglia, medial temporal, ventral streams, and cerebellum which negatively correlated with disease severity. Furthermore, ALS patients displayed higher inter-network Rs-FC between the orbitofrontal and basal ganglia RSNs which negatively correlated with cognitive impairment. In summary, in ALS there is an increase in intra- and inter-network functional connectivity of RSNs underpinning both motor and cognitive impairment. Moreover, the large multi-center CALSNIC dataset permitted the exploration of RSNs in unprecedented detail, revealing previously undescribed network involvement in ALS.
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Kowal JB, Verga SA, Pandeya SR, Cochran RJ, Sabol JC, Rutkove SB, Coates JR. Electrical Impedance Myography in Dogs With Degenerative Myelopathy. Front Vet Sci 2022; 9:874277. [PMID: 35711791 PMCID: PMC9196121 DOI: 10.3389/fvets.2022.874277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
Canine degenerative myelopathy (DM) leads to disuse and neurogenic muscle atrophy. Currently there is a lack of non-invasive quantitative measures of muscle health in dogs with DM. Muscle pathology has been previously quantified in other disorders using the technique of electrical impedance myography (EIM) but it has not been reported for DM. The objective of this study was to compare EIM between DM-affected and similar aged healthy dogs as well as assess EIM changes over time in DM-affected dogs. Multifrequency EIM was performed on DM affected dogs at baseline and during disease progression and on age-matched healthy dogs. Muscles evaluated in the pelvic limbs included the craniotibialis, gastrocnemius, gracilis, sartorius, and biceps femoris. The 100 kHz phase angle was extracted from the full frequency set for analysis. Phase values were lower in DM dogs as compared to healthy controls. Specifically, phase of the gastrocnemius was lower on the left (θ = 7.69, 13.06; p =0.002) and right (θ= 6.11, 11.72; p = 0.001) in DM vs. control dogs, respectively. The mean phase value of all measured muscles was also lower on the left (θ = 9.24, 11.62; p = 0.012) and right (θ = 9.18, 11.72; p = 0.021). Other individual muscles measured did not reach statistical significance, although values were consistently lower in DM-affected dogs. With disease progression, downward trends in phase values were detected in DM-affected dogs when monitored serially over time. This study demonstrates that EIM 100 kHz phase values are sensitive to muscle pathology in DM and that phase values are decreased in dogs with DM. Measurements from the gastrocnemius muscle show the greatest differences from similar aged healthy dogs suggesting it may be the preferred muscle for future EIM studies.
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Affiliation(s)
- Joseph B. Kowal
- Department of Veterinary Medicine and Surgery, University of Missouri, College of Veterinary Medicine, Columbia, MO, United States
- *Correspondence: Joseph B. Kowal
| | - Sarah A. Verga
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Sarbesh R. Pandeya
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Randall J. Cochran
- Department of Veterinary Medicine and Surgery, University of Missouri, College of Veterinary Medicine, Columbia, MO, United States
| | - Julianna C. Sabol
- Department of Veterinary Medicine and Surgery, University of Missouri, College of Veterinary Medicine, Columbia, MO, United States
| | - Seward B. Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Joan R. Coates
- Department of Veterinary Medicine and Surgery, University of Missouri, College of Veterinary Medicine, Columbia, MO, United States
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Cortical Hyperexcitability in the Driver’s Seat in ALS. CLINICAL AND TRANSLATIONAL NEUROSCIENCE 2022. [DOI: 10.3390/ctn6010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by the degeneration of cortical and spinal motor neurons. With no effective treatment available to date, patients face progressive paralysis and eventually succumb to the disease due to respiratory failure within only a few years. Recent research has revealed the multifaceted nature of the mechanisms and cell types involved in motor neuron degeneration, thereby opening up new therapeutic avenues. Intriguingly, two key features present in both ALS patients and rodent models of the disease are cortical hyperexcitability and hyperconnectivity, the mechanisms of which are still not fully understood. We here recapitulate current findings arguing for cell autonomous and non-cell autonomous mechanisms causing cortical excitation and inhibition imbalance, which is involved in the degeneration of motor neurons in ALS. Moreover, we will highlight recent evidence that strongly indicates a cardinal role for the motor cortex as a main driver and source of the disease, thus arguing for a corticofugal trajectory of the pathology.
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Zakharova MN, Abramova AA. Lower and upper motor neuron involvement and their impact on disease prognosis in amyotrophic lateral sclerosis. Neural Regen Res 2022; 17:65-73. [PMID: 34100429 PMCID: PMC8451581 DOI: 10.4103/1673-5374.314289] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by progressive muscle wasting, breathing and swallowing difficulties resulting in patient’s death in two to five years after disease onset. In amyotrophic lateral sclerosis, both upper and lower motor neurons of the corticospinal tracts are involved in the process of neurodegeneration, accounting for great clinical heterogeneity of the disease. Clinical phenotype has great impact on the pattern and rate of amyotrophic lateral sclerosis progression and overall survival prognosis. Creating more homogenous patient groups in order to study the effects of drug agents on specific manifestations of the disease is a challenging issue in amyotrophic lateral sclerosis clinical trials. Since amyotrophic lateral sclerosis has low incidence rates, conduction of multicenter trials requires certain standardized approaches to disease diagnosis and staging. This review focuses on the current approaches in amyotrophic lateral sclerosis classification and staging system based on clinical examination and additional instrumental methods, highlighting the role of upper and lower motor neuron involvement in different phenotypes of the disease. We demonstrate that both clinical and instrumental findings can be useful in evaluating severity of upper motor neuron and lower motor neuron involvement and predicting the following course of the disease. Addressing disease heterogeneity in amyotrophic lateral sclerosis clinical trials could lead to study designs that will assess drug efficacy in specific patient groups, based on the disease pathophysiology and spatiotemporal pattern. Although clinical evaluation can be a sufficient screening method for dividing amyotrophic lateral sclerosis patients into clinical subgroups, we provide proof that instrumental studies could provide valuable insights in the disease pathology.
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Di Lazzaro V, Bella R, Benussi A, Bologna M, Borroni B, Capone F, Chen KHS, Chen R, Chistyakov AV, Classen J, Kiernan MC, Koch G, Lanza G, Lefaucheur JP, Matsumoto H, Nguyen JP, Orth M, Pascual-Leone A, Rektorova I, Simko P, Taylor JP, Tremblay S, Ugawa Y, Dubbioso R, Ranieri F. Diagnostic contribution and therapeutic perspectives of transcranial magnetic stimulation in dementia. Clin Neurophysiol 2021; 132:2568-2607. [PMID: 34482205 DOI: 10.1016/j.clinph.2021.05.035] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 04/22/2021] [Accepted: 05/28/2021] [Indexed: 02/07/2023]
Abstract
Transcranial magnetic stimulation (TMS) is a powerful tool to probe in vivo brain circuits, as it allows to assess several cortical properties such asexcitability, plasticity and connectivity in humans. In the last 20 years, TMS has been applied to patients with dementia, enabling the identification of potential markers of thepathophysiology and predictors of cognitive decline; moreover, applied repetitively, TMS holds promise as a potential therapeutic intervention. The objective of this paper is to present a comprehensive review of studies that have employed TMS in dementia and to discuss potential clinical applications, from the diagnosis to the treatment. To provide a technical and theoretical framework, we first present an overview of the basic physiological mechanisms of the application of TMS to assess cortical excitability, excitation and inhibition balance, mechanisms of plasticity and cortico-cortical connectivity in the human brain. We then review the insights gained by TMS techniques into the pathophysiology and predictors of progression and response to treatment in dementias, including Alzheimer's disease (AD)-related dementias and secondary dementias. We show that while a single TMS measure offers low specificity, the use of a panel of measures and/or neurophysiological index can support the clinical diagnosis and predict progression. In the last part of the article, we discuss the therapeutic uses of TMS. So far, only repetitive TMS (rTMS) over the left dorsolateral prefrontal cortex and multisite rTMS associated with cognitive training have been shown to be, respectively, possibly (Level C of evidence) and probably (Level B of evidence) effective to improve cognition, apathy, memory, and language in AD patients, especially at a mild/early stage of the disease. The clinical use of this type of treatment warrants the combination of brain imaging techniques and/or electrophysiological tools to elucidate neurobiological effects of neurostimulation and to optimally tailor rTMS treatment protocols in individual patients or specific patient subgroups with dementia or mild cognitive impairment.
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Affiliation(s)
- Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy.
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, Section of Neurosciences, University of Catania, Catania, Italy
| | - Alberto Benussi
- Centre for Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli, IS, Italy
| | - Barbara Borroni
- Centre for Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Fioravante Capone
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Kai-Hsiang S Chen
- Department of Neurology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Robert Chen
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Canada; Division of Brain, Imaging& Behaviour, Krembil Brain Institute, Toronto, Canada
| | | | - Joseph Classen
- Department of Neurology, University Hospital Leipzig, Leipzig University Medical Center, Germany
| | - Matthew C Kiernan
- Department of Neurology, Royal Prince Alfred Hospital, Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Giacomo Koch
- Non Invasive Brain Stimulation Unit/Department of Behavioral and Clinical Neurology, Santa Lucia Foundation IRCCS, Rome, Italy; Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy; Department of Neurology IC, Oasi Research Institute-IRCCS, Troina, Italy
| | - Jean-Pascal Lefaucheur
- ENT Team, EA4391, Faculty of Medicine, Paris Est Créteil University, Créteil, France; Clinical Neurophysiology Unit, Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France
| | | | - Jean-Paul Nguyen
- Pain Center, clinique Bretéché, groupe ELSAN, Multidisciplinary Pain, Palliative and Supportive care Center, UIC 22/CAT2 and Laboratoire de Thérapeutique (EA3826), University Hospital, Nantes, France
| | - Michael Orth
- University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland; Swiss Huntington's Disease Centre, Siloah, Bern, Switzerland
| | - Alvaro Pascual-Leone
- Hinda and Arthur Marcus Institute for Aging Research, Center for Memory Health, Hebrew SeniorLife, USA; Department of Neurology, Harvard Medical School, Boston, MA, USA; Guttmann Brain Health Institute, Universitat Autonoma Barcelona, Spain
| | - Irena Rektorova
- Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University (CEITEC MU), Brno, Czech Republic; Department of Neurology, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Patrik Simko
- Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University (CEITEC MU), Brno, Czech Republic; Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - John-Paul Taylor
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Sara Tremblay
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, ON, Canada; Royal Ottawa Institute of Mental Health Research, Ottawa, ON, Canada
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Naples, Italy
| | - Federico Ranieri
- Unit of Neurology, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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11
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Ferrea S, Junker F, Korth M, Gruhn K, Grehl T, Schmidt-Wilcke T. Cortical Thinning of Motor and Non-Motor Brain Regions Enables Diagnosis of Amyotrophic Lateral Sclerosis and Supports Distinction between Upper- and Lower-Motoneuron Phenotypes. Biomedicines 2021; 9:biomedicines9091195. [PMID: 34572380 PMCID: PMC8468309 DOI: 10.3390/biomedicines9091195] [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: 08/01/2021] [Revised: 08/29/2021] [Accepted: 09/06/2021] [Indexed: 12/01/2022] Open
Abstract
Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder clinically characterized by muscle atrophy and progressive paralysis. In addition to the classical ALS affecting both the upper and lower motoneurons (UMN and LMN), other subtypes with the predominant (or even exclusive) affection of the UMN or LMN have been identified. This work sought to detect specific patterns of cortical brain atrophy in the UMN and LMN phenotypes to distinguish these two forms from the healthy state. Methods: Using high-resolution structural MRI and cortical thickness analysis, 38 patients with a diagnosis of ALS and predominance of either the UMN (n = 20) or the LMN (n = 18) phenotype were investigated. Results: Significant cortical thinning in the temporal lobe was found in both the ALS groups. Additionally, UMN patients displayed a significant thinning of the cortical thickness in the pre- and postcentral gyrus, as well as the paracentral lobule. By applying multivariate analyses based on the cortical thicknesses of 34 brain regions, ALS patients with either a predominant UMN or LMN phenotype were distinguished from healthy controls with an accuracy of 94% and UMN from LMN patients with an accuracy of 75%. Conclusions: These findings support previous hypothesis that neural degeneration in ALS is not confined to the sole motor regions. In addition, the amount of cortical thinning in the temporal lobe helps to distinguish ALS patients from healthy controls, that is, to support or discourage the diagnosis of ALS, while the cortical thickness of the precentral gyrus specifically helps to distinguish the UMN from the LMN phenotype.
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Affiliation(s)
- Stefano Ferrea
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University Dusseldorf, 40225 Dusseldorf, Germany; (F.J.); (T.S.-W.)
- Correspondence:
| | - Frederick Junker
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University Dusseldorf, 40225 Dusseldorf, Germany; (F.J.); (T.S.-W.)
| | - Mira Korth
- Evangelisches Krankenhaus Hattingen, 45525 Hattingen, Germany;
| | - Kai Gruhn
- Neuro Center Mettmann, 40822 Mettmann, Germany;
| | - Torsten Grehl
- ALS Outpatient Clinic, Alfried Krupp Krankenhaus Rüttenscheid, 45131 Essen, Germany;
| | - Tobias Schmidt-Wilcke
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University Dusseldorf, 40225 Dusseldorf, Germany; (F.J.); (T.S.-W.)
- Neurologisches Zentrum, Bezirksklinikum Mainkofen, 94469 Deggendorf, Germany
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12
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Lewis MJ, Shomper JL, Williamson BG, Vansteenkiste DP, Bibi KF, Lim SHY, Kowal JB, Coates JR. Brain diffusion tensor imaging in dogs with degenerative myelopathy. J Vet Intern Med 2021; 35:2342-2349. [PMID: 34410026 PMCID: PMC8478048 DOI: 10.1111/jvim.16248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Degenerative myelopathy (DM) in dogs shares similarities with superoxide dismutase 1-associated human amyotrophic lateral sclerosis (ALS). Brain microstructural lesions are quantified using diffusion tensor imaging (DTI) in ALS patients. OBJECTIVE Characterize brain neurodegenerative changes in DM-affected dogs using DTI. ANIMALS Sixteen DM-affected and 8 control dogs. METHODS Prospective observational study. Brain DTI was performed at baseline and every 3 months on DM-affected dogs and compared to controls. Fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated on specified regions of interest. Gait scores (0, normal to 14, tetraplegia) were assigned at each scan. Diffusion tensor imaging values in DM-affected dogs were compared to controls, gait scores, and evaluated over time. RESULTS Mean age was 5.7 years (SD 3.2) in controls and 9.7 years (SD 1.4) in DM-affected dogs. In DM-affected dogs, mean baseline gait score was 4 (SD 1), and mean score change from baseline to last scan was 4.82 (SD 2.67). Nine dogs had ≤3 scans; 7 had >3 scans. Accounting for age, no differences in DTI indices were identified for any brain or proximal spinal cord regions between DM-affected dogs and controls (P > .05). Diffusion tensor imaging values poorly correlated with gait scores (R2 < .2). No significant changes were identified in diffusion indices over time (P > .05). CONCLUSIONS AND CLINICAL IMPORTANCE Diffusion tensor imaging indices did not differentiate DM-affected from control dogs, detect longitudinal changes, or differentiate disease severity. Findings do not yet support brain DTI as an imaging biomarker.
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Affiliation(s)
- Melissa J. Lewis
- Department of Veterinary Clinical SciencesCollege of Veterinary Medicine, Purdue UniversityWest LafayetteINUSA
| | - Jeremy L. Shomper
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
| | - Baye G. Williamson
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
| | - Daniella P. Vansteenkiste
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
| | - Katherine F. Bibi
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
| | - Stefanie H. Y. Lim
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
| | - Joseph B. Kowal
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
| | - Joan R. Coates
- Department of Veterinary Medicine and SurgeryUniversity of Missouri, College of Veterinary MedicineColumbiaMOUSA
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13
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Dyer MS, Reale LA, Lewis KE, Walker AK, Dickson TC, Woodhouse A, Blizzard CA. Mislocalisation of TDP-43 to the cytoplasm causes cortical hyperexcitability and reduced excitatory neurotransmission in the motor cortex. J Neurochem 2020; 157:1300-1315. [PMID: 33064315 DOI: 10.1111/jnc.15214] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/04/2020] [Accepted: 10/06/2020] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a chronic neurodegenerative disease pathologically characterised by mislocalisation of the RNA-binding protein TAR-DNA-binding protein 43 (TDP-43) from the nucleus to the cytoplasm. Changes to neuronal excitability and synapse dysfunction in the motor cortex are early pathological changes occurring in people with ALS and mouse models of disease. To investigate the effect of mislocalised TDP-43 on the function of motor cortex neurons we utilised mouse models that express either human wild-type (TDP-43WT ) or nuclear localisation sequence-deficient TDP-43 (TDP-43ΔNLS ) on an inducible promoter that enriches expression to forebrain neurons. Pathophysiology was investigated through immunohistochemistry and whole-cell patch-clamp electrophysiology. Thirty days expression of TDP-43ΔNLS in adult mice did not cause any changes in the number of CTIP2-positive neurons in the motor cortex. However, at this time-point, the expression of TDP-43ΔNLS drives intrinsic hyperexcitability in layer V excitatory neurons of the motor cortex. This hyperexcitability occurs concomitantly with a decrease in excitatory synaptic input to these cells and fluctuations in both directions of ionotropic glutamate receptors. This pathophysiology is not present with TDP-43WT expression, demonstrating that the localisation of TDP-43 to the cytoplasm is crucial for the altered excitability phenotype. This study has important implications for the mechanisms of toxicity of one of the most notorious proteins linked to ALS, TDP-43. We provide the first evidence that TDP-43 mislocalisation causes aberrant synaptic function and a hyperexcitability phenotype in the motor cortex, linking some of the earliest dysfunctions to arise in people with ALS to mislocalisation of TDP-43.
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Affiliation(s)
- Marcus S Dyer
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Laura A Reale
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Katherine E Lewis
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Adam K Walker
- Neurodegeneration Pathobiology Laboratory, Queensland Brain Institute, University of Queensland, Brisbane, Qld, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Adele Woodhouse
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
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14
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Rawji V, Latorre A, Sharma N, Rothwell JC, Rocchi L. On the Use of TMS to Investigate the Pathophysiology of Neurodegenerative Diseases. Front Neurol 2020; 11:584664. [PMID: 33224098 PMCID: PMC7669623 DOI: 10.3389/fneur.2020.584664] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/05/2020] [Indexed: 12/22/2022] Open
Abstract
Neurodegenerative diseases are a collection of disorders that result in the progressive degeneration and death of neurons. They are clinically heterogenous and can present as deficits in movement, cognition, executive function, memory, visuospatial awareness and language. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation tool that allows for the assessment of cortical function in vivo. We review how TMS has been used for the investigation of three neurodegenerative diseases that differ in their neuroanatomical axes: (1) Motor cortex-corticospinal tract (motor neuron diseases), (2) Non-motor cortical areas (dementias), and (3) Subcortical structures (parkinsonisms). We also make four recommendations that we hope will benefit the use of TMS in neurodegenerative diseases. Firstly, TMS has traditionally been limited by the lack of an objective output and so has been confined to stimulation of the motor cortex; this limitation can be overcome by the use of concurrent neuroimaging methods such as EEG. Given that neurodegenerative diseases progress over time, TMS measures should aim to track longitudinal changes, especially when the aim of the study is to look at disease progression and symptomatology. The lack of gold-standard diagnostic confirmation undermines the validity of findings in clinical populations. Consequently, diagnostic certainty should be maximized through a variety of methods including multiple, independent clinical assessments, imaging and fluids biomarkers, and post-mortem pathological confirmation where possible. There is great interest in understanding the mechanisms by which symptoms arise in neurodegenerative disorders. However, TMS assessments in patients are usually carried out during resting conditions, when the brain network engaged during these symptoms is not expressed. Rather, a context-appropriate form of TMS would be more suitable in probing the physiology driving clinical symptoms. In all, we hope that the recommendations made here will help to further understand the pathophysiology of neurodegenerative diseases.
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Affiliation(s)
| | | | | | | | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
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15
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Häkkinen S, Chu SA, Lee SE. Neuroimaging in genetic frontotemporal dementia and amyotrophic lateral sclerosis. Neurobiol Dis 2020; 145:105063. [PMID: 32890771 DOI: 10.1016/j.nbd.2020.105063] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/30/2020] [Accepted: 08/26/2020] [Indexed: 02/06/2023] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) have a strong clinical, genetic and pathological overlap. This review focuses on the current understanding of structural, functional and molecular neuroimaging signatures of genetic FTD and ALS. We overview quantitative neuroimaging studies on the most common genes associated with FTD (MAPT, GRN), ALS (SOD1), and both (C9orf72), and summarize visual observations of images reported in the rarer genes (CHMP2B, TARDBP, FUS, OPTN, VCP, UBQLN2, SQSTM1, TREM2, CHCHD10, TBK1).
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Affiliation(s)
- Suvi Häkkinen
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Stephanie A Chu
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Suzee E Lee
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
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16
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Clark CM, Clark RM, Hoyle JA, Dickson TC. Pathogenic or protective? Neuropeptide Y in amyotrophic lateral sclerosis. J Neurochem 2020; 156:273-289. [PMID: 32654149 DOI: 10.1111/jnc.15125] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/16/2020] [Accepted: 06/24/2020] [Indexed: 12/13/2022]
Abstract
Neuropeptide Y (NPY) is an endogenous peptide of the central and enteric nervous systems which has gained significant interest as a potential neuroprotective agent for treatment of neurodegenerative disease. Amyotrophic lateral sclerosis (ALS) is an aggressive and fatal neurodegenerative disease characterized by motor deficits and motor neuron loss. In ALS, recent evidence from ALS patients and animal models has indicated that NPY may have a role in the disease pathogenesis. Increased NPY levels were found to correlate with disease progression in ALS patients. Similarly, NPY expression is increased in the motor cortex of ALS mice by end stages of the disease. Although the functional consequence of increased NPY levels in ALS is currently unknown, NPY has been shown to exert a diverse range of neuroprotective roles in other neurodegenerative diseases; through modulation of potassium channel activity, increased production of neurotrophins, inhibition of endoplasmic reticulum stress and autophagy, reduction of excitotoxicity, oxidative stress, neuroinflammation and hyperexcitability. Several of these mechanisms and signalling pathways are heavily implicated in the pathogenesis of ALS. Therefore, in this review, we discuss possible effects of NPY and NPY-receptor signalling in the ALS disease context, as determining NPY's contribution to, or impact on, ALS disease mechanisms will be essential for future studies investigating the NPY system as a therapeutic strategy in this devastating disease.
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Affiliation(s)
- Courtney M Clark
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Rosemary M Clark
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Joshua A Hoyle
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
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17
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Cengiz B, Kuruoğlu R. A new parameter to discriminate amyotrophic lateral sclerosis patients from healthy participants by motor cortical excitability changes. Muscle Nerve 2020; 61:354-362. [PMID: 31875983 DOI: 10.1002/mus.26786] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/08/2019] [Accepted: 12/22/2019] [Indexed: 12/13/2022]
Abstract
INTRODUCTION We sought a combination of abnormalities to define a more sensitive measure of cortical excitability in amyotrophic lateral sclerosis (ALS). METHODS The automatic threshold tracking method was employed to assess the resting motor threshold, intracortical facilitation (ICF), short-interval intracortical inhibition (SICI), and short-interval intracortical faciilitation (SICF) in patients and controls. RESULTS SICF at interstimulus intervals (ISI) between 1 and 1.8 ms and 2 and 3 ms as well as average SICI and SICI at ISIs of 1 and 2.5 ms were significantly reduced in ALS. The SICI curve was altered, displaying a solitary peak. Discriminant analysis revealed that the combination of SICI 2.5 ms and the mean SICF between 1 and 1.8 ms ISIs was the most sensitive parameter to distinguish patients with ALS from healthy participants. DISCUSSION Along with the reduced SICI and its altered shape, connectivity between motor cortical circuits is changed in ALS. Combination with SICF increases the diagnostic utility of SICI in ALS.
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Affiliation(s)
- Bülent Cengiz
- Department of Neurology, Clinical Neurophysiology Division, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Reha Kuruoğlu
- Department of Neurology, Clinical Neurophysiology Division, Gazi University Faculty of Medicine, Ankara, Turkey
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18
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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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McMackin R, Muthuraman M, Groppa S, Babiloni C, Taylor JP, Kiernan MC, Nasseroleslami B, Hardiman O. Measuring network disruption in neurodegenerative diseases: New approaches using signal analysis. J Neurol Neurosurg Psychiatry 2019; 90:1011-1020. [PMID: 30760643 PMCID: PMC6820156 DOI: 10.1136/jnnp-2018-319581] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/21/2019] [Accepted: 01/21/2019] [Indexed: 12/12/2022]
Abstract
Advanced neuroimaging has increased understanding of the pathogenesis and spread of disease, and offered new therapeutic targets. MRI and positron emission tomography have shown that neurodegenerative diseases including Alzheimer's disease (AD), Lewy body dementia (LBD), Parkinson's disease (PD), frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) are associated with changes in brain networks. However, the underlying neurophysiological pathways driving pathological processes are poorly defined. The gap between what imaging can discern and underlying pathophysiology can now be addressed by advanced techniques that explore the cortical neural synchronisation, excitability and functional connectivity that underpin cognitive, motor, sensory and other functions. Transcranial magnetic stimulation can show changes in focal excitability in cortical and transcortical motor circuits, while electroencephalography and magnetoencephalography can now record cortical neural synchronisation and connectivity with good temporal and spatial resolution.Here we reflect on the most promising new approaches to measuring network disruption in AD, LBD, PD, FTD, MS, and ALS. We consider the most groundbreaking and clinically promising studies in this field. We outline the limitations of these techniques and how they can be tackled and discuss how these novel approaches can assist in clinical trials by predicting and monitoring progression of neurophysiological changes underpinning clinical symptomatology.
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Affiliation(s)
- Roisin McMackin
- Academic Unit of Neurology, Trinity College Dublin, the University of Dublin, Dublin, Ireland
| | - Muthuraman Muthuraman
- Department of Neurology, Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Sergiu Groppa
- Department of Neurology, Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Claudio Babiloni
- Dipartimento di Fisiologia e Farmacologia "Vittorio Erspamer", Università degli Studi di Roma "La Sapienza", Roma, Italy
- Istituto di Ricovero e Cura San Raffaele Cassino, Cassino, Italy
| | - John-Paul Taylor
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew C Kiernan
- Brain & Mind Centre, University of Sydney, Sydney, Sydney, Australia
- Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Sydney, Australia
| | - Bahman Nasseroleslami
- Academic Unit of Neurology, Trinity College Dublin, the University of Dublin, Dublin, Ireland
| | - Orla Hardiman
- Academic Unit of Neurology, Trinity College Dublin, the University of Dublin, Dublin, Ireland
- Beaumont Hospital, Dublin, Ireland
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20
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Welton T, Maller JJ, Lebel RM, Tan ET, Rowe DB, Grieve SM. Diffusion kurtosis and quantitative susceptibility mapping MRI are sensitive to structural abnormalities in amyotrophic lateral sclerosis. NEUROIMAGE-CLINICAL 2019; 24:101953. [PMID: 31357149 PMCID: PMC6664242 DOI: 10.1016/j.nicl.2019.101953] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 06/24/2019] [Accepted: 07/19/2019] [Indexed: 12/11/2022]
Abstract
Objective To construct a clinical diagnostic biomarker using state-of-the-art microstructural MRI in the motor cortex of people with amyotrophic lateral sclerosis (ALS). Methods Clinical and MRI data were obtained from 21 ALS patients (aged 54 ± 14 years, 33% female) and 63 age- and gender-matched controls (aged 48 ± 18 years, 43% female). MRI was acquired at 3T and included T1-weighted scan (for volumetrics), arterial spin labelling (for cerebral blood flow), susceptibility-weighted angiography (for iron deposition) and multiband diffusion kurtosis imaging (for tissue microstructure). Group differences in imaging measures in the motor cortex were tested by general linear model and relationships to clinical variables by linear regression. Results The ALS group had mild-to-moderate impairment (disease duration: 1.8 ± 0.8 years; ALS functional rating scale 40.2 ± 6.0; forced vital capacity 83% ± 22%). No age or gender differences were present between groups. We found significant group differences in diffusion kurtosis metrics (apparent, mean, radial and axial kurtosis: p < .01) and iron deposition in the motor cortex (p = .03). Within the ALS group, we found significant relationships between motor cortex volume, apparent diffusion and disease duration (adjusted R2 = 0.27, p = .011); and between the apparent and radial kurtosis metrics and ALS functional rating scale (adjusted R2 = 0.25, p = .033). A composite imaging biomarker comprising kurtosis and iron deposition measures yielded a maximal diagnostic accuracy of 83% (81% sensitivity, 85% specificity) and an area-under-the-curve of 0.86. Conclusion Diffusion kurtosis is sensitive to early changes present in the motor region in ALS. We propose a composite imaging biomarker reflecting tissue microstructural changes in early ALS that may provide clinically valuable diagnostic information. A biomarker based on diffusion kurtosis imaging achieved an accuracy of 83%. Kurtosis-based measures were more abnormal in ALS than tensor-based measures. Motor cortex in the symptomatic hemisphere was smaller and had greater iron concentration. There was a 1 mL volume loss per year in ALS motor cortex.
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Affiliation(s)
- Thomas Welton
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia.
| | - Jerome J Maller
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia; GE Healthcare, Richmond, Victoria, Australia.
| | | | - Ek T Tan
- GE Global Research, Niskayuna, NY, USA.
| | - Dominic B Rowe
- MND Research Centre, Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia; Macquarie University Hospital, Macquarie, Australia
| | - Stuart M Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia; Macquarie University Hospital, Macquarie, Australia; Department of Radiology, Royal Prince Alfred Hospital, Sydney, Australia.
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21
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Pathophysiology and Diagnosis of ALS: Insights from Advances in Neurophysiological Techniques. Int J Mol Sci 2019; 20:ijms20112818. [PMID: 31185581 PMCID: PMC6600525 DOI: 10.3390/ijms20112818] [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: 05/01/2019] [Revised: 05/27/2019] [Accepted: 06/06/2019] [Indexed: 12/28/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neurodegenerative disorder of the motor neurons, characterized by focal onset of muscle weakness and incessant disease progression. While the presence of concomitant upper and lower motor neuron signs has been recognized as a pathognomonic feature of ALS, the pathogenic importance of upper motor neuron dysfunction has only been recently described. Specifically, transcranial magnetic stimulation (TMS) techniques have established cortical hyperexcitability as an important pathogenic mechanism in ALS, correlating with neurodegeneration and disease spread. Separately, ALS exhibits a heterogeneous clinical phenotype that may lead to misdiagnosis, particularly in the early stages of the disease process. Cortical hyperexcitability was shown to be a robust diagnostic biomarker if ALS, reliably differentiating ALS from neuromuscular mimicking disorders. The present review will provide an overview of key advances in the understanding of ALS pathophysiology and diagnosis, focusing on the importance of cortical hyperexcitability and its relationship to advances in genetic and molecular processes implicated in ALS pathogenesis.
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Christidi F, Karavasilis E, Velonakis G, Rentzos M, Zambelis T, Zouvelou V, Xirou S, Ferentinos P, Efstathopoulos E, Kelekis N, Evdokimidis I, Karandreas N. Motor and extra-motor gray matter integrity may underlie neurophysiologic parameters of motor function in amyotrophic lateral sclerosis: a combined voxel-based morphometry and transcranial stimulation study. Brain Imaging Behav 2019; 12:1730-1741. [PMID: 29417490 DOI: 10.1007/s11682-018-9841-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The association between gray matter (GM) density and neurophysiologic changes is still unclear in amyotrophic lateral sclerosis (ALS). We evaluated the relationship between GM density and motor system integrity combining voxel-based morphometry (VBM) and transcranial magnetic stimulation (TMS) in ALS. We included 17 ALS patients and 22 healthy controls (HC) who underwent 3D-T1-weighted imaging. Among the ALS group, we applied left motor cortex single-pulse TMS. We used whole-brain VBM comparing ALS and HC in GM density. We also conducted regression analysis to examine correlations between GM density and the following TMS parameters: motor evoked potential (MEP)/M ratio and central motor conduction time (CMCT). We found significantly decreased GM density in ALS patients in several frontal, temporal, parietal/occipital and cerebellar regions (p < 0.001 uncorrected; cluster-extent threshold k = 100 voxels per cluster). With regards to TMS parameters, ALS patients showed mostly increased MEP/M ratio and modest prolongation of CMCT. MEP/M ratio was associated with GM density in (a) rolandic operculum/inferior frontal gyrus/precentral gyrus; anterior cingulate gyrus; inferior temporal gyrus; superior parietal lobule; cuneus; superior occipital gyrus and cerebellum (positive association) and (b) paracentral lobule/supplementary motor area (negative association). CMCT was associated with GM density in (a) inferior frontal gyrus and middle cingulated gyrus (positive association) and (b) superior parietal lobule; cuneus and cerebellum (negative association). Our findings support a significant interaction between motor and extra-motor structural and functional changes and highlight that motor and extra-motor GM integrity may underlie TMS parameters of motor function in ALS patients.
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Affiliation(s)
- Foteini Christidi
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece.
| | - Efstratios Karavasilis
- Radiology and Medical Imaging Research Unit, Second Department of Radiology, Medical School, National & Kapodistrian University of Athens, Athens, Greece
| | - Georgios Velonakis
- Radiology and Medical Imaging Research Unit, Second Department of Radiology, Medical School, National & Kapodistrian University of Athens, Athens, Greece
| | - Michail Rentzos
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece
| | - Thomas Zambelis
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece
| | - Vasiliki Zouvelou
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece
| | - Sophia Xirou
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece
| | - Panagiotis Ferentinos
- Second Department of Psychiatry, Attikon University Hospital, Medical School, National & Kapodistrian University of Athens, Athens, Greece
| | - Efstathios Efstathopoulos
- Radiology and Medical Imaging Research Unit, Second Department of Radiology, Medical School, National & Kapodistrian University of Athens, Athens, Greece
| | - Nikolaos Kelekis
- Radiology and Medical Imaging Research Unit, Second Department of Radiology, Medical School, National & Kapodistrian University of Athens, Athens, Greece
| | - Ioannis Evdokimidis
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece
| | - Nikolaos Karandreas
- First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece
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Cengiz B, Fidanci H, Kiyak Keçeli Y, Baltaci H, KuruoĞlu R. Impaired short‐ and long‐latency afferent inhibition in amyotrophic lateral sclerosis. Muscle Nerve 2019; 59:699-704. [DOI: 10.1002/mus.26464] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/03/2019] [Accepted: 03/05/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Bülent Cengiz
- Department of NeurologyGazi University Faculty of Medicine Beşevler, 06500, Ankara Turkey
- Clinical Neurophysiology Division of the Department of NeurologyGazi University Faculty of Medicine Ankara Turkey
| | - Halit Fidanci
- Clinical Neurophysiology Division of the Department of NeurologyGazi University Faculty of Medicine Ankara Turkey
| | - Yeliz Kiyak Keçeli
- Department of NeurologyGazi University Faculty of Medicine Beşevler, 06500, Ankara Turkey
| | - Hande Baltaci
- Department of NeurologyGazi University Faculty of Medicine Beşevler, 06500, Ankara Turkey
| | - Reha KuruoĞlu
- Department of NeurologyGazi University Faculty of Medicine Beşevler, 06500, Ankara Turkey
- Clinical Neurophysiology Division of the Department of NeurologyGazi University Faculty of Medicine Ankara Turkey
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McMackin R, Bede P, Pender N, Hardiman O, Nasseroleslami B. Neurophysiological markers of network dysfunction in neurodegenerative diseases. Neuroimage Clin 2019; 22:101706. [PMID: 30738372 PMCID: PMC6370863 DOI: 10.1016/j.nicl.2019.101706] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/28/2019] [Accepted: 01/31/2019] [Indexed: 12/11/2022]
Abstract
There is strong clinical, imaging and pathological evidence that neurodegeneration is associated with altered brain connectivity. While functional imaging (fMRI) can detect resting and activated states of metabolic activity, its use is limited by poor temporal resolution, cost and confounding vascular parameters. By contrast, electrophysiological (e.g. EEG/MEG) recordings provide direct measures of neural activity with excellent temporal resolution, and source localization methodologies can address problems of spatial resolution, permitting measurement of functional activity of brain networks with a spatial resolution similar to that of fMRI. This opens an exciting therapeutic approach focussed on pharmacological and physiological modulation of brain network activity. This review describes current neurophysiological approaches towards evaluating cortical network dysfunction in common neurodegenerative disorders. It explores how modern neurophysiologic tools can provide markers for diagnosis, prognosis, subcategorization and clinical trial outcome measures, and how modulation of brain networks can contribute to new therapeutic approaches.
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Affiliation(s)
- Roisin McMackin
- Academic Unit of Neurology, Trinity Biomedical Sciences Institute, 152-160 Pearse St., Trinity College Dublin, The University of Dublin, Ireland.
| | - Peter Bede
- Academic Unit of Neurology, Trinity Biomedical Sciences Institute, 152-160 Pearse St., Trinity College Dublin, The University of Dublin, Ireland; Computational Neuroimaging Group, Trinity Biomedical Sciences Institute, 152-160 Pearse St., Trinity College Dublin, The University of Dublin, Ireland.
| | - Niall Pender
- Academic Unit of Neurology, Trinity Biomedical Sciences Institute, 152-160 Pearse St., Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Psychology, Beaumont Road, Beaumont, Dublin 9, Ireland.
| | - Orla Hardiman
- Academic Unit of Neurology, Trinity Biomedical Sciences Institute, 152-160 Pearse St., Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Neurology, Beaumont Road, Beaumont, Dublin 9, Ireland.
| | - Bahman Nasseroleslami
- Academic Unit of Neurology, Trinity Biomedical Sciences Institute, 152-160 Pearse St., Trinity College Dublin, The University of Dublin, Ireland.
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25
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McMackin R, Dukic S, Broderick M, Iyer PM, Pinto-Grau M, Mohr K, Chipika R, Coffey A, Buxo T, Schuster C, Gavin B, Heverin M, Bede P, Pender N, Lalor EC, Muthuraman M, Hardiman O, Nasseroleslami B. Dysfunction of attention switching networks in amyotrophic lateral sclerosis. Neuroimage Clin 2019; 22:101707. [PMID: 30735860 PMCID: PMC6365983 DOI: 10.1016/j.nicl.2019.101707] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/28/2019] [Accepted: 01/31/2019] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To localise and characterise changes in cognitive networks in Amyotrophic Lateral Sclerosis (ALS) using source analysis of mismatch negativity (MMN) waveforms. RATIONALE The MMN waveform has an increased average delay in ALS. MMN has been attributed to change detection and involuntary attention switching. This therefore indicates pathological impairment of the neural network components which generate these functions. Source localisation can mitigate the poor spatial resolution of sensor-level EEG analysis by associating the sensor-level signals to the contributing brain sources. The functional activity in each generating source can therefore be individually measured and investigated as a quantitative biomarker of impairment in ALS or its sub-phenotypes. METHODS MMN responses from 128-channel electroencephalography (EEG) recordings in 58 ALS patients and 39 healthy controls were localised to source by three separate localisation methods, including beamforming, dipole fitting and exact low resolution brain electromagnetic tomography. RESULTS Compared with controls, ALS patients showed significant increase in power of the left posterior parietal, central and dorsolateral prefrontal cortices (false discovery rate = 0.1). This change correlated with impaired cognitive flexibility (rho = 0.45, 0.45, 0.47, p = .042, .055, .031 respectively). ALS patients also exhibited a decrease in the power of dipoles representing activity in the inferior frontal (left: p = 5.16 × 10-6, right: p = 1.07 × 10-5) and left superior temporal gyri (p = 9.30 × 10-6). These patterns were detected across three source localisation methods. Decrease in right inferior frontal gyrus activity was a good discriminator of ALS patients from controls (AUROC = 0.77) and an excellent discriminator of C9ORF72 expansion-positive patients from controls (AUROC = 0.95). INTERPRETATION Source localization of evoked potentials can reliably discriminate patterns of functional network impairment in ALS and ALS subgroups during involuntary attention switching. The discriminative ability of the detected cognitive changes in specific brain regions are comparable to those of functional magnetic resonance imaging (fMRI). Source analysis of high-density EEG patterns has excellent potential to provide non-invasive, data-driven quantitative biomarkers of network disruption that could be harnessed as novel neurophysiology-based outcome measures in clinical trials.
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Affiliation(s)
- Roisin McMackin
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland.
| | - Stefan Dukic
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland.
| | - Michael Broderick
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Trinity Centre for Bioengineering, Trinity College Dublin, The University of Dublin, Ireland.
| | - Parameswaran M Iyer
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Neurology, Dublin, Ireland.
| | - Marta Pinto-Grau
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Psychology, Dublin, Ireland.
| | - Kieran Mohr
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland.
| | - Rangariroyashe Chipika
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Computational Neuroimaging Group, Trinity College Dublin, The University of Dublin, Ireland..
| | - Amina Coffey
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Neurology, Dublin, Ireland.
| | - Teresa Buxo
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland.
| | - Christina Schuster
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Computational Neuroimaging Group, Trinity College Dublin, The University of Dublin, Ireland..
| | - Brighid Gavin
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland
| | - Mark Heverin
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland.
| | - Peter Bede
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Computational Neuroimaging Group, Trinity College Dublin, The University of Dublin, Ireland..
| | - Niall Pender
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Neurology, Dublin, Ireland
| | - Edmund C Lalor
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Trinity College Institute of Neuroscience, Trinity College Dublin, The University of Dublin, Ireland.; Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA..
| | - Muthuraman Muthuraman
- Movement Disorders and Neurostimulation, Biomedical Statistics and Multimodal Signal Processing Unit, Department of Neurology, Johannes-Gutenberg-University Hospital, Mainz, Germany.
| | - Orla Hardiman
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland; Beaumont Hospital Dublin, Department of Neurology, Dublin, Ireland; Computational Neuroimaging Group, Trinity College Dublin, The University of Dublin, Ireland..
| | - Bahman Nasseroleslami
- Academic Unit of Neurology, Trinity College Dublin, The University of Dublin, Ireland.
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26
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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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27
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Vucic S, van den Bos M, Menon P, Howells J, Dharmadasa T, Kiernan MC. Utility of threshold tracking transcranial magnetic stimulation in ALS. Clin Neurophysiol Pract 2018; 3:164-172. [PMID: 30560220 PMCID: PMC6275211 DOI: 10.1016/j.cnp.2018.10.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/17/2018] [Accepted: 10/29/2018] [Indexed: 12/21/2022] Open
Abstract
Upper motor neuron [UMN] and lower motor neuron [LMN] dysfunction, in the absence of sensory features, is a pathognomonic feature of amyotrophic lateral sclerosis [ALS]. Although the precise mechanisms have yet to be elucidated, one leading hypothesis is that UMN precede LMN dysfunction, which is induced by anterograde glutamatergic excitotoxicity. Transcranial magnetic stimulation (TMS) is a neurophysiological tool that provides a non-invasive and painless assessment of cortical function. Threshold tracking methodologies have been recently adopted for TMS, whereby changes in threshold rather than motor evoked potential (MEP) amplitude serve as outcome measures. This technique is reliable and provides a rapid assessment of cortical function in ALS. Utilisng the threshold tracking TMS technique, cortical hyperexcitability was demonstrated as an early feature in sporadic ALS preceding the onset of LMN dysfunction and possibly contributing to disease spread. Separately, cortical hyperexcitability was reported to precede the clinical onset of familial ALS. Of further relevance, the threshold tracking TMS technique was proven to reliably distinguish ALS from mimicking disorders, even in the presence of a comparable degree of LMN dysfunction, suggesting a diagnostic utility of TMS. Taken in total, threshold tracking TMS has provided support for a cortical involvement at the earliest detectable stages of ALS, underscoring the utility of the technique for probing the underlying pathophysiology. The present review will discuss the physiological processes underlying TMS parameters, while further evaluating the pathophysiological and diagnostic utility of threshold tracking TMS in ALS.
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Affiliation(s)
- Steve Vucic
- Western Clinical School, University of Sydney, Sydney, Australia
| | | | - Parvathi Menon
- Western Clinical School, University of Sydney, Sydney, Australia
| | - James Howells
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
| | - Thanuja Dharmadasa
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney and Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia
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Driven to decay: Excitability and synaptic abnormalities in amyotrophic lateral sclerosis. Brain Res Bull 2018; 140:318-333. [PMID: 29870780 DOI: 10.1016/j.brainresbull.2018.05.023] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/26/2018] [Accepted: 05/31/2018] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron (MN) disease and is clinically characterised by the death of corticospinal motor neurons (CSMNs), spinal and brainstem MNs and the degeneration of the corticospinal tract. Degeneration of CSMNs and MNs leads inexorably to muscle wastage and weakness, progressing to eventual death within 3-5 years of diagnosis. The CSMNs, located within layer V of the primary motor cortex, project axons constituting the corticospinal tract, forming synaptic connections with brainstem and spinal cord interneurons and MNs. Clinical ALS may be divided into familial (∼10% of cases) or sporadic (∼90% of cases), based on apparent random incidence. The emergence of transgenic murine models, expressing different ALS-associated mutations has accelerated our understanding of ALS pathogenesis, although precise mechanisms remain elusive. Multiple avenues of investigation suggest that cortical electrical abnormalities have pre-eminence in the pathophysiology of ALS. In addition, glutamate-mediated functional and structural alterations in both CSMNs and MNs are present in both sporadic and familial forms of ALS. This review aims to promulgate debate in the field with regard to the common aetiology of sporadic and familial ALS. A specific focus on a nexus point in ALS pathogenesis, namely, the synaptic and intrinsic hyperexcitability of CSMNs and MNs and alterations to their structure are comprehensively detailed. The association of extramotor dysfunction with neuronal structural/functional alterations will be discussed. Finally, the implications of the latest research on the dying-forward and dying-back controversy are considered.
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Dharmadasa T, Huynh W, Tsugawa J, Shimatani Y, Ma Y, Kiernan MC. Implications of structural and functional brain changes in amyotrophic lateral sclerosis. Expert Rev Neurother 2018; 18:407-419. [PMID: 29667443 DOI: 10.1080/14737175.2018.1464912] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that causes progressive muscle weakness and disability, eventually leading to death. Heterogeneity of disease has become a major barrier to understanding key clinical questions such as prognosis and disease spread, and has disadvantaged clinical trials in search of therapeutic intervention. Patterns of disease have been explored through recent advances in neuroimaging, elucidating structural, molecular and functional changes. Unique brain signatures have emerged that have lent a greater understanding of critical disease mechanisms, offering opportunities to improve diagnosis, guide prognosis, and establish candidate biomarkers to direct future therapeutic strategies. Areas covered: This review explores patterns of cortical and subcortical change in ALS through advanced neuroimaging techniques and discusses the implications of these findings. Expert commentary: Cortical and subcortical signatures and patterns of atrophy are now consistently recognised, providing important pathophysiological insight into this heterogenous disease. The spread of cortical change, particularly involving frontotemporal networks, correlates with cognitive impairment and poorer prognosis. Cortical differences are also evident between ALS phenotypes and genotypes, which may partly explain the heterogeneity of prognosis. Ultimately, multimodal approaches with larger cohorts will be needed to provide sensitive biomarkers of disease spread at the level of the individual patient.
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Affiliation(s)
| | - William Huynh
- a Brain and Mind Centre , The University of Sydney , Sydney , Australia
| | - Jun Tsugawa
- c Department of Neurology , Fukuoka University Hospital , Fukuoka city , Japan
| | - Yoshimitsu Shimatani
- d Department of Neurology , Tokushima Prefectural Hospital , Tokushima city , Japan
| | - Yan Ma
- a Brain and Mind Centre , The University of Sydney , Sydney , Australia
| | - Matthew C Kiernan
- a Brain and Mind Centre , The University of Sydney , Sydney , Australia.,b Department of Neurology , Royal Prince Alfred Hospital , Sydney , Australia
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Kim HJ, Oh SI, de Leon M, Wang X, Oh KW, Park JS, Deshpande A, Buj M, Kim SH. Structural explanation of poor prognosis of amyotrophic lateral sclerosis in the non-demented state. Eur J Neurol 2016; 24:122-129. [PMID: 27753163 DOI: 10.1111/ene.13163] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/09/2016] [Indexed: 02/03/2023]
Abstract
BACKGROUND AND PURPOSE Amyotrophic lateral sclerosis (ALS), a motor neuron disease, is associated with various cortical symptoms including mild cognitive decline with behavior changes, suggesting the involvement of extra-motor areas in ALS. Our aim was to investigate the specific patterns of brain atrophy in sporadic, impaired ALS patients without commonly known genetic mutations using voxel-based morphometry. MATERIALS AND METHODS Forty-seven patients with sporadic ALS and 28 age-matched healthy controls were recruited. ALS participants were divided into three groups according to comprehensive neuropsychological testing: pure (ALS-pure), cognitive impairment (ALSci) and behavioral impairment (ALSbi). Quantitative comparison of brain atrophy patterns was performed amongst these three groups using voxel-based analysis. All analyses were adjusted for total intracranial volume, age, sex, disease duration and functional disability score. RESULTS The ALSci group exhibited decreased volume in the left cerebellum, fusiform gyrus, optic radiations and corticospinal tracts compared to healthy controls. ALSci patient imaging showed decreased brain volume in the bilateral cerebellum, right putamen gray matter and bilateral superior longitudinal fasciculi white matter compared to pure ALS patients (P < 0.001 uncorrected, corrected for the entire volume). Compared to healthy controls, ALS-pure and ALSbi groups did not show any significant volume changes in gray and white matter. CONCLUSIONS These findings also support the hypothesis that ALS pathogenesis has a dual focality of onset (cortex and anterior horn) with contiguous spread outwards. Additionally, neuropsychological features may be an important predictor of progression and survival rates in ALS.
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Affiliation(s)
- H-J Kim
- Department of Neurology, College of Medicine, Hanyang University, Seoul, Korea
| | - S-I Oh
- Department of Neurology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - M de Leon
- Department of Psychiatry, Center for Brain Health, NYU School of Medicine, New York, NY, USA
| | - X Wang
- Department of Neurology, NYU School of Medicine, New York, NY, USA
| | - K-W Oh
- Department of Neurology, College of Medicine, Hanyang University, Seoul, Korea
| | - J-S Park
- Department of Neurology, College of Medicine, Hanyang University, Seoul, Korea
| | - A Deshpande
- Department of Psychiatry, Center for Brain Health, NYU School of Medicine, New York, NY, USA
| | - M Buj
- Department of Psychiatry, Center for Brain Health, NYU School of Medicine, New York, NY, USA
| | - S H Kim
- Department of Neurology, College of Medicine, Hanyang University, Seoul, Korea
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Geevasinga N, Menon P, Özdinler PH, Kiernan MC, Vucic S. Pathophysiological and diagnostic implications of cortical dysfunction in ALS. Nat Rev Neurol 2016; 12:651-661. [DOI: 10.1038/nrneurol.2016.140] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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32
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Assessment of the upper motor neuron in amyotrophic lateral sclerosis. Clin Neurophysiol 2016; 127:2643-60. [PMID: 27291884 DOI: 10.1016/j.clinph.2016.04.025] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 04/22/2016] [Accepted: 04/27/2016] [Indexed: 02/07/2023]
Abstract
Clinical signs of upper motor neuron (UMN) involvement are an important component in supporting the diagnosis of amyotrophic lateral sclerosis (ALS), but are often not easily appreciated in a limb that is concurrently affected by muscle wasting and lower motor neuron degeneration, particularly in the early symptomatic stages of ALS. Whilst recent criteria have been proposed to facilitate improved detection of lower motor neuron impairment through electrophysiological features that have improved diagnostic sensitivity, assessment of upper motor neuron involvement remains essentially clinical. As a result, there is often a significant diagnostic delay that in turn may impact institution of disease-modifying therapy and access to other optimal patient management. Biomarkers of pathological UMN involvement are also required to ensure patients with suspected ALS have timely access to appropriate therapeutic trials. The present review provides an analysis of current and recently developed assessment techniques, including novel imaging and electrophysiological approaches used to study corticomotoneuronal pathology in ALS.
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33
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Blasco H, Patin F, Madji Hounoum B, Gordon PH, Vourc'h P, Andres CR, Corcia P. Metabolomics in amyotrophic lateral sclerosis: how far can it take us? Eur J Neurol 2016; 23:447-54. [PMID: 26822316 DOI: 10.1111/ene.12956] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/04/2015] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease. Alongside identification of aetiologies, development of biomarkers is a foremost research priority. Metabolomics is one promising approach that is being utilized in the search for diagnosis and prognosis markers. Our aim is to provide an overview of the principal research in metabolomics applied to ALS. References were identified using PubMed with the terms 'metabolomics' or 'metabolomic' and 'ALS' or 'amyotrophic lateral sclerosis' or 'MND' or 'motor neuron disorders'. To date, nine articles have reported metabolomics research in patients and a few additional studies examined disease physiology and drug effects in patients or models. Metabolomics contribute to a better understanding of ALS pathophysiology but, to date, no biomarker has been validated for diagnosis, principally due to the heterogeneity of the disease and the absence of applied standardized methodology for biomarker discovery. A consensus on best metabolomics methodology as well as systematic independent validation will be an important accomplishment on the path to identifying the long-awaited biomarkers for ALS and to improve clinical trial designs.
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Affiliation(s)
- H Blasco
- Inserm U930, Tours, France
- Université François-Rabelais, Tours, France
- Laboratoire de Biochimie et Biologie Moléculaire, CHRU de Tours, Tours, France
| | - F Patin
- Inserm U930, Tours, France
- Université François-Rabelais, Tours, France
- Laboratoire de Biochimie et Biologie Moléculaire, CHRU de Tours, Tours, France
| | - B Madji Hounoum
- Inserm U930, Tours, France
- Université François-Rabelais, Tours, France
| | - P H Gordon
- Northern Navajo Medical Center, Shiprock, NM, USA
| | - P Vourc'h
- Inserm U930, Tours, France
- Université François-Rabelais, Tours, France
- Laboratoire de Biochimie et Biologie Moléculaire, CHRU de Tours, Tours, France
| | - C R Andres
- Inserm U930, Tours, France
- Université François-Rabelais, Tours, France
- Laboratoire de Biochimie et Biologie Moléculaire, CHRU de Tours, Tours, France
| | - P Corcia
- Inserm U930, Tours, France
- Université François-Rabelais, Tours, France
- Centre SLA, Service de Neurologie, CHRU Bretonneau, Tours, France
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