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Northall A, Doehler J, Weber M, Tellez I, Petri S, Prudlo J, Vielhaber S, Schreiber S, Kuehn E. Multimodal layer modelling reveals in vivo pathology in amyotrophic lateral sclerosis. Brain 2024; 147:1087-1099. [PMID: 37815224 PMCID: PMC10907094 DOI: 10.1093/brain/awad351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/01/2023] [Accepted: 09/24/2023] [Indexed: 10/11/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease characterized by the loss of motor control. Current understanding of ALS pathology is largely based on post-mortem investigations at advanced disease stages. A systematic in vivo description of the microstructural changes that characterize early stage ALS, and their subsequent development, is so far lacking. Recent advances in ultra-high field (7 T) MRI data modelling allow us to investigate cortical layers in vivo. Given the layer-specific and topographic signature of ALS pathology, we combined submillimetre structural 7 T MRI data (qT1, QSM), functional localizers of body parts (upper limb, lower limb, face) and layer modelling to systematically describe pathology in the primary motor cortex (M1), in 12 living ALS patients with reference to 12 matched controls. Longitudinal sampling was performed for a subset of patients. We calculated multimodal pathology maps for each layer (superficial layer, layer 5a, layer 5b, layer 6) of M1 to identify hot spots of demyelination, iron and calcium accumulation in different cortical fields. We show preserved mean cortical thickness and layer architecture of M1, despite significantly increased iron in layer 6 and significantly increased calcium in layer 5a and superficial layer, in patients compared to controls. The behaviourally first-affected cortical field shows significantly increased iron in L6 compared to other fields, while calcium accumulation is atopographic and significantly increased in the low myelin borders between cortical fields compared to the fields themselves. A subset of patients with longitudinal data shows that the low myelin borders are particularly disrupted and that calcium hot spots, but to a lesser extent iron hot spots, precede demyelination. Finally, we highlight that a very slow progressing patient (Patient P4) shows a distinct pathology profile compared to the other patients. Our data show that layer-specific markers of in vivo pathology can be identified in ALS patients with a single 7 T MRI measurement after first diagnosis, and that such data provide critical insights into the individual disease state. Our data highlight the non-topographic architecture of ALS disease spread and the role of calcium, rather than iron accumulation, in predicting future demyelination. We also highlight a potentially important role of low myelin borders, that are known to connect to multiple areas within the M1 architecture, in disease spread. Finally, the distinct pathology profile of a very-slow progressing patient (Patient P4) highlights a distinction between disease duration and progression. Our findings demonstrate the importance of in vivo histology imaging for the diagnosis and prognosis of neurodegenerative diseases such as ALS.
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Affiliation(s)
- Alicia Northall
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University Magdeburg, Magdeburg 39120, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg 39120, Germany
| | - Juliane Doehler
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University Magdeburg, Magdeburg 39120, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg 39120, Germany
| | - Miriam Weber
- Department of Neurology, Otto-von-Guericke University Magdeburg (OVGU), Magdeburg 39120, Germany
| | - Igor Tellez
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University Magdeburg, Magdeburg 39120, Germany
| | - Susanne Petri
- Department of Neurology, Hannover Medical School (MHH), Hanover 30625, Germany
| | - Johannes Prudlo
- Department of Neurology, Rostock University Medical Centre, Rostock 18147, Germany
- German Center for Neurodegenerative Diseases (DZNE), Rostock 18147, Germany
| | - Stefan Vielhaber
- Department of Neurology, Otto-von-Guericke University Magdeburg (OVGU), Magdeburg 39120, Germany
| | - Stefanie Schreiber
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg 39120, Germany
- Department of Neurology, Otto-von-Guericke University Magdeburg (OVGU), Magdeburg 39120, Germany
- Center for Behavioral Brain Sciences (CBBS) Magdeburg, Magdeburg 39120, Germany
| | - Esther Kuehn
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University Magdeburg, Magdeburg 39120, Germany
- Center for Behavioral Brain Sciences (CBBS) Magdeburg, Magdeburg 39120, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen 72076, Germany
- Hertie Institute for Clinical Brain Research (HIH), Tübingen 72076, Germany
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2
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De Carvalho M, Swash M. Transcranial magnetic stimulation to monitor disease progression in ALS: a review. Amyotroph Lateral Scler Frontotemporal Degener 2022. [DOI: 10.1080/21678421.2022.2160649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Mamede De Carvalho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Centro de Estudos Egas Moniz, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Department of Neurosciences and Mental Health, Centro Hospitalar Universitário Lisboa Norte, Lisboa, Portugal, and
| | - Michael Swash
- Instituto de Fisiologia, Instituto de Medicina Molecular, Centro de Estudos Egas Moniz, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Barts and the London School of Medicine, Queen Mary University of London, UK
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3
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Ghaffari LT, Trotti D, Haeusler AR, Jensen BK. Breakdown of the central synapses in C9orf72-linked ALS/FTD. Front Mol Neurosci 2022; 15:1005112. [PMID: 36187344 PMCID: PMC9523884 DOI: 10.3389/fnmol.2022.1005112] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/29/2022] [Indexed: 01/07/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease that leads to the death of motor and cortical neurons. The clinical manifestations of ALS are heterogenous, and efficacious treatments to significantly slow the progression of the disease are lacking. Cortical hyper-excitability is observed pre-symptomatically across disease-causative genetic variants, as well as in the early stages of sporadic ALS, and typically precedes motor neuron involvement and overt neurodegeneration. The causes of cortical hyper-excitability are not yet fully understood but is mainly agreed to be an early event. The identification of the nucleotide repeat expansion (GGGGCC)n in the C9ORF72 gene has provided evidence that ALS and another neurodegenerative disease, frontotemporal dementia (FTD), are part of a disease spectrum with common genetic origins. ALS and FTD are diseases in which synaptic dysfunction is reported throughout disease onset and stages of progression. It has become apparent that ALS/FTD-causative genes, such as C9ORF72, may have roles in maintaining the normal physiology of the synapse, as mutations in these genes often manifest in synaptic dysfunction. Here we review the dysfunctions of the central nervous system synapses associated with the nucleotide repeat expansion in C9ORF72 observed in patients, organismal, and cellular models of ALS and FTD.
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Yu Z, Pan W, Chen J, Peng X, Ling Z, Zou X. Application of electrophysiological measures in degenerative cervical myelopathy. Front Cell Dev Biol 2022; 10:834668. [PMID: 36016659 PMCID: PMC9395596 DOI: 10.3389/fcell.2022.834668] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Degenerative cervical myelopathy (DCM) is one of the leading causes of progressive spinal cord dysfunction in the elderly. Early diagnosis and treatment of DCM are essential to avoid permanent disability. The pathophysiology of DCM includes chronic ischemia, destruction of the blood–spinal cord barrier, demyelination, and neuronal apoptosis. Electrophysiological studies including electromyography (EMG), nerve conduction study (NCS), motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) are useful in detecting the presymptomatic pathological changes of the spinal cord, and thus supplementing the early clinical and radiographic examinations in the management of DCM. Preoperatively, they are helpful in detecting DCM and ruling out other diseases, assessing the spinal cord compression level and severity, predicting short- and long-term prognosis, and thus deciding the treatment methods. Intra- and postoperatively, they are also useful in monitoring neurological function change during surgeries and disease progression during follow-up rehabilitation. Here, we reviewed articles from 1979 to 2021, and tried to provide a comprehensive, evidence-based review of electrophysiological examinations in DCM. With this review, we aim to equip spinal surgeons with the basic knowledge to diagnosis and treat DCM using ancillary electrophysiological tests.
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Affiliation(s)
- Zhengran Yu
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- Department of Spine Surgery, Orthopedics Center of Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Wenxu Pan
- Department of Gastroenterology, Guangzhou Women and Children’s Medical Center, Jinan University, Guangzhou, China
| | - Jiacheng Chen
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xinsheng Peng
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zemin Ling
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- *Correspondence: Zemin Ling, ; Xuenong Zou, ,
| | - Xuenong Zou
- Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- *Correspondence: Zemin Ling, ; Xuenong Zou, ,
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Helekar SA, Thonhoff J, John BS, Nguyen L, Rosenfield DB, Appel SH. Modulation of spontaneous motor unit potentials by a new motor cortical magnetic stimulation method in amyotrophic lateral sclerosis. J Neurol 2022; 269:5487-5496. [PMID: 35704101 DOI: 10.1007/s00415-022-11214-8] [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: 02/02/2022] [Revised: 05/28/2022] [Accepted: 06/03/2022] [Indexed: 12/01/2022]
Abstract
BACKGROUND Patients with amyotrophic lateral sclerosis (ALS) show altered cortical excitability. In this study, we measure modulation of spontaneous motor unit potentials (sMUPs) in hand muscles by multifocal cortical stimulation with a newly developed wearable transcranial rotating permanent magnet stimulator (TRPMS). METHODS We conducted cross-sectional and longitudinal electromyographic assessments in 40 and 20 ALS patients, respectively, of the stimulation-induced peak increase in the count of sMUPs in two hand muscles modulated by unilateral TRPMS stimulation of the primary motor cortex. We measured peak sMUP counts during several short sessions consisting of 10 stimuli over 60 s and 30 s post-stimulation periods. The longitudinal component involved an initial assessment at an early stage of the disease and up to five follow-up assessments at least 3 months apart. RESULTS TRPMS stimulation produced no device-related adverse effects. It showed an inverted V-shaped modulation of the peak sMUP counts as a function of ALS functional rating scale revised scores. The ratios of ALS subjects showing peak sMUP count increases between early and intermediate stages (χ2 = 4.086, df = 1, p = 0.043) and intermediate and late stages (χ2 = 4.29, df = 1, p = 0.038) in cross-sectional data were significantly different. Longitudinal assessment also produced a significant (z = 2.31, p = 0.021) result, with all subjects showing a post-initial visit increase in peak sMUP counts. CONCLUSIONS These results are consistent with delayed onset of upper motor neuronal dysfunction with respect to onset of clinical features. However, the above results need to be confirmed in a larger sample of patients and with multiple lines of evidence.
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Affiliation(s)
- Santosh A Helekar
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, TX, 77030, USA. .,Weill Cornell Medical College, New York, NY, 10065, USA.
| | - Jason Thonhoff
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Blessy S John
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Lisa Nguyen
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - David B Rosenfield
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, TX, 77030, USA.,Weill Cornell Medical College, New York, NY, 10065, USA
| | - Stanley H Appel
- Stanley H. Appel Department of Neurology, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, TX, 77030, USA.,Weill Cornell Medical College, New York, NY, 10065, USA
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Verma S, Khurana S, Vats A, Sahu B, Ganguly NK, Chakraborti P, Gourie-Devi M, Taneja V. Neuromuscular Junction Dysfunction in Amyotrophic Lateral Sclerosis. Mol Neurobiol 2022; 59:1502-1527. [PMID: 34997540 DOI: 10.1007/s12035-021-02658-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 11/18/2021] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder characterized by progressive degeneration of motor neurons leading to skeletal muscle denervation. Earlier studies have shown that motor neuron degeneration begins in motor cortex and descends to the neuromuscular junction (NMJ) in a dying forward fashion. However, accumulating evidences support that ALS is a distal axonopathy where early pathological changes occur at the NMJ, prior to onset of clinical symptoms and propagates towards the motor neuron cell body supporting "dying back" hypothesis. Despite several evidences, series of events triggering NMJ disassembly in ALS are still obscure. Neuromuscular junction is a specialized tripartite chemical synapse which involves a well-coordinated communication among the presynaptic motor neuron, postsynaptic skeletal muscle, and terminal Schwann cells. This review provides comprehensive insight into the role of NMJ in ALS pathogenesis. We have emphasized the molecular alterations in cellular components of NMJ leading to loss of effective neuromuscular transmission in ALS. Further, we provide a preview into research involved in exploring NMJ as potential target for designing effective therapies for ALS.
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Affiliation(s)
- Sagar Verma
- Department of Research, Sir Ganga Ram Hospital, Delhi, India.,Department of Biotechnology, Jamia Hamdard, Delhi, India
| | - Shiffali Khurana
- Department of Research, Sir Ganga Ram Hospital, Delhi, India.,Department of Biomedical Science, Bhaskaracharya College of Applied Sciences, University of Delhi, Delhi, India
| | - Abhishek Vats
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bandana Sahu
- Department of Research, Sir Ganga Ram Hospital, Delhi, India
| | | | | | | | - Vibha Taneja
- Department of Research, Sir Ganga Ram Hospital, Delhi, India.
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7
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Neurophysiological Mechanisms Underlying Cortical Hyper-Excitability in Amyotrophic Lateral Sclerosis: A Review. Brain Sci 2021; 11:brainsci11050549. [PMID: 33925493 PMCID: PMC8145013 DOI: 10.3390/brainsci11050549] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neuromotor disease characterized by the loss of upper and lower motor neurons (MNs), resulting in muscle paralysis and death. Early cortical hyper-excitability is a common pathological process observed clinically and in animal disease models. Although the mechanisms that underlie cortical hyper-excitability are not completely understood, the molecular and cellular mechanisms that cause enhanced neuronal intrinsic excitability and changes in excitatory and inhibitory synaptic activity are starting to emerge. Here, we review the evidence for an anterograde glutamatergic excitotoxic process, leading to cortical hyper-excitability via intrinsic cellular and synaptic mechanisms and for the role of interneurons in establishing disinhibition in clinical and experimental settings. Understanding the mechanisms that lead to these complex pathological processes will likely produce key insights towards developing novel therapeutic strategies to rescue upper MNs, thus alleviating the impact of this fatal disease.
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8
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Corticomotor Excitability in Two Kinds of Motor Neuron Diseases: A Study on the Patients With Amyotrophic Lateral Sclerosis and Poliomyelitis Survivors. J Clin Neurophysiol 2020; 38:448-455. [DOI: 10.1097/wnp.0000000000000707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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9
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Jara JH, Sheets PL, Nigro MJ, Perić M, Brooks C, Heller DB, Martina M, Andjus PR, Ozdinler PH. The Electrophysiological Determinants of Corticospinal Motor Neuron Vulnerability in ALS. Front Mol Neurosci 2020; 13:73. [PMID: 32508590 PMCID: PMC7248374 DOI: 10.3389/fnmol.2020.00073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/15/2020] [Indexed: 12/12/2022] Open
Abstract
The brain is complex and heterogeneous. Even though numerous independent studies indicate cortical hyperexcitability as a potential contributor to amyotrophic lateral sclerosis (ALS) pathology, the mechanisms that are responsible for upper motor neuron (UMN) vulnerability remain elusive. To reveal the electrophysiological determinants of corticospinal motor neuron (CSMN, a.k.a UMN in mice) vulnerability, we investigated the motor cortex of hSOD1G93A mice at P30 (postnatal day 30), a presymptomatic time point. Glutamate uncaging by laser scanning photostimulation (LSPS) revealed altered dynamics especially within the inhibitory circuitry and more specifically in L2/3 of the motor cortex, whereas the excitatory microcircuits were unchanged. Observed microcircuitry changes were specific to CSMN in the motor column. Electrophysiological evaluation of the intrinsic properties in response to the microcircuit changes, as well as the exon microarray expression profiles of CSMN isolated from hSOD1G93A and healthy mice at P30, revealed the presence of a very dynamic set of events, ultimately directed to establish, maintain and retain the balance at this early stage. Also, the expression profile of key voltage-gated potassium and sodium channel subunits as well as of the inhibitory GABA receptor subunits and modulatory proteins began to suggest the challenges CSMN face at this early age. Since neurodegeneration is initiated when neurons can no longer maintain balance, the complex cellular events that occur at this critical time point help reveal how CSMN try to cope with the challenges of disease manifestation. This information is critically important for the proper modulation of UMNs and for developing effective treatment strategies.
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Affiliation(s)
- Javier H Jara
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Patrick L Sheets
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Maximiliano José Nigro
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Mina Perić
- Institute for Physiology and Biochemistry "Ivan Djaja", Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Carolyn Brooks
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Daniel B Heller
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Pavle R Andjus
- Institute for Physiology and Biochemistry "Ivan Djaja", Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - P Hande Ozdinler
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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10
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Brunet A, Stuart-Lopez G, Burg T, Scekic-Zahirovic J, Rouaux C. Cortical Circuit Dysfunction as a Potential Driver of Amyotrophic Lateral Sclerosis. Front Neurosci 2020; 14:363. [PMID: 32410944 PMCID: PMC7201269 DOI: 10.3389/fnins.2020.00363] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/25/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that affects selected cortical and spinal neuronal populations, leading to progressive paralysis and death. A growing body of evidences suggests that the disease may originate in the cerebral cortex and propagate in a corticofugal manner. In particular, transcranial magnetic stimulation studies revealed that ALS patients present with early cortical hyperexcitability arising from a combination of increased excitability and decreased inhibition. Here, we discuss the possibility that initial cortical circuit dysfunction might act as the main driver of ALS onset and progression, and review recent functional, imaging and transcriptomic studies conducted on ALS patients, along with electrophysiological, pathological and transcriptomic studies on animal and cellular models of the disease, in order to evaluate the potential cellular and molecular origins of cortical hyperexcitability in ALS.
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Affiliation(s)
| | | | | | | | - Caroline Rouaux
- INSERM UMR_S 1118, Mécanismes Centraux et Périphériques de la Neurodégénérescence, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
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11
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Fogarty MJ. Needles in straw-stacks on camel’s backs: Globalized versus specific loci of dysfunction in amyotrophic lateral sclerosis. Clin Neurophysiol 2020; 131:940-941. [DOI: 10.1016/j.clinph.2019.12.402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 12/26/2019] [Indexed: 11/29/2022]
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12
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Swash M, Burke D, Turner MR, Grosskreutz J, Leigh PN, deCarvalho M, Kiernan MC. Occasional essay: Upper motor neuron syndrome in amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2020; 91:227-234. [PMID: 32054724 DOI: 10.1136/jnnp-2019-321938] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/17/2019] [Accepted: 10/24/2019] [Indexed: 11/04/2022]
Affiliation(s)
- Michael Swash
- Barts and the London School of Medicine, QMUL, Instituto de Medicina Molecular, Faculdade de Medicina, Univeridade de Lisboa, London, UK
| | - David Burke
- University of Sydney and Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Julian Grosskreutz
- Universitätsklinikum Jena, Friedrich-Schiller-University Jena, Jena, Germany
| | - P Nigel Leigh
- Trafford Centre for Biomedical Research, Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, UK
| | - Mamede deCarvalho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Univeridade de Lisboa, and Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Universitário de Lisboa Norte, Lisbon, Portugal
| | - Matthew C Kiernan
- University of Sydney and Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.,Neurology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
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13
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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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14
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Civardi C, Collini A, Mazzini L, Monaco F, Geda C. Single-pulse transcranial magnetic stimulation in amyotrophic lateral sclerosis. Muscle Nerve 2019; 61:330-337. [PMID: 31837153 DOI: 10.1002/mus.26780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 12/04/2019] [Accepted: 12/07/2019] [Indexed: 11/07/2022]
Abstract
INTRODUCTION Transcranial magnetic stimulation (TMS) is one of the best methods to identify changes in the corticospinal tract. We used single-pulse TMS at the beginning of the disease and in the follow-up in a group of patients with amyotrophic lateral sclerosis (ALS). METHODS We evaluated the corticospinal tract in the bulbar, upper, and lower regions in 55 patients with ALS, and we monitored them for a period of 24 months. Data were correlated with clinical scales. RESULTS An increase of central motor conduction time (CMCT) was the most sensitive marker of upper motor neuron involvement. The resting motor threshold, CMCT, and the central silent period increased linearly with disease duration and upper/lower motor neuron involvement. DISCUSSION Transcranial magnetic stimulation could be an essential neurophysiological technique in the early phase of ALS because it has been shown to be useful in detecting subclinical upper motor neuron involvement. Multiple evaluations of several regions increase TMS sensitivity.
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Affiliation(s)
| | | | - Letizia Mazzini
- ALS Centre Department of Neurology Maggiore della Carità University Hospital, Novara, Italy
| | - Francesco Monaco
- Department of Neurology Maggiore della Carità University Hospital, Novara, Italy
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15
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Petel Légaré V, Harji ZA, Rampal CJ, Allard-Chamard X, Rodríguez EC, Armstrong GAB. Augmentation of spinal cord glutamatergic synaptic currents in zebrafish primary motoneurons expressing mutant human TARDBP (TDP-43). Sci Rep 2019; 9:9122. [PMID: 31235725 PMCID: PMC6591224 DOI: 10.1038/s41598-019-45530-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
Though there is compelling evidence that de-innervation of neuromuscular junctions (NMJ) occurs early in amyotrophic lateral sclerosis (ALS), defects arising at synapses in the spinal cord remain incompletely understood. To investigate spinal cord synaptic dysfunction, we took advantage of a zebrafish larval model and expressed either wild type human TARDBP (wtTARDBP) or the ALS-causing G348C variant (mutTARDBP). The larval zebrafish is ideally suited to examine synaptic connectivity between descending populations of neurons and spinal cord motoneurons as a fully intact spinal cord is preserved during experimentation. Here we provide evidence that the tail-beat motor pattern is reduced in both frequency and duration in larvae expressing mutTARDBP. In addition, we report that motor-related synaptic depolarizations in primary motoneurons of the spinal cord are shorter in duration and fewer action potentials are evoked in larvae expressing mutTARDBP. To more thoroughly examine spinal cord synaptic dysfunction in our ALS model, we isolated AMPA/kainate-mediated glutamatergic miniature excitatory post-synaptic currents in primary motoneurons and found that in addition to displaying a larger amplitude, the frequency of quantal events was higher in larvae expressing mutTARDBP when compared to larvae expressing wtTARDBP. In a final series of experiments, we optogenetically drove neuronal activity in the hindbrain and spinal cord population of descending ipsilateral glutamatergic interneurons (expressing Chx10) using the Gal4-UAS system and found that larvae expressing mutTARDBP displayed abnormal tail-beat patterns in response to optogenetic stimuli and augmented synaptic connectivity with motoneurons. These findings indicate that expression of mutTARDBP results in functionally altered glutamatergic synapses in the spinal cord.
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Affiliation(s)
- Virginie Petel Légaré
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Ziyaan A Harji
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Christian J Rampal
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Xavier Allard-Chamard
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Esteban C Rodríguez
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Gary A B Armstrong
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada.
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16
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Superconditioning TMS for examining upper motor neuron function in MND. Exp Brain Res 2019; 237:2087-2103. [PMID: 31175383 DOI: 10.1007/s00221-019-05573-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 05/30/2019] [Indexed: 01/09/2023]
Abstract
We used transcranial magnetic stimulation (TMS) of motor cortex, including a novel four-pulse superconditioning (TMSsc) paradigm, in repeated examinations of motor-evoked potentials (MEPs) in eight subjects with motor neuron disease (MND), including seven with amyotrophic lateral sclerosis (ALS). The goals were: (1) to look for evidence of cortical hyperexcitability, including a reduction in short-interval intracortical inhibition (SICI); and (2) to examine the utility of using TMSsc for quantifying upper motor neuron function during MND progression. Testing of abductor pollicis brevis (APB) and tibialis anterior (TA) muscles bilaterally was carried out every 3 months in MND subjects for up to 2 years; results were compared to those from a cohort of 15 control subjects. Measures of SICI were not significantly different between control and MND subjects for either APB or TA muscles. Other measures of cortical excitability, including TMS threshold and MEP amplitude, were consistent with lowered cortical excitability in MND subjects. Certain combinations of superconditioning TMS were capable of causing stronger inhibition or facilitation of MEPs compared to dual-pulse TMS, for both APB and TA target muscles. Moreover, there were multiple cases in which target muscles unresponsive to strong single-pulse TMS, whether at rest or when tested with an active contraction, showed an MEP in response to TMSsc optimized for facilitation. Our findings suggest that a multi-faceted neurophysiologic protocol for examining upper motor neuron function in MND subjects might benefit from inclusion of TMSsc testing.
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17
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Jiang T, Handley E, Brizuela M, Dawkins E, Lewis KEA, Clark RM, Dickson TC, Blizzard CA. Amyotrophic lateral sclerosis mutant TDP-43 may cause synaptic dysfunction through altered dendritic spine function. Dis Model Mech 2019; 12:dmm.038109. [PMID: 31036551 PMCID: PMC6550035 DOI: 10.1242/dmm.038109] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 04/12/2019] [Indexed: 12/12/2022] Open
Abstract
Altered cortical excitability and synapse dysfunction are early pathogenic events in amyotrophic lateral sclerosis (ALS) patients and animal models. Recent studies propose an important role for TAR DNA-binding protein 43 (TDP-43), the mislocalization and aggregation of which are key pathological features of ALS. However, the relationship between ALS-linked TDP-43 mutations, excitability and synaptic function is not fully understood. Here, we investigate the role of ALS-linked mutant TDP-43 in synapse formation by examining the morphological, immunocytochemical and excitability profile of transgenic mouse primary cortical pyramidal neurons that over-express human TDP-43A315T. In TDP-43A315T cortical neurons, dendritic spine density was significantly reduced compared to wild-type controls. TDP-43A315T over-expression increased the total levels of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropinionic acid (AMPA) glutamate receptor subunit GluR1, yet the localization of GluR1 to the dendritic spine was reduced. These postsynaptic changes were coupled with a decrease in the amount of the presynaptic marker synaptophysin that colocalized with dendritic spines. Interestingly, action potential generation was reduced in TDP-43A315T pyramidal neurons. This work reveals a crucial effect of the over-expression mutation TDP-43A315T on the formation of synaptic structures and the recruitment of GluR1 to the synaptic membrane. This pathogenic effect may be mediated by cytoplasmic mislocalization of TDP-43A315T. Loss of synaptic GluR1, and reduced excitability within pyramidal neurons, implicates hypoexcitability and attenuated synaptic function in the pathogenic decline of neuronal function in TDP-43-associated ALS. Further studies into the mechanisms underlying AMPA receptor-mediated excitability changes within the ALS cortical circuitry may yield novel therapeutic targets for treatment of this devastating disease. Summary: Loss of synaptic GluR1, and reduced excitability within pyramidal neurons, implicates hypoexcitability and attenuated synaptic function in the pathogenic decline of neuronal function in TDP-43-associated ALS.
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Affiliation(s)
- Tongcui Jiang
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Emily Handley
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Mariana Brizuela
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Edgar Dawkins
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Katherine E A Lewis
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Rosemary M Clark
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Medical Sciences Precinct, 17 Liverpool Street, Hobart, TAS 7000, Australia
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18
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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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19
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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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20
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Gautam M, Jara JH, Kocak N, Rylaarsdam LE, Kim KD, Bigio EH, Hande Özdinler P. Mitochondria, ER, and nuclear membrane defects reveal early mechanisms for upper motor neuron vulnerability with respect to TDP-43 pathology. Acta Neuropathol 2019; 137:47-69. [PMID: 30450515 DOI: 10.1007/s00401-018-1934-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/09/2018] [Accepted: 11/10/2018] [Indexed: 12/11/2022]
Abstract
Insoluble aggregates containing TDP-43 are widely observed in the diseased brain, and defined as "TDP-43 pathology" in a spectrum of neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), Alzheimer's disease and ALS with frontotemporal dementia. Here we report that Betz cells of patients with TDP-43 pathology display a distinct set of intracellular defects especially at the site of nuclear membrane, mitochondria and endoplasmic reticulum (ER). Numerous TDP-43 mouse models have been generated to discern the cellular and molecular basis of the disease, but mechanisms of neuronal vulnerability remain unknown. In an effort to define the underlying causes of corticospinal motor neuron (CSMN) degeneration, we generated and characterized a novel CSMN reporter line with TDP-43 pathology, the prp-TDP-43A315T-UeGFP mice. We find that TDP-43 pathology related intracellular problems emerge very early in the disease. The Betz cells in humans and CSMN in mice both have impaired mitochondria, and display nuclear membrane and ER defects with respect to TDP-43 pathology.
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21
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Nana AL, Sidhu M, Gaus SE, Hwang JHL, Li L, Park Y, Kim EJ, Pasquini L, Allen IE, Rankin KP, Toller G, Kramer JH, Geschwind DH, Coppola G, Huang EJ, Grinberg LT, Miller BL, Seeley WW. Neurons selectively targeted in frontotemporal dementia reveal early stage TDP-43 pathobiology. Acta Neuropathol 2019; 137:27-46. [PMID: 30511086 PMCID: PMC6339592 DOI: 10.1007/s00401-018-1942-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/22/2018] [Accepted: 11/23/2018] [Indexed: 12/26/2022]
Abstract
TAR DNA-binding protein 43 (TDP-43) aggregation is the most common pathological hallmark in frontotemporal dementia (FTD) and characterizes nearly all patients with motor neuron disease (MND). The earliest stages of TDP-43 pathobiology are not well-characterized, and whether neurodegeneration results from TDP-43 loss-of-function or aggregation remains unclear. In the behavioral variant of FTD (bvFTD), patients undergo selective dropout of von Economo neurons (VENs) and fork cells within the frontoinsular (FI) and anterior cingulate cortices. Here, we examined TDP-43 pathobiology within these vulnerable neurons in the FI across a clinical spectrum including 17 patients with sporadic bvFTD, MND, or both. In an exploratory analysis based on our initial observations, we further assessed ten patients with C9orf72-associated bvFTD/MND. VENs and fork cells showed early, disproportionate TDP-43 aggregation that correlated with anatomical and clinical severity, including loss of emotional empathy. The presence of a TDP-43 inclusion was associated with striking nuclear and somatodendritic atrophy. An intriguing minority of neurons lacked detectable nuclear TDP-43 despite the apparent absence of a cytoplasmic TDP-43 inclusion. These cells showed neuronal atrophy comparable to inclusion-bearing neurons, suggesting that the loss of nuclear TDP-43 function promotes neurodegeneration, even when TDP-43 aggregation is inconspicuous or absent.
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Affiliation(s)
- Alissa L Nana
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Manu Sidhu
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Stephanie E Gaus
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Ji-Hye L Hwang
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Libo Li
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Psychopharmacology, Qiqihar Medical University, Qiqihar, China
| | - Youngsoon Park
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Eun-Joo Kim
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Lorenzo Pasquini
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Isabel E Allen
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Katherine P Rankin
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Gianina Toller
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Joel H Kramer
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Daniel H Geschwind
- Neurogenetics Program, Department of Neurology and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Giovanni Coppola
- Neurogenetics Program, Department of Neurology and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Eric J Huang
- Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Lea T Grinberg
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Global Brain Health Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce L Miller
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - William W Seeley
- Department of Neurology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA.
- Department of Pathology and Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA.
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22
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Abstract
ALS is a neurodegenerative disease in which the primary symptoms result in progressive neuromuscular weakness. Recent studies have highlighted that there is significant heterogeneity with regard to anatomical and temporal disease progression. Importantly, more recent advances in genetics have revealed new causative genes to the disease. New efforts have focused on the development of biomarkers that could aid in diagnosis, prognosis, and serve as pharmacodynamics markers. Although traditional pharmaceuticals continue to undergo trials for ALS, new therapeutic strategies including stem cell transplantation studies, gene therapies, and antisense therapies targeting some of the familial forms of ALS are gaining momentum.
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23
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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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24
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Fogarty MJ, Mu EWH, Lavidis NA, Noakes PG, Bellingham MC. Motor Areas Show Altered Dendritic Structure in an Amyotrophic Lateral Sclerosis Mouse Model. Front Neurosci 2017; 11:609. [PMID: 29163013 PMCID: PMC5672020 DOI: 10.3389/fnins.2017.00609] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/18/2017] [Indexed: 12/11/2022] Open
Abstract
Objective: Motor neurons (MNs) die in amyotrophic lateral sclerosis (ALS), a clinically heterogeneous neurodegenerative disease of unknown etiology. In human or rodent studies, MN loss is preceded by increased excitability. As increased neuronal excitability correlates with structural changes in dendritic arbors and spines, we have examined longitudinal changes in dendritic structure in vulnerable neuron populations in a mouse model of familial ALS. Methods: We used a modified Golgi-Cox staining method to determine the progressive changes in dendritic structure of hippocampal CA1 pyramidal neurons, striatal medium spiny neurons, and resistant (trochlear, IV) or susceptible (hypoglossal, XII; lumbar) MNs from brainstem and spinal cord of mice over-expressing the human SOD1G93A (SOD1) mutation, in comparison to wild-type (WT) mice, at four postnatal (P) ages of 8–15, 28–35, 65–75, and 120 days. Results: In SOD1 mice, dendritic changes occur at pre-symptomatic ages in both XII and spinal cord lumbar MNs. Spine loss without dendritic changes was present in striatal neurons from disease onset. Spine density increases were present at all ages studied in SOD1 XII MNs. Spine density increased in neonatal lumbar MNs, before decreasing to control levels by P28-35 and was decreased by P120. SOD1 XII MNs and lumbar MNs, but not trochlear MNs showed vacuolization from the same time-points. Trochlear MN dendrites were unchanged. Interpretation: Dendritic structure and spine alterations correlate with the neuro-motor phenotype in ALS and with cognitive and extra-motor symptoms seen in patients. Prominent early changes in dendritic arbors and spines occur in susceptible cranial and spinal cord MNs, but are absent in MNs resistant to loss in ALS.
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Affiliation(s)
- Matthew J Fogarty
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Erica W H Mu
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Nickolas A Lavidis
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Peter G Noakes
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia.,Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
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25
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Clark RM, Blizzard CA, Young KM, King AE, Dickson TC. Calretinin and Neuropeptide Y interneurons are differentially altered in the motor cortex of the SOD1 G93A mouse model of ALS. Sci Rep 2017; 7:44461. [PMID: 28294153 PMCID: PMC5353592 DOI: 10.1038/srep44461] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/08/2017] [Indexed: 12/13/2022] Open
Abstract
Increasing evidence indicates an excitatory/inhibitory imbalance may have a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS). Impaired inhibitory circuitry is consistently reported in the motor cortex of both familial and sporadic patients, closely associated with cortical hyperexcitability and ALS onset. Inhibitory network dysfunction is presumably mediated by intra-cortical inhibitory interneurons, however, the exact cell types responsible are yet to be identified. In this study we demonstrate dynamic changes in the number of calretinin- (CR) and neuropeptide Y-expressing (NPY) interneurons in the motor cortex of the familial hSOD1G93A ALS mouse model, suggesting their potential involvement in motor neuron circuitry defects. We show that the density of NPY-populations is significantly decreased by ~17% at symptom onset (8 weeks), and by end-stage disease (20 weeks) is significantly increased by ~30%. Conversely, the density of CR-populations is progressively reduced during later symptomatic stages (~31%) to end-stage (~36%), while CR-expressing interneurons also show alteration of neurite branching patterns at symptom onset. We conclude that a differential capacity for interneurons exists in the ALS motor cortex, which may not be a static phenomenon, but involves early dynamic changes throughout disease, implicating specific inhibitory circuitry.
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Affiliation(s)
- Rosemary M Clark
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
| | - Anna E King
- Wicking Dementia Research &Education Centre2, University of Tasmania, Hobart, 7000, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
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26
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Cortical synaptic and dendritic spine abnormalities in a presymptomatic TDP-43 model of amyotrophic lateral sclerosis. Sci Rep 2016; 6:37968. [PMID: 27897242 PMCID: PMC5126629 DOI: 10.1038/srep37968] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/31/2016] [Indexed: 12/11/2022] Open
Abstract
Layer V pyramidal neurons (LVPNs) within the motor cortex integrate sensory cues and co-ordinate voluntary control of motor output. In amyotrophic lateral sclerosis (ALS) LVPNs and spinal motor neurons degenerate. The pathogenesis of neural degeneration is unknown in ALS; 10% of cases have a genetic cause, whereas 90% are sporadic, with most of the latter showing TDP-43 inclusions. Clinical and experimental evidence implicate excitotoxicity as a prime aetiological candidate. Using patch clamp and dye-filling techniques in brain slices, combined with high-resolution confocal microscopy, we report increased excitatory synaptic inputs and dendritic spine densities in early presymptomatic mice carrying a TDP-43Q331K mutation. These findings demonstrate substantive alterations in the motor cortex neural network, long before an overt degenerative phenotype has been reported. We conclude that increased excitatory neurotransmission is a common pathophysiology amongst differing genetic cases of ALS and may be of relevance to the 95% of sporadic ALS cases that exhibit TDP-43 inclusions.
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27
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Fogarty MJ, Mu EWH, Noakes PG, Lavidis NA, Bellingham MC. Marked changes in dendritic structure and spine density precede significant neuronal death in vulnerable cortical pyramidal neuron populations in the SOD1(G93A) mouse model of amyotrophic lateral sclerosis. Acta Neuropathol Commun 2016; 4:77. [PMID: 27488828 PMCID: PMC4973034 DOI: 10.1186/s40478-016-0347-y] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/12/2016] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterised by the death of upper (corticospinal) and lower motor neurons (MNs) with progressive muscle weakness. This incurable disease is clinically heterogeneous and its aetiology remains unknown. Increased excitability of corticospinal MNs has been observed prior to symptoms in human and rodent studies. Increased excitability has been correlated with structural changes in neuronal dendritic arbors and spines for decades. Here, using a modified Golgi-Cox staining method, we have made the first longitudinal study examining the dendrites of pyramidal neurons from the motor cortex, medial pre-frontal cortex, somatosensory cortex and entorhinal cortex of hSOD1G93A (SOD1) mice compared to wild-type (WT) littermate controls at postnatal (P) days 8–15, 28–35, 65–75 and 120. Progressive decreases in dendritic length and spine density commencing at pre-symptomatic ages (P8-15 or P28-35) were observed in layer V pyramidal neurons within the motor cortex and medial pre-frontal cortex of SOD1 mice compared to WT mice. Spine loss without concurrent dendritic pathology was present in the pyramidal neurons of the somatosensory cortex from disease-onset (P65-75). Our results from the SOD1 model suggest that dendritic and dendritic spine changes foreshadow and underpin the neuromotor phenotypes present in ALS and may contribute to the varied cognitive, executive function and extra-motor symptoms commonly seen in ALS patients. Determining if these phenomena are compensatory or maladaptive may help explain differential susceptibility of neurons to degeneration in ALS.
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28
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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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Spalloni A, Longone P. Cognitive impairment in amyotrophic lateral sclerosis, clues from the SOD1 mouse. Neurosci Biobehav Rev 2016; 60:12-25. [DOI: 10.1016/j.neubiorev.2015.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 11/09/2015] [Accepted: 11/16/2015] [Indexed: 12/11/2022]
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Clark R, Blizzard C, Dickson T. Inhibitory dysfunction in amyotrophic lateral sclerosis: future therapeutic opportunities. Neurodegener Dis Manag 2015; 5:511-25. [DOI: 10.2217/nmt.15.49] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In amyotrophic lateral sclerosis, motor neuron hyperexcitability and inhibitory dysfunction is emerging as a potential causative link in the dysfunction and degeneration of the motoneuronal circuitry that characterizes the disease. Interneurons, as key regulators of excitability, may mediate much of this imbalance, yet we know little about the way in which inhibitory deficits perturb excitability. In this review, we explore inhibitory control of excitability and the potential contribution of altered inhibition to amyotrophic lateral sclerosis disease processes and vulnerabilities, identifying important windows of therapeutic opportunity and potential interventions, specifically targeting inhibitory control at key disease stages.
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Affiliation(s)
- Rosemary Clark
- Menzies Institute for Medical Research, University of Tasmania, Hobart TAS 7000, Australia
| | - Catherine Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Hobart TAS 7000, Australia
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart TAS 7000, Australia
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Abstract
ABSTRACT:Glutamate excitotoxicity is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). We report the results of a double blind, placebo controlled, trial using 100 mg of oral daily lamotrigine (3,5-diamino-6-(2,3 dichlorophenyl)-l,2,4-triazine) which inhibits glutamate release. 67 patients were entered and at trial termination of 1.5 years 15 had withdrawn (9 active and 6 placebo) and 12 had died (6 active and 6 placebo). Mean age at entry was 57.5 years for the active and 58.6 years for the placebo groups. Patients were seen at 3 monthly intervals and scored according to neurological deficit based upon age of onset, bulbar and respiratory involvement, ambulation and functional disability. The mean change in clinical scores for the active versus placebo groups over the trial period was 7.1 ± 3.3 and 9.0 ± 3.3 respectively (0.05 < p < 0.10). Changes in cortical threshold and MEP/CMAP ratios to magnetic stimulation also did not differ significantly between the two groups. We conclude that lamotrigine in the doses administered does not alter the course of ALS.
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Mancuso R, Navarro X. Amyotrophic lateral sclerosis: Current perspectives from basic research to the clinic. Prog Neurobiol 2015; 133:1-26. [PMID: 26253783 DOI: 10.1016/j.pneurobio.2015.07.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 07/30/2015] [Accepted: 07/31/2015] [Indexed: 02/07/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of upper and lower motoneurons, leading to muscle weakness and paralysis, and finally death. Considerable recent advances have been made in basic research and preclinical therapeutic attempts using experimental models, leading to increasing clinical and translational research in the context of this disease. In this review we aim to summarize the most relevant findings from a variety of aspects about ALS, including evaluation methods, animal models, pathophysiology, and clinical findings, with particular emphasis in understanding the role of every contributing mechanism to the disease for elucidating the causes underlying degeneration of motoneurons and the development of new therapeutic strategies.
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Affiliation(s)
- Renzo Mancuso
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Xavier Navarro
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain.
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Neurophysiological Differences between Flail Arm Syndrome and Amyotrophic Lateral Sclerosis. PLoS One 2015; 10:e0127601. [PMID: 26056822 PMCID: PMC4461255 DOI: 10.1371/journal.pone.0127601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 04/16/2015] [Indexed: 11/19/2022] Open
Abstract
There are many clinical features of flail arm syndrome (FAS) that are different from amyotrophic lateral sclerosis (ALS), suggesting they are probably different entities. Studies on electrophysiological differences between them are limited at present, and still inconclusive. Therefore, we aimed to find clinical and neurophysiological differences between FAS and ALS. Eighteen healthy control subjects, six FAS patients and forty-one ALS patients were recruited. The upper motor neuron signs (UMNS), split-hand index (SI), resting motor threshold (RMT), central motor conduction time (CMCT) were evaluated and compared. There was no obvious upper motor neuron signs in FAS. The SI and RMT level in FAS was similar to control subjects, but significantly lower than that of in ALS. Compared with control group, the RMT and SI in ALS group were both significantly increased to higher level. However, no significant difference of CMCT was found between any two of these three groups. The differences in clinical and neurophysiological findings between FAS and ALS, argue against they are the same disease entity. Since there was no obvious UMNS, no split-hand phenomenon, and no obvious changes of RMT and CMCT in FAS patients, the development of FAS might be probably not originated from motor cortex.
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Brown KE, Neva JL, Ledwell NM, Boyd LA. Use of transcranial magnetic stimulation in the treatment of selected movement disorders. Degener Neurol Neuromuscul Dis 2014; 4:133-151. [PMID: 32669907 PMCID: PMC7337234 DOI: 10.2147/dnnd.s70079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 04/23/2014] [Indexed: 11/23/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is a valuable technique for assessing the underlying neurophysiology associated with various neuropathologies, and is a unique tool for establishing potential neural mechanisms responsible for disease progression. Recently, repetitive TMS (rTMS) has been advanced as a potential therapeutic technique to treat selected neurologic disorders. In healthy individuals, rTMS can induce changes in cortical excitability. Therefore, targeting specific cortical areas affected by movement disorders theoretically may alter symptomology. This review discusses the evidence for the efficacy of rTMS in Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and multiple sclerosis. It is hoped that gaining a more thorough understanding of the timing and parameters of rTMS in individuals with neurodegenerative disorders may advance both clinical care and research into the most effective uses of this technology.
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Affiliation(s)
| | - Jason L Neva
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | - Lara A Boyd
- Graduate Program in Rehabilitation Science.,Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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Chervyakov AV, Bakulin IS, Savitskaya NG, Arkhipov IV, Gavrilov AV, Zakharova MN, Piradov MA. Navigated transcranial magnetic stimulation in amyotrophic lateral sclerosis. Muscle Nerve 2014; 51:125-31. [PMID: 25049055 DOI: 10.1002/mus.24345] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2014] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is a set of disorders associated with preferential degeneration of both upper and lower motor neurons. Navigated transcranial magnetic stimulation (nTMS) is a tool used to perform noninvasive functional brain mapping. We aimed to assess function of upper motor neurons in ALS. METHODS nTMS was performed on 30 patients with ALS (mean age 54.4 ± 12.1 years) and 24 healthy volunteers (mean age 32.7 ± 13.3 years). RESULTS The resting motor threshold (MT) was significantly higher in ALS patients compared with controls (P < 0.001). The mean map areas were smaller in patients with ALS than in healthy individuals, although some patients with short disease duration had extended maps. CONCLUSIONS Motor area maps serve as markers of upper motor neuron damage in ALS. Further research may elucidate the pathogenic mechanisms of the neurodegenerative process and aid in development of diagnostic and prognostic markers.
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Menon P, Kiernan MC, Vucic S. Cortical hyperexcitability precedes lower motor neuron dysfunction in ALS. Clin Neurophysiol 2014; 126:803-9. [PMID: 25227219 DOI: 10.1016/j.clinph.2014.04.023] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 04/07/2014] [Accepted: 04/24/2014] [Indexed: 01/12/2023]
Abstract
OBJECTIVE To determine whether cortical hyperexcitability preceded the development of lower motor neuron (LMN) dysfunction in sporadic amyotrophic lateral sclerosis (ALS). METHODS Cortical excitability studies were undertaken in 24 ALS patients with motor evoked potential (MEP) recorded over the abductor pollicis brevis (APB) muscle. In the same sitting, LMN function of the target APB muscle was assessed utilising qualitative and quantitative electromyography techniques along with axonal excitability studies. RESULTS At time of assessment, the anatomical and functional integrity of the lower motor neuronal circuits innervating the target APB muscle was preserved in all patients, confirmed by a normal CMAP amplitude (P=0.37), absence of fasciculations, or features of neurogenic change. Despite this apparent 'normality' cortical dysfunction was evident, with significant reduction of short interval intracortical inhibition (P<0.01), resting motor threshold (P<0.05) and cortical silent period duration (P<0.001), along with increases in MEP amplitude (P<0.05) and intracortical facilitation (P<0.05). CONCLUSION The findings in the present study suggest that cortical hyperexcitability occurs upstream to a seemingly intact lower motor neuronal system. SIGNIFICANCE Corticomotoneuronal dysfunction appears to be a primary event in ALS, suggesting a cortical origin of the disease.
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Affiliation(s)
- Parvathi Menon
- Sydney Medical School Westmead, University of Sydney, Australia
| | - Matthew C Kiernan
- Brain and Mind Research Institute, University of Sydney, Sydney, Australia
| | - Steve Vucic
- Sydney Medical School Westmead, University of Sydney, Australia.
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Decreased movement-related beta desynchronization and impaired post-movement beta rebound in amyotrophic lateral sclerosis. Clin Neurophysiol 2014; 125:1689-99. [PMID: 24457137 DOI: 10.1016/j.clinph.2013.12.108] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/21/2013] [Accepted: 12/25/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVE This study explored event-related desynchronization (ERD) and synchronization (ERS) in amyotrophic lateral sclerosis (ALS) to quantify cortical sensorimotor processes during volitional movements. We furthermore compared ERD/ERS measures with clinical scores and movement-related cortical potential (MRCP) amplitudes. METHODS Electroencephalograms were recorded while 21 ALS patients and 19 controls performed two self-paced motor tasks: sniffing and right index finger flexion. Based on Wavelet analysis the alpha and beta frequency bands were selected for subsequent evaluation. RESULTS Patients generated significantly smaller resting alpha spectral power density (SPD) and smaller beta ERD compared to controls. Additionally patients exhibited merely unilateral post-movement ERS (beta rebound) whereas this phenomenon was bilateral in controls. ERD/ERS amplitudes did not correlate with corresponding MRCPs for either patients or controls. CONCLUSIONS The smaller resting alpha SPD and beta ERD and asymmetrical appearance of beta ERS in patients compared to controls could be the result of pyramidal cell degeneration and/or corpus callosum involvement in ALS. SIGNIFICANCE These results support the notion of reduced movement preparation in ALS involving also areas outside the motor cortex. Furthermore post-movement cortical inhibition seems to be impaired in ALS. ERD/ERS and MRCP are found to be independent measures of cortical motor functions in ALS.
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Vucic S, Ziemann U, Eisen A, Hallett M, Kiernan MC. Transcranial magnetic stimulation and amyotrophic lateral sclerosis: pathophysiological insights. J Neurol Neurosurg Psychiatry 2013; 84:1161-70. [PMID: 23264687 PMCID: PMC3786661 DOI: 10.1136/jnnp-2012-304019] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the motor neurons in the motor cortex, brainstem and spinal cord. A combination of upper and lower motor neuron dysfunction comprises the clinical ALS phenotype. Although the ALS phenotype was first observed by Charcot over 100 years ago, the site of ALS onset and the pathophysiological mechanisms underlying the development of motor neuron degeneration remain to be elucidated. Transcranial magnetic stimulation (TMS) enables non-invasive assessment of the functional integrity of the motor cortex and its corticomotoneuronal projections. To date, TMS studies have established motor cortical and corticospinal dysfunction in ALS, with cortical hyperexcitability being an early feature in sporadic forms of ALS and preceding the clinical onset of familial ALS. Taken together, a central origin of ALS is supported by TMS studies, with an anterograde transsynaptic mechanism implicated in ALS pathogenesis. Of further relevance, TMS techniques reliably distinguish ALS from mimic disorders, despite a compatible peripheral disease burden, thereby suggesting a potential diagnostic utility of TMS in ALS. This review will focus on the mechanisms underlying the generation of TMS measures used in assessment of cortical excitability, the contribution of TMS in enhancing the understanding of ALS pathophysiology and the potential diagnostic utility of TMS techniques in ALS.
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Affiliation(s)
- Steve Vucic
- Sydney Medical School Westmead, University of Sydney, Sydney, New South Wales, Australia.
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Vucic S, Lin CSY, Cheah BC, Murray J, Menon P, Krishnan AV, Kiernan MC. Riluzole exerts central and peripheral modulating effects in amyotrophic lateral sclerosis. ACTA ACUST UNITED AC 2013; 136:1361-70. [PMID: 23616585 DOI: 10.1093/brain/awt085] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Riluzole, a benzothiazole derivative, has been shown to be effective in prolonging survival in amyotrophic lateral sclerosis. The mechanisms by which riluzole exerts neuroprotective effects in amyotrophic lateral sclerosis remains to be fully elucidated, although inhibition of glutamatergic transmission and modulation of Na+ channel function have been proposed. In an attempt to determine the mechanisms by which riluzole exerts neuroprotective effects, in particular to dissect the relative contributions of inhibition of glutamatergic transmission and Na+ channel modulation, the present study utilized a combination of cortical and peripheral axonal excitability approaches to monitor changes in excitability and function in patients with amyotrophic lateral sclerosis. Cortical assessment was undertaken by utilising the threshold tracking transcranial magnetic stimulation (TMS) technique and combined with peripheral axonal excitability studies in 25 patients with amyotrophic lateral sclerosis. Studies were performed at baseline and repeated when patients were receiving riluzole 100 mg/day. At the time of second testing all patients were tolerating the medication well. Motor evoked potential and compound muscle action potential responses were recorded over the abductor pollicis brevis muscle. At baseline, features of cortical hyperexcitability were evident in patients with amyotrophic lateral sclerosis, indicated by marked reduction in short interval intracortical inhibition (P < 0.001) and cortical silent period duration (P < 0.001), as well as an increase in the motor evoked potential amplitude (P < 0.01). Riluzole therapy partially normalized cortical excitability by significantly increasing short interval intracortical inhibition (short interval intracortical inhibitionbaseline 0.5 ± 1.8%; short interval intracortical inhibitionON riluzole 7.9 ± 1.7%, P < 0.01). In contrast, riluzole did not exert any modulating effect on cortical silent period duration (P = 0.45) or motor evoked potential amplitude (P = 0.31). In terms of peripheral nerve function, axonal excitability studies established that, relative to control subjects, patients with amyotrophic lateral sclerosis had significant increases in depolarizing threshold electrotonus [amyotrophic lateral sclerosisbaseline TEd (90-100 ms) 49.1 ± 1.8%; controlsTEd (90-100 ms) 45.2 ± 0.6%, P < 0.01] and superexcitability (amyotrophic lateral sclerosisbaseline 30.1 ± 2.3%; control subjects 23.4 ± 1.0%, P < 0.01) at baseline. Following institution of riluzole therapy there was a significant reduction in superexcitability (amyotrophic lateral sclerosisbaseline 30.1 ± 2.3%; amyotrophic lateral sclerosisON riluzole 27.3 ± 2.3%, P < 0.05) and refractoriness at 2 ms (amyotrophic lateral sclerosisbaseline 98.7 ± 10.7%; amyotrophic lateral sclerosisON riluzole 67.8 ± 9.3%, P < 0.001). In conclusion, the present study has established that riluzole exerts effects on both central and peripheral nerve function, interpreted as partial normalization of cortical hyperexcitability and reduction of transient Na+ conductances. Taken together, these findings suggest that the neuroprotective effects of riluzole in amyotrophic lateral sclerosis are complex, with evidence of independent effects across both compartments of the nervous system.
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Affiliation(s)
- Steve Vucic
- Neuroscience Research Australia, Barker Street, Randwick, Sydney, NSW 2031, Australia
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Bae JS, Simon NG, Menon P, Vucic S, Kiernan MC. The puzzling case of hyperexcitability in amyotrophic lateral sclerosis. J Clin Neurol 2013; 9:65-74. [PMID: 23626643 PMCID: PMC3633193 DOI: 10.3988/jcn.2013.9.2.65] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 08/24/2012] [Accepted: 08/24/2012] [Indexed: 12/11/2022] Open
Abstract
The development of hyperexcitability in amyotrophic lateral sclerosis (ALS) is a well-known phenomenon. Despite controversy as to the underlying mechanisms, cortical hyperexcitability appears to be closely related to the interplay between excitatory corticomotoneurons and inhibitory interneurons. Hyperexcitability is not a static phenomenon but rather shows a pattern of progression in a spatiotemporal aspect. Cortical hyperexcitability may serve as a trigger to the development of anterior horn cell degeneration through a 'dying forward' process. Hyperexcitability appears to develop during the early disease stages and gradually disappears in the advanced stages of the disease, linked to the destruction of corticomotorneuronal pathways. As such, a more precise interpretation of these unique processes may provide new insight regarding the pathophysiology of ALS and its clinical features. Recently developed technologies such as threshold tracking transcranial magnetic stimulation and automated nerve excitability tests have provided some clues about underlying pathophysiological processes linked to hyperexcitability. Additionally, these novel techniques have enabled clinicians to use the specific finding of hyperexcitability as a useful diagnostic biomarker, enabling clarification of various ALS-mimic syndromes, and the prediction of disease development in pre-symptomatic carriers of familial ALS. In terms of nerve excitability tests for peripheral nerves, an increase in persistent Na+ conductances has been identified as a major determinant of peripheral hyperexcitability in ALS, inversely correlated with the survival in ALS. As such, the present Review will focus primarily on the puzzling theory of hyperexcitability in ALS and summarize clinical and pathophysiological implications for current and future ALS research.
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Affiliation(s)
- Jong Seok Bae
- Department of Neurology, College of Medicine, Inje University, Busan, Korea. ; Neuroscience Research Australia, Sydney, Australia
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Vucic S, Kiernan MC. Utility of transcranial magnetic stimulation in delineating amyotrophic lateral sclerosis pathophysiology. HANDBOOK OF CLINICAL NEUROLOGY 2013; 116:561-575. [PMID: 24112924 DOI: 10.1016/b978-0-444-53497-2.00045-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the motor neurons in the motor cortex, brainstem, and spinal cord. The clinical phenotype of ALS is underscored by a combination of upper and lower motor neuron dysfunction. Although this phenotype was observed over 100 years ago, the site of ALS onset and the pathophysiological mechanisms underlying the development of motor neuron degeneration remain to be elucidated. Transcranial magnetic stimulation (TMS) enables noninvasive assessment of the functional integrity of the motor cortex and its corticomotoneuronal projections. To date, TMS studies have established cortical dysfunction in ALS, with cortical hyperexcitability being an early feature in sporadic forms of ALS and preceding the clinical onset of familial ALS. Taken together, a central origin of ALS is supported by TMS studies, with an anterograde dying-forward mechanism implicated in ALS pathogenesis. Of further relevance, TMS techniques reliably distinguish ALS from mimic disorders, despite a compatible peripheral disease burden, thereby suggesting a potential diagnostic utility of TMS in ALS. This chapter reviews the mechanisms underlying the generation of TMS parameters utilized in assessment of cortical excitability, the contribution of TMS in enhancing the understanding of ALS pathophysiology, and the potential diagnostic utility of TMS techniques in ALS.
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Affiliation(s)
- Steve Vucic
- Sydney Medical School Westmead, University of Sydney, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia
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Cipresso P, Carelli L, Solca F, Meazzi D, Meriggi P, Poletti B, Lulé D, Ludolph AC, Silani V, Riva G. The use of P300-based BCIs in amyotrophic lateral sclerosis: from augmentative and alternative communication to cognitive assessment. Brain Behav 2012; 2:479-98. [PMID: 22950051 PMCID: PMC3432970 DOI: 10.1002/brb3.57] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 03/06/2012] [Accepted: 03/13/2012] [Indexed: 12/11/2022] Open
Abstract
The use of augmentative and alternative communication (AAC) tools in patients with amyotrophic lateral sclerosis (ALS), as effective means to compensate for the progressive loss of verbal and gestural communication, has been deeply investigated in the recent literature. The development of advanced AAC systems, such as eye-tracking (ET) and brain-computer interface (BCI) devices, allowed to bypass the important motor difficulties present in ALS patients. In particular, BCIs could be used in moderate to severe stages of the disease, since they do not require preserved ocular-motor ability, which is necessary for ET applications. Furthermore, some studies have proved the reliability of BCIs, regardless of the severity of the disease and the level of physical decline. However, the use of BCI in ALS patients still shows some limitations, related to both technical and neuropsychological issues. In particular, a range of cognitive deficits in most ALS patients have been observed. At the moment, no effective verbal-motor free measures are available for the evaluation of ALS patients' cognitive integrity; BCIs could offer a new possibility to administer cognitive tasks without the need of verbal or motor responses, as highlighted by preliminary studies in this field. In this review, we outline the essential features of BCIs systems, considering advantages and challenges of these tools with regard to ALS patients and the main applications developed in this field. We then outline the main findings with regard to cognitive deficits observed in ALS and some preliminary attempts to evaluate them by means of BCIs. The definition of specific cognitive profiles could help to draw flexible approaches tailored on patients' needs. It could improve BCIs efficacy and reduce patients' efforts. Finally, we handle the open question, represented by the use of BCIs with totally locked in patients, who seem unable to reliably learn to use such tool.
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Affiliation(s)
- Pietro Cipresso
- Applied Technology for Neuro‐Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Laura Carelli
- Department of Neurology and Laboratory of Neuroscience ‐ “Dino Ferrari” Center ‐ Università degli Studi di Milano ‐ IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Federica Solca
- Department of Neurology and Laboratory of Neuroscience ‐ “Dino Ferrari” Center ‐ Università degli Studi di Milano ‐ IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Daniela Meazzi
- Applied Technology for Neuro‐Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Paolo Meriggi
- Polo Tecnologico–Biomedical Technology Department, Fondazione Don Carlo Gnocchi Onlus, Milano, Italy
| | - Barbara Poletti
- Department of Neurology and Laboratory of Neuroscience ‐ “Dino Ferrari” Center ‐ Università degli Studi di Milano ‐ IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Dorothée Lulé
- Department of Neurology ‐ University of Ulm, Ulm, Germany
| | | | - Vincenzo Silani
- Department of Neurology and Laboratory of Neuroscience ‐ “Dino Ferrari” Center ‐ Università degli Studi di Milano ‐ IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Giuseppe Riva
- Applied Technology for Neuro‐Psychology Lab, IRCCS Istituto Auxologico Italiano, Milan, Italy
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Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease that results in increasing disability and that is uniformly fatal. Since its approval in the 1990s, riluzole remains the sole treatment for ALS offering modest survival benefit. While significant advances have been made in the symptomatic management of the disease, more effective drug therapy targeting disease progression is sorely needed. AREAS COVERED Advances in the understanding of pathogenic mechanisms involved in disease development and progression have provided multiple avenues for developing effective treatment strategies. This review highlights recent discoveries relating to these diverse mechanisms and their implications for the development of drug therapy. Previous human clinical trials that have targeted these pathways are mentioned and ongoing drug trials are discussed. EXPERT OPINION The search for effective drug therapy faces important challenges in the areas of basic science and animal research, translation of these results into human clinical trials, inherent bias in human studies and issues related to delays in clinical diagnosis. How these issues may be addressed and why ALS research constitutes fertile grounds for drug development not only for this devastating disease, but also for other more prevalent neurodegenerative diseases, is discussed in this review.
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Affiliation(s)
- Ali Aamer Habib
- The Neurological Institute of Columbia University, Eleanor and Lou Gehrig MDA/ALS Center, NY 10032, USA.
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de Carvalho M. Why is ALS so excited? Clin Neurophysiol 2011; 122:1689-90. [PMID: 21377922 DOI: 10.1016/j.clinph.2011.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 02/03/2011] [Accepted: 02/05/2011] [Indexed: 12/13/2022]
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Carunchio I, Curcio L, Pieri M, Pica F, Caioli S, Viscomi MT, Molinari M, Canu N, Bernardi G, Zona C. Increased levels of p70S6 phosphorylation in the G93A mouse model of Amyotrophic Lateral Sclerosis and in valine-exposed cortical neurons in culture. Exp Neurol 2010; 226:218-30. [DOI: 10.1016/j.expneurol.2010.08.033] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 08/30/2010] [Accepted: 08/30/2010] [Indexed: 12/11/2022]
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Vucic S, Winhammar JM, Rowe DB, Kiernan MC. Corticomotoneuronal function in asymptomatic SOD-1 mutation carriers. Clin Neurophysiol 2010; 121:1781-5. [DOI: 10.1016/j.clinph.2010.02.164] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/11/2010] [Accepted: 02/16/2010] [Indexed: 12/13/2022]
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Vucic S, Cheah BC, Yiannikas C, Vincent A, Kiernan MC. Corticomotoneuronal function and hyperexcitability in acquired neuromyotonia. ACTA ACUST UNITED AC 2010; 133:2727-33. [PMID: 20736187 PMCID: PMC2929332 DOI: 10.1093/brain/awq188] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Acquired neuromyotonia encompasses a group of inflammatory disorders characterized by symptoms reflecting peripheral nerve hyperexcitability, which may be clinically confused in the early stages with amyotrophic lateral sclerosis. Despite a clear peripheral nerve focus, it remains unclear whether the ectopic activity in acquired neuromyotonia receives a central contribution. To clarify whether cortical hyperexcitability contributes to development of clinical features of acquired neuromyotonia, the present study investigated whether threshold tracking transcranial magnetic stimulation could detect cortical hyperexcitability in acquired neuromyotonia, and whether this technique could differentiate acquired neuromyotonia from amyotrophic lateral sclerosis. Cortical excitability studies were undertaken in 18 patients with acquired neuromyotonia and 104 patients with amyotrophic lateral sclerosis, with results compared to 62 normal controls. Short-interval intracortical inhibition in patients with acquired neuromyotonia was significantly different when compared to patients with amyotrophic lateral sclerosis (averaged short interval intracortical inhibition acquired neuromyotonia 11.3 ± 1.9%; amyotrophic lateral sclerosis 2.6 ± 0.9%, P < 0.001). In addition, the motor evoked potential amplitudes (acquired neuromyotonia 21.0 ± 3.1%; amyotrophic lateral sclerosis 38.1 ± 2.2%, P < 0.0001), intracortical facilitation (acquired neuromyotonia −0.9 ± 1.3%; amyotrophic lateral sclerosis −2.3 ± 0.6%, P < 0.0001), resting motor thresholds (acquired neuromyotonia 62.2 ± 1.6%; amyotrophic lateral sclerosis 57.2 ± 0.9%, P < 0.05) and cortical silent period durations (acquired neuromyotonia 212.8 ± 6.9 ms; amyotrophic lateral sclerosis 181.1 ± 4.3 ms, P < 0.0001) were significantly different between patients with acquired neuromyotonia and amyotrophic lateral sclerosis. Threshold tracking transcranial magnetic stimulation established corticomotoneuronal integrity in acquired neuromyotonia, arguing against a contribution of central processes to the development of nerve hyperexcitability in acquired neuromyotonia.
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Affiliation(s)
- Steve Vucic
- Neuroscience Research Australia, Barker Street, Randwick, Sydney, NSW 2031, Australia
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de Carvalho M, Chio A, Dengler R, Hecht M, Weber M, Swash M. Neurophysiological measures in amyotrophic lateral sclerosis: Markers of progression in clinical trials. ACTA ACUST UNITED AC 2009; 6:17-28. [PMID: 16036422 DOI: 10.1080/14660820410020600] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this review we evaluate clinical neurophysiological methods, originally described for use in diagnosis that can be applied to measurement of change during the progress of amyotrophic lateral sclerosis (ALS). Such measurements are potentially important in clinical trials, and also in clinical practice. We have assessed methods for lower and upper motor neuron function, including conventional EMG, nerve conduction and F-wave studies, the derived Neurophysiological Index, motor unit counting methods (MUNE), and transcranial magnetic motor cortex stimulation. We have also addressed the validity of measurements of electromechanical coupling. Methods for measuring muscle strength are beyond the scope of this review. We conclude that MUNE, M-wave amplitude and the Neurophysiological Index are sufficiently reliable, sensitive, and relevant to the clinical problem of ALS, to be used in clinical trials in the disease. Transcranial magnetic stimulation is of limited value, but a combination of the measurements made as part of this technique may also be useful. We conclude that clinical neurophysiological techniques should now be used in measuring change in clinical trials in ALS.
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Affiliation(s)
- Mamede de Carvalho
- Department of Neurology at Hospital de Santa Maria, Institute for Molecular Medecine, University of Lisbon, Portugal.
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Lanka V, Cudkowicz M. Therapy development for ALS: Lessons learned and path forward. ACTA ACUST UNITED AC 2009; 9:131-40. [DOI: 10.1080/17482960802112819] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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