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Zoccolella S, Milella G, Giugno A, Devitofrancesco V, Damato R, Tamburrino L, Misceo S, Filardi M, Logroscino G. Neurophysiological indices for split phenomena: correlation with age and sex and potential implications in amyotrophic lateral sclerosis. Front Neurol 2024; 15:1371953. [PMID: 38515451 PMCID: PMC10956616 DOI: 10.3389/fneur.2024.1371953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 02/19/2024] [Indexed: 03/23/2024] Open
Abstract
Background Split phenomena (SP) are characterized by patterns of differential muscle wasting and atrophy, which are highly prevalent in amyotrophic lateral sclerosis (ALS) patients. Several neurophysiological indicators, including the split-hand index (SHI), split-leg index (SLI), and split-elbow index (SEI), have been proposed to assess SP. Nevertheless, their cutoff values and the impact of age and sex on these measures remain unclear. Methods We prospectively collected neurophysiological data from 300 healthy adult subjects. The following indices were measured from compound muscle action potentials (CMAPs): SHI [abductor pollicis brevis (APBcmap) x first dorsal interosseous (FDI)cmap/adductor digiti minimi (ADMcmap)], SEI (BICEPScmap/TRICEPScmap), SLI (extensor digit brevis (EDB)cmap/abductor Hallucis (AH)cmap), and the neurophysiological ratios APBcmap /ADMcmap and FDIcmap/ADMcmap. Multiple linear regression analysis was used to investigate the association between age, sex, CMAPs, and neurophysiological indicators. Results The median SHI was 10.4, with a median APBcmap/ADMcmap ratio of 0.9 and a median FDIcmap/ADMcmap ratio of 1.2. The median SEI was 1.6 (IQR:1.1-2.4) and the median SLI was 0.7 (IQR:0.5-1.0). Negative associations were observed between age, most of the CMAPs, and all the neurophysiological indices, except for SLI. The male subjects exhibited significantly higher CMAP values for the first dorsal interosseous (FDI), biceps, and SHI compared to the female participants. Conclusion Our findings highlight the importance of age- and sex-adjusted normative data for SP indices, which could enhance their diagnostic accuracy and clinical utility in patients with ALS. The SL index appears to be the most reliable indicator, as it showed no significant association with age or sex.
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Affiliation(s)
- Stefano Zoccolella
- Neurology Unit, San Paolo Hospital, Azienda Sanitaria Locale (ASL) Bari, Bari, Italy
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy
| | - Giammarco Milella
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
| | - Alessia Giugno
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy
| | - Vito Devitofrancesco
- Neurology Unit, San Paolo Hospital, Azienda Sanitaria Locale (ASL) Bari, Bari, Italy
| | - Rosaria Damato
- Neurology Unit, San Paolo Hospital, Azienda Sanitaria Locale (ASL) Bari, Bari, Italy
| | - Ludovica Tamburrino
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
| | - Salvatore Misceo
- Neurology Unit, San Paolo Hospital, Azienda Sanitaria Locale (ASL) Bari, Bari, Italy
| | - Marco Filardi
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
| | - Giancarlo Logroscino
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy
- Department of Translational Biomedicine and Neurosciences (DiBraiN), University of Bari Aldo Moro, Bari, Italy
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Baertsch H, Cvancara DJ, Paniello RC, Hillel AD, Bhatt NK. Recurrent laryngeal motor nerve conduction studies in a rat model: Establishing an objective measure for investigating laryngeal innervation. Muscle Nerve 2023; 68:471-475. [PMID: 37575043 DOI: 10.1002/mus.27932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 08/15/2023]
Abstract
INTRODUCTION/AIMS Disease or injury can cause neuromuscular changes to the larynx that can affect voice, breathing, and swallowing. Motor nerve conduction studies have had limited use in the study of laryngeal neurophysiology, despite their importance in other anatomic sites. The aim of this study was to explore the feasibility of performing recurrent laryngeal motor nerve conduction studies (rlMNCS) in a rat model. METHODS rlMNCS were performed in 15 rats under anesthesia. A bipolar stimulating electrode was placed on the recurrent laryngeal nerve (RLN) 5 mm below the cricoid cartilage. Via direct laryngoscopy, a recording electrode was placed transorally into the thyroarytenoid muscle. The RLN was maximally stimulated to determine the compound muscle action potential (CMAP). Three consecutive trials were averaged. RESULTS The mean stimulating threshold to the RLN to achieve a CMAP from the thyroarytenoid was 1.7 ± 0.6 mA. RLN stimulation caused a visible adductor twitch of the vocal fold in all animals. The mean negative amplitude was 2.0 ± 0.8 mV, and the total area was 1.0 ± 0.4 mV ms. The CMAP latency and negative duration were 1.0 ± 0.1 ms and 0.9 ± 0.2 ms, respectively. DISCUSSION rlMNCS are feasible and may be useful in understanding laryngeal neurophysiology with disease or injury. This work could provide a tractable animal model for studying and monitoring treatment of neuromuscular conditions affecting voice, breathing, and swallowing.
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Affiliation(s)
- Hans Baertsch
- Department of Otolaryngology - Head and Neck Surgery, University of Washington School of Medicine, Seattle, Washington, USA
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - David J Cvancara
- Department of Otolaryngology - Head and Neck Surgery, University of Washington School of Medicine, Seattle, Washington, USA
| | - Randal C Paniello
- Department of Otolaryngology - Head and Neck Surgery, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Allen D Hillel
- Department of Otolaryngology - Head and Neck Surgery, University of Washington School of Medicine, Seattle, Washington, USA
| | - Neel K Bhatt
- Department of Otolaryngology - Head and Neck Surgery, University of Washington School of Medicine, Seattle, Washington, USA
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Santos Silva C, Swash M, de Carvalho M. Exploring the split hand phenomenon with the neurophysiological index. Neurophysiol Clin 2023; 53:102864. [PMID: 37224600 DOI: 10.1016/j.neucli.2023.102864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 05/26/2023] Open
Abstract
In 164 subjects of different age groups, we studied the neurophysiological index (NI) ([CMAP amplitude/Distal motor latency] *[F-wave frequency]; CMAP=compound muscle action potential) for three hand muscles (APB= abductor pollicis brevis; FDI= first dorsal interosseous; ADM= abductor digiti minimi). A split hand index based on CMAP amplitude (SHI_CMAP) and NI (SHI_NI) were calculated ([APB CMAP amplitude or NI * FDI CMAP amplitude or NI]/[ADM CMAP amplitude or NI]). All these neurophysiological measurements differed between age groups (p<0.001). Hand muscle NIs, as well as SHI_NI and SHI_CMAP were age dependent. This may be relevant for diagnostic purposes in motor neuron diseases.
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Affiliation(s)
- Cláudia Santos Silva
- Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa-Norte, Lisbon, Portugal; Faculdade de Medicina- Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal.
| | - Michael Swash
- Faculdade de Medicina- Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal; Departments of Neurology and Neuroscience, Barts and the London School of Medicine, Queen Mary University of London and Royal London Hospital, UK
| | - Mamede de Carvalho
- Department of Neurosciences and Mental Health, Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa-Norte, Lisbon, Portugal; Faculdade de Medicina- Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
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Baertsch HC, Cvancara D, Bhatt NK. Utilizing novel recurrent laryngeal motor nerve conduction studies to characterize the aging larynx: A pilot study. Laryngoscope Investig Otolaryngol 2023; 8:739-745. [PMID: 37342107 PMCID: PMC10278111 DOI: 10.1002/lio2.1071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 04/17/2023] [Indexed: 06/22/2023] Open
Abstract
Objectives Age-related changes to the larynx are associated with dysphonia and contribute to reduced quality of life. This study utilizes recurrent laryngeal motor nerve conduction studies (rlMNCS) to determine if neurophysiologic changes occur in the aging larynx using an aging rat model. Study Design Animal study. Methods In vivo rlMNCS were performed in 10 young hemi-larynges (3-4 months) and 10 aged hemi-larynges (18-19 months) rats (Fischer 344 × Brown Norway F344BN). Recording electrodes were placed into the thyroarytenoid (TA) muscle through direct laryngoscopy. Recurrent laryngeal nerves (RLNs) were directly stimulated with bipolar electrodes. Compound motor action potentials (CMAPs) were obtained. RLN cross-sections were stained with toluidine blue. Axon count, myelination, and g-ratio were quantified utilizing AxonDeepSeg analysis software. Results rlMNCS were successfully obtained in all animals. Mean CMAP amplitude and negative durations in young rats were 3.58 ± 2.20 mV and 0.93 ± 0.14 mS (mean dif: 0.17; 95% CI: -2.21 to 2.54), respectively, and 3.74 ± 2.81 mV and 0.98 ± 0.11 mS (mean dif: 0.050; 95% CI: -0.07 to 0.17). No significant differences in onset latency or negative area were observed. Mean axon count in young rats (176 ± 35) was comparable to that in old rats (173 ± 31). Myelin thickness and g-ratio did not differ between groups. Conclusions There were no statistically significant differences in RLN conduction or axon histology between young and aged rats in this pilot study. This work provides a basis for future, adequately powered studies, and may lead to a tractable animal model to study the aging larynx. Level of Evidence 5.
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Affiliation(s)
- Hans C. Baertsch
- Department of Otolaryngology—Head and Neck Surgery, Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - David Cvancara
- Department of Otolaryngology—Head and Neck SurgeryUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Neel K. Bhatt
- Department of Otolaryngology—Head and Neck SurgeryUniversity of Washington School of MedicineSeattleWashingtonUSA
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Zoccolella S, Giugno A, Logroscino G. Split phenomena in amyotrophic lateral sclerosis: Current evidences, pathogenetic hypotheses and diagnostic implications. Front Neurosci 2023; 16:1100040. [PMID: 36699516 PMCID: PMC9868395 DOI: 10.3389/fnins.2022.1100040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 12/16/2022] [Indexed: 01/11/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease and has emerged among the disorders with the largest increasing incidence in Western countries. Although the diagnosis is based on clinical grounds, electromyography (EMG), and nerve conduction studies (NCS) play a crucial role to exclude other potential etiologies of lower motor neuron (LMN) dysfunction. Based on clinical grounds, a peculiar pattern of dissociated atrophy of the intrinsic hand and foot muscles, termed the "split-hand" (SH) and "split-leg" (SL) signs, has been described in a significant proportion of subjects with ALS, even at the early stages of the disease, when symptoms are focal. These signs are rare in neurological and non-neurological diseases other than ALS. In this review, we discussed current evidences concerning SH and SL signs, their pathogenetic hypotheses and neurophysiological findings. We also analyze whether SH and SL signs can be reliable markers in the differential diagnosis and in the prognosis of ALS.
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Affiliation(s)
- Stefano Zoccolella
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy,Neurology Unit, Azienda Sanitaria Locale (ASL) Bari, San Paolo Hospital, Bari, Italy,*Correspondence: Stefano Zoccolella,
| | - Alessia Giugno
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy,Department of Medical Sciences, Institute of Neurology, Magna Græcia University, Catanzaro, Italy
| | - Giancarlo Logroscino
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari Aldo Moro at Pia Fondazione “Card. G. Panico”, Tricase, Italy,Department of Translational Biomedicine and Neuroscience (DiBraiN), University of Bari Aldo Moro, Bari, Italy
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Strong MJ, Swash M. Finding Common Ground on the Site of Onset of Amyotrophic Lateral Sclerosis. Neurology 2022; 99:1042-1048. [PMID: 36261296 PMCID: PMC9754652 DOI: 10.1212/wnl.0000000000201387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/26/2022] [Indexed: 11/15/2022] Open
Abstract
The fundamental origin of amyotrophic lateral sclerosis (ALS) has remained an enigma since its earliest description as a relentlessly progressive degeneration with prominent neuromuscular manifestations that are associated with upper and lower motor neuron dysfunction. Although this remains the hallmark of ALS, a significant proportion of patients will also demonstrate one or more features of frontotemporal dysfunction, including a frontotemporal dementia (FTD). Understanding whether these 2 seemingly disparate syndromes are simply reflective of the co-occurrence of 2 distinct pathologic processes or the clinical manifestations of a common pathophysiologic derangement involving the brain more widely has gripped contemporary ALS researchers. Supporting a commonality of causation, both ALS and FTD show an alteration in the metabolism of TAR DNA-binding protein 43, marked by a shift in nucleocytoplasmic localization alongside a broad range of neuronal cytoplasmic inclusions consisting of pathologic aggregates of RNA-binding proteins. Similarly, several disease-associated or disease-modifying genetic variants that are shared between the 2 disorders suggest shared underlying mechanisms. In both, a prominent glial response has been postulated to contribute to non-cell-autonomous spread. A more contemporary hypothesis, however, suggests that syndromes of cortical and subcortical dysfunction are driven by impairments in discrete neural networks. This postulates that such networks, including networks subserving motor or cognitive function, possess unique and selective vulnerabilities to either single molecular toxicities or combinations thereof. The co-occurrence of one or more network dysfunctions in ALS and FTD is thus a reflection not of unique neuroanatomic correlates but rather of shared molecular vulnerabilities. The basis of such shared vulnerabilities becomes the fulcrum around which the next advances in our understanding of ALS and its possible therapy will develop.
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Affiliation(s)
- Michael J Strong
- From the Department of Clinical Neurological Sciences (M.J.S.), Western University, London, Canada; Department of Neurology (M.S.), Barts and the London School of Medicine QMUL, United Kingdom; and Institute of Neuroscience (M.S.), University of Lisbon, Portugal.
| | - Michael Swash
- From the Department of Clinical Neurological Sciences (M.J.S.), Western University, London, Canada; Department of Neurology (M.S.), Barts and the London School of Medicine QMUL, United Kingdom; and Institute of Neuroscience (M.S.), University of Lisbon, Portugal
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Theme 08 - Clinical Imaging and Electrophysiology. Amyotroph Lateral Scler Frontotemporal Degener 2022. [DOI: 10.1080/21678421.2022.2120684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Verschueren A, Palminha C, Delmont E, Attarian S. Changes in neuromuscular function in elders: Novel techniques for assessment of motor unit loss and motor unit remodeling with aging. Rev Neurol (Paris) 2022; 178:780-787. [PMID: 35863917 DOI: 10.1016/j.neurol.2022.03.019] [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: 01/19/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 11/24/2022]
Abstract
Functional muscle fiber denervation is a major contributor to the decline in physical function observed with aging and is now a recognized cause of sarcopenia, a muscle disorder characterized by progressive and generalized degenerative loss of skeletal muscle mass, quality, and strength. There is an interrelationship between muscle strength, motor unit (MU) number, and aging, which suggests that a portion of muscle weakness in seniors may be attributable to the loss of functional MUs. During normal aging, there is a time-related progression of MU loss, an adaptive sprouting followed by a maladaptive sprouting, and continuing recession of terminal Schwann cells leading to a reduced capacity for compensatory reinnervation in elders. In amyotrophic lateral sclerosis, increasing age at onset predicts worse survival ALS and it is possible that age-related depletion of the motor neuron pool may worsen motor neuron disease. MUNE methods are used to estimate the number of functional MU, data from MUNIX arguing for motor neuron loss with aging will be reviewed. Recently, a new MRI technique MU-MRI could be used to assess the MU recruitment or explore the activity of a single MU. This review presents published studies on the changes of neuromuscular function with aging, then focusing on these two novel techniques for assessment of MU loss and MU remodeling.
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Affiliation(s)
- A Verschueren
- Reference Centre for Neuromuscular Disorders and ALS, CHU La Timone, Aix-Marseille University, 264, rue Saint Pierre, 13005 Marseille, France.
| | - C Palminha
- Reference Centre for Neuromuscular Disorders and ALS, CHU La Timone, Aix-Marseille University, 264, rue Saint Pierre, 13005 Marseille, France
| | - E Delmont
- Reference Centre for Neuromuscular Disorders and ALS, CHU La Timone, Aix-Marseille University, 264, rue Saint Pierre, 13005 Marseille, France
| | - S Attarian
- Reference Centre for Neuromuscular Disorders and ALS, CHU La Timone, Aix-Marseille University, 264, rue Saint Pierre, 13005 Marseille, France
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