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Shin-Yi Lin C, Howells J, Rutkove S, Nandedkar S, Neuwirth C, Noto YI, Shahrizaila N, Whittaker RG, Bostock H, Burke D, Tankisi H. Neurophysiological and imaging biomarkers of lower motor neuron dysfunction in motor neuron diseases/amyotrophic lateral sclerosis: IFCN handbook chapter. Clin Neurophysiol 2024; 162:91-120. [PMID: 38603949 DOI: 10.1016/j.clinph.2024.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 02/07/2024] [Accepted: 03/12/2024] [Indexed: 04/13/2024]
Abstract
This chapter discusses comprehensive neurophysiological biomarkers utilised in motor neuron disease (MND) and, in particular, its commonest form, amyotrophic lateral sclerosis (ALS). These encompass the conventional techniques including nerve conduction studies (NCS), needle and high-density surface electromyography (EMG) and H-reflex studies as well as novel techniques. In the last two decades, new methods of assessing the loss of motor units in a muscle have been developed, that are more convenient than earlier methods of motor unit number estimation (MUNE),and may use either electrical stimulation (e.g. MScanFit MUNE) or voluntary activation (MUNIX). Electrical impedance myography (EIM) is another novel approach for the evaluation that relies upon the application and measurement of high-frequency, low-intensity electrical current. Nerve excitability techniques (NET) also provide insights into the function of an axon and reflect the changes in resting membrane potential, ion channel dysfunction and the structural integrity of the axon and myelin sheath. Furthermore, imaging ultrasound techniques as well as magnetic resonance imaging are capable of detecting the constituents of morphological changes in the nerve and muscle. The chapter provides a critical description of the ability of each technique to provide neurophysiological insight into the complex pathophysiology of MND/ALS. However, it is important to recognise the strengths and limitations of each approach in order to clarify utility. These neurophysiological biomarkers have demonstrated reliability, specificity and provide additional information to validate and assess lower motor neuron dysfunction. Their use has expanded the knowledge about MND/ALS and enhanced our understanding of the relationship between motor units, axons, reflexes and other neural circuits in relation to clinical features of patients with MND/ALS at different stages of the disease. Taken together, the ultimate goal is to aid early diagnosis, distinguish potential disease mimics, monitor and stage disease progression, quantify response to treatment and develop potential therapeutic interventions.
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Affiliation(s)
- Cindy Shin-Yi Lin
- Faculty of Medicine and Health, Central Clinical School, Brain and Mind Centre, University of Sydney, Sydney 2006, Australia.
| | - James Howells
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Seward Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Sanjeev Nandedkar
- Natus Medical Inc, Middleton, Wisconsin, USA and Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christoph Neuwirth
- Neuromuscular Diseases Unit/ALS Clinic, Kantonsspital, St. Gallen, Switzerland
| | - Yu-Ichi Noto
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Nortina Shahrizaila
- Division of Neurology, Department of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Roger G Whittaker
- Newcastle University Translational and Clinical Research Institute (NUTCRI), Newcastle University., Newcastle Upon Tyne, United Kingdom
| | - Hugh Bostock
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, WC1N 3BG, London, United Kingdom
| | - David Burke
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
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Lugg A, Schindle M, Sivak A, Tankisi H, Jones KE. Nerve excitability measured with the TROND protocol in amyotrophic lateral sclerosis: a systematic review and meta-analysis. J Neurophysiol 2023; 130:1480-1491. [PMID: 37910562 DOI: 10.1152/jn.00174.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 11/03/2023] Open
Abstract
This meta-analysis assessed the 30+ nerve excitability indices generated by the TROND protocol to identify potential biomarkers for amyotrophic lateral sclerosis (ALS). A comprehensive search was conducted in multiple databases to identify human studies that tested median motor axons. Forest plot analyses were performed using a random-effects model to determine the pooled effect (Z-score), heterogeneity (I2), and Cohen's d for potential biomarker identification. Out of 2,866 studies, 23 studies met the inclusion criteria, incorporating data from 719 controls and 942 patients with ALS. Seven indices emerged as potential biomarkers: depolarizing threshold electrotonus (TEd) 90-100 ms, strength-duration time constant (SDTC), superexcitability, TEd 40-60 ms, resting I/V slope, 50% depolarizing I/V, and subexcitability (ranked by the magnitude of the difference between patients and controls from largest to smallest). In a sensitivity analysis focusing on patients with larger compound muscle action potentials (CMAPs), only four indices were potential biomarkers: TEd 10-20 ms, TEd 90-100 ms, superexcitability, and SDTC. Among the extensive range of 30+ excitability indices generated by the TROND protocol, we have identified seven indices that effectively differentiate patients with ALS from healthy controls. Furthermore, a smaller subset of four indices shows promise as potential biomarkers when the CMAP remains relatively large. However, most studies were considered to be at moderate risk of bias due to case-control designs and absence of sensitivity and specificity calculations, underscoring the need for more prospective diagnostic test-accuracy studies with appropriate disease controls.NEW & NOTEWORTHY This meta-analysis uncovers seven potential axonal excitability biomarkers for lower motor neuron pathology in ALS, shedding light on ion channel dysfunction. The identified dysfunction aligns with the primary pathology-protein homeostasis disruption. These biomarkers could fill a gap to detect presymptomatic spread of the disease in the spinal cord and monitor treatments targeting protein homeostasis and limiting spread, toward enhancing patient care.
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Affiliation(s)
- Anna Lugg
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Mason Schindle
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Allison Sivak
- University of Alberta Library, Edmonton, Alberta, Canada
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - Kelvin E Jones
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, Edmonton, Alberta, Canada
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Chen K, Yang Y, Sun C, Zhu Y, Wang H, Lyu F, Jiang J, Zheng C. Loss of cervical sagittal alignment worsens the cervical spinal lesions in patients with Hirayama disease. Neurol Sci 2023; 44:2103-2111. [PMID: 36697854 DOI: 10.1007/s10072-023-06621-2] [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: 11/07/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To quantify the cervical sagittal alignment in patients with Hirayama disease (HD) and to investigate the effect of loss of cervical sagittal alignment upon the cervical spinal lesions in HD. METHODS Cervical sagittal alignments were measured in 253 HD patients and 63 healthy subjects by C2-C7 Cobb and a modified method of Toyama et al. Motor unit number estimation (MUNE) was performed in bilateral abductor pollicis brevis (APB) in all HD patients, and 31 patients further underwent cervical diffusion tensor imaging (DTI). RESULTS Compared with healthy subjects, HD patients showed lower C2-C7 Cobb (P < 0.05), and 83.4% patients showed loss of cervical lordosis (cervical straight or kyphosis), which was greater than healthy subjects (55.6%, P < 0.05). Compared with lordotic/straight group, patients with cervical kyphosis showed lower MUNE values and greater single motor unit potential (SMUP) in bilateral APB, and higher apparent dispersion coefficient (ADC) and lower fractional anisotropy were observed at C4/C5 level in the latter than the former (P < 0.05). C2-C7 Cobb was associated with both C4/C5 ADC and bilateral SMUP (P < 0.05). CONCLUSIONS Most HD patients showed loss of cervical sagittal alignments, and both MUNE and DTI detections demonstrated a positive correlation between loss of cervical sagittal alignments and cervical spinal lesions in HD. These findings supported that loss of cervical sagittal alignments may worsen motor impairments in HD. Therefore, it is necessary for clinicians to be aware of restoring cervical sagittal alignments during HD treatment.
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Affiliation(s)
- Kaiwen Chen
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Mid-Wulumuqi Road, Shanghai, 200040, China
| | - Yang Yang
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Chi Sun
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Mid-Wulumuqi Road, Shanghai, 200040, China
| | - Yu Zhu
- Department of Physical Medicine and Rehabilitation, Upstate Medical University, State University of New York at Syracuse, Syracuse, NY, 10212, USA
| | - Hongli Wang
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Mid-Wulumuqi Road, Shanghai, 200040, China
| | - Feizhou Lyu
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Mid-Wulumuqi Road, Shanghai, 200040, China.,Department of Orthopedics, The Fifth People's Hospital, Fudan University, Shanghai, 200240, China
| | - Jianyuan Jiang
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Mid-Wulumuqi Road, Shanghai, 200040, China.
| | - Chaojun Zheng
- Department of Orthopedics, Huashan Hospital, Fudan University, 12 Mid-Wulumuqi Road, Shanghai, 200040, China.
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Yamada S, Hashizume A, Hijikata Y, Inagaki T, Ito D, Kishimoto Y, Kinoshita F, Hirakawa A, Shimizu S, Nakamura T, Katsuno M. Mexiletine in spinal and bulbar muscular atrophy: a randomized controlled trial. Ann Clin Transl Neurol 2022; 9:1702-1714. [PMID: 36208052 PMCID: PMC9639628 DOI: 10.1002/acn3.51667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
Objective Patients with spinal and bulbar muscular atrophy (SBMA) often experience muscular weakness under cold exposure. Methods In our previously conducted observational study, we assessed nerve conduction and grip strength to examine the effect of cold exposure on motor function, based on which we conducted a randomized controlled trial to evaluate the efficacy and safety of mexiletine hydrochloride in SBMA (MEXPRESS). Results In the observational study, 51 consecutive patients with SBMA and 18 healthy controls (HCs) were enrolled. Of the patients with SBMA, 88.0% experienced cold paresis. Patients with SBMA exhibited greater prolongation of ulnar nerve distal latency under cold (SBMA, 5.6 ± 1.1 msec; HC, 4.3 ± 0.6 msec; p <0.001); the change in the distal latencies between room temperature and cold exposure conditions correlated with the change in grip power. In the MEXPRESS trial, 20 participants took mexiletine or lactose, three times a day for 4 weeks with a crossover design. There was no difference in distal latencies at room temperature and under cold exposure between mexiletine and placebo groups as the primary endpoint. However, tongue pressure and 10‐sec grip and release test under cold exposure were improved in the mexiletine group. There were no serious adverse events throughout the study period. Interpretation Cold paresis is common and associated with prolongation of distal latency in SBMA. The results of the phase II clinical trial revealed that mexiletine showed short‐term safety, but it did not restore cold exposure‐induced prolongation of distal latency.
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Affiliation(s)
- Shinichiro Yamada
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Atsushi Hashizume
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Clinical Research Education, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yasuhiro Hijikata
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomonori Inagaki
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daisuke Ito
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshiyuki Kishimoto
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Fumie Kinoshita
- Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Akihiro Hirakawa
- Department of Clinical Biostatistics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinobu Shimizu
- Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Tomohiko Nakamura
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Clinical Research Education, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Wang H, Tian Y, Wu J, Luo S, Zheng C, Sun C, Nie C, Xia X, Ma X, Lyu F, Jiang J, Wang H. Update on the Pathogenesis, Clinical Diagnosis, and Treatment of Hirayama Disease. Front Neurol 2022; 12:811943. [PMID: 35178023 PMCID: PMC8844368 DOI: 10.3389/fneur.2021.811943] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/24/2021] [Indexed: 11/29/2022] Open
Abstract
Hirayama disease (HD) is characterized by the juvenile onset of unilateral or asymmetric weakness and amyotrophy of the hand and ulnar forearm and is most common in males in Asia. A perception of compliance with previous standards of diagnosis and treatment appears to be challenged, so the review is to update on HD. First, based on existing theory, the factors related to HD includes, (1) cervical cord compression during cervical flexion, (2) immunological factors, and (3) other musculoskeletal dynamic factors. Then, we review the clinical manifestations: typically, (1) distal weakness and wasting in one or both upper extremities, (2) insidious onset and initial progression for 3-5 years, (3) coarse tremors in the fingers, (4) cold paralysis, and (5) absence of objective sensory loss; and atypically, (1) positive pyramidal signs, (2) atrophy of the muscles of the proximal upper extremity, (3) long progression, and (4) sensory deficits. Next, updated manifestations of imaging are reviewed, (1) asymmetric spinal cord flattening, and localized lower cervical spinal cord atrophy, (2) loss of attachment between the posterior dural sac and the subjacent lamina, (3) forward displacement of the posterior wall of the cervical dural sac, (4) intramedullary high signal intensity in the anterior horn cells on T2-weighted imaging, and (5) straight alignment or kyphosis of cervical spine. Thus, the main manifestations of eletrophysiological examinations in HD include segmental neurogenic damages of anterior horn cells or anterior roots of the spinal nerve located in the lower cervical spinal cord, without disorder of the sensory nerves. In addition, definite HD needs three-dimensional diagnostic framework above, while probable HD needs to exclude other diseases via "clinical manifestations" and "electrophysiological examinations". Finally, the main purpose of treatment is to avoid neck flexion. Cervical collar is the first-line treatment for HD, while several surgical methods are available and have achieved satisfactory results. This review aimed to improve the awareness of HD in clinicians to enable early diagnosis and treatment, which will enable patients to achieve a better prognosis.
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Affiliation(s)
- Hongwei Wang
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Ye Tian
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Jianwei Wu
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chaojun Zheng
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Chi Sun
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Cong Nie
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Xinlei Xia
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Xiaosheng Ma
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Feizhou Lyu
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
- Department of Orthopedics, Shanghai Fifth People's Hospital, Fudan University, Shanghai, China
| | - Jianyuan Jiang
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
| | - Hongli Wang
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China
- Spine Center Fudan University, Shanghai, China
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Zheng C, Zhu D, Zhu Y, Lyu F, Weber R, Jin X, Jiang J. Early surgery improves peripheral motor axonal dysfunction in acute traumatic central cord syndrome: A prospective cohort study. Clin Neurophysiol 2021; 132:1398-1406. [PMID: 34038847 DOI: 10.1016/j.clinph.2021.02.401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/02/2021] [Accepted: 02/10/2021] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To investigate the impact of early vs. delayed surgical decompression on peripheral motor axonal dysfunction following acute traumatic central cord syndrome (ATCCS). METHODS Both axonal excitability testing and motor unit number estimation (MUNE) were performed in 30 ATCCS patients (early- vs. delayed-surgical treatment: 12 vs. 18) before operation and 28 healthy subjects. Axonal excitability testing was repeated 3-5 days and 1-year after operation, and MUNE was re-evaluated 1-year after operation. RESULTS Preoperatively, an obvious modification in membrane potentials was observed in ATCCS patients that mostly coincided with depolarization-like features, and MUNE further revealed reduced motor units in tested muscles (P < 0.05). Unlike delayed-surgical cases, early-surgical cases showed recoveries of most measurements of axonal excitabilities soon after operation (P < 0.05). Postoperative one-year follow-up demonstrated that greater motor unit numbers in tested muscles were obtained in early-surgical cases than in delayed-surgical cases (P < 0.05). CONCLUSIONS ATCCS has adverse downstream effects on peripheral nervous system, even in the early stage of ATCCS. Early surgical treatment can ameliorate both excitability abnormalities and motor unit loss in distal motor axons. SIGNIFICANCE Optimizing axonal excitability in the early phases of ATCCS may alleviate peripheral nerve injury secondary to lesions of upper motor neuron and improve clinical outcomes.
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Affiliation(s)
- Chaojun Zheng
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Dongqing Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yu Zhu
- Department of Physical Medicine and Rehabilitation, Upstate Medical University, State University of New York at Syracuse, Syracuse, NY 10212, USA
| | - Feizhou Lyu
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China; Department of Orthopedics, The Fifth People's Hospital, Fudan University, Shanghai 200240, China
| | - Robert Weber
- Department of Physical Medicine and Rehabilitation, Upstate Medical University, State University of New York at Syracuse, Syracuse, NY 10212, USA
| | - Xiang Jin
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jianyuan Jiang
- Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China.
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Lyu F, Zheng C, Wang H, Nie C, Ma X, Xia X, Zhu W, Jin X, Hu Y, Sun Y, Zhu Y, Kuwabara S, Cortese R, Maqbool Hassan K, Takai K, Paredes I, Webere R, Turk M, Kimura J, Jiang J. Establishment of a clinician-led guideline on the diagnosis and treatment of Hirayama disease using a modified Delphi technique. Clin Neurophysiol 2020; 131:1311-1319. [DOI: 10.1016/j.clinph.2020.02.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 01/21/2020] [Accepted: 02/11/2020] [Indexed: 11/27/2022]
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Zheng C, Zhu Y, Nie C, Lu F, Zhu D, Weber R, Jiang J. Altered motor axonal excitability in patients with cervical spondylotic amyotrophy. Clin Neurophysiol 2018; 129:1383-1389. [DOI: 10.1016/j.clinph.2018.03.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 03/19/2018] [Accepted: 03/30/2018] [Indexed: 12/13/2022]
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Abstract
Hirayama disease (HD) is a rare motor neuron disorder that involves a single upper extremity. It is clinically characterized by weakness and atrophy of the muscles of the hand and forearm. This article presents a 19-year-old woman who visited the orthopedics outpatient clinic with weakness and atrophy in her right hand and was clinically diagnosed with advanced stage carpal tunnel syndrome and scheduled for surgical intervention; she was later diagnosed with HD by an electrophysiological study. As a result, it has been found that a careful electrophysiological study and neurological examination can be used to diagnose HD. In this way, advanced stage carpal tunnel syndrome will be ruled out and patients will be spared from an unnecessary surgical operation.
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Affiliation(s)
- Halil Ay
- Neurology Department of Medical Faculty, Harran University, Sanliurfa, Turkey
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Abstract
OBJECTIVE To evaluate corticomotoneuronal integrity in monomelic amyotrophy using threshold tracking transcranial magnetic stimulation (TT-TMS). METHODS Cortical excitability studies were prospectively performed in 8 monomelic amyotrophy patients and compared to 21 early-onset amyotrophic lateral sclerosis (ALS) patients and 40 healthy controls. Motor evoked potentials responses were recorded over abductor pollicis brevis. RESULTS Maximal motor evoked potential (MEP/CMAP ratio) was significantly increased in monomelic amyotrophy compared with controls (monomelic amyotrophy 51.2±12.4%; control 22.7±2.1%, p=0.04). Averaged short-interval intracortical inhibition (SICI, ISI 1-7ms) in monomelic amyotrophy patients was similar to controls (monomelic amyotrophy 9.6±2.1%; control 10.0±0.9%, p=0.98). However, it was significantly reduced in early-onset ALS in comparison with monomelic amyotrophy patients (monomelic amyotrophy 9.6±2.1%; ALS 2.3±1.7%, p<0.001). Averaged SICI is a good parameter (area under the curve 0.79, p=0.02) to discriminate between monomelic amyotrophy and early-onset ALS patients. CONCLUSIONS TT-TMS technique has identified normal cortical function in monomelic amyotrophy, a feature that distinguishes it from early-onset ALS. The greater corticomotoneuronal projections to spinal motoneurons may represent central nervous system adaptive change in monomelic amyotrophy. SIGNIFICANCE Corticomotoneuronal dysfunction does not drive the lower motor neurone loss presented in monomelic amyotrophy.
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Miao P, Tang Y, Wang B, Han K, Chen X, Sun H. An aptasensor for detection of potassium ions based on RecJ(f) exonuclease mediated signal amplification. Analyst 2015; 139:5695-9. [PMID: 25248650 DOI: 10.1039/c4an01350f] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
An electrochemical biosensor for potassium has been developed combining specific potassium-aptamer binding and RecJf exonuclease mediated signal amplification. Generally, the DNA probe with a stem-loop structure containing an anti-K(+) aptamer sequence is designed and modified on a gold electrode. K(+) can specifically bind to the aptamer and a G-quadruplex structure forms, which breaks the original stem-loop structure. The induced single-stranded 5' end can be further digested by RecJf exonuclease, releasing K(+) which can bind to another DNA probe on the electrode. After cycles of RecJf exonuclease cleavage initiated by K(+), the electrochemical signal intensity is significantly decreased, and can be used to determine the concentration of K(+). This aptasensor shows high sensitivity, selectivity as well as excellent stability and accuracy, which provides possibilities for further applications of K(+) assay in clinical diagnosis.
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Affiliation(s)
- Peng Miao
- CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China.
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Foster E, Tsang BKT, Kam A, Storey E, Day B, Hill A. Hirayama disease. J Clin Neurosci 2015; 22:951-4. [DOI: 10.1016/j.jocn.2014.11.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 11/25/2014] [Indexed: 11/30/2022]
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Bibliography Current World Literature. CURRENT ORTHOPAEDIC PRACTICE 2012. [DOI: 10.1097/bco.0b013e3182434f58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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