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Nagaratnam SA, Harinesan N, Silsby M, Fung VSC. Unilateral Upper-Limb Tremor Due to C6 Radiculopathy and Demyelinating Neuropathy. Mov Disord Clin Pract 2024; 11:1287-1290. [PMID: 39212305 DOI: 10.1002/mdc3.14180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 07/01/2024] [Accepted: 07/13/2024] [Indexed: 09/04/2024] Open
Affiliation(s)
- Sai A Nagaratnam
- Movement Disorders Unit, Department of Neurology, Westmead Hospital, Westmead, New South Wales, Australia
| | - Nimalan Harinesan
- Department of Neurophysiology, Westmead Hospital, Westmead, New South Wales, Australia
| | - Matthew Silsby
- Department of Neurophysiology, Westmead Hospital, Westmead, New South Wales, Australia
- Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Victor S C Fung
- Movement Disorders Unit, Department of Neurology, Westmead Hospital, Westmead, New South Wales, Australia
- Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
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Silsby M, Yiannikas C, Fois AF, Kennerson ML, Kiernan MC, Fung VSC, Vucic S. Upper and lower limb tremor in Charcot-Marie-Tooth neuropathy type 1A and the implications for standing balance. J Neurol 2024; 271:1776-1786. [PMID: 38051345 PMCID: PMC10972941 DOI: 10.1007/s00415-023-12124-z] [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: 09/25/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 12/07/2023]
Abstract
BACKGROUND Neuropathic tremor occurs in Charcot-Marie-Tooth neuropathy type 1A (CMT1A; hereditary motor and sensory neuropathy, HMSN), although the pathophysiological mechanisms remain to be elucidated. Separately, lower limb tremor has not been explored in CMT1A and could be associated with imbalance as in other neuropathies. The present study aimed to determine tremor characteristics in the upper and lower limbs in CMT1A and relate these findings to clinical disability, particularly imbalance. METHODS Tremor and posturography studies were undertaken in phenotyped and genotyped CMT1A patients. Participants underwent detailed clinical assessment, tremor study recordings, and nerve conduction studies. Tremor stability index was calculated for upper limb tremor and compared to essential tremor. RESULTS Seventeen patients were enrolled. Postural and kinetic upper limb tremors were evident in 65%, while postural and orthostatic lower limb tremors were seen in 35% of CMT1A patients. Peak upper limb frequencies were lower distally (~ 6 Hz) and higher proximally (~ 9 Hz), were unchanged by weight-loading, and not impacted by fatigue. The tremor stability index was significantly higher in CMT1A than in essential tremor. A 5-6 Hz lower limb tremor was recorded which did not vary along the limb and was unaffected by fatigue. Balance was impaired in patients with postural lower limb tremor. A high frequency peak on posturography was associated with 'good' balance. CONCLUSIONS Tremor is a common clinical feature in CMT1A, distinct from essential tremor, mediated by a complex interaction between peripheral and central mechanisms. Postural lower limb tremor is associated with imbalance; strategies aimed at tremor modulation could be of therapeutic utility.
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Affiliation(s)
- Matthew Silsby
- Neurology Department, Westmead Hospital, Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
- Brain and Nerve Research Centre, University of Sydney, Concord, NSW, Australia
- Neurology Department, Concord Hospital, Sydney, NSW, Australia
| | - Con Yiannikas
- Neurology Department, Concord Hospital, Sydney, NSW, Australia
- Neurology Department, Royal North Shore Hospital, Sydney, NSW, Australia
| | - Alessandro F Fois
- Neurology Department, Westmead Hospital, Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Marina L Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, University of Sydney, Sydney, NSW, Australia
- Molecular Medicine Laboratory, Concord Hospital, Concord, NSW, Australia
| | - Matthew C Kiernan
- Neurology Department, Royal Prince Alfred Hospital Sydney, Sydney, NSW, Australia
- Brain and Mind Centre, University of Sydney, Camperdown, NSW, Australia
| | - Victor S C Fung
- Neurology Department, Westmead Hospital, Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Steve Vucic
- Brain and Nerve Research Centre, University of Sydney, Concord, NSW, Australia.
- Neurology Department, Concord Hospital, Sydney, NSW, Australia.
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Silsby M, Yiannikas C, Fois AF, Kiernan MC, Fung VSC, Vucic S. Upper and lower limb tremor in inflammatory neuropathies. Clin Neurophysiol 2024; 158:69-78. [PMID: 38194761 DOI: 10.1016/j.clinph.2023.12.005] [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: 08/04/2023] [Revised: 11/23/2023] [Accepted: 12/06/2023] [Indexed: 01/11/2024]
Abstract
OBJECTIVE The mechanisms underlying neuropathic tremor remain incompletely understood and a distinction has not been drawn between proximal and distal neuropathies. Lower limb tremor contributes to imbalance in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but this is unexplored in other neuropathies. We characterized upper and lower limb tremor in chronic immune sensory polyradiculopathy (CISP) and distal acquired demyelinating neuropathy with anti-MAG antibodies (DADS-MAG), contrasted to CIDP. METHODS This was a cross-sectional study of 38 patients (CIDP [n = 25], CISP [n = 7], DADS-MAG [n = 6]). Clinical assessment, tremor study recordings, nerve conduction studies, and somatosensory evoked potentials were performed. Balance was measured by force platform. RESULTS Upper limb tremor was prevalent (CIDP 66%, CISP 70%, DADS-MAG 100%). Peak frequencies followed a gradient along the upper limb, unchanged by weight-loading. Lower limb tremor was also present (CIDP 32%, CISP 29%, DADS-MAG 66%) and associated with imbalance. Nerve conduction parameters correlated with upper limb tremor in DADS-MAG and CISP, and imbalance in CISP. CONCLUSIONS Upper limb tremor is mediated by peripheral and central mechanisms regardless of distal or proximal pathology. Lower limb tremor correlates with peripheral nerve function and contributes to imbalance. SIGNIFICANCE This study contributes to the understanding of neuropathic tremor. Addressing lower limb tremor may be of therapeutic importance for neuropathy-associated imbalance.
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Affiliation(s)
- Matthew Silsby
- Neurology Department, Westmead Hospital; Westmead Clinical School, University of Sydney, Australia; Brain and Nerve Research Centre, University of Sydney, Australia; Neurology Department, Concord Hospital Sydney, Australia
| | - Con Yiannikas
- Neurology Department, Concord Hospital Sydney, Australia; Neurology Department, Royal North Shore Hospital Sydney, Australia
| | - Alessandro F Fois
- Neurology Department, Westmead Hospital; Westmead Clinical School, University of Sydney, Australia
| | - Matthew C Kiernan
- Neurology Department, Royal Prince Alfred Hospital Sydney, Australia; Brain and Mind Centre, University of Sydney, Australia
| | - Victor S C Fung
- Neurology Department, Westmead Hospital; Westmead Clinical School, University of Sydney, Australia
| | - Steve Vucic
- Brain and Nerve Research Centre, University of Sydney, Australia; Neurology Department, Concord Hospital Sydney, Australia.
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Angelini L, Terranova R, Lazzeri G, van den Berg KRE, Dirkx MF, Paparella G. The role of laboratory investigations in the classification of tremors. Neurol Sci 2023; 44:4183-4192. [PMID: 37814130 PMCID: PMC10641063 DOI: 10.1007/s10072-023-07108-w] [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: 08/23/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023]
Abstract
INTRODUCTION Tremor is the most common movement disorder. Although clinical examination plays a significant role in evaluating patients with tremor, laboratory tests are useful to classify tremors according to the recent two-axis approach proposed by the International Parkinson and Movement Disorders Society. METHODS In the present review, we will discuss the usefulness and applicability of the various diagnostic methods in classifying and diagnosing tremors. We will evaluate a number of techniques, including laboratory and genetic tests, neurophysiology, and neuroimaging. The role of newly introduced innovative tremor assessment methods will also be discussed. RESULTS Neurophysiology plays a crucial role in tremor definition and classification, and it can be useful for the identification of specific tremor syndromes. Laboratory and genetic tests and neuroimaging may be of paramount importance in identifying specific etiologies. Highly promising innovative technologies are being developed for both clinical and research purposes. CONCLUSIONS Overall, laboratory investigations may support clinicians in the diagnostic process of tremor. Also, combining data from different techniques can help improve understanding of the pathophysiological bases underlying tremors and guide therapeutic management.
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Affiliation(s)
- Luca Angelini
- Department of Human Neurosciences, Sapienza University of Rome, Viale Dell'Università 30, 00185, Rome, Italy.
| | - Roberta Terranova
- Department of Medical, Surgical Sciences and Advanced Technologies "GF Ingrassia," University of Catania, Catania, Italy
| | - Giulia Lazzeri
- IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Kevin R E van den Berg
- Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
- Department of Neurology, Center of Expertise for Parkinson and Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Michiel F Dirkx
- Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
- Department of Neurology, Center of Expertise for Parkinson and Movement Disorders, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Giulia Paparella
- Department of Human Neurosciences, Sapienza University of Rome, Viale Dell'Università 30, 00185, Rome, Italy
- IRCCS Neuromed, Pozzilli (IS), Italy
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Silsby M, Yiannikas C, Fois AF, Ng K, Kiernan MC, Fung VSC, Vucic S. Imbalance and lower limb tremor in chronic inflammatory demyelinating polyradiculoneuropathy. J Peripher Nerv Syst 2023; 28:415-424. [PMID: 37314215 DOI: 10.1111/jns.12574] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/08/2023] [Accepted: 06/11/2023] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND AIMS Imbalance is a prominent symptom of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Although upper limb tremor in CIDP is described, lower limb tremor has not been assessed. The aim of this study was to determine whether lower limb tremor was present in CIDP and assess potential relationships with imbalance. METHODS This was a cross-sectional observational study of prospectively recruited consecutive patients with typical CIDP (N = 25). Clinical phenotyping, lower limb nerve conduction and tremor studies, and posturography analyses were performed. The Berg Balance Scale (BBS) divided CIDP patients into those with "good" and "poor" balance. RESULTS Lower limb tremor was evident in 32% of CIDP patients and associated with poor balance (BBSTremor 35 [23-46], BBSNo Tremor 52 [44-55], p = .035). Tremor frequency was 10.2-12.5 Hz with legs outstretched and on standing, apart from four patients with a lower frequency tremor (3.8-4.6 Hz) while standing. Posturography analysis revealed a high-frequency spectral peak in the vertical axis in 44% of CIDP patients (16.0 ± 0.4 Hz). This was more likely in those with "good" balance (40% vs. 4%, p = .013). INTERPRETATION Lower limb tremor is present in one third of CIDP patients and is associated with poor balance. A high-frequency peak on posturography is associated with better balance in CIDP. Lower limb tremor and posturography assessments could serve as important biomarkers of balance in a clinical setting.
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Affiliation(s)
- Matthew Silsby
- Neurology Department, Westmead Hospital Sydney & Sydney Medical School, University of Sydney, Sydney, NSW, Australia
- Brain and Nerve Research Centre, Concord Hospital, University of Sydney, Sydney, Australia
- Neurology Department, Concord Hospital Sydney, Sydney, Australia
| | - Con Yiannikas
- Neurology Department, Concord Hospital Sydney, Sydney, Australia
- Neurology Department, Royal North Shore Hospital Sydney & Sydney Medical School, University of Sydney, Sydney, Australia
| | - Alessandro F Fois
- Neurology Department, Westmead Hospital Sydney & Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Karl Ng
- Neurology Department, Royal North Shore Hospital Sydney & Sydney Medical School, University of Sydney, Sydney, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney & Neurology Department, Royal Prince Alfred Hospital, Sydney, Australia
| | - Victor S C Fung
- Neurology Department, Westmead Hospital Sydney & Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Steve Vucic
- Brain and Nerve Research Centre, Concord Hospital, University of Sydney, Sydney, Australia
- Neurology Department, Concord Hospital Sydney, Sydney, Australia
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