1
|
Gong Z, Bilgel M, An Y, Bergeron CM, Bergeron J, Zukley L, Ferrucci L, Resnick SM, Bouhrara M. Cerebral white matter myelination is associated with longitudinal changes in processing speed across the adult lifespan. Brain Commun 2024; 6:fcae412. [PMID: 39697833 PMCID: PMC11653079 DOI: 10.1093/braincomms/fcae412] [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: 02/28/2024] [Revised: 10/16/2024] [Accepted: 11/15/2024] [Indexed: 12/20/2024] Open
Abstract
Myelin's role in processing speed is pivotal, as it facilitates efficient neural conduction. Its decline could significantly affect cognitive efficiency during ageing. In this work, myelin content was quantified using our advanced MRI method of myelin water fraction mapping. We examined the relationship between myelin water fraction at the time of MRI and retrospective longitudinal change in processing speed among 121 cognitively unimpaired participants, aged 22-94 years, from the Baltimore Longitudinal Study of Aging and the Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing (a mean follow-up duration of 4.3 ± 6.3 years) using linear mixed-effects models, adjusting for demographics. We found that higher myelin water fraction values correlated with longitudinally better-maintained processing speed, with particularly significant associations in several white matter regions. Detailed voxel-wise analysis provided further insight into the specific white matter tracts involved. This research underscores the essential role of myelin in preserving processing speed and highlights its potential as a sensitive biomarker for interventions targeting age-related cognitive decline, thereby offering a foundation for preventative strategies in neurological health.
Collapse
Affiliation(s)
- Zhaoyuan Gong
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Murat Bilgel
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Yang An
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Christopher M Bergeron
- Clinical Research Core, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Jan Bergeron
- Clinical Research Core, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Linda Zukley
- Clinical Research Core, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Luigi Ferrucci
- Longitudinal Studies Section, Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Susan M Resnick
- Brain Aging and Behavior Section, Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Mustapha Bouhrara
- Magnetic Resonance Physics of Aging and Dementia Unit, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| |
Collapse
|
2
|
Klein C, Liu H, Zhao C, Huang W. Altered flexor carpi radialis motor axon excitability properties after cerebrovascular stroke. Front Neurol 2023; 14:1172960. [PMID: 37284180 PMCID: PMC10240235 DOI: 10.3389/fneur.2023.1172960] [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: 02/24/2023] [Accepted: 04/12/2023] [Indexed: 06/08/2023] Open
Abstract
Background Spinal motoneurons may become hyperexcitable after a stroke. Knowledge about motoneuron hyperexcitability remains clinically important as it may contribute to a number of phenomena including spasticity, flexion synergies, and abnormal limb postures. Hyperexcitability seems to occur more often in muscles that flex the wrist and fingers (forearm flexors) compared to other upper limb muscles. The cause of hyperexcitability remains uncertain but may involve plastic changes in motoneurons and their axons. Aim To characterize intrinsic membrane properties of flexor carpi radialis (FCR) motor axons after stroke using nerve excitability testing. Methods Nerve excitability testing using threshold tracking techniques was applied to characterize FCR motor axon properties in persons who suffered a first-time unilateral cortical/subcortical stroke 23 to 308 days earlier. The median nerve was stimulated at the elbow bilaterally in 16 male stroke subjects (51.4 ± 2.9 y) with compound muscle action potentials recorded from the FCR. Nineteen age-matched males (52.7 ± 2.4 y) were also tested to serve as controls. Results Axon parameters after stroke were consistent with bilateral hyperpolarization of the resting potential. Nonparetic and paretic side axons were modeled by a 2.6-fold increase in pump currents (IPumpNI) together with an increase (38%-33%) in internodal leak conductance (GLkI) and a decrease (23%-29%) in internodal H conductance (Ih) relative to control axons. A decrease (14%) in Na+ channel inactivation rate (Aah) was also needed to fit the paretic axon recovery cycle. "Fanning out" of threshold electrotonus and the resting I/V slope (stroke limbs combined) correlated with blood potassium [K+] (R = -0.61 to 0.62, p< 0.01) and disability (R = -0.58 to 0.55, p < 0.05), but not with spasticity, grip strength, or maximal FCR activity. Conclusion In contrast to our expectations, FCR axons were not hyperexcitable after stroke. Rather, FCR axons were found to be hyperpolarized bilaterally post stroke, and this was associated with disability and [K+]. Reduced FCR axon excitability may represent a kind of bilateral trans-synaptic homeostatic mechanism that acts to minimize motoneuron hyperexcitability.
Collapse
|
3
|
Neuroplasticity of peripheral axonal properties after ischemic stroke. PLoS One 2022; 17:e0275450. [PMID: 36194586 PMCID: PMC9531785 DOI: 10.1371/journal.pone.0275450] [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: 06/23/2022] [Accepted: 09/15/2022] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE This study investigated how peripheral axonal excitability changes in ischemic stroke patients with hemiparesis or hemiplegia, reflecting the plasticity of motor axons due to corticospinal tract alterations along the poststroke stage. METHODS Each subject received a clinical evaluation, nerve conduction study, and nerve excitability test. Nerve excitability tests were performed on motor median nerves in paretic and non-paretic limbs in the acute stage of stroke. Control nerve excitability test data were obtained from age-matched control subjects. Some patients underwent excitability examinations several times in subacute or chronic stages. RESULTS A total of thirty patients with acute ischemic stroke were enrolled. Eight patients were excluded due to severe entrapment neuropathy in the median nerve. The threshold current for 50% compound muscle action potential (CMAP) was higher in paretic limbs than in control subjects. Furthermore, in the cohort with severe patients (muscle power ≤ 3/5 in affected hands), increased threshold current for 50% CMAP and reduced subexcitability were noted in affected limbs than in unaffected limbs. In addition, in the subsequent study of those severe patients, threshold electrotonus increased in the hyperpolarization direction: TEh (100-109 ms), and the minimum I/V slope decreased. The above findings suggest the less excitable and less accommodation in lower motor axons in the paretic limb caused by ischemic stroke. CONCLUSION Upper motor neuron injury after stroke can alter nerve excitability in lower motor neurons, and the changes are more obvious in severely paretic limbs. The accommodative changes of axons progress from the subacute to the chronic stage after stroke. Further investigation is necessary to explore the downstream effects of an upper motor neuron insult in the peripheral nerve system.
Collapse
|
4
|
Silverstein JW, Block J, Smith ML, Bomback DA, Sanderson S, Paul J, Ball H, Ellis JA, Goldstein M, Kramer DL, Arutyunyan G, Marcus J, Mermelstein S, Slosar P, Goldthwaite N, Lee SI, Reynolds J, Riordan M, Pirnia N, Kunwar S, Abbi G, Bizzini B, Gupta S, Porter D, Mermelstein LE. Femoral nerve neuromonitoring for lateral lumbar interbody fusion surgery. Spine J 2022; 22:296-304. [PMID: 34343664 DOI: 10.1016/j.spinee.2021.07.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/26/2021] [Accepted: 07/26/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT The transpsoas lateral lumbar interbody fusion (LLIF) technique is an effective alternative to traditional anterior and posterior approaches to the lumbar spine; however, nerve injuries are the most reported postoperative complication. Commonly used strategies to avoid nerve injury (eg, limiting retraction duration) have not been effective in detecting or preventing femoral nerve injuries. PURPOSE To evaluate the efficacy of emerging intraoperative femoral nerve monitoring techniques and the importance of employing prompt surgical countermeasures when degraded femoral nerve function is detected. STUDY DESIGN/SETTING We present the results from a retrospective analysis of a multi-center study conducted over the course of 3 years. PATIENT SAMPLE One hundred and seventy-two lateral lumbar interbody fusion procedures were reviewed. OUTCOME MEASURES Intraoperative femoral nerve monitoring data was correlated to immediate postoperative neurologic examinations. METHODS Femoral nerve evoked potentials (FNEP) including saphenous nerve somatosensory evoked potentials (snSSEP) and motor evoked potentials with quadriceps recordings were used to detect evidence of degraded femoral nerve function during the time of surgical retraction. RESULTS In 89% (n=153) of the surgeries, there were no surgeon alerts as the FNEP response amplitudes remained relatively unchanged throughout the surgery (negative group). The positive group included 11% of the cases (n=19) where the surgeon was alerted to a deterioration of the FNEP amplitudes during surgical retraction. Prompt surgical countermeasures to an FNEP alert included loosening, adjusting, or removing surgical retraction, and/or requesting an increase in blood pressure from the anesthesiologist. All the cases where prompt surgical countermeasures were employed resulted in recovery of the degraded FNEP amplitudes and no postoperative femoral nerve injuries. In two cases, the surgeons were given verbal alerts of degraded FNEPs but did not employ prompt surgical countermeasures. In both cases, the degraded FNEP amplitudes did not recover by the time of surgical closure, and both patients exhibited postoperative signs of sensorimotor femoral nerve injury including anterior thigh numbness and weakened knee extension. CONCLUSIONS Multimodal femoral nerve monitoring can provide surgeons with a timely alert to hyperacute femoral nerve conduction failure, enabling prompt surgical countermeasures to be employed that can mitigate or avoid femoral nerve injury. Our data also suggests that the common strategy of limiting retraction duration may not be effective in preventing iatrogenic femoral nerve injuries.
Collapse
Affiliation(s)
- Justin W Silverstein
- Neuro Protective Solutions, New York, NY 11788, USA; Northwell Health Lenox Hill Hospital, New York, NY, USA; Northwell Health Huntington Hospital, Huntington, NY, USA.
| | - Jon Block
- ION Intraoperative Neurophysiology, Orinda, CA, USA
| | - Michael L Smith
- Rothman Orthopedic Institute, New York, NY, USA; Northwell Health Lenox Hill Hospital, New York, NY, USA
| | - David A Bomback
- Connecticut Neck and Back Specialists, Danbury, CT, USA; Nuvance Health, Danbury, CT, USA
| | - Scott Sanderson
- Elite Brain and Spine of Connecticut, Danbury CT, USA; Nuvance Health, Danbury, CT, USA
| | - Justin Paul
- OrthoConnecticut, Danbury CT, USA; Nuvance Health, Danbury, CT, USA
| | - Hieu Ball
- San Ramone Regional Medical Center, San Ramon, CA, USA
| | - Jason A Ellis
- Northwell Health Lenox Hill Hospital, New York, NY, USA
| | - Matthew Goldstein
- Orthopedic Associates of Manhasset, Great Neck, NY, USA; St. Francis Hospital, Roslyn, NY, USA
| | - David L Kramer
- Connecticut Neck and Back Specialists, Danbury, CT, USA; Nuvance Health, Danbury, CT, USA
| | - Grigoriy Arutyunyan
- Rothman Orthopedic Institute, New York, NY, USA; Northwell Health Lenox Hill Hospital, New York, NY, USA
| | - Joshua Marcus
- Elite Brain and Spine of Connecticut, Danbury CT, USA; Nuvance Health, Danbury, CT, USA
| | - Sara Mermelstein
- New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, USA
| | | | | | | | | | | | | | | | | | | | - Sarita Gupta
- ION Intraoperative Neurophysiology, Orinda, CA, USA
| | | | - Laurence E Mermelstein
- Long Island Spine Specialists, Long Island, NY, USA; Northwell Health Huntington Hospital, Huntington, NY, USA
| |
Collapse
|
5
|
Altered sensory nerve excitability in fibromyalgia. J Formos Med Assoc 2021; 120:1611-1619. [PMID: 33642123 DOI: 10.1016/j.jfma.2021.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/23/2020] [Accepted: 02/02/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND/PURPOSE To investigate nerve excitability changes in patients with fibromyalgia and the correlation with clinical severity. METHODS We enrolled 20 subjects with fibromyalgia and 22 sex and age-matched healthy subjects to receive nerve excitability test and nerve conduction study to evaluate the peripheral axonal function. RESULTS In the fibromyalgia cohort, the sensory axonal excitability test revealed increased superexcitability (%) (P = 0.029) compared to healthy control. Correlational study showed a negative correlation between increased subexcitability (%) (r = -0.534, P = 0.022) with fibromyalgia impact questionnaire (FIQ) score. Computer modeling confirmed that the sensory axon excitability pattern we observed in fibromyalgia cohort was best explained by increased Barrett-Barrett conductance, which was thought to be attributed to paranodal fast K+ channel dysfunction. CONCLUSION The present study revealed that paranodal sensory K+ conductance was altered in patients with fibromyalgia. The altered conductance indicated dysfunction of paranodal fast K+ channels, which is known to be associated with the generation of pain.
Collapse
|
6
|
Chiang MC, Yeh TY, Sung JY, Hsueh HW, Kao YH, Hsueh SJ, Chang KC, Feng FP, Lin YH, Chao CC, Hsieh ST. Early changes of nerve integrity in preclinical carriers of hereditary transthyretin Ala117Ser amyloidosis with polyneuropathy. Eur J Neurol 2021; 28:982-991. [PMID: 33369810 DOI: 10.1111/ene.14698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/29/2020] [Accepted: 12/22/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE Disease-modifying therapies provide new horizons for hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) to slow neuropathic progression. Initiating treatment at the earliest time requires biomarkers reflecting both small- and large-fiber degeneration in carriers. METHODS This study included examinations of pathology (intraepidermal nerve fiber [IENF] density), physiology (nerve conduction studies, autonomic function test, and nerve excitability), and psychophysics (thermal thresholds) in carriers to compare to healthy controls and asymptomatic diabetic patients. RESULTS There were 43 carriers (44.2 ± 11.4 years, p.Ala117Ser in 42 carriers), 43 controls (43.4 ± 12.7 years) including 26 noncarrier families, and 50 asymptomatic diabetic patients (58.1 ± 9.5 years). Carriers had lower IENF densities than controls and similar densities as diabetic patients. Median nerve conduction parameters, especially distal motor latency, were the most frequent neurophysiological abnormality in carriers, could differentiate carriers from controls and diabetic patients, were correlated with IENF densities in carriers but not in controls and diabetic patients, and were correlated with nerve excitability parameters in carriers but not in controls. Fifteen carriers (34.9%) with electrophysiological evidence of median nerve entrapment at the wrist had lower IENF densities and more abnormal conduction parameters than carriers without. We defined nerve dysfunction index-the ratio of median distal motor latency to IENF density-which differentiated carriers from controls. CONCLUSIONS In late-onset ATTRv-PN carriers with predominant p.Ala117Ser, median conduction parameters were the most common neurophysiological abnormalities and served as surrogate signatures of small- and large-fiber impairment. Combination of median distal motor latency and IENF density can reflect early neuropathy in carriers.
Collapse
Affiliation(s)
- Ming-Chang Chiang
- Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan
| | - Ti-Yen Yeh
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Jia-Ying Sung
- Department of Neurology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Hsueh-Wen Hsueh
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yi-Hui Kao
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Sung-Ju Hsueh
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Kai-Chieh Chang
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Fang-Ping Feng
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yea-Huey Lin
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Chao Chao
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Sung-Tsang Hsieh
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.,Center of Precision Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
| |
Collapse
|
7
|
Visual loss and recovery in chiasmal compression. Prog Retin Eye Res 2019; 73:100765. [DOI: 10.1016/j.preteyeres.2019.06.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 12/18/2022]
|
8
|
Bolon B, Krinke GJ, Pardo ID. Essential References for Structural Analysis of the Peripheral Nervous System for Pathologists and Toxicologists. Toxicol Pathol 2019; 48:87-95. [DOI: 10.1177/0192623319868160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Toxicologic neuropathology for the peripheral nervous system (PNS) is a vital but often underappreciated element of basic translational research and safety assessment. Evaluation of the PNS may be complicated by unfamiliarity with normal nerve and ganglion biology, which differs to some degree among species; the presence of confounding artifacts related to suboptimal sampling and processing; and limited experience with differentiating such artifacts from genuine disease manifestations and incidental background changes. This compilation of key PNS neurobiology, neuropathology, and neurotoxicology references is designed to allow pathologists and toxicologists to readily access essential information that is needed to enhance their proficiency in evaluating and interpreting toxic changes in PNS tissues from many species.
Collapse
|
9
|
Yamazaki Y. Oligodendrocyte Physiology Modulating Axonal Excitability and Nerve Conduction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:123-144. [PMID: 31760642 DOI: 10.1007/978-981-32-9636-7_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Oligodendrocytes enable saltatory conduction by forming a myelin sheath around axons, dramatically boosts action potential conduction velocity. In addition to this canonical function of oligodendrocytes, it is now known that oligodendrocytes can respond to neuronal activity and regulate axonal conduction. Importantly, white matter plasticity, including adaptive responses by oligodendrocytes, has been shown to be involved in learning and memory. In this chapter, the role of oligodendrocytes in axonal conduction and axonal excitability will be reviewed. Focus will be paid to the mechanisms through which oligodendrocytes, including perineuronal oligodendrocytes, facilitate and suppress axonal conduction.
Collapse
Affiliation(s)
- Yoshihiko Yamazaki
- Department of Physiology, Yamagata University School of Medicine, Yamagata, Japan.
| |
Collapse
|
10
|
Lefaucheur JP. New insights into the pathophysiology of primary hemifacial spasm. Neurochirurgie 2018; 64:87-93. [DOI: 10.1016/j.neuchi.2017.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 12/21/2022]
|
11
|
Matamala JM, Howells J, Dharmadasa T, Huynh W, Park SB, Burke D, Kiernan MC. Excitability of sensory axons in amyotrophic lateral sclerosis. Clin Neurophysiol 2018; 129:1472-1478. [PMID: 29661595 DOI: 10.1016/j.clinph.2018.03.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/22/2018] [Accepted: 03/11/2018] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To evaluate the excitability of sensory axons in patients with amyotrophic lateral sclerosis (ALS). METHODS Comprehensive sensory nerve excitability studies were prospectively performed on 28 sporadic ALS patients, compared to age-matched controls. Sensory nerve action potentials were recorded from digit 2 following median nerve stimulation at the wrist. Disease severity was measured using motor unit number estimation (MUNE), the revised ALS Functional Rating Scale (ALSFRS-R) and the MRC scale. RESULTS There were no significant differences in standard and extended measures of nerve excitability between ALS patients and controls. These unchanged excitability measures included accommodation to long-lasting hyperpolarization and the threshold changes after two supramaximal stimuli during the recovery cycle. Excitability parameters did not correlate with MUNE, ALSFRS-R, APB MRC scale or disease duration. CONCLUSIONS This cross-sectional study has identified normal axonal membrane properties in myelinated sensory axons of ALS patients. Previously described sensory abnormalities could be the result of axonal fallout, possibly due to a ganglionopathy, or to involvement of central sensory pathways rostral to gracile and cuneate nuclei. SIGNIFICANCE These results demonstrate the absence of generalized dysfunction of the membrane properties of sensory axons in ALS in the face of substantial deficits in motor function.
Collapse
Affiliation(s)
| | - James Howells
- Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
| | - Thanuja Dharmadasa
- Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
| | - William Huynh
- Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
| | - Susanna B Park
- Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
| | - David Burke
- Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| |
Collapse
|
12
|
Heide R, Bostock H, Ventzel L, Grafe P, Bergmans J, Fuglsang-Frederiksen A, Finnerup NB, Tankisi H. Axonal excitability changes and acute symptoms of oxaliplatin treatment: In vivo evidence for slowed sodium channel inactivation. Clin Neurophysiol 2017; 129:694-706. [PMID: 29233604 DOI: 10.1016/j.clinph.2017.11.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 10/16/2017] [Accepted: 11/05/2017] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Neurotoxicity is the most frequent dose-limiting side effect of the anti-cancer agent oxaliplatin, but the mechanisms are not well understood. This study used nerve excitability testing to investigate the pathophysiology of the acute neurotoxicity. METHODS Questionnaires, quantitative sensory tests, nerve conduction studies and nerve excitability testing were undertaken in 12 patients with high-risk colorectal cancer treated with adjuvant oxaliplatin and in 16 sex- and age-matched healthy controls. Examinations were performed twice for patients: once within 3 days after oxaliplatin treatment (post-infusion examination) and once shortly before the following treatment (recovery examination). RESULTS The most frequent post-infusion symptoms were tingling paresthesias and cold allodynia. The most prominent nerve excitability change was decreased superexcitability of motor axons which correlated with the average intensity of abnormal sensations (Spearman Rho = 0.80, p < .01). The motor nerve excitability changes were well modeled by a slowing of sodium channel inactivation, and were proportional to dose/m2 with a half-life of about 10d. CONCLUSIONS Oxaliplatin induces reversible slowing of sodium channel inactivation in motor axons, and these changes are closely related to the reversible cold allodynia. However, further studies are required due to small sample size in this study. SIGNIFICANCE Nerve excitability data provide an index of sodium channel dysfunction: an objective biomarker of acute oxaliplatin neurotoxicity.
Collapse
Affiliation(s)
- Rikke Heide
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark; Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Hugh Bostock
- Institute of Neurology, Queen Square House, London, United Kingdom
| | - Lise Ventzel
- Department of Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Grafe
- Institute of Physiology, Ludwig-Maximilians University Munich, Munich, Germany
| | - Joseph Bergmans
- Laboratory of Clinical Neurophysiology, Faculty of Medicine, University of Louvain, Brussels, Belgium
| | | | - Nanna B Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
| |
Collapse
|
13
|
Bolzoni F, Esposti R, Bruttini C, Zenoni G, Jankowska E, Cavallari P. Direct current stimulation modulates the excitability of the sensory and motor fibres in the human posterior tibial nerve, with a long-lasting effect on the H-reflex. Eur J Neurosci 2017; 46:2499-2506. [PMID: 28892581 DOI: 10.1111/ejn.13696] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 02/06/2023]
Abstract
Several studies demonstrated that transcutaneous direct current stimulation (DCS) may modulate central nervous system excitability. However, much less is known about how DC affects peripheral nerve fibres. We investigated the action of DCS on motor and sensory fibres of the human posterior tibial nerve, with supplementary analysis in acute experiments on rats. In forty human subjects, electric pulses at the popliteal fossa were used to elicit either M-waves or H-reflexes in the Soleus, before (15 min), during (10 min) and after (30 min) DCS. Cathodal or anodal current (2 mA) was applied to the same nerve. Cathodal DCS significantly increased the H-reflex amplitude; the post-polarization effect lasted up to ~ 25 min after the termination of DCS. Anodal DCS instead significantly decreased the reflex amplitude for up to ~ 5 min after DCS end. DCS effects on M-wave showed the same polarity dependence but with considerably shorter after-effects, which never exceeded 5 min. DCS changed the excitability of both motor and sensory fibres. These effects and especially the long-lasting modulation of the H-reflex suggest a possible rehabilitative application of DCS that could be applied either to compensate an altered peripheral excitability or to modulate the afferent transmission to spinal and supraspinal structures. In animal experiments, DCS was applied, under anaesthesia, to either the exposed peroneus nerve or its Dorsal Root, and its effects closely resembled those found in human subjects. They validate therefore the use of the animal models for future investigations on the DCS mechanisms.
Collapse
Affiliation(s)
- Francesco Bolzoni
- Human Physiology Section of the De.P.T., Università degli Studi di Milano, Via Mangiagalli 32, I-20133, Milan, Italy.,Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Roberto Esposti
- Human Physiology Section of the De.P.T., Università degli Studi di Milano, Via Mangiagalli 32, I-20133, Milan, Italy
| | - Carlo Bruttini
- Human Physiology Section of the De.P.T., Università degli Studi di Milano, Via Mangiagalli 32, I-20133, Milan, Italy
| | - Giuseppe Zenoni
- Human Physiology Section of the De.P.T., Università degli Studi di Milano, Via Mangiagalli 32, I-20133, Milan, Italy
| | - Elzbieta Jankowska
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Paolo Cavallari
- Human Physiology Section of the De.P.T., Università degli Studi di Milano, Via Mangiagalli 32, I-20133, Milan, Italy
| |
Collapse
|
14
|
Banzrai C, Nodera H, Kawarai T, Higashi S, Okada R, Mori A, Shimatani Y, Osaki Y, Kaji R. Impaired Axonal Na(+) Current by Hindlimb Unloading: Implication for Disuse Neuromuscular Atrophy. Front Physiol 2016; 7:36. [PMID: 26909041 PMCID: PMC4754663 DOI: 10.3389/fphys.2016.00036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/26/2016] [Indexed: 12/12/2022] Open
Abstract
This study aimed to characterize the excitability changes in peripheral motor axons caused by hindlimb unloading (HLU), which is a model of disuse neuromuscular atrophy. HLU was performed in normal 8-week-old male mice by fixing the proximal tail by a clip connected to the top of the animal's cage for 3 weeks. Axonal excitability studies were performed by stimulating the sciatic nerve at the ankle and recording the compound muscle action potential (CMAP) from the foot. The amplitudes of the motor responses of the unloading group were 51% of the control amplitudes [2.2 ± 1.3 mV (HLU) vs. 4.3 ± 1.2 mV (Control), P = 0.03]. Multiple axonal excitability analysis showed that the unloading group had a smaller strength-duration time constant (SDTC) and late subexcitability (recovery cycle) than the controls [0.075 ± 0.01 (HLU) vs. 0.12 ± 0.01 (Control), P < 0.01; 5.4 ± 1.0 (HLU) vs. 10.0 ± 1.3 % (Control), P = 0.01, respectively]. Three weeks after releasing from HLU, the SDTC became comparable to the control range. Using a modeling study, the observed differences in the waveforms could be explained by reduced persistent Na+ currents along with parameters related to current leakage. Quantification of RNA of a SCA1A gene coding a voltage-gated Na+ channel tended to be decreased in the sciatic nerve in HLU. The present study suggested that axonal ion currents are altered in vivo by HLU. It is still undetermined whether the dysfunctional axonal ion currents have any pathogenicity on neuromuscular atrophy or are the results of neural plasticity by atrophy.
Collapse
Affiliation(s)
| | - Hiroyuki Nodera
- Department of Neurology, Tokushima University Tokushima, Japan
| | | | - Saki Higashi
- Department of Neurology, Tokushima University Tokushima, Japan
| | - Ryo Okada
- Department of Neurology, Tokushima University Tokushima, Japan
| | - Atsuko Mori
- Department of Neurology, Tokushima University Tokushima, Japan
| | | | - Yusuke Osaki
- Department of Neurology, Tokushima University Tokushima, Japan
| | - Ryuji Kaji
- Department of Neurology, Tokushima University Tokushima, Japan
| |
Collapse
|
15
|
Sung JY, Tani J, Hung KS, Lui TN, Lin CSY. Sensory axonal dysfunction in cervical radiculopathy. J Neurol Neurosurg Psychiatry 2015; 86:640-5. [PMID: 25143629 DOI: 10.1136/jnnp-2014-308088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 08/01/2014] [Indexed: 11/03/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate changes in sensory axonal excitability in the distal nerve in patients with cervical radiculopathy. METHODS The patients were classified by the findings of cervical MRI into two subgroups: 22 patients with C6/7 root compression and 25 patients with cervical cord and root compression above/at C6/7. Patients were investigated using conventional nerve conduction studies (NCS) and nerve excitability testing. Sensory nerve excitability testing was undertaken with stimulation at the wrist and recording from digit II (dermatome C6/7). The results were compared with healthy controls. Both preoperative and postoperative tests were performed if the patient underwent surgery. RESULTS Sensory axonal excitability was significantly different in both cohorts compared with healthy controls, including prolonged strength-duration time constant, reduced S2 accommodation, increased threshold electrotonus hyperpolarisation (TEh (90-100 ms)), and increased superexcitability. The changes in these excitability indices are compatible with axonal membrane hyperpolarisation. In five patients who underwent surgery, the postoperative sensory excitability was tested after 1 week, and showed significant changes in TE (TEh (90-100 ms) and TEh slope, p<0.05) between presurgery and postsurgery. CONCLUSIONS The present study demonstrated distal nerve axonal hyperpolarisation in patients with cervical radiculopathy. These findings suggest that the hyperpolarised pattern might be due to Na(+)-K(+) ATPase overactivation induced by proximal ischaemia, or could reflect the remyelinating process. Distal sensory axons were hyperpolarised even though there were no changes in NCS, suggesting that nerve excitability testing may be more sensitive to clinical symptoms than NCS in patients with cervical radiculopathy.
Collapse
Affiliation(s)
- Jia-Ying Sung
- Department of Neurology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jowy Tani
- Department of Neurology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Kuo-Sheng Hung
- Division of Neurosurgery, Department of Surgery, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan Department of Neurosurgery, Clinical Research Center, Graduate Institute of Injury Prevention and Control, Taipei Medical University, Wan Fang Hospital, Taipei, Taiwan
| | - Tai-Ngar Lui
- Division of Neurosurgery, Department of Surgery, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Cindy Shin-Yi Lin
- Department of Neurology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan Translational Neuroscience, Department of Physiology, School of Medicine Science, Faculty of Medicine, University of New South Wales, Sydney, Australia
| |
Collapse
|
16
|
Block J, Silverstein JW, Ball HT, Mermelstein LE, DeWal HS, Madhok R, Basra SK, Goldstein MJ. Motor evoked potentials for femoral nerve protection in transpsoas lateral access surgery of the spine. Neurodiagn J 2015; 55:36-45. [PMID: 26036119 DOI: 10.1080/21646821.2015.1012456] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Detecting potential intraoperative injuries to the femoral nerve should be the main goal of neuromonitoring of lateral lumber interbody fusion (LLIF) procedures. We propose a theory and technique to utilize motor evoked potentials (MEPs) to protect the femoral nerve (a peripheral nerve), which is at risk in LLIF procedures. MEPs have been advocated and widely used for monitoring spinal cord function during surgical correction of spinal deformity and surgery of the cervical and thoracic spine, but have had limited acceptance for use in lumbar procedures. This is due to the theoretical possibility that MEP recordings may not be sensitive in detecting an injury to a single nerve root considering there is overlapping muscle innervation of adjacent root levels. However, in LLIF procedures, the surgeon is more likely to encounter lumbar plexus elements than nerve roots. Within the substance of the psoas muscle, the L2, L3, and L4 nerve roots combine in the lumbar plexus to form the trunk of the femoral nerve. At the point where the nerve roots become the trunk of the femoral nerve, there is no longer any alternative overlapping innervation to the quadriceps muscles. Insult to the fully formed femoral nerve, which completely blocks conduction in motor axons, should theoretically abolish all MEP responses to the quadriceps muscles. On multiple occasions over the past year, our neuro-monitoring groups have observed significantly degraded amplitudes of the femoral motor and/or sensory evoked potentials limited to only the surgical side. Most of these degraded response amplitudes rapidly returned to baseline values with a surgical intervention (i.e., prompt removal of surgical retraction).
Collapse
|