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Lanza G, Salemi M, Mogavero MP, Catania V, Galeano A, Garifoli A, Lanuzza B, Morreale M, Tripodi M, Cantone M, Cappellani F, Concerto C, Rodolico A, Pennisi M, Bella R, Ferri R. Targeting the adenosinergic system in restless legs syndrome: A pilot, "proof-of-concept" placebo-controlled TMS-based protocol. PLoS One 2024; 19:e0302829. [PMID: 38728342 PMCID: PMC11086884 DOI: 10.1371/journal.pone.0302829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/10/2024] [Indexed: 05/12/2024] Open
Abstract
Restless Legs Syndrome (RLS) is a common sleep disorder characterized by an urge to move the legs that is responsive to movement (particularly during rest), periodic leg movements during sleep, and hyperarousal. Recent evidence suggests that the involvement of the adenosine system may establish a connection between dopamine and glutamate dysfunction in RLS. Transcranial magnetic stimulation (TMS) is a non-invasive electrophysiological technique widely applied to explore brain electrophysiology and neurochemistry under different experimental conditions. In this pilot study protocol, we aim to investigate the effects of dipyridamole (a well-known enhancer of adenosinergic transmission) and caffeine (an adenosine receptor antagonist) on measures of cortical excitation and inhibition in response to TMS in patients with primary RLS. Initially, we will assess cortical excitability using both single- and paired-pulse TMS in patients with RLS. Then, based on the measures obtained, we will explore the effects of dipyridamole and caffeine, in comparison to placebo, on various TMS parameters related to cortical excitation and inhibition. Finally, we will evaluate the psycho-cognitive performance of RLS patients to screen them for cognitive impairment and/or mood-behavioral dysfunction, thus aiming to correlate psycho-cognitive findings with TMS data. Overall, this study protocol will be the first to shed lights on the neurophysiological mechanisms of RLS involving the modulation of the adenosine system, thus potentially providing a foundation for innovative "pharmaco-TMS"-based treatments. The distinctive TMS profile observed in RLS holds indeed the potential utility for both diagnosis and treatment, as well as for patient monitoring. As such, it can be considered a target for both novel pharmacological (i.e., drug) and non-pharmacological (e.g., neuromodulatory), "TMS-guided", interventions.
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Affiliation(s)
- Giuseppe Lanza
- Oasi Research Institute-IRCCS, Troina, Italy
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | | | - Maria P. Mogavero
- Vita-Salute San Raffaele University, Milan, Italy
- Division of Neuroscience, San Raffaele Scientific Institute, Sleep Disorders Center, Milan, Italy
| | | | | | | | | | | | | | - Mariagiovanna Cantone
- Neurology Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Francesco Cappellani
- Ophtalomolgy Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Carmen Concerto
- Psychiatry Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Alessandro Rodolico
- Psychiatry Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Manuela Pennisi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
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Strunge K, Bostock H, Howells J, Cengiz B, Samusyte G, Koltzenburg M, Tankisi H. Caffeine and cortical excitability, as measured with paired-pulse transcranial magnetic stimulation. Muscle Nerve 2024; 69:206-212. [PMID: 38124685 DOI: 10.1002/mus.28027] [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: 12/08/2022] [Revised: 11/27/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023]
Abstract
INTRODUCTION/AIMS The transcranial magnetic stimulation tests of short-interval intracortical inhibition (SICI) by both conventional amplitude measurements (A-SICI) and threshold-tracking (T-SICI) are important methods to investigate intracortical inhibitory circuits, and T-SICI has been proposed to aid the diagnosis of amyotrophic lateral sclerosis. Beverages containing caffeine are widely consumed, and caffeine has been reported to affect cortical excitability. The aim of this study was to determine whether these SICI tests are affected by caffeine. METHODS Twenty-four healthy subjects (13 females, 11 males, aged from 19 to 31, mean: 26.2 ± 2.4 years) were studied in a single fixed-dose randomized double-blind placebo-controlled cross-over trial of 200 mg caffeine or placebo ingested as chewing gum. A-SICI and T-SICI, using parallel tracking (T-SICIp), were performed before and after chewing gum. RESULTS There was no significant change in SICI parameters after placebo in A-SICI (p > .10) or T-SICIp (p > .30), and no significant effect of caffeine was found on A-SICI (p > .10) or T-SICIp (p > .50) for any of the interstimulus intervals. DISCUSSION There is no need for caffeine abstention before measurements of SICI by either the T-SICI or A-SICI measurements.
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Affiliation(s)
- Kristine Strunge
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - Hugh Bostock
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - James Howells
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Bülent Cengiz
- Department of Neurology, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Gintaute Samusyte
- Department of Neurology, Hospital of Lithuanian University of Health Sciences Kauno Klinikos, Kaunas, Lithuania
- Department of Neurology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Martin Koltzenburg
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, London, UK
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Bergevin M, Steele J, Payen de la Garanderie M, Feral-Basin C, Marcora SM, Rainville P, Caron JG, Pageaux B. Pharmacological Blockade of Muscle Afferents and Perception of Effort: A Systematic Review with Meta-analysis. Sports Med 2023; 53:415-435. [PMID: 36318384 DOI: 10.1007/s40279-022-01762-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2022] [Indexed: 01/27/2023]
Abstract
BACKGROUND The perception of effort provides information on task difficulty and influences physical exercise regulation and human behavior. This perception differs from other-exercise related perceptions such as pain. There is no consensus on the role of group III/IV muscle afferents as a signal processed by the brain to generate the perception of effort. OBJECTIVE The aim of this meta-analysis was to investigate the effect of pharmacologically blocking muscle afferents on the perception of effort. METHODS Six databases were searched to identify studies measuring the ratings of perceived effort during physical exercise, with and without pharmacological blockade of muscle afferents. Articles were coded based on the operational measurement used to distinguish studies in which perception of effort was assessed specifically (effort dissociated) or as a composite experience including other exercise-related perceptions (effort not dissociated). Articles that did not provide enough information for coding were assigned to the unclear group. RESULTS The effort dissociated group (n = 6) demonstrated a slight increase in ratings of perceived effort with reduced muscle afferent feedback (standard mean change raw, 0.39; 95% confidence interval 0.13-0.64). The group effort not dissociated (n = 2) did not reveal conclusive results (standard mean change raw, - 0.29; 95% confidence interval - 2.39 to 1.8). The group unclear (n = 8) revealed a slight ratings of perceived effort decrease with reduced muscle afferent feedback (standard mean change raw, - 0.27; 95% confidence interval - 0.50 to - 0.04). CONCLUSIONS The heterogeneity in results between groups reveals that the inclusion of perceptions other than effort in its rating influences the ratings of perceived effort reported by the participants. The absence of decreased ratings of perceived effort in the effort dissociated group suggests that muscle afferent feedback is not a sensory signal for the perception of effort.
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Affiliation(s)
- Maxime Bergevin
- École de kinésiologie et des sciences de l'activite physique (EKSAP), Faculté de médecine, Université́ de Montréal, Montreal, QC, Canada.,Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montreal, Canada
| | - James Steele
- School of Sport, Health and Social Sciences, Southampton, UK
| | - Marie Payen de la Garanderie
- École de kinésiologie et des sciences de l'activite physique (EKSAP), Faculté de médecine, Université́ de Montréal, Montreal, QC, Canada.,Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montreal, Canada
| | - Camille Feral-Basin
- École de kinésiologie et des sciences de l'activite physique (EKSAP), Faculté de médecine, Université́ de Montréal, Montreal, QC, Canada.,Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montreal, Canada
| | - Samuele M Marcora
- Department of Biomedical and Neuromotor Sciences (DiBiNeM), University of Bologna, Bologna, Italy
| | - Pierre Rainville
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montreal, Canada.,Département de stomatologie, Faculté de médecine dentaire, Université de Montréal, Montreal, QC, Canada
| | - Jeffrey G Caron
- École de kinésiologie et des sciences de l'activite physique (EKSAP), Faculté de médecine, Université́ de Montréal, Montreal, QC, Canada.,Centre de recherche interdisciplinaire en réadaptation du Montréal métropolitain, Montreal, QC, Canada
| | - Benjamin Pageaux
- École de kinésiologie et des sciences de l'activite physique (EKSAP), Faculté de médecine, Université́ de Montréal, Montreal, QC, Canada. .,Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Montreal, Canada. .,Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA), Montreal, QC, Canada.
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Gambino G, Brighina F, Allegra M, Marrale M, Collura G, Gagliardo C, Attanzio A, Tesoriere L, Di Majo D, Ferraro G, Sardo P, Giglia G. Modulation of Human Motor Cortical Excitability and Plasticity by Opuntia Ficus Indica Fruit Consumption: Evidence from a Preliminary Study through Non-Invasive Brain Stimulation. Nutrients 2022; 14:nu14224915. [PMID: 36432601 PMCID: PMC9694319 DOI: 10.3390/nu14224915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/05/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
Indicaxanthin (IX) from Opuntia Ficus Indica (OFI) has been shown to exert numerous biological effects both in vitro and in vivo, such as antioxidant, anti-inflammatory, neuro-modulatory activity in rodent models. Our goal was to investigate the eventual neuro-active role of orally assumed fruits containing high levels of IX at nutritionally-relevant amounts in healthy subjects, exploring cortical excitability and plasticity in the human motor cortex (M1). To this purpose, we applied paired-pulse transcranial magnetic stimulation and anodal transcranial direct current stimulation (a-tDCS) in basal conditions and followed the consumption of yellow cactus pear fruits containing IX or white cactus pear fruits devoid of IX (placebo). Furthermore, resting state-functional MRI (rs-fMRI) preliminary acquisitions were performed before and after consumption of the same number of yellow fruits. Our data revealed that the consumption of IX-containing fruits could specifically activate intracortical excitatory circuits, differently from the placebo-controlled group. Furthermore, we found that following the ingestion of IX-containing fruits, elevated network activity of glutamatergic intracortical circuits can homeostatically be restored to baseline levels following a-tDCS stimulation. No significant differences were observed through rs-fMRI acquisitions. These outcomes suggest that IX from OFI increases intracortical excitability of M1 and leads to homeostatic cortical plasticity responses.
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Affiliation(s)
- Giuditta Gambino
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
- Correspondence: (G.G.); (P.S.)
| | - Filippo Brighina
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
| | - Mario Allegra
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90134 Palermo, Italy
- Postgraduate School of Nutrition and Food Science, University of Palermo, 90134 Palermo, Italy
| | - Maurizio Marrale
- Department of Physics and Chemistry “Emilio Segrè”, University of Palermo, 90134 Palermo, Italy
| | - Giorgio Collura
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
| | - Cesare Gagliardo
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
| | - Alessandro Attanzio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90134 Palermo, Italy
| | - Luisa Tesoriere
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90134 Palermo, Italy
- Postgraduate School of Nutrition and Food Science, University of Palermo, 90134 Palermo, Italy
| | - Danila Di Majo
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
- Postgraduate School of Nutrition and Food Science, University of Palermo, 90134 Palermo, Italy
| | - Giuseppe Ferraro
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
- Postgraduate School of Nutrition and Food Science, University of Palermo, 90134 Palermo, Italy
| | - Pierangelo Sardo
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
- Postgraduate School of Nutrition and Food Science, University of Palermo, 90134 Palermo, Italy
- Correspondence: (G.G.); (P.S.)
| | - Giuseppe Giglia
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90134 Palermo, Italy
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Jannati A, Ryan MA, Kaye HL, Tsuboyama M, Rotenberg A. Biomarkers Obtained by Transcranial Magnetic Stimulation in Neurodevelopmental Disorders. J Clin Neurophysiol 2022; 39:135-148. [PMID: 34366399 PMCID: PMC8810902 DOI: 10.1097/wnp.0000000000000784] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
SUMMARY Transcranial magnetic stimulation (TMS) is a method for focal brain stimulation that is based on the principle of electromagnetic induction where small intracranial electric currents are generated by a powerful fluctuating magnetic field. Over the past three decades, TMS has shown promise in the diagnosis, monitoring, and treatment of neurological and psychiatric disorders in adults. However, the use of TMS in children has been more limited. We provide a brief introduction to the TMS technique; common TMS protocols including single-pulse TMS, paired-pulse TMS, paired associative stimulation, and repetitive TMS; and relevant TMS-derived neurophysiological measurements including resting and active motor threshold, cortical silent period, paired-pulse TMS measures of intracortical inhibition and facilitation, and plasticity metrics after repetitive TMS. We then discuss the biomarker applications of TMS in a few representative neurodevelopmental disorders including autism spectrum disorder, fragile X syndrome, attention-deficit hyperactivity disorder, Tourette syndrome, and developmental stuttering.
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Affiliation(s)
- Ali Jannati
- Neuromodulation Program and Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Mary A. Ryan
- Neuromodulation Program and Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Harper Lee Kaye
- Behavioral Neuroscience Program, Division of Medical Sciences, Boston University School of Medicine, Boston, USA
| | - Melissa Tsuboyama
- Neuromodulation Program and Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexander Rotenberg
- Neuromodulation Program and Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
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Taga M, Charalambous CC, Raju S, Lin J, Zhang Y, Stern E, Schambra HM. Corticoreticulospinal tract neurophysiology in an arm and hand muscle in healthy and stroke subjects. J Physiol 2021; 599:3955-3971. [PMID: 34229359 DOI: 10.1113/jp281681] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 06/30/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The corticoreticulospinal tract (CReST) is a descending motor pathway that reorganizes after corticospinal tract (CST) injury in animals. In humans, the pattern of CReST innervation to upper limb muscles has not been carefully examined in healthy individuals or individuals with CST injury. In the present study, we assessed CReST projections to an arm and hand muscle on the same side of the body in healthy and chronic stoke subjects using transcranial magnetic stimulation. We show that CReST connection strength to the muscles differs between healthy and stroke subjects, with stronger connections to the hand than arm in healthy subjects, and stronger connections to the arm than hand in stroke subjects. These results help us better understand CReST innervation patterns in the upper limb, and may point to its role in normal motor function and motor recovery in humans. ABSTRACT The corticoreticulospinal tract (CReST) is a major descending motor pathway in many animals, but little is known about its innervation patterns in proximal and distal upper extremity muscles in humans. The contralesional CReST furthermore reorganizes after corticospinal tract (CST) injury in animals, but it is less clear whether CReST innervation changes after stroke in humans. We thus examined CReST functional connectivity, connection strength, and modulation in an arm and hand muscle of healthy (n = 15) and chronic stroke (n = 16) subjects. We delivered transcranial magnetic stimulation to the contralesional hemisphere (assigned in healthy subjects) to elicit ipsilateral motor evoked potentials (iMEPs) from the paretic biceps (BIC) and first dorsal interosseous (FDI) muscle. We operationalized CReST functional connectivity as iMEP presence/absence, CReST projection strength as iMEP size and CReST modulation as change in iMEP size by head rotation. We found comparable CReST functional connectivity to the BICs and FDIs in both subject groups. However, the pattern of CReST connection strength to the muscles diverged between groups, with stronger connections to FDIs than BICs in healthy subjects and stronger connections to BICs than FDIs in stroke subjects. Head rotation modulated only FDI iMEPs of healthy subjects. Our findings indicate that the healthy CReST does not have a proximal innervation bias, and its strong FDI connections may have functional relevance to finger individuation. The reversed CReST innervation pattern in stroke subjects confirms its reorganization after CST injury, and its strong BIC connections may indicate upregulation for particular upper extremity muscles or their functional actions.
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Affiliation(s)
- Myriam Taga
- Department of Neurology, School of Medicine, NYU Langone, New York, NY, USA
| | - Charalambos C Charalambous
- Department of Neurology, School of Medicine, NYU Langone, New York, NY, USA.,Department of Basic and Clinical Sciences, University of Nicosia Medical School, Nicosia, Cyprus.,Center for Neuroscience and Integrative Brain Research (CENIBRE), University of Nicosia Medical School, Nicosia, Cyprus
| | - Sharmila Raju
- Department of Neurology, School of Medicine, NYU Langone, New York, NY, USA
| | - Jing Lin
- Department of Neurology, School of Medicine, NYU Langone, New York, NY, USA
| | - Yian Zhang
- Division of Biostatistics, Department of Population Health, School of Medicine, New York University, New York, NY, USA
| | - Elisa Stern
- Department of Neurology, School of Medicine, NYU Langone, New York, NY, USA
| | - Heidi M Schambra
- Department of Neurology, School of Medicine, NYU Langone, New York, NY, USA
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Taylor JJ, Newberger NG, Stern AP, Phillips A, Feifel D, Betensky RA, Press DZ. Seizure risk with repetitive TMS: Survey results from over a half-million treatment sessions. Brain Stimul 2021; 14:965-973. [PMID: 34133991 DOI: 10.1016/j.brs.2021.05.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/24/2021] [Accepted: 05/29/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Seizures are rare during repetitive transcranial magnetic stimulation (rTMS) treatment, but estimating risk is difficult because of study heterogeneity and sampling limitations. Moreover, there are few studies comparing rates between device manufacturers. OBJECTIVE The objective of this study was to calculate rTMS seizure rates across various FDA-cleared devices in naturalistic clinical settings. METHODS In July and August 2018, approximately 500 members of the Clinical TMS Society (CTMSS) were electronically surveyed about seizures in their practices. Seizures were distinguished from non-seizures by a remote semi-structured interview with a Board-certified neurologist and Co-Chair of the CTMSS Standards Committee. Exact Poisson calculations were used to estimate seizure rates and confidence intervals across the four most widely used manufacturers. RESULTS The survey was completed by 134 members, with 9 responses excluded because of data inconsistencies. In total, 18 seizures were reported in 586,656 sessions and 25,526 patients across all device manufacturers. The overall seizure rate was 0.31 (95% CI: 0.18, 0.48) per 10,000 sessions, and 0.71 (95% CI: 0.42, 1.11) per 1000 patients. The Brainsway H-coil seizure rate of 5.56 per 1000 patients (95% CI: 2.77,9.95) was significantly higher (p < 0.001) than the three most widely used figure- 8 coil devices' combined seizure rate of 0.14 per 1000 patients (95% CI: 0.01, 0.51). CONCLUSION The absolute risk of a seizure with rTMS is low, but generic Brainsway H-coil treatment appears to be associated with a higher relative risk than generic figure- 8 coil treatment. Well-designed prospective studies are warranted to further investigate this risk.
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Affiliation(s)
- Joseph J Taylor
- Center for Brain Circuit Therapeutics, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | | | - Adam P Stern
- Berenson Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Angela Phillips
- Department of Veterans Affairs, Palo Alto, CA, USA; Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, CA, USA
| | - David Feifel
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Kadima Neuropsychiatry Institute, La Jolla, CA, USA
| | - Rebecca A Betensky
- Department of Biostatistics, School of Global Public Health, New York University, New York, NY, USA
| | - Daniel Z Press
- Berenson Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Confounding effects of caffeine on neuroplasticity induced by transcranial alternating current stimulation and paired associative stimulation. Clin Neurophysiol 2021; 132:1367-1379. [PMID: 33762129 DOI: 10.1016/j.clinph.2021.01.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/27/2020] [Accepted: 01/06/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We examined the effects of caffeine, time of day, and alertness fluctuation on plasticity effects after transcranial alternating current stimulation (tACS) or 25 ms paired associative stimulation (PAS25) in caffeine-naïve and caffeine-adapted subjects. METHODS In two randomised, double-blinded, cross-over or placebo-controlled (caffeine) studies, we measured sixty subjects in eight sessions (n = 30, Male: Female = 1:1 in each study). RESULTS We found caffeine increased motor cortex excitability in caffeine naïve subjects. The aftereffects in caffeine naïve subjects were enhanced and prolonged when combined with PAS 25. Caffeine also increased alertness and the motor evoked potentials (MEPs) were reduced under light deprivation in caffeine consumers both with and without caffeine. In caffeine consumers, the time of day had no effect on tACS-induced plasticity. CONCLUSIONS We conclude that caffeine should be avoided or controlled as confounding factor for brain stimulation protocols. It is also important to keep the brightness constant in all sessions and study groups should not be mixed with caffeine-naïve and caffeine consuming participants. SIGNIFICANCE Caffeine is one of the confounding factors in the plasticity induction studies and it induces different excitability effects in caffeine-naïve and caffeine-adapted subjects. This study was registered in the ClinicalTrials.gov with these registration IDs: 1) NCT03720665 https://clinicaltrials.gov/ct2/results?cond=NCT03720665&term=&cntry=&state=&city=&dist= 2) NCT04011670 https://clinicaltrials.gov/ct2/results?cond=&term=NCT04011670&cntry=&state=&city=&dist=.
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Pellegrini M, Zoghi M, Jaberzadeh S. Genetic Polymorphisms Do Not Predict Interindividual Variability to Cathodal Transcranial Direct Current Stimulation of the Primary Motor Cortex. Brain Connect 2020; 11:56-72. [PMID: 33198509 DOI: 10.1089/brain.2020.0762] [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] [Indexed: 11/13/2022] Open
Abstract
Introduction: High variability between individuals (i.e., interindividual variability) in response to transcranial direct current stimulation (tDCS) has become a commonly reported issue in the tDCS literature in recent years. Inherent genetic differences between individuals have been proposed as a contributing factor to observed response variability. This study investigated whether tDCS interindividual variability was genetically mediated. Methods: A large sample size of 61 healthy males received cathodal tDCS (c-tDCS) and sham-tDCS of the primary motor cortex at 1 mA and 10 min via 6 × 4 cm active and 7 × 5 cm return electrodes. Corticospinal excitability (CSE) was assessed via 25 single-pulse transcranial magnetic stimulation motor-evoked potentials (MEPs). Intracortical inhibition was assessed via twenty-five 3 msec interstimulus interval (ISI) paired-pulse MEPs, known as short-interval intracortical inhibition (SICI). Intracortical facilitation (ICF) was assessed via twenty-five 10 msec ISI paired-pulse MEPs. Gene variants encoding for excitatory and inhibitory neuroreceptors were determined via saliva samples. Predetermined thresholds and statistical cluster analyses were used to subgroup individuals. Results: Two distinct subgroups were identified, "responders" reducing CSE following c-tDCS and "nonresponders" showing no reduction or even increase in CSE. Differences in CSE between responders and nonresponders following c-tDCS were not explained by changes in SICI or ICF. Conclusions: No significant relationships were reported between gene variants and interindividual variability to c-tDCS, suggesting that the chosen gene variants did not influence the activity of the neuroreceptors involved in eliciting changes in CSE in responders following c-tDCS. In this largest c-tDCS study of its kind, novel insights were reported into the contribution genetic factors may play in observed interindividual variability to c-tDCS. Impact statement This study adds insight into the issue of interindividual variability to c-tDCS. It highlights not all individuals respond to c-tDCS similarly when exposed to the same stimulus parameters. This disparity in response to c-tDCS between individuals does not appear to be genetically mediated. For c-tDCS to progress to large-scale clinical application, reliability, predictability and reproducibility are essential. Systematically investigating factors contributing to interindividual variability take steps towards this progress the c-tDCS field towards the potential development of screening tools to determine clinical suitability to c-tDCS to ensure its application in those who may benefit the most.
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Affiliation(s)
- Michael Pellegrini
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
| | - Maryam Zoghi
- Department of Rehabilitation, Nutrition and Sport, School of Allied Health, Discipline of Physiotherapy, La Trobe University, Melbourne, Australia
| | - Shapour Jaberzadeh
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
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10
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Lopez AJ, Xu J, Hoque MM, McMullen C, Kesar TM, Borich MR. Integration of Convergent Sensorimotor Inputs Within Spinal Reflex Circuits in Healthy Adults. Front Hum Neurosci 2020; 14:592013. [PMID: 33324184 PMCID: PMC7725688 DOI: 10.3389/fnhum.2020.592013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/03/2020] [Indexed: 11/25/2022] Open
Abstract
The output from motor neuron pools is influenced by the integration of synaptic inputs originating from descending corticomotor and spinal reflex pathways. In this study, using paired non-invasive brain and peripheral nerve stimulation, we investigated how descending corticomotor pathways influence the physiologic recruitment order of the soleus Hoffmann (H-) reflex. Eleven neurologically unimpaired adults (9 females; mean age 25 ± 3 years) completed an assessment of transcranial magnetic stimulation (TMS)-conditioning of the soleus H-reflex over a range of peripheral nerve stimulation (PNS) intensities. Unconditioned H-reflex recruitment curves were obtained by delivering PNS pulses to the posterior tibial nerve. Subsequently, TMS-conditioned H-reflex recruitment curves were obtained by pairing PNS with subthreshold TMS at short (−1.5 ms) and long (+10 ms) intervals. We evaluated unconditioned and TMS-conditioned H-reflex amplitudes along the ascending limb, peak, and descending limb of the H-reflex recruitment curve. Our results revealed that, for long-interval facilitation, TMS-conditioned H-reflex amplitudes were significantly larger than unconditioned H-reflex amplitudes along the ascending limb and peak of the H-reflex recruitment curve. Additionally, significantly lower PNS intensities were needed to elicit peak H-reflex amplitude (Hmax) for long-interval facilitation compared to unconditioned. These findings suggest that the influence of descending corticomotor pathways, particularly those mediating long-interval facilitation, contribute to changing the recruitment gain of the motor neuron pool, and can inform future methodological protocols for TMS-conditioning of H-reflexes. By characterizing and inducing short-term plasticity in circuitry mediating short- and long-interval TMS-conditioning of H-reflex amplitudes, future studies can investigate supraspinal and spinal circuit contributions to abnormal motor control, as well as develop novel therapeutic targets for neuromodulation.
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Affiliation(s)
- Alejandro J Lopez
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Jiang Xu
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Maruf M Hoque
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Carly McMullen
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States.,Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Trisha M Kesar
- Motion Analysis Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
| | - Michael R Borich
- Neural Plasticity Research Laboratory, Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
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11
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Turco CV, Arsalan SO, Nelson AJ. The Influence of Recreational Substance Use in TMS Research. Brain Sci 2020; 10:E751. [PMID: 33080965 PMCID: PMC7603156 DOI: 10.3390/brainsci10100751] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 12/30/2022] Open
Abstract
(1) Background: Transcranial magnetic stimulation (TMS) approaches are widely used to study cortical and corticospinal function. However, responses to TMS are subject to significant intra-and inter-individual variability. Acute and chronic exposure to recreational substances alters the excitability of the sensorimotor system and may contribute to the variability in TMS outcome measures. The increasing prevalence of recreational substance use poses a significant challenge for executing TMS studies, but there is a lack of clarity regarding the influence of these substances on sensorimotor function. (2) Methods: The literature investigating the influence of alcohol, nicotine, caffeine and cannabis on TMS outcome measures of corticospinal, intracortical and interhemispheric excitability was reviewed. (3) Results: Both acute and chronic use of recreational substances modulates TMS measures of excitability. Despite the abundance of research in this field, we identify knowledge gaps that should be addressed in future studies to better understand the influence of these substances on TMS outcomes. (4) Conclusions: This review highlights the need for TMS studies to take into consideration the history of participant substance use and to control for acute substance use prior to testing.
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Affiliation(s)
| | | | - Aimee J. Nelson
- Department of Kinesiology, McMaster University, Hamilton, ON L8S 4L8, Canada; (C.V.T.); (S.O.A.)
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12
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Pellegrini M, Zoghi M, Jaberzadeh S. Can genetic polymorphisms predict response variability to anodal transcranial direct current stimulation of the primary motor cortex? Eur J Neurosci 2020; 53:1569-1591. [PMID: 33048398 DOI: 10.1111/ejn.15002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 09/17/2020] [Accepted: 10/02/2020] [Indexed: 11/28/2022]
Abstract
Genetic mediation of cortical plasticity and the role genetic variants play in previously observed response variability to transcranial direct current stimulation (tDCS) have become important issues in the tDCS literature in recent years. This study investigated whether inter-individual variability to tDCS was in-part genetically mediated. In 61 healthy males, anodal-tDCS (a-tDCS) and sham-tDCS were administered to the primary motor cortex at 1 mA for 10-min via 6 × 4 cm active and 7 × 5 cm return electrodes. Twenty-five single-pulse transcranial magnetic stimulation (TMS) motor evoked potentials (MEP) were recorded to represent corticospinal excitability (CSE). Twenty-five paired-pulse MEPs were recorded with 3 ms inter-stimulus interval (ISI) to assess intracortical inhibition (ICI) via short-interval intracranial inhibition (SICI) and 10 ms ISI for intracortical facilitation (ICF). Saliva samples were tested for specific genetic polymorphisms in genes encoding for excitatory and inhibitory neuroreceptors. Individuals were sub-grouped based on a pre-determined threshold and via statistical cluster analysis. Two distinct subgroups were identified, increases in CSE following a-tDCS (i.e. Responders) and no increase or even reductions in CSE (i.e. Non-responders). No changes in ICI or ICF were reported. No relationships were reported between genetic polymorphisms in excitatory receptor genes and a-tDCS responders. An association was reported between a-tDCS responders and GABRA3 gene polymorphisms encoding for GABA-A receptors suggesting potential relationships between GABA-A receptor variations and capacity to undergo tDCS-induced cortical plasticity. In the largest tDCS study of its kind, this study presents an important step forward in determining the contribution genetic factors play in previously observed inter-individual variability to tDCS.
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Affiliation(s)
- Michael Pellegrini
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
| | - Maryam Zoghi
- Department of Rehabilitation, Nutrition and Sport, School of Allied Health, Discipline of Physiotherapy, La Trobe University, Melbourne, Australia
| | - Shapour Jaberzadeh
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
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13
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Pellegrini M, Zoghi M, Jaberzadeh S. A Checklist to Reduce Response Variability in Studies Using Transcranial Magnetic Stimulation for Assessment of Corticospinal Excitability: A Systematic Review of the Literature. Brain Connect 2020; 10:53-71. [PMID: 32093486 DOI: 10.1089/brain.2019.0715] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Response variability between individuals (interindividual variability) and within individuals (intraindividual variability) is an important issue in the transcranial magnetic stimulation (TMS) literature. This has raised questions of the validity of TMS to assess changes in corticospinal excitability (CSE) in a predictable and reliable manner. Several participant-specific factors contribute to this observed response variability with a current lack of consensus on the degree each factor contributes. This highlights a need for consistency and structure in reporting study designs and methodologies. Currently, there is no summarized review of the participant-specific factors that can be controlled and may contribute to response variability. This systematic review aimed to develop a checklist of methodological measures taken by previously published research to increase the homogeneity of participant selection criteria, preparation of participants before experimental testing, participant scheduling, and the instructions given to participants throughout experimental testing to minimize their effect on response variability. Seven databases were searched in full. Studies were included if CSE was measured via TMS and included methodological measures to increase the homogeneity of the participants. Eighty-four studies were included. Twenty-three included measures to increase participant selection homogeneity, 21 included measures to increase participant preparation homogeneity, while 61 included measures to increase participant scheduling and instructions during experimental testing homogeneity. These methodological measures were summarized into a user-friendly checklist with considerations, suggestions, and rationale/justification for their inclusion. This may provide the framework for further insights into ways to reduce response variability in TMS research.
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Affiliation(s)
- Michael Pellegrini
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Victoria, Australia
| | - Maryam Zoghi
- Department of Rehabilitation, Nutrition and Sport, Discipline of Physiotherapy, School of Allied Health, La Trobe University, Melbourne, Victoria, Australia
| | - Shapour Jaberzadeh
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Victoria, Australia
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14
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Aleman M, Zhang R, Feng W, Qi L, Lopez JR, Crowe C, Dong Y, Cherednichenko G, Pessah IN. Dietary Caffeine Synergizes Adverse Peripheral and Central Responses to Anesthesia in Malignant Hyperthermia Susceptible Mice. Mol Pharmacol 2020; 98:351-363. [PMID: 32764093 DOI: 10.1124/mol.120.119412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 07/31/2020] [Indexed: 11/22/2022] Open
Abstract
Ryanodine receptor (RYR) mutations confer stress-triggered malignant hyperthermia (MH) susceptibility. Dietary caffeine (CAF) is the most commonly consumed psychoactive compound by humans. CAF-triggered Ca2+ release and its influences on skeletal muscle contractility are widely used as experimental tools to study RYR function/dysfunction and diagnose MH susceptibility. We hypothesize that dietary CAF achieving blood levels measured in human plasma exacerbates the penetrance of RYR1 MH susceptibility mutations triggered by gaseous anesthetic, affecting both central and peripheral adverse responses. Heterozygous R163C-RYR1 (HET) MH susceptible mice are used to investigate the influences of dietary CAF on both peripheral and central responses before and after induction of halothane (HAL) maintenance anesthesia under experimental conditions that maintain normal core body temperature. HET mice receiving CAF (plasma CAF 893 ng/ml) have significantly shorter times to respiratory arrest compared with wild type, without altering blood chemistry or displaying hyperthermia or muscle rigor. Intraperitoneal bolus dantrolene before HAL prolongs time to respiratory arrest. A pilot electrographic study using subcutaneous electrodes reveals that dietary CAF does not alter baseline electroencephalogram (EEG) total power, but significantly shortens delay to isoelectric EEG, which precedes respiratory and cardiac arrest. CAF ± HAL are studied on RYR1 single-channel currents and HET myotubes to define molecular mechanisms of gene-by-environment synergism. Strong pharmacological synergism between CAF and HAL is demonstrated in both single-channel and myotube preparations. Central and peripheral nervous systems mediate adverse responses to HAL in a HET model of MH susceptibility exposed to dietary CAF, a modifiable lifestyle factor that may mitigate risks of acute and chronic diseases associated with RYR1 mutations. SIGNIFICANCE STATEMENT: Dietary caffeine at a human-relevant dose synergizes adverse peripheral and central responses to anesthesia in malignant hyperthermia susceptible mice. Synergism of these drugs can be attributed to their actions at ryanodine receptors.
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Affiliation(s)
- Monica Aleman
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Rui Zhang
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Wei Feng
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Lihong Qi
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Jose R Lopez
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Chelsea Crowe
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Yao Dong
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Genady Cherednichenko
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
| | - Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine (R.Z., W.F., J.R.L., Y.D., G.C., I.N.P.), Department of Medicine and Epidemiology, The William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine (M.A., C.C.), and Department of Public Health Sciences, School of Medicine, School of Medicine (L.Q.), University of California, Davis, California
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15
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Pellegrini M, Zoghi M, Jaberzadeh S. The effects of transcranial direct current stimulation on corticospinal and cortico-cortical excitability and response variability: Conventional versus high-definition montages. Neurosci Res 2020; 166:12-25. [PMID: 32610058 DOI: 10.1016/j.neures.2020.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 01/19/2023]
Abstract
Response variability following transcranial direct current stimulation (tDCS) highlights need for exploring different tDCS electrode montages. Corticospinal excitability (CSE), cortico-cortical excitability and intra-individual variability was compared following conventional and high-definition (HD) anodal (a-tDCS) and cathodal (c-tDCS) tDCS. Fifteen healthy males attended four sessions at-least one-week apart: conventional a-tDCS, conventional c-tDCS, HD-a-tDCS, HD-c-tDCS. TDCS was administered (1 mA, 10-minutes) over primary motor cortex (M1), via 6 × 4 cm active and 7 × 5 cm return electrodes (conventional tDCS) and 4 × 1 ring-electrodes 3.5 cm apart over M1 (HD-tDCS). For CSE, twenty-five single-pulse transcranial magnetic stimulation (TMS) peak-to-peak motor evoked potentials (MEP) were recorded at baseline, 0-minutes and 30-minutes post-tDCS. Twenty-five paired-pulse MEPs with 3-millisecond (ms) inter-pulse interval (IPI) and twenty-five at 10 ms assessed short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). MEP standardised z-values standard deviations represented intra-individual variability. No significant changes in CSE from baseline were reported for all four interventions. No significant differences were reported in CSE between conventional and HD a-tDCS, but significant differences between conventional and HD c-tDCS 0-minutes post-tDCS. Conventional tDCS significantly reduced intra-individual variability compared to HD-tDCS for a-tDCS (0-minutes) and c-tDCS (30-minutes). No changes were reported for SICI/ICF. These novel findings of increased intra-individual variability following HD-tDCS, at the current stimulus parameters, highlight need for further nuanced research and refinement to optimise the HD-tDCS dosage-response relationship.
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Affiliation(s)
- Michael Pellegrini
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia.
| | - Maryam Zoghi
- Department of Rehabilitation, Nutrition and Sport, School of Allied Health, Discipline of Physiotherapy, La Trobe University, Melbourne, Australia
| | - Shapour Jaberzadeh
- Non-Invasive Brain Stimulation and Neuroplasticity Laboratory, Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
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16
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Yamazaki R, Kito S, Matsuda Y, Shigeta M. Thumb twitch during repetitive transcranial magnetic stimulation in a case with medication-resistant depression: A potential role of caffeine. Psychiatry Clin Neurosci 2020; 74:372-373. [PMID: 32196820 DOI: 10.1111/pcn.13002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 03/07/2020] [Accepted: 03/14/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Ryuichi Yamazaki
- Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan
| | - Shinsuke Kito
- Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan
| | - Yuki Matsuda
- Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan
| | - Masahiro Shigeta
- Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan
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17
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Mesquita RNO, Cronin NJ, Kyröläinen H, Hintikka J, Avela J. Effects of caffeine on neuromuscular function in a non-fatigued state and during fatiguing exercise. Exp Physiol 2020; 105:690-706. [PMID: 32092208 DOI: 10.1113/ep088265] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/27/2020] [Indexed: 12/22/2022]
Abstract
NEW FINDINGS What is the central question of the study? What are the effects of caffeine on neuromuscular function in a non-fatigued state and during fatiguing exercise? What is the main finding and its importance? In a non-fatigued state, caffeine decreased the duration of the silent period evoked by transcranial magnetic stimulation. Caffeine-induced reduction of inhibitory mechanisms in the central nervous system before exercise was associated with an increased performance. Individuals who benefit from caffeine ingestion may experience lower perception of effort during exercise and an accelerated recovery of M-wave amplitude postfatigue. This study elucidates the mechanisms of action of caffeine and demonstrates that inter-individual variability of its effects on neuromuscular function is a fruitful area for further work. ABSTRACT Caffeine enhances exercise performance, but its mechanisms of action remain unclear. In this study, we investigated its effects on neuromuscular function in a non-fatigued state and during fatiguing exercise. Eighteen men participated in this randomized, double-blind, placebo-controlled crossover trial. Baseline measures included plantarflexion force, drop jump, squat jump, voluntary activation of triceps surae muscle, soleus muscle contractile properties, M-wave, α-motoneuron excitability (H-reflex), corticospinal excitability, short-interval intracortical inhibition, intracortical facilitation, silent period evoked by transcranial magnetic stimulation (SP) and plasma potassium and caffeine concentrations. Immediately after baseline testing, participants ingested caffeine (6 mg·kg-1 ) or placebo. After a 1-h rest, baseline measures were repeated, followed by a fatiguing stretch-shortening cycle exercise (sets of 40 bilateral rebound jumps on a sledge apparatus) until task failure. Neuromuscular testing was carried out throughout the fatigue protocol and afterwards. Caffeine enhanced drop jump height (by 4.2%) and decreased the SP (by 12.6%) in a non-fatigued state. A caffeine-related decrease in SP and short-interval intracortical inhibition before the fatiguing activity was associated with an increased time to task failure. The participants who benefitted from an improved performance on the caffeine day reported a significantly lower sense of effort during exercise and had an accelerated postexercise recovery of M-wave amplitude. Caffeine modulates inhibitory mechanisms of the CNS, recovery of M-wave amplitude and perception of effort. This study lays the groundwork for future examinations of differences in caffeine-induced neuromuscular changes between those who are deemed to benefit from caffeine ingestion and those who are not.
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Affiliation(s)
- Ricardo N O Mesquita
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia.,Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Neil J Cronin
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.,Department for Health, Bath University, Bath, UK
| | - Heikki Kyröläinen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Jukka Hintikka
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Janne Avela
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
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18
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Fernandes SR, Pereira M, Salvador R, Miranda PC, de Carvalho M. Cervical trans-spinal direct current stimulation: a modelling-experimental approach. J Neuroeng Rehabil 2019; 16:123. [PMID: 31653265 PMCID: PMC6815068 DOI: 10.1186/s12984-019-0589-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/06/2019] [Indexed: 11/18/2022] Open
Abstract
Background Trans-spinal direct current stimulation (tsDCS) is a non-invasive technique with promising neuromodulatory effects on spinal cord (SC) circuitry. Computational studies are essential to guide effective tsDCS protocols for specific clinical applications. This study aims to combine modelling and experimental studies to determine the electrode montage that maximizes electric field (E-field) delivery during cervical tsDCS. Methods Current and E-field distributions in the cervical SC were predicted for four electrode montages in a human realistic model using computational methods. A double-blind crossover and randomized exploratory study was conducted using the montage that maximized E-field delivery. tsDCS was applied for 15 min in 10 healthy subjects (anodal, cathodal, sham, with polarity assigned to the cervical electrode), with a current intensity of 2.5 mA, resulting in a total current charge density delivery of 90 mC/cm2. Upper limb motor (transcranial magnetic stimulation) and sensory evoked potentials (MEP, SEP), M-waves, H-reflex and F-wave responses were analysed. Central and peripheral conduction times were determined using MEP. Repeated measures ANOVA and Friedman test were used for statistical analysis (significance level α = 0.05). Results All montages presented higher current density and E-field magnitudes in the cervical SC region between the electrodes. However, electrodes at C3 and T3 spinous processes (C3-T3) originated the highest E-field magnitude (0.50 V/m). Using C3-T3 montage we observed significant changes in N9 SEP latency (p = 0.006), but significance did not persist in pairwise comparisons (sham-anodal: p = 0.022; sham-cathodal: p = 0.619; anodal-cathodal: p = 0.018; α = 0.017, Bonferroni corrected). MEP latency and central motor conduction time (CMCT) modified significantly on stimulation (p = 0.007 and p = 0.015, respectively). In addition, pairwise comparisons confirmed significant differences between sham and cathodal conditions after Bonferroni correction for MEP latency (sham-anodal: p = 0.868; sham-cathodal: p = 0.011; anodal-cathodal: p = 0.023) and CMCT (sham-anodal: p = 0.929; sham-cathodal: p = 0.010; anodal-cathodal: p = 0.034). Conclusions Computational models predicted higher E-field delivery in the cervical SC for the C3-T3 montage. Polarity-dependent effects in motor responses were reported using this montage consistent with spinal motor modulation. tsDCS experimental protocol designs should be guided by modelling studies to improve effectiveness.
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Affiliation(s)
- Sofia Rita Fernandes
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal. .,Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
| | - Mariana Pereira
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal
| | - Ricardo Salvador
- Neuroelectrics, Avinguda Tibidabo, 47 bis, 08035, Barcelona, Spain
| | - Pedro Cavaleiro Miranda
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Mamede de Carvalho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal.,Departamento de Neurociências e Saúde Mental, Hospital de Santa Maria - Centro Hospitalar Lisboa Norte, Avenida Professor Egas Moniz, 1649-035, Lisbon, Portugal
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19
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Caffeine Increased Muscle Endurance Performance Despite Reduced Cortical Activation and Unchanged Neuromuscular Efficiency and Corticomuscular Coherence. Nutrients 2019; 11:nu11102471. [PMID: 31618910 PMCID: PMC6836165 DOI: 10.3390/nu11102471] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/25/2019] [Accepted: 08/26/2019] [Indexed: 01/06/2023] Open
Abstract
The central and peripheral effects of caffeine remain debatable. We verified whether increases in endurance performance after caffeine ingestion occurred together with changes in primary motor cortex (MC) and prefrontal cortex (PFC) activation, neuromuscular efficiency (NME), and electroencephalography–electromyography coherence (EEG–EMG coherence). Twelve participants performed a time-to-task failure isometric contraction at 70% of the maximal voluntary contraction after ingesting 5 mg/kg of caffeine (CAF) or placebo (PLA), in a crossover and counterbalanced design. MC (Cz) and PFC (Fp1) EEG alpha wave and vastus lateralis (VL) muscle EMG were recorded throughout the exercise. EEG–EMG coherence was calculated through the magnitude squared coherence analysis in MC EEG gamma-wave (CI > 0.0058). Moreover, NME was obtained as the force–VL EMG ratio. When compared to PLA, CAF improved the time to task failure (p = 0.003, d = 0.75), but reduced activation in MC and PFC throughout the exercise (p = 0.027, d = 1.01 and p = 0.045, d = 0.95, respectively). Neither NME (p = 0.802, d = 0.34) nor EEG–EMG coherence (p = 0.628, d = 0.21) was different between CAF and PLA. The results suggest that CAF improved muscular performance through a modified central nervous system (CNS) response rather than through alterations in peripheral muscle or central–peripheral coupling.
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Magalhães SC, Queiroz de Paiva JP, Kaelin-Lang A, Sterr A, Eckeli AL, Winkler AM, Fernandes do Prado G, Amaro E, Conforto AB. Short-interval intracortical inhibition is decreased in restless legs syndrome across a range of severity. Sleep Med 2019; 62:34-42. [PMID: 31539846 DOI: 10.1016/j.sleep.2019.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/10/2019] [Accepted: 03/12/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND Decreased short-interval intracortical inhibition (SICI) to transcranial magnetic stimulation (TMS) of the primary motor cortex was described in subjects with restless legs syndrome/Willis-Ekbom disease (RLS/WED). It remained to be determined whether the magnitude of SICI decrease would be similar across levels of RLS/WED severity. Moreover, it was unknown whether, in addition to decreases in SICI, changes in cortical thickness or area could be detected in subjects with RLS/WED compared to controls. The objective of this study was to compare SICI, cortical thickness, and cortical area in subjects with idiopathic mild to moderate RLS/WED, severe to very severe RLS/WED, and controls. METHODS The severity of RLS/WED was assessed by the International Restless Legs Syndrome Severity Scale (IRLSS). SICI and 3T magnetic resonance imaging (MRI) data of subjects with RLS/WED and controls were compared. A receiver operating characteristic curve for SICI was designed for discrimination of participants with RLS/WED from controls. Cortical thickness and area were assessed by automated surface-based analysis. RESULTS SICI was significantly reduced in patients with mild to moderate and severe to very severe RLS/WED, compared to controls (one-way analysis of variance: F = 9.62, p < 0.001). Receiver operating characteristic curve analysis predicted RLS/WED when SICI was above 35% (area under the curve = 0.79, 95% CI 0.67-0.91, p < 0.001). Analyses of the whole brain and of regions of interest did not reveal differences in gray matter thickness or area between controls and subjects with RLS/WED. CONCLUSION SICI is an accurate cortical biomarker that can support the diagnosis of RLS/WED even in subjects with mild symptoms, but cortical thickness and area were not useful for discriminating subjects with this condition from controls.
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Affiliation(s)
- Samir Câmara Magalhães
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Universidade de Fortaleza, Unifor, Fortaleza, CE, Brazil.
| | | | | | - Annette Sterr
- Department of Psychology, University of Surrey, Guildford, Surrey, UK
| | - Alan Luiz Eckeli
- Departamento de Neurociências e Ciências do Comportamento, Divisão de Neurologia, Hospital das Clínicas da Faculdade de Medicina da USP-Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | | | | | - Edson Amaro
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Departamento de Radiologia, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Adriana Bastos Conforto
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Departamento de Neurologia, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil
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Patel R, Madhavan S. Comparison of Transcranial Direct Current Stimulation Electrode Montages for the Lower Limb Motor Cortex. Brain Sci 2019; 9:brainsci9080189. [PMID: 31390741 PMCID: PMC6721300 DOI: 10.3390/brainsci9080189] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/01/2019] [Accepted: 08/04/2019] [Indexed: 12/19/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) has been widely explored as a neuromodulatory adjunct to modulate corticomotor excitability and improve motor behavior. However, issues with the effectiveness of tDCS have led to the exploration of empirical and experimental alternate electrode placements to enhance neuromodulatory effects. Here, we conducted a preliminary study to compare a novel electrode montage (which involved placing 13 cm2 electrodes anterior and posterior to the target location) to the traditionally used electrode montage (13 cm2 stimulating electrode over the target area and the 35 cm2 reference electrode over the contralateral orbit). We examined the effects of tDCS of the lower limb motor area (M1) by measuring the corticomotor excitability (CME) of the tibialis anterior muscle using transcranial magnetic stimulation in twenty healthy participants. We examined behavioral effects using a skilled motor control task performed with the ankle. We did not find one electrode montage to be superior to the other for changes in the CME or motor control. When the group was dichotomized into responders and non-responders (based on upregulation in CME), we found that the responders showed significant upregulation from baseline after tDCS for both montages. However, only the responders in the traditional montage group showed significant changes in motor control after tDCS. These results do not support the superiority of the new anterior–posterior montage over the traditional montage. Further work with a larger cohort and multiple cumulative sessions may be necessary to confirm our results.
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Affiliation(s)
- Radhika Patel
- Department of Physical Therapy, University of Illinois at Chicago (UIC), Chicago, IL 60612, USA
| | - Sangeetha Madhavan
- Department of Physical Therapy, University of Illinois at Chicago (UIC), Chicago, IL 60612, USA.
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Jannati A, Fried PJ, Block G, Oberman LM, Rotenberg A, Pascual-Leone A. Test-Retest Reliability of the Effects of Continuous Theta-Burst Stimulation. Front Neurosci 2019; 13:447. [PMID: 31156361 PMCID: PMC6533847 DOI: 10.3389/fnins.2019.00447] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Accepted: 04/18/2019] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVES The utility of continuous theta-burst stimulation (cTBS) as index of cortical plasticity is limited by inadequate characterization of its test-retest reliability. We thus evaluated the reliability of cTBS aftereffects, and explored the roles of age and common single-nucleotide polymorphisms in the brain-derived neurotrophic factor (BDNF) and apolipoprotein E (APOE) genes. METHODS Twenty-eight healthy adults (age range 21-65) underwent two identical cTBS sessions (median interval = 9.5 days) targeting the motor cortex. Intraclass correlation coefficients (ICCs) of the log-transformed, baseline-corrected amplitude of motor evoked potentials (ΔMEP) at 5-60 min post-cTBS (T5-T60) were calculated. Adjusted effect sizes for cTBS aftereffects were then calculated by taking into account the reliability of each cTBS measure. RESULTS ΔMEP at T50 was the most-reliable cTBS measure in the whole sample (ICC = 0.53). Area under-the-curve (AUC) of ΔMEPs was most reliable when calculated over the full 60 min post-cTBS (ICC = 0.40). cTBS measures were substantially more reliable in younger participants (< 35 years) and in those with BDNF Val66Val and APOE ε4- genotypes. CONCLUSION cTBS aftereffects are most reliable when assessed 50 min post-cTBS, or when cumulative ΔMEP measures are calculated over 30-60 min post-cTBS. Reliability of cTBS aftereffects is influenced by age, and BDNF and APOE polymorphisms. Reliability coefficients are used to adjust effect-size calculations for interpretation and planning of cTBS studies.
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Affiliation(s)
- Ali Jannati
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Peter J. Fried
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Gabrielle Block
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Lindsay M. Oberman
- Neuroplasticity and Autism Spectrum Disorder Program, Department of Psychiatry and Human Behavior, E.P. Bradley Hospital, Warren Alpert Medical School, Brown University, East Providence, RI, United States
| | - Alexander Rotenberg
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
- Neuromodulation Program and Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Alvaro Pascual-Leone
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
- Institut Guttman de Neurorehabilitació, Universitat Autónoma de Barcelona, Barcelona, Spain
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Effect of caffeine on long-term potentiation-like effects induced by quadripulse transcranial magnetic stimulation. Exp Brain Res 2018; 237:647-651. [DOI: 10.1007/s00221-018-5450-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/06/2018] [Indexed: 10/27/2022]
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Charalambous CC, Dean JC, Adkins DL, Hanlon CA, Bowden MG. Characterizing the corticomotor connectivity of the bilateral ankle muscles during rest and isometric contraction in healthy adults. J Electromyogr Kinesiol 2018; 41:9-18. [PMID: 29715530 DOI: 10.1016/j.jelekin.2018.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 01/19/2023] Open
Abstract
The investigation of the corticomotor connectivity (CMC) to leg muscles is an emerging research area, and establishing reliability of measures is critical. This study examined the measurement reliability and the differences between bilateral soleus (SOL) and tibialis anterior (TA) CMC in 21 neurologically intact adults. Using single pulse transcranial magnetic stimulation (TMS), each muscle's CMC was assessed twice (7 ± 2 days apart) during rest and active conditions. CMC was quantified using a standardized battery of eight measures (4/condition): motor threshold during resting (RMT), motor evoked potential amplitude and latency (raw and normalized to height) in both conditions, contralateral silent period (CSP) during active. Using two reliability metrics (intraclass correlation coefficient and coefficient of variation of method error; good reliability: ≥0.75 and ≤15, respectively) and repeated-measures ANOVA, we investigated the reliability and Muscle X Body Side interaction. For both muscles, RMT, resting raw and normalized latencies, and active raw latency demonstrated good reliability, while CSP had good reliability only for TA. Amplitude did not demonstrate good reliability for both muscles. SOL CMC was significantly different from TA CMC for all measures but CSP; body side had no significant effect. Therefore, only certain measures may reliably quantify SOL and TA CMC while different CMC (except CSP) between SOL and TA suggests dissimilar corticospinal drive to each muscle regardless of the side.
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Affiliation(s)
- Charalambos C Charalambous
- Department of Neurology, New York University School of Medicine, New York, NY, USA; Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA.
| | - Jesse C Dean
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Division of Physical Therapy, Medical University of South Carolina, Charleston, SC, USA
| | - DeAnna L Adkins
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Colleen A Hanlon
- Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA
| | - Mark G Bowden
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Division of Physical Therapy, Medical University of South Carolina, Charleston, SC, USA
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Beyond fractional anisotropy in amyotrophic lateral sclerosis: the value of mean, axial, and radial diffusivity and its correlation with electrophysiological conductivity changes. Neuroradiology 2018; 60:505-515. [PMID: 29564498 DOI: 10.1007/s00234-018-2012-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 02/26/2018] [Indexed: 01/06/2023]
Abstract
PURPOSE This paper aims to analyze the contribution of mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in the detection of microstructural abnormalities in amyotrophic lateral sclerosis (ALS) and to evaluate the degree of agreement between structural and functional changes through concomitant diffusion tensor imaging (DTI), transcranial magnetic stimulation (TMS), and clinical assessment. METHODS Fourteen patients with ALS and 11 healthy, age- and gender-matched controls were included. All participants underwent magnetic resonance imaging including DTI. TMS was additionally performed in ALS patients. Differences in the distribution of DTI-derived measures were assessed using tract-based spatial statistical (TBSS) and volume of interest (VOI) analyses. Correlations between clinical, imaging, and neurophysiological findings were also assessed through TBSS. RESULTS ALS patients showed a significant increase in AD and MD involving the corticospinal tract (CST) and the pre-frontal white matter in the right posterior limb of the internal capsule (p < 0.05) when compared to the control group using TBSS, confirmed by VOI analyses. VOI analyses also showed increased AD in the corpus callosum (p < 0.05) in ALS patients. Fractional anisotropy (FA) in the right CST correlated significantly with upper motor neuron (UMN) score (r = - 0.79, p < 0.05), and right abductor digiti minimi central motor conduction time was highly correlated with RD in the left posterior internal capsule (r = - 0.81, p < 0.05). No other significant correlation was found. CONCLUSION MD, AD, and RD, besides FA, are able to further detect and characterize neurodegeneration in ALS. Furthermore, TMS and DTI appear to have a role as complementary diagnostic biomarkers of UMN dysfunction.
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Caffeinated energy drink intake modulates motor circuits at rest, before and after a movement. Physiol Behav 2017; 179:361-368. [DOI: 10.1016/j.physbeh.2017.07.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/03/2017] [Accepted: 07/07/2017] [Indexed: 11/20/2022]
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de Goede AA, van Putten MJAM. Repeatability of long intracortical inhibition in healthy subjects. Clin Neurophysiol Pract 2016; 2:26-34. [PMID: 30214967 PMCID: PMC6123853 DOI: 10.1016/j.cnp.2016.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/13/2016] [Accepted: 12/07/2016] [Indexed: 12/04/2022] Open
Abstract
LICI repeatability showed a large variation at the subject level and ISI level. Good repeatability at group level decreased when including inter-subject variation. Added value of robot-guided coil positioning seems limited for paired pulse TMS.
Objectives Transcranial magnetic stimulation (TMS) is widely used to assess cortical excitability. To detect changes in excitability with longitudinal studies, it is important to validate the repeatability of excitability measures within a subject between different sessions. Repeatability studies on long intracortical inhibition (LICI) are limited and reported agreement ranges from poor to good. This study aims to evaluate the repeatability of LICI in healthy subjects using paired pulse TMS. In addition, it investigates whether LICI repeatability differs for manual and robot-guided coil positioning. Methods Thirty healthy subjects (10 males, mean age 28.4 ± 8.2 years) were studied twice, approximately one week apart. Both motor cortices were stimulated with 50 paired pulses (intensity 120% of resting motor threshold) at interstimulus intervals (ISIs): 50, 100, 150, 200, 250 and 300 ms. In twenty subjects a figure-of-eight coil was positioned and held in place manually during both sessions, while in ten subjects a robot-navigated arm was used. LICI repeatability was assessed using the intraclass correlation coefficient (ICC). Results For manual and robot-guided coil positioning we found a large variation in repeatability at the subject level and ISI level, ranging from poor to good agreement. On a group level, we found good repeatability for averaged LICI curves (manual: ICC = 0.91, robot-guided: ICC = 0.95), which decreased when individual curves were correlated between sessions (manual: ICC = 0.76, robot-guided: ICC = 0.84). Conclusion For a correct interpretation of longitudinal study outcomes it is important to know the subject specific LICI repeatability and to analyze each ISI individually. Furthermore, the added value of robot-guided coil positioning for paired pulse TMS seems limited. Significance The large variation in LICI repeatability at the subject level and ISI level should be taken into account in longitudinal studies, while robot-guided coil positioning seems unnecessary.
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Affiliation(s)
- Annika A de Goede
- Department of Clinical Neurophysiology, MIRA - Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Michel J A M van Putten
- Department of Clinical Neurophysiology, MIRA - Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.,Department of Neurology and Clinical Neurophysiology, Medisch Spectrum Twente, P.O. Box 50000, 7500 KA Enschede, The Netherlands
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Hortensius R, de Gelder B, Schutter DJLG. When anger dominates the mind: Increased motor corticospinal excitability in the face of threat. Psychophysiology 2016; 53:1307-16. [PMID: 27325519 PMCID: PMC5113684 DOI: 10.1111/psyp.12685] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 05/10/2016] [Indexed: 02/06/2023]
Abstract
Threat demands fast and adaptive reactions that are manifested at the physiological, behavioral, and phenomenological level and are responsive to the direction of threat and its severity for the individual. Here, we investigated the effects of threat directed toward or away from the observer on motor corticospinal excitability and explicit recognition. Sixteen healthy right‐handed volunteers completed a transcranial magnetic stimulation (TMS) task and a separate three‐alternative forced‐choice emotion recognition task. Single‐pulse TMS to the left primary motor cortex was applied to measure motor evoked potentials from the right abductor pollicis brevis in response to dynamic angry, fearful, and neutral bodily expressions with blurred faces directed toward or away from the observer. Results showed that motor corticospinal excitability increased independent of direction of anger compared with fear and neutral. In contrast, anger was better recognized when directed toward the observer compared with when directed away from the observer, while the opposite pattern was found for fear. The present results provide evidence for the differential effects of threat direction on explicit recognition and motor corticospinal excitability. In the face of threat, motor corticospinal excitability increases independently of the direction of anger, indicative of the importance of more automatic reactions to threat.
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Affiliation(s)
- Ruud Hortensius
- Brain and Emotion Laboratory, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.,Cognitive and Affective Neuroscience Laboratory, Department of Medical and Clinical Psychology, Tilburg School of Social and Behavioral Sciences, Tilburg University, Tilburg, The Netherlands.,Department of Psychiatry and Mental Health, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Beatrice de Gelder
- Brain and Emotion Laboratory, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.,Department of Psychiatry and Mental Health, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Dennis J L G Schutter
- Donders Institute of Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
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de Morree HM, Klein C, Marcora SM. Cortical substrates of the effects of caffeine and time-on-task on perception of effort. J Appl Physiol (1985) 2014; 117:1514-23. [DOI: 10.1152/japplphysiol.00898.2013] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Caffeine intake results in a decrease in perception of effort, but the cortical substrates of this perceptual effect of caffeine are unknown. The aim of this randomized counterbalanced double-blind crossover study was to investigate the effect of caffeine on the motor-related cortical potential (MRCP) and its relationship with rating of perceived effort (RPE). We also investigated whether MRCP is associated with the increase in RPE occurring over time during submaximal exercise. Twelve healthy female volunteers performed 100 intermittent isometric knee extensions at 61 ± 5% of their maximal torque 1.5 h after either caffeine (6 mg/kg) or placebo ingestion, while RPE, vastus lateralis electromyogram (EMG), and MRCP were recorded. RPE and MRCP amplitude at the vertex during the first contraction epoch (0–1 s) were significantly lower after caffeine ingestion compared with placebo ( P < 0.05) and were significantly higher during the second half of the submaximal intermittent isometric knee-extension protocol compared with the first half ( P < 0.05). No significant effects of caffeine and time-on-task were found for EMG amplitude and submaximal force output variables. The covariation between MRCP and RPE across both caffeine and time-on-task ( r10 = −0.335, P < 0.05) provides evidence in favor of the theory that perception of effort arises from neurocognitive processing of corollary discharges from premotor and motor areas of the cortex. Caffeine seems to reduce perception of effort through a reduction in the activity of cortical premotor and motor areas necessary to produce a submaximal force, and time-on-task has the opposite effect.
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Affiliation(s)
- Helma M. de Morree
- School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
| | - Christoph Klein
- School of Psychology, Bangor University, Bangor, United Kingdom
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Freiburg, Freiburg, Germany; and
| | - Samuele M. Marcora
- School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham, United Kingdom
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Bortolotti H, Altimari LR, Vitor-Costa M, Cyrino ES. Performance during a 20-km cycling time-trial after caffeine ingestion. J Int Soc Sports Nutr 2014; 11:45. [PMID: 25302056 PMCID: PMC4190929 DOI: 10.1186/s12970-014-0045-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 07/11/2014] [Indexed: 11/21/2022] Open
Abstract
Background The objective of this study was to analyze the effect of caffeine ingestion on the performance and physiological variables associated with fatigue in 20-km cycling time trials. Methods In a double-blind placebo-controlled crossover study, 13 male cyclists (26 ± 10 y, 71 ± 9 kg, 176 ± 6 cm) were randomized into 2 groups and received caffeine (CAF) capsules (6 mg.kg−1) or placebo (PLA) 60 min before performing 20-km time trials. Distance, speed, power, rpm, rating of perceived exertion (RPE), electromyography (EMG) of the quadriceps muscles and heart rate (HR) were continuously measured during the tests. In addition, BRUMS questionnaire was applied before and after the tests. Results Significant interactions were found in power and speed (P = 0.001), which were significantly higher at the end of the test (final 2 km) after CAF condition. A main effect of time (P = 0.001) was observed for RPE and HR, which increased linearly until the end of exercise in both conditions. The time taken to complete the test was similar in both conditions (PLA = 2191 ± 158 s vs. CAF = 2181 ± 194 s, P = 0.61). No significant differences between CAF and PLA conditions were identified for speed, power, rpm, RPE, EMG, HR, and BRUMS (P > 0.05). Conclusion The results suggest that caffeine intake 60 min before 20-km time trials has no effect on the performance or physiological responses of cyclists.
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Affiliation(s)
- Henrique Bortolotti
- Metabolism, Nutrition, and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; Neuromuscular System and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Leandro Ricardo Altimari
- Metabolism, Nutrition, and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; Neuromuscular System and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; Department of Physical Education, Centre for Physical Education and Sport, Londrina State University, Londrina, Paraná, Brazil
| | - Marcelo Vitor-Costa
- Metabolism, Nutrition, and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; Neuromuscular System and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil
| | - Edilson Serpeloni Cyrino
- Metabolism, Nutrition, and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; Neuromuscular System and Exercise Research Group, Londrina State University, Londrina, Paraná, Brazil ; Department of Physical Education, Centre for Physical Education and Sport, Londrina State University, Londrina, Paraná, Brazil
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BAUER PRISCAR, KALITZIN STILIYAN, ZIJLMANS MAEIKE, SANDER JOSEMIRW, VISSER GERHARDH. CORTICAL EXCITABILITY AS A POTENTIAL CLINICAL MARKER OF EPILEPSY: A REVIEW OF THE CLINICAL APPLICATION OF TRANSCRANIAL MAGNETIC STIMULATION. Int J Neural Syst 2014; 24:1430001. [DOI: 10.1142/s0129065714300010] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Transcranial magnetic stimulation (TMS) can be used for safe, noninvasive probing of cortical excitability (CE). We review 50 studies that measured CE in people with epilepsy. Most showed cortical hyperexcitability, which can be corrected with anti-epileptic drug treatment. Several studies showed that decrease of CE after epilepsy surgery is predictive of good seizure outcome. CE is a potential biomarker for epilepsy. Clinical application may include outcome prediction of drug treatment and epilepsy surgery.
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Affiliation(s)
- PRISCA R. BAUER
- SEIN - Epilepsy Institute in the Netherlands Foundation, Heemstede, The Netherlands, P.O. Box 540, 2130 AM Hoofddorp, The Netherlands
| | - STILIYAN KALITZIN
- SEIN - Epilepsy Institute in the Netherlands Foundation, Heemstede, The Netherlands, P.O. Box 540, 2130 AM Hoofddorp, The Netherlands
| | - MAEIKE ZIJLMANS
- SEIN - Epilepsy Institute in the Netherlands Foundation, Heemstede, The Netherlands, P.O. Box 540, 2130 AM Hoofddorp, The Netherlands
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - JOSEMIR W. SANDER
- SEIN - Epilepsy Institute in the Netherlands Foundation, Heemstede, The Netherlands, P.O. Box 540, 2130 AM Hoofddorp, The Netherlands
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
- Epilepsy Society, Chalfont St Peter, SL9 0RJ, United Kingdom
| | - GERHARD H. VISSER
- SEIN - Epilepsy Institute in the Netherlands Foundation, Heemstede, The Netherlands, P.O. Box 540, 2130 AM Hoofddorp, The Netherlands
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Chipchase L, Schabrun S, Cohen L, Hodges P, Ridding M, Rothwell J, Taylor J, Ziemann U. A checklist for assessing the methodological quality of studies using transcranial magnetic stimulation to study the motor system: an international consensus study. Clin Neurophysiol 2012; 123:1698-704. [PMID: 22647458 DOI: 10.1016/j.clinph.2012.05.003] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 04/30/2012] [Accepted: 05/03/2012] [Indexed: 11/16/2022]
Abstract
In the last decade transcranial magnetic stimulation (TMS) has been the subject of more than 20,000 original research articles. Despite this popularity, TMS responses are known to be highly variable and this variability can impact on interpretation of research findings. There are no guidelines regarding the factors that should be reported and/or controlled in TMS studies. This study aimed to develop a checklist to be recommended to evaluate the methodology and reporting of studies that use single or paired pulse TMS to study the motor system. A two round international web-based Delphi study was conducted. Panellists rated the importance of a number of subject, methodological and analytical factors to be reported and/or controlled in studies that use single or paired pulse TMS to study the motor system. Twenty-seven items for single pulse studies and 30 items for paired pulse studies were included in the final checklist. Eight items related to subjects (e.g. age, gender), 21 to methodology (e.g. coil type, stimulus intensity) and two to analysis (e.g. size of the unconditioned motor evoked potential). The checklist is recommended for inclusion when submitting manuscripts for publication to ensure transparency of reporting and could also be used to critically appraise previously published work. It is envisaged that factors could be added and deleted from the checklist on the basis of future research. Use of the TMS methodological checklist should improve the quality of data collection and reporting in TMS studies of the motor system.
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Affiliation(s)
- Lucy Chipchase
- The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, Australia.
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Duarte JMN, Agostinho PM, Carvalho RA, Cunha RA. Caffeine consumption prevents diabetes-induced memory impairment and synaptotoxicity in the hippocampus of NONcZNO10/LTJ mice. PLoS One 2012; 7:e21899. [PMID: 22514596 PMCID: PMC3326010 DOI: 10.1371/journal.pone.0021899] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 06/08/2011] [Indexed: 12/20/2022] Open
Abstract
Diabetic conditions are associated with modified brain function, namely with cognitive deficits, through largely undetermined processes. More than understanding the underlying mechanism, it is important to devise novel strategies to alleviate diabetes-induced cognitive deficits. Caffeine (a mixed antagonist of adenosine A(1) and A(2A) receptors) emerges as a promising candidate since caffeine consumption reduces the risk of diabetes and effectively prevents memory deficits caused by different noxious stimuli. Thus, we took advantage of a novel animal model of type 2 diabetes to investigate the behavioural, neurochemical and morphological modifications present in the hippocampus and tested if caffeine consumption might prevent these changes. We used a model closely mimicking the human type 2 diabetes condition, NONcNZO10/LtJ mice, which become diabetic at 7-11 months when kept under an 11% fat diet. Caffeine (1 g/l) was applied in the drinking water from 7 months onwards. Diabetic mice displayed a decreased spontaneous alternation in the Y-maze accompanied by a decreased density of nerve terminal markers (synaptophysin, SNAP25), mainly glutamatergic (vesicular glutamate transporters), and increased astrogliosis (GFAP immunoreactivity) compared to their wild type littermates kept under the same diet. Furthermore, diabetic mice displayed up-regulated A(2A) receptors and down-regulated A(1) receptors in the hippocampus. Caffeine consumption restored memory performance and abrogated the diabetes-induced loss of nerve terminals and astrogliosis. These results provide the first evidence that type 2 diabetic mice display a loss of nerve terminal markers and astrogliosis, which is associated with memory impairment; furthermore, caffeine consumption prevents synaptic dysfunction and astrogliosis as well as memory impairment in type 2 diabetes.
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Affiliation(s)
- João M. N. Duarte
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Paula M. Agostinho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Rui A. Carvalho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A. Cunha
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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de Carvalho M, Swash M. Sensitivity of electrophysiological tests for upper and lower motor neuron dysfunction in ALS: a six-month longitudinal study. Muscle Nerve 2010; 41:208-11. [PMID: 19697379 DOI: 10.1002/mus.21495] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
By following a group of amyotrophic lateral sclerosis (ALS) patients longitudinally using lower motor neuron (LMN) and upper motor neuron (UMN) markers of dysfunction it may be possible to better understand the functional relationships between these motor systems in this disease. We used neurophysiological techniques to follow UMN and LMN dysfunction in a group of 28 patients with ALS, in comparison with the ALS functional rating scale (ALS-FRS) score and the forced vital capacity (FVC). We used motor unit number estimation (MUNE), compound muscle action potential (CMAP) amplitude, and the Neurophysiological Index (NI) to quantify the LMN disorder, and transcranial motor stimulation to study cortical motor threshold, motor-evoked response amplitude, central motor conduction time, and cortical silent period (CSP). The patients were studied shortly after diagnosis and then 6 months later, using both abductor digiti minimi muscles (ADM); ADM strength was initially >MRC 3 (Medical Research Council, UK). The NI and MUNE changed more than any other variable. CSP increased by about 30%, a change more marked than the slight increase observed in the cortical motor threshold (9%). The normal increase of CSP after acute muscle fatigue was preserved during disease progression. The CSP increase correlated with the MUNE rate of decay but not to the NI reduction, perhaps because NI includes F-wave frequency in itscalculation. There was no definite correlation between UMN and LMNdysfunction or progression, but there was a link between CSP and LMN changes in ALS. The CSP may be a useful variable in following UMN dysfunction in clinical practice and in clinical trials.
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Affiliation(s)
- Mamede de Carvalho
- Neuroscience Department and Institute of Molecular Medicine, Faculty of Medicine, University of Lisbon, Santa Maria Hospital, Ave Egas Moniz, 1649 035, Lisbon, Portugal.
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Cunha RA, Ferré S, Vaugeois JM, Chen JF. Potential therapeutic interest of adenosine A2A receptors in psychiatric disorders. Curr Pharm Des 2008; 14:1512-24. [PMID: 18537674 DOI: 10.2174/138161208784480090] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The interest on targeting adenosine A(2A) receptors in the realm of psychiatric diseases first arose based on their tight physical and functional interaction with dopamine D(2) receptors. However, the role of central A(2A) receptors is now viewed as much broader than just controlling D(2) receptor function. Thus, there is currently a major interest in the ability of A(2A) receptors to control synaptic plasticity at glutamatergic synapses. This is due to a combined ability of A(2A) receptors to facilitate the release of glutamate and the activation of NMDA receptors. Therefore, A(2A) receptors are now conceived as a normalizing device promoting adequate adaptive responses in neuronal circuits, a role similar to that fulfilled, in essence, by dopamine. This makes A(2A) receptors particularly attractive targets to manage psychiatric disorders since adenosine may act as go-between glutamate and dopamine, two of the key players in mood processing. Furthermore, A(2A) receptors also control glia function and brain metabolic adaptation, two other emerging mechanisms to understand abnormal processing of mood, and A(2A) receptors are important players in controlling the demise of neurodegeneration, considered an amplificatory loop in psychiatric disorders. Current data only provide an indirect confirmation of this putative role of A(2A) receptors, based on the effects of caffeine (an antagonist of both A(1) and A(2A) receptors) in psychiatric disorders. However, the introduction of A(2A) receptors antagonists in clinics as anti-parkinsonian agents is hoped to bolster our knowledge on the role of A(2A) receptors in mood disorders in the near future.
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Affiliation(s)
- Rodrigo A Cunha
- Center for Neuroscience of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, Portugal.
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Chen JF, Sonsalla PK, Pedata F, Melani A, Domenici MR, Popoli P, Geiger J, Lopes LV, de Mendonça A. Adenosine A2A receptors and brain injury: Broad spectrum of neuroprotection, multifaceted actions and “fine tuning” modulation. Prog Neurobiol 2007; 83:310-31. [DOI: 10.1016/j.pneurobio.2007.09.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 08/10/2007] [Accepted: 09/21/2007] [Indexed: 10/22/2022]
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