scholarly journals Clinically significant acute pain disturbs motor cortex intracortical inhibition and facilitation in orthopedic trauma patients: A TMS study

2019 ◽  
Author(s):  
Marianne Jodoin ◽  
Dominique M. Rouleau ◽  
Audrey Bellemare ◽  
Catherine Provost ◽  
Camille Larson-Dupuis ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Severe Pain ◽  
Cortical Excitability ◽  
Intracortical Inhibition ◽  
Cortical Inhibition ◽  
Trauma Patients ◽  
Orthopedic Trauma ◽  
Resting Motor Threshold ◽  
Clinically Significant ◽  
Intracortical Inhibition And Facilitation

AbstractObjectivePrimary motor (M1) cortical excitability alterations are involved in the development and maintenance of chronic pain. Less is known about M1-cortical excitability implications in the acute phase of an orthopedic trauma. This study aims to assess acute M1-cortical excitability in patients with an isolated upper limb fracture (IULF) in relation to pain intensity.MethodsEighty-four (56 IULF patients <14 days post-trauma and 28 healthy controls) performed a single transcranial magnetic stimulation (TMS) session over M1 (resting motor threshold (rMT); short-intracortical inhibition (SICI); intracortical facilitation (ICF); long-interval cortical inhibition (LICI)). IULF patients were divided into two subgroups according to pain intensity (mild versus moderate to severe pain).ResultsReduced SICI and ICF were found in IULF patients with moderate to severe pain, whereas mild pain was not associated with M1 alterations. Age, sex, and time since the accident had no influence on TMS measures.DiscussionThese findings show altered M1 in the context of acute moderate to severe pain, suggesting early signs of altered GABAergic inhibitory and glutamatergic facilitatory activities.

scholarly journals Moderate to severe acute pain disturbs motor cortex intracortical inhibition and facilitation in orthopedic trauma patients: A TMS study

PLoS ONE ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. e0226452
Author(s):  
Marianne Jodoin ◽  
Dominique M. Rouleau ◽  
Audrey Bellemare ◽  
Catherine Provost ◽  
Camille Larson-Dupuis ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Acute Pain ◽  
Intracortical Inhibition ◽  
Trauma Patients ◽  
Orthopedic Trauma ◽  
Intracortical Inhibition And Facilitation

Cortical dysfunction underlies disability in multiple sclerosis

2011 ◽  
Vol 18 (4) ◽  
pp. 425-432 ◽  
Author(s):  
Steve Vucic ◽  
Therese Burke ◽  
Kerry Lenton ◽  
Sudarshini Ramanathan ◽  
Lavier Gomes ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Cortical Excitability ◽  
Short Interval ◽  
Motor Evoked Potential ◽  
Intracortical Inhibition ◽  
Progressive Multiple Sclerosis ◽  
Conduction Time ◽  
Cortical Function ◽  
Resting Motor Threshold ◽  
Cortical Dysfunction

Background: Gray matter atrophy has been implicated in the development of secondary progressive multiple sclerosis (SPMS). Cortical function may be assessed by transcranial magnetic stimulation (TMS). Determining whether cortical dysfunction was a feature of SPMS could be of pathophysiological significance. Objectives: Consequently, novel paired-pulse threshold tracking TMS techniques were used to assess whether cortical dysfunction was a feature of SPMS. Methods: Cortical excitability studies were undertaken in 15 SPMS, 25 relapsing–remitting MS patients (RRMS) and 66 controls. Results: Short interval intracortical inhibition (SPMS 3.0 ± 2.1%; RRMS 12.8 ± 1.7%, p < 0.01; controls 10.5 ± 0.7%, p < 0.01) and motor evoked potential (MEP) amplitude (SPMS 11.5 ± 2.2%; RRMS 26.3 ± 3.6%, p <0.05; controls 24.7 ± 1.8%, p < 0.01) were reduced in SPMS, while intracortical facilitation (SPMS -5.2 ± 1.9%; RRMS -2.0 ± 1.4, p < 0.05; controls -0.9 ± 0.7, p < 0.01) and resting motor threshold were increased (SPMS 67.5 ± 4.5%; RRMS 56.0 ± 1.5%, p < 0.01; controls 59.0 ± 1.1%, p < 0.001). Further, central motor conduction time was prolonged in SPMS (9.1 ± 1.2 ms, p < 0.001) and RRMS (7.0 ± 0.9 ms, p < 0.05) patients compared with controls (5.5 ± 0.2 ms). The observed changes in cortical function correlated with the Expanded Disability Status Scale. Conclusion: Together, these findings suggest that cortical dysfunction is associated with disability in MS, and documentation of such cortical dysfunction may serve to quantify disease severity in MS.

Abstract TMP43: Differential Cortical Effect Modulated by Anodal, Cathodal and Bihemispheric Transcranial Direct Current Stimulation (tDCS) in Patients With Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Pratik Y Chhatbar ◽  
William DeVries ◽  
Emily Grattan ◽  
Steven A Kautz ◽  
Wuwei Feng
Keyword(s):  
Ischemic Stroke ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Single Pulse ◽  
Intracortical Inhibition ◽  
Motor Threshold ◽  
Stroke Patients ◽  
Intracortical Facilitation ◽  
Abductor Pollicis Brevis ◽  
Resting Motor Threshold

Introduction: The differential brain modulatory effects across hemispheres from different montages in stroke patients is not well established. We aimed to investigate the cortical excitability on lesional and contra-lesional hemisphere modulated by anodal, cathodal and bihemispheric montage at 4 mA tDCS strengths. Hypothesis: Bihemispheric tDCS montage induces more cortical excitability on the lesional hemisphere. Methods: Eighteen aging stroke patients with unilateral ischemic stroke of 6 or more months and inducible motor evoked potentials (MEP) underwent 3 sessions of 30 minutes 4 mA tDCS combined with occupational therapy. Each session was at least 2 days apart and consisted of one of the 3 different montages: anodal (Anode: lesional C3/C4, Cathode: non-lesional FP1/FP2), cathodal (Anode: lesional FP1/FP2, Cathode: non-lesional C3/C4), or bihemispheric (Anode: lesional C3/C4, Cathode: non-lesional C3/C4). We collected MEP size, short intracortical inhibition (SICI, 3 ms) and intracortical facilitation (ICF, 15 ms) on bilateral abductor pollicis brevis (APB) muscles using single or paired pulse TMS at 5 timepoints (baseline and four post-tDCS 12 minutes apart sessions). Results: All 18 subjects had comparable resting motor threshold (rMT) across 3 montages (see A). Bihemispheric tDCS montage offered significantly larger peak-to-peak MEP responses on the lesioned cortex (ANOVA, F=8.97, P<0.01) but not on the non-lesioned cortex (ANOVA, F=0.86, P=0.42). These differences were apparent in single pulse, SICI and ICF (see B). Conclusion: Our findings support that bihemispheric montage is better suited in post-stroke motor recovery tDCS applications.

Acute muscle pain alters corticomotor output of the affected muscle stronger than a synergistic, ipsilateral muscle

2017 ◽  
Vol 16 (1) ◽  
pp. 177-177
Author(s):  
Dennis Boye Larsen ◽  
Thomas Graven-Nielsen ◽  
Rogerio Pessoto Hirata ◽  
Shellie A. Boudreau
Keyword(s):  
Pain Intensity ◽  
Muscle Pain ◽  
Repeated Measures ◽  
Cortical Excitability ◽  
Motor Evoked Potentials ◽  
Post Injection ◽  
Repeated Measures Analysis ◽  
Resting Motor Threshold ◽  
First Dorsal Interosseus ◽  
Extensor Carpi Radialis

Abstract Aims Muscle pain affects corticomotor areas representing the affected muscle, by changing the size of representation and reduces the corticospinal output as assessed by transcranial magnetic stimulation (TMS). Less work has been done to understand how pain in one muscle group may affect synergistic ipsilateral muscles distal to the pain. This study aimed to explore the effects of acute extensor carpi radialis (ECR) muscle pain on TMS motor-evoked potentials (MEPs) of the ECR and the first dorsal interosseus (FDI) muscle, which are known to strongly overlap within the corticomotor area. Methods Eight healthy volunteers (1 woman) were injected with hypertonic saline (5.8%, 0.5 mL) into the ECR muscle. Pain intensity was assessed by the visual analogue scale (VAS) every minute for 10 min. TMS was applied at 120% of ECR resting motor threshold, and MEPs were acquired from the ECR and the FDI muscles. At baseline, 10 TMS pulses were delivered. Temporal mapping of ECR and FDI MEPs over 10 min duration was performed by delivering 100 single-pulses of TMS, at 6 s interstimulus-interval. The MEPs for each muscle were averaged at baseline, peak-pain (1 –2 min epoch), and 10 min post-injection Results Pain intensity reduced significantly at 10 min postinjection as compared to peak-pain (P = 0.011). Further, one-way repeated measures analysis of variance revealed that ECR MEPs were altered at peak-pain compared to baseline (P > 0.05), but not 10 min post-injection (P > 0.05). Baseline and 10 min post-injection of ECR MEPs did not differ significantly (P = 0.67). The MEPs of the FDI muscle did not show a similar alteration over time (P = 0.1). Conclusions Despite the overlap between ECR and FDI representations, acute muscle pain of the ECR only significantly altered cortical excitability of the ECR muscle representation.

Cortical Inhibition in Symptomatic and Remitted Mania Compared to Healthy Subjects: A Paired-pulse TMS Study

2017 ◽  
Vol 41 (S1) ◽  
pp. S76-S76
Author(s):  
N. Sanjay ◽  
R. Basavaraju ◽  
S. Biradar ◽  
U. Mehta ◽  
M. Kesavan ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Intracortical Inhibition ◽  
Cortical Inhibition ◽  
First Episode ◽  
Future Research ◽  
Motor Threshold ◽  
Gaba A ◽  
Paired Pulse ◽  
Resting Motor Threshold ◽  
First Dorsal Interosseous Muscle

IntroductionCortical inhibition (CI) is a neurophysiological outcome of the interaction between GABA inhibitory interneurons and other excitatory neurons. Transcranial magnetic stimulation (TMS) measures of CI deficits have been documented in both symptomatic and remitted bipolar disorder (BD) suggesting it could be a trait marker. The effects of medications and duration of illness may contribute to these findings.ObjectiveTo study CI in BD.AimsTo compare CI across early-course medication-naive BD-mania, remitted first episode mania (FEM) and healthy subjects (HS).MethodsSymptomatic BD subjects having < 3 episodes, currently in mania and medication-naive (n = 27), remitted FEM (n = 27; YMRS < 12 and HDRS < 8) and 45 HS, matched for age and gender, were investigated. Resting motor threshold (RMT) and 1-millivolt motor threshold (MT1) were estimated from the right first dorsal interosseous muscle. Paired-pulse TMS measures of short (SICI; 3ms) and long interval intracortical inhibition (LICI; 100ms) were acquired. Group differences in measures of CI were examined using ANOVA.ResultsTable 1.ConclusionsSymptomatic mania patients had the highest motor thresholds and the maximum LICI indicating a state of an excessive GABA-B neurotransmitter tone. Remitted mania patients had deficits in SICI indicating reduced GABA-A neurotransmitter tone. Putative changes in GABA-A neurotransmitter system activity with treatment may be investigated in future studies. CI has received less attention in BD as compared to schizophrenia and is a potential avenue for future research in this area.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Cortical excitability varies across different muscles

2018 ◽  
Vol 120 (3) ◽  
pp. 1397-1403 ◽  
Author(s):  
Parvathi Menon ◽  
Matthew C. Kiernan ◽  
Steve Vucic
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Functional Organization ◽  
Cortical Excitability ◽  
Short Interval ◽  
Intracortical Inhibition ◽  
Body Regions ◽  
Threshold Tracking ◽  
Resting Motor Threshold ◽  
Limb Muscles

The aim of the present study was to determine whether significant differences in cortical excitability were evident across different body regions in healthy humans. Threshold tracking transcranial magnetic stimulation (TMS) was undertaken in 28 healthy controls. Short-interval intracortical inhibition [SICI between interstimulus intervals (ISI) 1–7 ms], intracortical facilitation (ICF, between ISI 10–30 ms), resting motor threshold (RMT), cortical silent period (CSP) duration (generated at stimulus intensity 150% RMT), and motor evoked potential amplitude were recorded from the abductor pollicis brevis (APB), tibialis anterior (TA), and trapezius muscles. These muscles were selected as they are frequently affected in neurodegenerative diseases, such as amyotrophic lateral sclerosis. SICI and ICF are measured as a percentage difference between conditioned and an unconditioned test response. SICI was significantly greater when recorded over the APB (9.9 ± 1.5%) and TA (8.6 ± 1.4%) muscles compared with the trapezius (4.5 ± 1.9%, P < 0.05). The CSP duration was significantly shorter (CSPtrapezius, 131.0 ± 6.3 ms; CSPTA, 175.7 ± 9.9 ms; CSPAPB, 188.3 ± 4.0 ms; P < 0.001) and ICF greater ( P < 0.01) in the trapezius muscle. There were no significant correlations between inhibitory and facilitatory processes recorded across the three muscles. The present study established significant differences in cortical excitability across three body regions, with evidence of more prominent inhibition and less facilitation in the limb muscles. NEW & NOTEWORTHY Cortical excitability of muscles with differing motor functions was assessed using threshold tracking transcranial magnetic stimulation. Significantly greater intracortical inhibition and less facilitation were evident over the limb muscles. These findings could relate to differences in the functional organization of the corticomotoneuronal system innervating different muscle regions.

Pain assessment and management in critically ill postoperative and trauma patients: a multisite study

1999 ◽  
Vol 8 (2) ◽  
pp. 105-117 ◽  
Author(s):  
KC Carroll ◽  
PJ Atkins ◽  
GR Herold ◽  
CA Mlcek ◽  
M Shively ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Pain Management ◽  
Pain Relief ◽  
Pain Intensity ◽  
Critically Ill ◽  
Severe Pain ◽  
Management Practices ◽  
Management Plan ◽  
Trauma Patients

BACKGROUND: Pain in critically ill patients is undertreated. OBJECTIVES: To examine patients' perceptions of pain and acute pain management practices in a large metropolitan area to provide direction for improvements in pain relief. METHODS: In a descriptive, correlational study, data were collected from 213 patients in 13 hospitals. Interviews with patients, chart reviews, and interviews with nurse leaders were used to examine institutional and individual approaches to pain management. RESULTS: Twenty-eight percent of patients did not recall an explanation of a pain management plan, and 64% were often in moderate to severe pain while in the intensive care unit. High pain intensity correlated with wait for an analgesic (P &lt; .001), expectations of less pain (P &lt; .001), and longer stay in the intensive care unit (P &lt; .001). Low satisfaction correlated with expectations of less pain (P &lt; .001), often being in moderate to severe pain (P &lt; .001), and long wait for an analgesic (P &lt; .001). In the first 24 hours postoperatively, only 54% of patients had a numerical pain rating documented; 91% had a pain description. The amount of opioid given on postoperative day 1 was influenced by pain intensity (P &lt; .001), the patient's age (P = .03), type of surgery (P = .002), and route of analgesic (P &lt; .001). Only 33% of patients had nonpharmacological pain interventions documented. CONCLUSIONS: Despite moderate to severe pain, patients are generally satisfied with their pain relief. Measuring patients' satisfaction alone is not a reliable outcome for determining the effectiveness of pain management. Realistic expectations of patients about their pain may enhance coping, increase satisfaction, and decrease pain intensity after surgery.

Intracortical Inhibition and Facilitation after congenital stroke

2006 ◽  
Vol 37 (01) ◽  
Author(s):  
S Berweck ◽  
V Brodbeck ◽  
M Walther ◽  
N Wagner ◽  
M Staudt ◽  
...  
Keyword(s):  
Intracortical Inhibition ◽  
Intracortical Inhibition And Facilitation

The Frequency of Random Findings on Abdominal / Pelvis Computed Tomography in Pediatric Trauma Patients

2020 ◽  
Vol 16 ◽  
Author(s):  
Betül Tiryaki Baştuğ
Keyword(s):  
Computed Tomography ◽  
Incidental Findings ◽  
Pediatric Population ◽  
Pediatric Trauma ◽  
Trauma Patients ◽  
Injured Child ◽  
Level 3 ◽  
Male Patients ◽  
Clinically Significant ◽  
Discharge Summaries

Aims: In this study, we aimed to find the percentage of random pathologies and abdominopelvic region anomalies that are not related to trauma in pediatric patients. Background: An abdominal assessment of an injured child usually involves computed tomography imaging of the abdomen and pelvis (CTAP) to determine the presence and size of injuries. Imaging may accidentally reveal irrelevant findings. Objectives: Although the literature in adults has reviewed the frequency of discovering these random findings, few studies have been identified in the pediatric population. Methods: Data on 142( 38 female, 104 male) patients who underwent CTAP during their trauma evaluation between January 2019 and January 2020 dates were obtained from our level 3 pediatric trauma center trauma records. The records and CTAP images were examined retrospectively for extra traumatic pathologies and anomalies. Results: 67 patients (47%) had 81 incidental findings. There were 17 clinically significant random findings. No potential tumors were found in this population. Conclusion: Pediatric trauma CTAP reveals random findings. For further evaluation, incidental findings should be indicated in the discharge summaries.

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