Mapping From Motor Cortex to Biceps and Triceps Altered By Elbow Angle

2004 ◽  
Vol 92 (1) ◽  
pp. 395-407 ◽  
Author(s):  
Michael S. A. Graziano ◽  
Kaushal T. Patel ◽  
Charlotte S. R. Taylor
Keyword(s):  
Motor Cortex ◽  
Opposite Effect ◽  
Primary Motor Cortex ◽  
Joint Angle ◽  
Normal Function ◽  
Ventral Part ◽  
The Difference ◽  
Evoked Activity ◽  
Cortical Map ◽  
Intermediate Effect

This experiment used cortical microstimulation to probe the mapping from primary motor cortex to the biceps and triceps muscles of the arm in monkeys. The mapping appeared to change depending on the angle at which the elbow was fixed. For sites in the dorsal part of the arm and hand representation, the effects of stimulation were consistent with initiating a movement of the elbow to an extended angle. Stimulation evoked more triceps activity than biceps activity, and this difference was largest when the elbow was fixed in a flexed angle. For sites in the ventral part of the arm and hand representation, stimulation had the opposite effect, consistent with initiating a movement of the elbow to a flexed angle. For these sites, stimulation evoked more biceps activity than triceps activity, and the difference was largest when the elbow was fixed in an extended angle. For sites located in intermediate positions, stimulation evoked an intermediate effect consistent with initiating a movement of the elbow to a middle, partially flexed angle. For these sites, when the elbow was fixed at a flexed angle, the evoked activity was largest in the triceps, and when the elbow was fixed at an extended angle, the evoked activity was largest in the biceps. These effects were obtained with 400-ms-long trains of biphasic pulses presented at 200 Hz and 30 μA. They were also obtained by averaging the effects of individual, 30-μA pulses presented at 15 Hz. How this stimulation-evoked topography relates to the normal function of motor cortex is not yet clear. One hypothesis is that these results reflect a cortical map of desired joint angle.

SURG-03. FUNCTIONAL OUTCOMES OF LASER INTERSTITIAL THERMAL THERAPY (LITT) VERSUS RESECTION IN THE TREATMENT OF LESIONS IN OR NEAR THE PRIMARY MOTOR CORTEX

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi195-vi195
Author(s):  
Ethan Srinivasan ◽  
Emily Lerner ◽  
Ryan Edwards ◽  
David Huie ◽  
Peter Fecci
Keyword(s):  
Motor Cortex ◽  
Functional Outcomes ◽  
Primary Motor Cortex ◽  
Thermal Therapy ◽  
Invasive Treatment ◽  
Motor Mapping ◽  
Laser Interstitial Thermal Therapy ◽  
Hospital Stays ◽  
The Difference ◽  
Pre Treatment

Abstract INTRODUCTION Laser interstitial thermal therapy (LITT) is a minimally-invasive treatment option for radiographically-progressive (RP) brain metastases. This study compares the functional outcomes of LITT vs resection (RS) for lesions in or near the primary motor cortex (PMC). METHODS Retrospective review was performed of patients treated for PMC lesions by LITT or RS. Functional outcomes were graded relative to pre-treatment symptoms and categorized as improved, stable, or worsened at 30, 90, and 180 days post-LITT/RS. RESULTS 36 patients were identified with median follow-up of 194 days (IQR 72-503), age 64 years (57-72), and estimated baseline KPS 80 (80-90). 35 (98%) had pre-treatment weakness or motor seizure; 15 (42%) received LITT and 21 (58%) RS; all RS were performed with intra-operative motor mapping while LITT were not. All LITT patients were treated for RP lesions (radiation necrosis (RN) or disease progression) vs. 24% of RS patients (p< 0.01). LITT patients trended towards smaller lesions (1.9 cm vs 2.7 cm, p=0.03) and were more likely to show RN (67% vs 5%, p< 0.01) and be discharged home (87% vs 52%, p=0.04), with shorter ICU (0 vs 1 day, p< 0.01) and hospital stays (1 vs. 2 days, p< 0.01). At 30 days, 89% of surviving patients who received RS had stable or improved symptoms, compared to 46% of the LITT cohort (p=0.02). At 90 days, the difference was 88% to 50% (p=0.07), and at 180 days 100% to 80% (p=0.2941). CONCLUSIONS In the short term (30 days), patients with PMC lesions have better functional outcomes when treated with RS compared to LITT, while those who survive to the 180-day timepoint experience similar outcomes. These differences are likely due to transient, expected post-LITT edema that subsides with time. Taken together, prognosis and patient priorities are important considerations in the decision between LITT and RS.

scholarly journals Muscle and Timing-specific Functional Connectivity between the Dorsolateral Prefrontal Cortex and the Primary Motor Cortex

2013 ◽  
Vol 25 (4) ◽  
pp. 558-570 ◽  
Author(s):  
Alkomiet Hasan ◽  
Joseph M. Galea ◽  
Elias P. Casula ◽  
Peter Falkai ◽  
Sven Bestmann ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Animal Studies ◽  
Primary Motor Cortex ◽  
Adjacent Area ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal ◽  
The Difference ◽  
Selection Tasks ◽  
The Right

The pFC has a crucial role in cognitive control, executive function, and sensory processing. Functional imaging, neurophysiological, and animal studies provide evidence for a functional connectivity between the dorsolateral pFC (DLPFC) and the primary motor cortex (M1) during free choice but not instructed choice selection tasks. In this study, twin coil, neuronavigated TMS was used to examine the precise timing of the functional interaction between human left DLPFC and ipsilateral M1 during the execution of a free/specified choice selection task involving the digits of the right hand. In a thumb muscle that was not involved in the task, a conditioning pulse to the left DLPFC enhanced the excitability of the ipsilateral M1 during free selection more than specified selection 100 msec after presentation of the cue; the opposite effect was seen at 75 msec. However, the difference between free and externally specified conditions disappeared when a task-specific muscle was investigated. In this case, the influence from DLPFC was dominated by task involvement rather than mode of selection, suggesting that other processes related to movement execution were also operating. Finally, we show that the effects were spatially specific because they were absent when an adjacent area of DLPFC was stimulated. These results reveal temporally and spatially selective interactions between BA 46 and M1 that are both task and muscle specific.

scholarly journals SURG-08. Laser Interstitial Thermal Therapy (LITT) versus Resection in the Treatment of Lesions In or Near the Primary Motor Cortex

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii25-iii25
Author(s):  
Ethan Srinivasan ◽  
Emily Lerner ◽  
Ryan Edwards ◽  
David Huie ◽  
Peter Fecci
Keyword(s):  
Motor Cortex ◽  
Functional Outcomes ◽  
Primary Motor Cortex ◽  
Thermal Therapy ◽  
Invasive Treatment ◽  
Motor Mapping ◽  
Laser Interstitial Thermal Therapy ◽  
Hospital Stays ◽  
The Difference ◽  
Pre Treatment

Abstract Introduction Laser interstitial thermal therapy (LITT) is a minimally-invasive treatment option for radiographically-progressive (RP) brain metastases. This study compares the functional outcomes of LITT vs resection (RS) for lesions in or near the primary motor cortex (PMC). Methods Retrospective review was performed of patients treated for PMC lesions by LITT or RS. Functional outcomes were graded relative to pre-treatment symptoms and categorized as improved, stable, or worsened at 30, 90, and 180 days post-LITT/RS. Results 36 patients were identified with median follow-up of 194 days (IQR 72–503), age 64 years (57–72), and estimated baseline KPS 80 (80–90). 35 (98%) had pre-treatment weakness or motor seizure; 15 (42%) received LITT and 21 (58%) RS; all RS were performed with intra-operative motor mapping while LITT were not. All LITT patients were treated for RP lesions (radiation necrosis (RN) or disease progression) vs. 24% of RS patients (p<0.01). LITT patients trended towards smaller lesions (1.9 cm vs 2.7 cm, p=0.03) and were more likely to show RN (67% vs 5%, p<0.01) and be discharged home (87% vs 52%, p=0.04), with shorter ICU (0 vs 1 day, p<0.01) and hospital stays (1 vs. 2 days, p<0.01). At 30 days, 89% of surviving patients who received RS had stable or improved symptoms, compared to 46% of the LITT cohort (p=0.02). At 90 days, the difference was 88% to 50% (p=0.07), and at 180 days 100% to 80% (p=0.2941). Conclusion In the short term (30 days), patients with PMC lesions have better functional outcomes when treated with RS compared to LITT, while those who survive to the 180-day timepoint experience similar outcomes. These differences are likely due to transient, expected post-LITT edema that subsides with time. Taken together, prognosis and patient priorities are important considerations in the decision between LITT and RS.

scholarly journals Repetitive transcranial magnetic stimulation of the primary motor cortex in management of chronic neuropathic pain: a systematic review

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kliment Gatzinsky ◽  
Christina Bergh ◽  
Ann Liljegren ◽  
Hans Silander ◽  
Jennifer Samuelsson ◽  
...  
Keyword(s):  
Pain Relief ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Positive Response ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Pain Reduction ◽  
Chronic Neuropathic Pain ◽  
Percentage Points ◽  
The Difference

AbstractObjectivesRepetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) with frequencies 5–20 Hz is an expanding non-invasive treatment for chronic neuropathic pain (NP). Outcome data, however, show considerable inhomogeneity with concern to the levels of effect due to the great diversity of treated conditions. The aim of this review was to survey the literature regarding the efficacy and safety of M1 rTMS, and the accuracy to predict a positive response to epidural motor cortex stimulation (MCS) which is supposed to give a more longstanding pain relief.MethodsA systematic literature search was conducted up to June 2019 in accordance with the PRISMA guidelines. We used the PICO Model to define two specific clinical questions: (1) Does rTMS of M1 relieve NP better than sham treatment? (2) Can the response to rTMS be used to predict the effect of epidural MCS? After article selection, data extraction, and study quality assessment, the certainty of evidence of treatment effect was defined using the GRADE system.ResultsData on 5–20 Hz (high-frequency) rTMS vs. sham was extracted from 24 blinded randomised controlled trials which were of varying quality, investigated highly heterogeneous pain conditions, and used excessively variable stimulation parameters. The difference in pain relief between active and sham stimulation was statistically significant in 9 of 11 studies using single-session rTMS, and in 9 of 13 studies using multiple sessions. Baseline data could be extracted from 6 single and 12 multiple session trials with a weighted mean pain reduction induced by active rTMS, compared to baseline, of −19% for single sessions, −32% for multiple sessions with follow-up <30 days, and −24% for multiple sessions with follow-up ≥30 days after the last stimulation session. For single sessions the weighted mean difference in pain reduction between active rTMS and sham was 15 percentage points, for multiple sessions the difference was 22 percentage points for follow-ups <30 days, and 15 percentage points for follow-ups ≥30 days. Four studies reported data that could be used to evaluate the accuracy of rTMS to predict response to MCS, showing a specificity of 60–100%, and a positive predictive value of 75–100%. No serious adverse events were reported.ConclusionsrTMS targeting M1 can result in significant reduction of chronic NP which, however, is transient and shows a great heterogeneity between studies; very low certainty of evidence for single sessions and low for multiple sessions. Multiple sessions of rTMS can maintain a more longstanding effect. rTMS seems to be a fairly good predictor of a positive response to epidural MCS and may be used to select patients for implantation of permanent epidural electrodes. More studies are needed to manifest the use of rTMS for this purpose. Pain relief outcomes in a longer perspective, and outcome variables other than pain reduction need to be addressed more consistently in future studies to consolidate the applicability of rTMS in routine clinical practice.

I Like Her, Because I Like Myself: Self-Evaluation as a Source of Interpersonal Attitudes

2003 ◽  
Vol 50 (4) ◽  
pp. 239-246 ◽  
Author(s):  
Eva Walther ◽  
Claudia Trasselli
Keyword(s):  
Opposite Effect ◽  
Learning Phase ◽  
The Self ◽  
Attitude Formation ◽  
Formation Processes ◽  
False Feedback ◽  
Self Evaluation ◽  
Evaluation Group ◽  
Group A ◽  
The Difference

Abstract. Two experiments tested the hypothesis that self-evaluation can serve as a source of interpersonal attitudes. In the first study, self-evaluation was manipulated by means of false feedback. A subsequent learning phase demonstrated that the co-occurrence of the self with another individual influenced the evaluation of this previously neutral target. Whereas evaluative self-target similarity increased under conditions of negative self-evaluation, an opposite effect emerged in the positive self-evaluation group. A second study replicated these findings and showed that the difference between positive and negative self-evaluation conditions disappeared when a load manipulation was applied. The implications of self-evaluation for attitude formation processes are discussed.

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