Fibers from the dorsal premotor cortex elicit motor-evoked potential in a cortical dysplasia

NeuroImage ◽  
2007 ◽  
Vol 34 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Nobuhiro Mikuni ◽  
Tsutomu Okada ◽  
Junya Taki ◽  
Riki Matsumoto ◽  
Namiko Nishida ◽  
...  
2021 ◽  
Author(s):  
Hina Sharma ◽  
Nand Kumar ◽  
Sreenivas Vishnubhatla ◽  
Rajeswari MR ◽  
M.V. Padma Srivast

Abstract Background: The therapeutic benefits of repetitive trans cranial magnetic stimulation along with physical therapy to study the neuroplasticity and neurogenesis in ischemic stroke patients has not been fully elucidated. The aim of this study is to determine the neuroplasticity using serum growth factors as a surrogate marker, using 1Hz rTMS with conventional physiotherapy in patients with sub acute ischemic stroke.Methods: In this study, participants with first ever ischemic stroke (N = 96), onset within 15 days were randomized after a run-in period of 75 ± 7 days along with standard physical therapy to receive 10 sessions of real 1Hz rTMS (N = 47) on contralesional premotor cortex or to sham stimulation (N = 49) for 2 weeks. Participants, investigators and outcome assessors were blinded. The primary efficacy outcome was change in the level of peripheral serum growth factors VEGF & BDNF at third month. The secondary outcome was measurement of neurophysiological parameters and their correlation with growth factors levels.Results: Modified intention to treat analysis showed significant up regulation in the mean level of serum VEGF & BDNF from pre to post rTMS in Real rTMS Group. Trend of decrease in Resting Motor Threshold and increase in Motor Evoked Potential in the affected hand was seen. Statistically significant negative correlation between motor evoked potential and mean VEGF (rho = -1.000, P<0.001) in the affected hand in Real rTMS Group was seen.Conclusion: Total ten sessions of 1Hz rTMS plus physical therapy on contralateral hemisphere resulted in up regulation of serum growth factors possible reflecting improved neuroplasticity. Trial funded by Indian Council of Medical Research (ICMR), India, CTRI/2016/02/006620. Retrospectively registered. Note: As this is not a regulatory trial, therefore under Indian regulatory authorities, ICMR, any trial registered before 1st April 2018 was registered as retrospective study. Ethics committee approval for this study was taken in 2012.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Davide Giampiccolo ◽  
Cristiano Parisi ◽  
Pietro Meneghelli ◽  
Vincenzo Tramontano ◽  
Federica Basaldella ◽  
...  

Abstract Muscle motor-evoked potentials are commonly monitored during brain tumour surgery in motor areas, as these are assumed to reflect the integrity of descending motor pathways, including the corticospinal tract. However, while the loss of muscle motor-evoked potentials at the end of surgery is associated with long-term motor deficits (muscle motor-evoked potential-related deficits), there is increasing evidence that motor deficit can occur despite no change in muscle motor-evoked potentials (muscle motor-evoked potential-unrelated deficits), particularly after surgery of non-primary regions involved in motor control. In this study, we aimed to investigate the incidence of muscle motor-evoked potential-unrelated deficits and to identify the associated brain regions. We retrospectively reviewed 125 consecutive patients who underwent surgery for peri-Rolandic lesions using intra-operative neurophysiological monitoring. Intraoperative changes in muscle motor-evoked potentials were correlated with motor outcome, assessed by the Medical Research Council scale. We performed voxel–lesion–symptom mapping to identify which resected regions were associated with short- and long-term muscle motor-evoked potential-associated motor deficits. Muscle motor-evoked potentials reductions significantly predicted long-term motor deficits. However, in more than half of the patients who experienced long-term deficits (12/22 patients), no muscle motor-evoked potential reduction was reported during surgery. Lesion analysis showed that muscle motor-evoked potential-related long-term motor deficits were associated with direct or ischaemic damage to the corticospinal tract, whereas muscle motor-evoked potential-unrelated deficits occurred when supplementary motor areas were resected in conjunction with dorsal premotor regions and the anterior cingulate. Our results indicate that long-term motor deficits unrelated to the corticospinal tract can occur more often than currently reported. As these deficits cannot be predicted by muscle motor-evoked potentials, a combination of awake and/or novel asleep techniques other than muscle motor-evoked potentials monitoring should be implemented.


2007 ◽  
Vol 578 (2) ◽  
pp. 551-562 ◽  
Author(s):  
Giacomo Koch ◽  
Michele Franca ◽  
Hitoshi Mochizuki ◽  
Barbara Marconi ◽  
Carlo Caltagirone ◽  
...  

2002 ◽  
Vol 88 (2) ◽  
pp. 1064-1072 ◽  
Author(s):  
Paul Cisek ◽  
John F. Kalaska

Recent studies have shown that gaze angle modulates reach-related neural activity in many cortical areas, including the dorsal premotor cortex (PMd), when gaze direction is experimentally controlled by lengthy periods of imposed fixation. We looked for gaze-related modulation in PMd during the brief fixations that occur when a monkey is allowed to look around freely without experimentally imposed gaze control while performing a center-out delayed arm-reaching task. During the course of the instructed-delay period, we found significant effects of gaze angle in 27–51% of PMd cells. However, for 90–95% of cells, these effects accounted for <20% of the observed discharge variance. The effect of gaze was significantly weaker than the effect of reach-related variables. In particular, cell activity during the delay period was more strongly related to the intended movement expressed in arm-related coordinates than in gaze-related coordinates. Under the same experimental conditions, many cells in medial parietal cortex exhibited much stronger gaze-related modulation and expressed intended movement in gaze-related coordinates. In summary, gaze direction-related modulation of cell activity is indeed expressed in PMd during the brief fixations that occur in natural oculomotor behavior, but its overall effect on cell activity is modest.


2021 ◽  
pp. 1-8
Author(s):  
Hao You ◽  
Xing Fan ◽  
Jiajia Liu ◽  
Dongze Guo ◽  
Zhibao Li ◽  
...  

OBJECTIVE The current study investigated the correlation between intraoperative motor evoked potential (MEP) and somatosensory evoked potential (SSEP) monitoring and both short-term and long-term motor outcomes in aneurysm patients treated with surgical clipping. Moreover, the authors provide a relatively optimal neurophysiological predictor of postoperative motor deficits (PMDs) in patients with ruptured and unruptured aneurysms. METHODS A total of 1017 patients (216 with ruptured aneurysms and 801 with unruptured aneurysms) were included. Patient demographic characteristics, clinical features, intraoperative monitoring data, and follow-up data were retrospectively reviewed. The efficacy of using changes in MEP/SSEP to predict PMDs was assessed using binary logistic regression analysis. Subsequently, receiver operating characteristic curve analysis was performed to determine the optimal critical value for duration of MEP/SSEP deterioration. RESULTS Both intraoperative MEP and SSEP monitoring were significantly effective for predicting short-term (p < 0.001 for both) and long-term (p < 0.001 for both) PMDs in aneurysm patients. The critical values for predicting short-term PMDs were amplitude decrease rates of 57.30% for MEP (p < 0.001 and area under the curve [AUC] 0.732) and 64.10% for SSEP (p < 0.001 and AUC 0.653). In patients with an unruptured aneurysm, the optimal critical values for predicting short-term PMDs were durations of deterioration of 17 minutes for MEP (p < 0.001 and AUC 0.768) and 21 minutes for SSEP (p < 0.001 and AUC 0.843). In patients with a ruptured aneurysm, the optimal critical values for predicting short-term PMDs were durations of deterioration of 12.5 minutes for MEP (p = 0.028 and AUC 0.706) and 11 minutes for SSEP (p = 0.043 and AUC 0.813). CONCLUSIONS The authors found that both intraoperative MEP and SSEP monitoring are useful for predicting short-term and long-term PMDs in patients with unruptured and ruptured aneurysms. The optimal intraoperative neuromonitoring method for predicting PMDs varies depending on whether the aneurysm has ruptured or not.


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