Association of the N100 TMS-evoked potential with attentional processes: A motor cortex TMS–EEG study

2018 ◽  
Vol 122 ◽  
pp. 9-16 ◽  
Author(s):  
Outi Kaarre ◽  
Marja Äikiä ◽  
Elisa Kallioniemi ◽  
Mervi Könönen ◽  
Virve Kekkonen ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Evoked Potential ◽  
Attentional Processes

Intraoperative Motor Evoked Potential Alteration in Intracranial Tumor Surgery and Its Relation to Signal Alteration in Postoperative Magnetic Resonance Imaging

Neurosurgery ◽  
2010 ◽  
Vol 67 (2) ◽  
pp. 302-313 ◽  
Author(s):  
Andrea Szelényi ◽  
Elke Hattingen ◽  
Stefan Weidauer ◽  
Volker Seifert ◽  
Ulf Ziemann
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Evoked Potential ◽  
Corticospinal Tract ◽  
Motor Evoked Potential ◽  
Motor Deficit ◽  
Warning Sign ◽  
Precentral Gyrus ◽  
Resonance Imaging

Abstract OBJECTIVE To determine the degree to which the pattern of intraoperative isolated, unilateral alteration of motor evoked potential (MEP) in intracranial surgery was related to motor outcome and location of new postoperative signal alterations on magnetic resonance imaging (MRI). METHODS In 29 patients (age, 42.8 ± 18.2 years; 15 female patients; 25 supratentorial, 4 infratentorial procedures), intraoperative MEP alterations in isolation (without significant alteration in other evoked potential modalities) were classified as deterioration (> 50% amplitude decrease and/or motor threshold increase) or loss, respectively, or reversible and irreversible. Postoperative MRI was described for the location and type of new signal alteration. RESULTS New motor deficit was present in all 5 patients with irreversible MEP loss, in 7 of 10 patients with irreversible MEP deterioration, in 1 of 6 patients with reversible MEP loss, and in 0 of 8 patients with reversible MEP deterioration. Irreversible compared with reversible MEP alteration was significantly more often correlated with postoperative motor deficit (P < .0001). In 20 patients, 22 new signal alterations affected 29 various locations (precentral gyrus, n = 5; corticospinal tract, n = 19). Irreversible MEP alteration was more often associated with postoperative new signal alteration in MRI compared with reversible MEP alteration (P = .02). MEP loss was significantly more often associated with subcortically located new signal alteration (P = .006). MEP deterioration was significantly more often followed by new signal alterations located in the precentral gyrus (P = .04). CONCLUSION MEP loss bears a higher risk than MEP deterioration for postoperative motor deficit resulting from subcortical postoperative MR changes in the corticospinal tract. In contrast, MEP deterioration points to motor cortex lesion. Thus, even MEP deterioration should be considered a warning sign if surgery close to the motor cortex is performed.

scholarly journals Pathophysiology of Central Poststroke Pain

Stroke ◽  
2019 ◽  
Vol 50 (10) ◽  
pp. 2851-2857 ◽  
Author(s):  
Sung-Chun Tang ◽  
Lukas Jyuhn-Hsiarn Lee ◽  
Jiann-Shing Jeng ◽  
Sung-Tsang Hsieh ◽  
Ming-Chang Chiang ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Motor Cortex ◽  
Evoked Potential ◽  
Short Interval ◽  
Intracortical Inhibition ◽  
Contact Heat ◽  
Sensorimotor Interaction ◽  
Motor Cortex Excitability ◽  
Impaired Quality

Background and Purpose— Central poststroke pain (CPSP) is a disabling condition in stroke patients, and evidence suggests that altered corticospinal and motor intracortical excitability occurs in neuropathic pain. The objective of this study was to investigate changes in motor cortex excitability and sensorimotor interaction and their correlates with clinical manifestations and alterations in somatosensory systems in CPSP patients. Methods— Fourteen patients with CPSP but no motor weakness were compared with age- and sex-matched healthy controls for motor cortex excitability and sensorimotor interaction assessed by transcranial magnetic stimulation to measure resting motor thresholds, short-interval intracortical inhibition, intracortical facilitation, and afferent inhibitions. The sensory pathway was evaluated by quantitative sensory testing, contact heat evoked potential, and somatosensory evoked potentials. Clinical pain and quality of life were assessed with validated tools. Results— The duration of CPSP was 3.3±3.0 years (ranging 0.5–10 years), and pain significantly impaired quality of life. Compared with the unaffected hemisphere, the stroke hemisphere had higher thermal thresholds, lower contact heat evoked potential amplitudes, and prolonged cortical somatosensory evoked potential latencies. There was no difference in resting motor thresholds between the stroke and unaffected hemisphere or between patients and controls. CPSP patients had a reduction in short-interval intracortical inhibition in the stroke hemisphere compared with that in the unaffected hemispheres of patients and controls. No changes were noted in afferent inhibitions between the stroke and unaffected hemispheres. The short-interval intracortical inhibition of the stroke hemisphere was negatively correlated with self-rated health on a visual analog scale and positively correlated with cortical somatosensory evoked potential latencies. Conclusions— CPSP patients with intact corticospinal tracts showed reduced motor intracortical inhibition in the stroke hemisphere, suggesting defective gamma-aminobutyric acid-ergic inhibition. This disinhibition was associated with impaired quality of life and was related to dorsal column–medial lemniscus pathway dysfunction.

Does Navigated Transcranial Stimulation Increase the Accuracy of Tractography? A Prospective Clinical Trial Based on Intraoperative Motor Evoked Potential Monitoring During Deep Brain Stimulation

Neurosurgery ◽  
2015 ◽  
Vol 76 (6) ◽  
pp. 766-776 ◽  
Author(s):  
Marie-Therese Forster ◽  
Alexander Claudius Hoecker ◽  
Jun-Suk Kang ◽  
Johanna Quick ◽  
Volker Seifert ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Motor Cortex ◽  
Brain Stimulation ◽  
Evoked Potential ◽  
Motor Evoked Potential ◽  
Fiber Tracking ◽  
Active Electrode ◽  
Electrode Contact ◽  
Evoked Potential Monitoring ◽  
Deep Brain

AbstractBACKGROUND:Tractography based on diffusion tensor imaging has become a popular tool for delineating white matter tracts for neurosurgical procedures.OBJECTIVE:To explore whether navigated transcranial magnetic stimulation (nTMS) might increase the accuracy of fiber tracking.METHODS:Tractography was performed according to both anatomic delineation of the motor cortex (n = 14) and nTMS results (n = 9). After implantation of the definitive electrode, stimulation via the electrode was performed, defining a stimulation threshold for eliciting motor evoked potentials recorded during deep brain stimulation surgery. Others have shown that of arm and leg muscles. This threshold was correlated with the shortest distance between the active electrode contact and both fiber tracks. Results were evaluated by correlation to motor evoked potential monitoring during deep brain stimulation, a surgical procedure causing hardly any brain shift.RESULTS:Distances to fiber tracks clearly correlated with motor evoked potential thresholds. Tracks based on nTMS had a higher predictive value than tracks based on anatomic motor cortex definition (P < .001 and P = .005, respectively). However, target site, hemisphere, and active electrode contact did not influence this correlation.CONCLUSION:The implementation of tractography based on nTMS increases the accuracy of fiber tracking. Moreover, this combination of methods has the potential to become a supplemental tool for guiding electrode implantation.

scholarly journals Agency Improves Working Memory and Accelerates Visual and Attentional Processing

2021 ◽  
Author(s):  
Rocio Loyola-Navarro ◽  
Cristóbal Moënne-Loccoz ◽  
Rodrigo Vergara ◽  
Alexandre Hyafil ◽  
Francisco Aboitiz ◽  
...  
Keyword(s):  
Working Memory ◽  
Healthy Subjects ◽  
Evoked Potential ◽  
Stimulus Onset ◽  
Attentional State ◽  
Random Delay ◽  
Attentional Processing ◽  
Attentional Processes ◽  
Electroencephalographic Signals ◽  
Temporal Stimuli

Abstract Agency, understood as the ability of an organism to control stimuli onset, modulates perceptual and attentional functions. Since stimulus encoding is an essential component of working memory (WM), we conjectured that the perceptual process's agency would positively modulate WM. To corroborate this proposition, we tested twenty-five healthy subjects in a modified-Sternberg WM task under three stimuli presentation conditions: an unpredictable presentation of encoding stimulus, a self-initiated presentation of the stimulus, and self-initiation presentation with random-delay stimulus onset. Concurrently, we recorded the subjects' electroencephalographic signals during WM encoding. We found that the self-initiated condition was associated with better WM accuracy, and earlier latencies of N100 and P200 evoked potential components representing visual and attentional processes, respectively. Our work demonstrates that agency enhances WM performance and accelerates early visual and attentional processes deployed during WM encoding. We also found that self-initiation presentation correlates with an increased attentional state compared to the other two conditions, suggesting a role for temporal stimuli predictability. Our study remarks on the relevance of agency in sensory and attentional processing for WM.

Gross Total Resection of a Grade IV Astrocytoma Adjacent to the Precentral Gyrus With Nonawake Motor Mapping and Motor-Evoked Potential Monitoring: 3-Dimensional Operative Video

2019 ◽  
Author(s):  
Burak Ozaydin ◽  
Ihsan Dogan ◽  
Bryan J Wheeler ◽  
Mustafa K Baskaya
Keyword(s):  
Motor Cortex ◽  
Evoked Potential ◽  
Primary Motor Cortex ◽  
Motor Evoked Potential ◽  
Gross Total Resection ◽  
Precentral Gyrus ◽  
Total Resection ◽  
Motor Mapping ◽  
3 Dimensional ◽  
Intraoperative Adjuncts

Abstract Surgical treatment of the gliomas located in or adjacent to the eloquent areas poses significant challenge to neurosurgeons. The main goal of the surgery is to achieve maximal safe resection while preserving the neurological function. This might be possible with utilizing pre- and intraoperative adjuncts such as functional magnetic resonance imaging (MRI), image guidance, mapping of the function of interest, intraoperative MRI, and neurophysiological monitoring. In this video, we demonstrate the utilization of nonawake mapping and motor-evoked potential (MEP) monitoring for the resection of a right-sided posterior superior frontal gyrus grade IV astrocytoma adjacent to the primary motor cortex. The patient is a 69-yr-old woman presented with multiple episodes of simple partial seizures involving her left leg and spreading to the left arm. MRI and functional MRI examinations showed a heterogeneously enhancing mass with peritumoral edema adjacent to the primary motor cortex. Because the patient did not want to undergo an awake craniotomy, a decision was made to perform the resection of the tumor with nonawake motor mapping and continuous MEP monitoring. Nonawake motor mapping and MEP monitoring enabled us to perform gross total resection. Because it has been shown that supratotal resection may provide improved survival outcome,1,2 we extended the white matter resection beyond the contrast enhancing area in noneloquent parts of the tumor. Surgical steps in dealing with vascular anatomy as well as utilizing intraoperative adjuncts such as motor mapping and MEP monitoring to enhance the extent of resection while preserving the function are demonstrated in this 3-dimensional surgical video.  The patient consented to publication of her operative video.

EVOKED POTENTIAL PRIMITIVES OF RAT MOTOR CORTEX SIGNAL ANALYSIS BASED ON ITERATED FUNCTION SYSTEMS

2020 ◽  
Vol 32 (04) ◽  
pp. 2050033
Author(s):  
Rong-Chin Lo ◽  
Tung-Tai Kuo ◽  
Ren-Guey Lee ◽  
Yuan-Hao Chen ◽  
Chuan Chin Lim
Keyword(s):  
Motor Cortex ◽  
Signal Analysis ◽  
Evoked Potential ◽  
Iterated Function Systems ◽  
File Size ◽  
Classification Result ◽  
Independent Source ◽  
Iterated Function ◽  
Source Signals ◽  
The Brain

The function of the brain has been the focus of neuroscience studies for nearly half a century. The studies found that the evoked potential signals of the motor cortex are the main source to command action. An action signal is composed of several signal primitives that are mainly generated by the motor cortex. It was found that signal primitives of the motor cortex can be produced by several fixed rules and a group of codes called iterated function systems (IFS) code. The goal of our research is to find the relationships between the signal primitives of the motor cortex and actions. We recorded the action signals of the rat motor cortex using 8-channel micro-electrodes and used independent component analysis (ICA) to find the independent source signals called signal primitives. Then, the IFS algorithm was used to find the signal primitive codes, which is the IFS code. The experimental results showed that the source signals of actions produce the IFS rules and a set of codes by the IFS algorithm and conversely, using the IFS rules and the set of codes can reconstruct the source signals. Every 20-character length of action signals will generate unique 6-character IFS codes, meaning that the action signals can be replaced with IFS codes to achieve the compression. We found that the IFS rules and codes can be used to represent different cortex commands which have distinct IFS codes that can be used to classify the movements of rat. The classification result reached 78.75% for rough movement and nearly 50% for subtle movement, where the rough movement is that the rat performs two motions and the subtle movement is three motions. This result shows that the motor cortex command can consist of distinct signal primitives and the huge file size of the motor cortex command is reduced three times by the IFS algorithm.

scholarly journals A combined TMS-EEG study of short-latency afferent inhibition in the motor and dorsolateral prefrontal cortex

2016 ◽  
Vol 116 (3) ◽  
pp. 938-948 ◽  
Author(s):  
Yoshihiro Noda ◽  
Robin F. H. Cash ◽  
Reza Zomorrodi ◽  
Luis Garcia Dominguez ◽  
Faranak Farzan ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Motor Cortex ◽  
Nerve Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Evoked Potential ◽  
Short Latency Afferent Inhibition ◽  
Afferent Inhibition ◽  
Median Nerve Stimulation ◽  
Dorsolateral Prefrontal ◽  
Neural Signature

Combined transcranial magnetic stimulation and electroencephalography (TMS-EEG) enables noninvasive neurophysiological investigation of the human cortex. A TMS paradigm of short-latency afferent inhibition (SAI) is characterized by attenuation of the motor-evoked potential (MEP) and modulation of N100 of the TMS-evoked potential (TEP) when TMS is delivered to motor cortex (M1) following median nerve stimulation. SAI is a marker of cholinergic activity in the motor cortex; however, the SAI has not been tested from the prefrontal cortex. We aimed to explore the effect of SAI in dorsolateral prefrontal cortex (DLPFC). SAI was examined in 12 healthy subjects with median nerve stimulation and TMS delivered to M1 and DLPFC at interstimulus intervals (ISIs) relative to the individual N20 latency. SAI in M1 was tested at the optimal ISI of N20 + 2 ms. SAI in DLPFC was investigated at a range of ISI from N20 + 2 to N20 + 20 ms to explore its temporal profile. For SAI in M1, the attenuation of MEP amplitude was correlated with an increase of TEP N100 from the left central area. A similar spatiotemporal neural signature of SAI in DLPFC was observed with a marked increase of N100 amplitude. SAI in DLPFC was maximal at ISI N20 + 4 ms at the left frontal area. These findings establish the neural signature of SAI in DLPFC. Future studies could explore whether DLPFC-SAI is neurophysiological marker of cholinergic dysfunction in cognitive disorders.

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