Epilepsia partialis continua: active cortical spike discharges and high cerebral blood flow in the motor cortex and enhanced transcortical long loop reflex

1985 ◽  
Vol 232 (3) ◽  
pp. 162-166 ◽  
Author(s):  
Y. Kuroiwa ◽  
H. Tohgi ◽  
A. Takahashi ◽  
H. Kanaya
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Motor Cortex ◽  
Epilepsia Partialis Continua ◽  
Long Loop Reflex

Cerebral Blood-Flow Changes Induced by Paired-Pulse Transcranial Magnetic Stimulation of the Primary Motor Cortex

2001 ◽  
Vol 85 (6) ◽  
pp. 2624-2629 ◽  
Author(s):  
A. P. Strafella ◽  
T. Paus
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Single Pulse ◽  
Paired Pulse ◽  
Positive Correlation

Positron emission tomography (PET) was used to assess changes in regional cerebral blood flow (CBF) induced by paired-pulse transcranial magnetic stimulation (TMS) of primary motor cortex (M1). The study was performed in eight normal volunteers using two Magstim-200 stimulators linked with a Bistim module. A circular TMS coil was held in the scanner by a mechanical arm and located over the left M1. Surface electrodes were used to record motor evoked potentials (MEPs) from the contralateral first dorsal interosseous muscle (FDI). Cortical excitability was evaluated in the relaxed FDI using a paired conditioning-test stimulus paradigm with two interstimulus intervals (ISIs): 3 and 12 ms. The subjects were scanned three times during each of the following four conditions: 1) baseline with no TMS (BASE); 2) single-pulse TMS (TMSsing); 3) 3-ms paired-pulse TMS (TMS3); and 4) 12-ms paired-pulse TMS (TMS12). CBF and peak-to-peak MEP amplitudes were measured over each 60-s scanning period. To assess TMS-induced changes in CBF, a t-statistic map was generated by first subtracting the single-pulse TMS condition from the 3- and 12-ms paired-pulse TMS conditions and then correlating the CBF differences, respectively, with the amount of suppression and facilitation of the EMG responses. A significant positive correlation was observed between the CBF difference (TMS3-TMSsing) and the amount of suppression of EMG response, as well as between the CBF difference (TMS12-TMSsing) and the amount of facilitation of EMG response. This positive correlation was observed in the left M1, left lateral premotor cortex, and right M1 in the case of 3-ms paired-pulse TMS, but only in the left M1 in the case of 12-ms paired-pulse TMS. The above pattern of CBF response to paired-pulse TMS supports the possibility that suppression and facilitation of the EMG response are mediated by different populations of cortical interneurons.

Frequency specific changes in regional cerebral blood flow and motor system connectivity following rTMS to the primary motor cortex

NeuroImage ◽  
2005 ◽  
Vol 26 (1) ◽  
pp. 164-176 ◽  
Author(s):  
Elisabeth Rounis ◽  
Lucy Lee ◽  
Hartwig R. Siebner ◽  
James B. Rowe ◽  
Karl J. Friston ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Motor Cortex ◽  
Regional Cerebral Blood Flow ◽  
Motor System ◽  
Primary Motor Cortex ◽  
Regional Cerebral Blood

scholarly journals Altered task-induced cerebral blood flow and oxygen metabolism underlies motor impairment in multiple sclerosis

2020 ◽  
Vol 41 (1) ◽  
pp. 182-193 ◽  
Author(s):  
Kathryn L West ◽  
Dinesh K Sivakolundu ◽  
Mark D Zuppichini ◽  
Monroe P Turner ◽  
Jeffrey S Spence ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Motor Cortex ◽  
Healthy Volunteers ◽  
Primary Motor Cortex ◽  
Motor Impairment ◽  
Oxygen Metabolism ◽  
Button Press

The neural mechanisms underlying motor impairment in multiple sclerosis (MS) remain unknown. Motor cortex dysfunction is implicated in blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) studies, but the role of neural–vascular coupling underlying BOLD changes remains unknown. We sought to independently measure the physiologic factors (i.e., cerebral blood flow (ΔCBF), cerebral metabolic rate of oxygen (ΔCMRO2), and flow–metabolism coupling (ΔCBF/ΔCMRO2), utilizing dual-echo calibrated fMRI (cfMRI) during a bilateral finger-tapping task. We utilized cfMRI to measure physiologic responses in 17 healthy volunteers and 32 MS patients (MSP) with and without motor impairment during a thumb-button-press task in thumb-related (task-central) and surrounding primary motor cortex (task-surround) regions of interest (ROIs). We observed significant ΔCBF and ΔCMRO2 increases in all MSP compared to healthy volunteers in the task-central ROI and increased flow–metabolism coupling (ΔCBF/ΔCMRO2) in the MSP without motor impairment. In the task-surround ROI, we observed decreases in ΔCBF and ΔCMRO2 in MSP with motor impairment. Additionally, ΔCBF and ΔCMRO2 responses in the task-surround ROI were associated with motor function and white matter damage in MSP. These results suggest an important role for task-surround recruitment in the primary motor cortex to maintain motor dexterity and its dependence on intact white matter microstructure and neural–vascular coupling.

scholarly journals Cerebral Blood Flow, Blood Volume, and Oxygen Metabolism Dynamics in Human Visual and Motor Cortex as Measured by Whole-Brain Multi-Modal Magnetic Resonance Imaging

2009 ◽  
Vol 29 (11) ◽  
pp. 1856-1866 ◽  
Author(s):  
Manus J Donahue ◽  
Jakob U Blicher ◽  
Leif Østergaard ◽  
David A Feinberg ◽  
Bradley J MacIntosh ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Visual Cortex ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Blood Volume ◽  
Bold Signal ◽  
Resonance Imaging ◽  
Whole Brain

The development of neuroimaging methods to characterize flow-metabolism coupling is crucial for understanding mechanisms that subserve oxygen delivery. Functional magnetic resonance imaging (fMRI) using blood-oxygenation-level-dependent (BOLD) contrast reflects composite changes in cerebral blood volume (CBV), cerebral blood flow (CBF), and the cerebral metabolic rate of oxygen consumption (CMRO2). However, it is difficult to separate these parameters from the composite BOLD signal, thereby hampering MR-based flow-metabolism coupling studies. Here, a novel, noninvasive CBV-weighted MRI approach (VASO-FLAIR with 3D GRASE (GRadient-And-Spin-Echo)) is used in conjunction with CBF-weighted and BOLD fMRI in healthy volunteers ( n=7) performing simultaneous visual (8 Hz flashing-checkerboard) and motor (1 Hz unilateral joystick) tasks. This approach allows for CBV, CBF, and CMRO2 to be estimated, yielding (mean±s.d.): ΔCBF=63%±12%, ΔCBV=17%±7%, and ΔCMRO2=13%±11% in the visual cortex, and ΔCBF=46%±11%, ΔCBV=8%±3%, and ΔCMRO2=12%±13% in the motor cortex. Following the visual and motor tasks, the BOLD signal became more negative ( P=0.003) and persisted longer ( P=0.006) in the visual cortex compared with the motor cortex, whereas CBV and CBF returned to baseline earlier and equivalently. The proposed whole-brain technique should be useful for assessing regional discrepancies in hemodynamic reactivity without the use of intravascular contrast agents.

scholarly journals Motor cortex neurovascular coupling: inputs from ultra–high-frequency ultrasound imaging in humans

2019 ◽  
Vol 131 (5) ◽  
pp. 1632-1638 ◽  
Author(s):  
Fabien Almairac ◽  
Denys Fontaine ◽  
Thomas Demarcy ◽  
Hervé Delingette ◽  
Stéphanie Beuil ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Motor Cortex ◽  
High Frequency ◽  
Cortical Area ◽  
Neurovascular Coupling ◽  
Doppler Imaging ◽  
High Frequency Ultrasound ◽  
Local Cerebral Blood Flow ◽  
Frequency Ultrasound

OBJECTIVENeurovascular coupling reflects the link between neural activity and changes in cerebral blood flow. Despite many technical advances in functional exploration of the brain, including functional MRI, there are only a few reports of direct evidence of neurovascular coupling in humans. The authors aimed to explore, for the first time in humans, the local cerebral blood flow of the primary motor cortex using ultra–high-frequency ultrasound (UHF-US) Doppler imaging to detect low blood flow velocity (1 mm/sec).METHODSFour consecutive patients underwent awake craniotomy for glioma resection using cortical direct electrostimulation for brain mapping. The primary motor cortical area eliciting flexion of the contralateral forearm was identified. UHF-US color Doppler imaging of this cortical area was acquired at rest, during repeated spontaneous forearm flexion, and immediately after the movement’s termination. In each condition, the surface areas of the detectable vessels were measured after extraction of non–zero-velocity colored pixels and summed.RESULTSDuring movement, local cerebral blood flow increased significantly by 14.4% (range 5%–30%) compared with baseline. Immediately after the termination of movements, the local hyperemia decreased significantly by 8.6% (range 1.9%–15.7%).CONCLUSIONSTo the authors’ knowledge, this study is the first to provide a real-time demonstration of the neurovascular coupling in the human cortex by ultrasound imaging. They assume that UHF-US may be used to gather original and advanced data on brain functioning, which could be used to help in the identification of functional cortical areas during brain surgery.Clinical trial registration no.: NCT03179176 (clinicaltrials.gov)

scholarly journals Sciatic Nerve Stimulation Does Not Increase Endogenous Adenosine Production in Sensory-Motor Cortex

1992 ◽  
Vol 12 (5) ◽  
pp. 835-843 ◽  
Author(s):  
Frances J. Northington ◽  
G. Paul Matherne ◽  
Sharon D. Coleman ◽  
Robert M. Berne
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Oxygen Consumption ◽  
Motor Cortex ◽  
Sciatic Nerve ◽  
Nerve Stimulation ◽  
Somatosensory Stimulation ◽  
Sensory Motor ◽  
Adenosine Antagonist ◽  
Sciatic Nerve Stimulation

Adenosine participates in the coupling of cerebral blood flow to oxygen consumption in the brain during such stimuli as hypoxia, ischemia, and seizures. It has been suggested that it also participates in the regulation of cerebral blood flow during somatosensory stimulation, a condition during which cerebral blood flow and oxygen consumption appear to be uncoupled. Interstitial adenosine was estimated by the microdialysis technique and cerebral blood flow was measured by hydrogen clearance in the hindlimb sensory-motor cortex during sciatic nerve stimulation. Cerebral blood flow increased from 102 to 188 ml min−1 100 g−1 (p < 0.001) in the cortex contralateral to the stimulated leg without an associated increase in interstitial adenosine (baseline 0.624 μ M, stimulation 0.583 μ M). Infusion of the adenosine antagonist 8-sulfophenyltheophylline failed to block an increase in cerebral blood flow during central sciatic nerve stimulation, but decreased basal cerebral blood flow (69 ml min−1 100 g−1). These results suggest that adenosine does not mediate changes in cerebral blood flow during somatosensory stimulation, but may participate in the regulation of cerebral blood flow in the basal state.

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