Repetitive motor cortex stimulation reinforces the pain modulation circuits of peripheral neuropathic pain

It is well known that the insular cortex is involved in the processing of painful input. The aim of this study was to evaluate the pain modulation role of the insular cortex during motor cortex stimulation (MCS). After inducing neuropathic pain (NP) rat models by the spared nerve injury method, we made a lesion on the rostral agranular insular cortex (RAIC) unilaterally and compared behaviorally determined pain threshold and latency in 2 groups: Group A (NP + MCS;n=7) and Group B (NP + RAIC lesion + MCS;n=7). Also, we simultaneously recorded neuronal activity (NP;n=9) in the thalamus of the ventral posterolateral nucleus and RAIC to evaluate electrophysiological changes from MCS. The pain threshold and tolerance latency increased in Group A with “MCS on” and in Group B with or without “MCS on.” Moreover, its increase in Group B with “MCS on” was more than that of Group B without MCS or of Group A, suggesting that MCS and RAIC lesioning are involved in pain modulation. Compared with the “MCS off” condition, the “MCS on” induced significant threshold changes in an electrophysiological study. Our data suggest that the RAIC has its own pain modulation effect, which is influenced by MCS.

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Faculty Opinions recommendation of Treatment of central deafferentation and trigeminal neuropathic pain by motor cortex stimulation: report of a series of 20 patients.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725993347.793558721 ◽

2019 ◽

Author(s):

Mark Obermann

Keyword(s):

Neuropathic Pain ◽

Motor Cortex ◽

Motor Cortex Stimulation ◽

Trigeminal Neuropathic Pain

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Pre-motor versus motor cerebral cortex neuromodulation for chronic neuropathic pain

Scientific Reports ◽

10.1038/s41598-021-91872-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Igor Lavrov ◽

Timur Latypov ◽

Elvira Mukhametova ◽

Brian Lundstrom ◽

Paola Sandroni ◽

...

Keyword(s):

Neuropathic Pain ◽

Cerebral Cortex ◽

Motor Cortex ◽

Initial Assessment ◽

Motor Cortex Stimulation ◽

Chronic Neuropathic Pain ◽

Long Term Effect ◽

Stimulation Of

AbstractElectrical stimulation of the cerebral cortex (ESCC) has been used to treat intractable neuropathic pain for nearly two decades, however, no standardized approach for this technique has been developed. In order to optimize targeting and validate the effect of ESCC before placing the permanent grid, we introduced initial assessment with trial stimulation, using a temporary grid of subdural electrodes. In this retrospective study we evaluate the role of electrode location on cerebral cortex in control of neuropathic pain and the role of trial stimulation in target-optimization for ESCC. Location of the temporary grid electrodes and location of permanent electrodes were evaluated in correlation with the long-term efficacy of ESCC. The results of this study demonstrate that the long-term effect of subdural pre-motor cortex stimulation is at least the same or higher compare to effect of subdural motor or combined pre-motor and motor cortex stimulation. These results also demonstrate that the initial trial stimulation helps to optimize permanent electrode positions in relation to the optimal functional target that is critical in cases when brain shift is expected. Proposed methodology and novel results open a new direction for development of neuromodulation techniques to control chronic neuropathic pain.

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