Long-latency gamma modulation after median nerve stimulation delineates the central sulcus and contrasts the states of consciousness
Long-latency gamma modulation after median nerve stimulation delineates the central sulcus and contrasts the states of consciousness
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DOI：
10.1016/j.clinph.2022.10.008
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发表时间：
2022-11-10
影响因子：
4.7
通讯作者：
Ince，Nuri F.
中科院分区：
文献类型：
--
作者：
Asman，Priscella;Pellizzer，Giuseppe;Ince，Nuri F.
目的评价体感诱发电位（ssep）子带调制在区分初级体感区（S1）和运动区（M1）以及对比意识状态方面的功能。方法在常规术中皮质作图时，用皮质电图（ECoG）网格记录8例麻醉和清醒状态下感觉运动皮层的ssep。我们对SSEP轨迹进行时频分析，提取每个状态下的频谱调制，并可视化其空间地形。结果我们观察到所有受试者在刺激开始后约50 ms出现晚伽马调制（60-250 Hz），每种状态延长至250 ms。在清醒状态下，晚期伽玛活动增强在S1中占主导地位，与麻醉状态相比，它区分S1和M1的准确率（92%）更高（准确率= 70%）。结论感觉运动定位不需要仅仅依赖于SSEP相位反转。长潜伏期伽马调制可以作为初级感觉运动定位的生物标志物，并在神经外科实践中监测意识水平。术中应用ECoG评估SSEP相位逆转被广泛用于描绘中央沟，而正中神经刺激诱导的空间频谱模式可以清晰地定位中央沟并区分意识状态。
ObjectiveTo evaluate the functional use of sub-band modulations in somatosensory evoked potentials (SSEPs) to discriminate between the primary somatosensory (S1) and motor (M1) areas and contrast the states of consciousness.MethodsDuring routine intraoperative cortical mapping, SSEPs were recorded with electrocorticography (ECoG) grids from the sensorimotor cortex of eight patients in the anesthetized and awake states. We conducted a time–frequency analysis on the SSEP trace to extract the spectral modulations in each state and visualize their spatial topography.ResultsWe observed late gamma modulation (60–250 Hz) in all subjects approximately 50 ms after stimulation onset, extending up to 250 ms in each state. The late gamma activity enhancement was predominant in S1 in the awake state, where it discriminated S1 from M1 at a higher accuracy (92 %) than in the anesthetized state (accuracy = 70 %).ConclusionsThese results showed that sensorimotor mapping does not need to rely on only SSEP phase reversal. The long latency gamma modulation can serve as a biomarker for primary sensorimotor localization and monitor the level of consciousness in neurosurgical practice.SignificanceWhile the intraoperative assessment of SSEP phase reversal with ECoG is widely employed to delineate the central sulcus, the median nerve stimulation-induced spatio-spectral patterns can distinctly localize it and distinguish between conscious states.