Department of Neurosurgery, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland.
Department of Neurology, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland.
Front Neural Circuits. 2018 Apr 4;12:22. doi: 10.3389/fncir.2018.00022. eCollection 2018.
Deep brain stimulation (DBS) could become a palliative treatment for patients with drug-resistant epilepsy for which surgery cannot be proposed. The objective of this study was to perform microstimulation to measure the effects of DBS in epilepsy locally at the level of a few neurons, with microelectrode recordings, for the first time in patients with epilepsy. Microelectrode recordings were performed before, during and after microstimulation in nine patients with refractory epilepsy. Neuronal spikes were successfully extracted from multi-unit recordings with clustering in six out of seven patients during hippocampal and in one out of two patients during cortical dysplasia microstimulation (1 Hz, charge-balanced biphasic waveform, 60 μs/ph, 25 μA). The firing rates increased in four out of the six periods of microstimulation that could be analyzed. The firing rates were found higher than before microstimulation in all eight periods with increases reaching significance in six out of eight periods. Low-frequency microstimulation was hence sufficient to induce neuronal excitation lasting beyond the stimulation period. No inhibition was observed. This report presents the first evidence that microstimulation performed in epileptic patients produced locally neuronal excitation. Hence neuronal excitation is shown here as the local mechanism of action of DBS. This local excitation is in agreement with epileptogenic effects of low-frequency hippocampal macrostimulation.
深部脑刺激（DBS）可能成为一种姑息性治疗方法，适用于无法进行手术的耐药性癫痫患者。本研究的目的是首次在癫痫患者中进行微刺激，以测量 DBS 在局部几个神经元水平上对癫痫的影响，通过微电极记录进行测量。在 9 名耐药性癫痫患者中，在微刺激之前、期间和之后进行了微电极记录。在 7 名患者中的 6 名患者的海马体微刺激（1 Hz、平衡双相波、60 μs/ph、25 μA）和 2 名患者中的 1 名患者的皮质发育不良微刺激期间，成功地从多单位记录中提取出神经元尖峰，并通过聚类进行分析。在可分析的 6 个微刺激期间中的 4 个期间，放电率增加。在 8 个期间中的 6 个期间，放电率高于微刺激前，在 8 个期间中的 6 个期间达到显著增加。低频微刺激足以产生持续超过刺激期的神经元兴奋。未观察到抑制。本报告首次证明，在癫痫患者中进行的微刺激会产生局部神经元兴奋。因此，这里显示神经元兴奋是 DBS 的局部作用机制。这种局部兴奋与低频海马体大刺激的致痫作用一致。
