Impairment of consciousness induced by bilateral electrical stimulation of the frontal convexity.
Impairment of consciousness induced by bilateral electrical stimulation of the frontal convexity.
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DOI：
10.1016/j.ebcr.2017.09.006
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发表时间：
2017
影响因子：
--
通讯作者：
Alkawadri R
中科院分区：
文献类型：
--
作者：
Quraishi IH;Benjamin CF;Spencer DD;Blumenfeld H;Alkawadri R
我们报告一例内科难治性癫痫患者因额叶外侧凸部同源区域的电皮质刺激(ECS)而导致意识障碍的病例。患者具有特发性全身性癫痫和局灶性癫痫的混合特征。在颅内脑电记录中，发作间期和发作期放电在广泛的双侧额顶区显示高度同步性。我们确定了额叶外侧的可靠区域，并通过ECS产生了意识丧失。在刺激过程中，伴随着额顶、额叶内侧和颞区混合频率的诱发脑电活动，与后放电无关。一旦停止刺激，症状立即可逆转。这一发现表明，局灶性皮质刺激可以扰乱构成意识的广泛网络。推测丘脑-额叶皮质连接程度高的人可能更容易受到这种影响，这一发现突显了在测绘过程中标准化意识水平测试的重要性。虽然癫痫发作时意识通常受损，但有关电皮质刺激(ECS)导致意识丧失的文献有限，在接受颅内EEG检查的人类中，癫痫灶的定位。一种理论主张在皮质下结构中存在意识“开关”。虽然这个模型新颖而简单化，但它也有其固有的局限性。在这个病例研究中，我们提出了一种可供选择的方法，讨论了它背后的复杂回路，并将其与电生理发现和疾病表型的病理生理学联系起来，并讨论了有关该主题的报道罕见的潜在原因。
We report a case of impairment of consciousness (IOC) induced by electrical cortical stimulation (ECS) of homologous regions within the lateral frontal convexities in a patient with medically intractable epilepsy. The patient had mixed features of idiopathic generalized and focal epilepsy. On intracranial EEG recording, interictal and ictal discharges showed a high degree of synchrony across widespread bilateral fronto-parietal areas. We identified regions in the lateral frontal lobes that reliably and produced loss of consciousness by ECS. This was accompanied by evoked EEG activity of admixed frequencies over the fronto-parietal, mesial frontal and temporal regions during stimulation and was not associated with after-discharges. Symptoms were immediately reversible upon cessation of stimulation. This finding suggests that focal cortical stimulation can disrupt widespread networks that underlie consciousness. Individuals with high degrees of speculated thalamo-frontal cortical connectivity might be more susceptible to this effect, and the findings highlight the importance of standardizing the testing of level of consciousness during mapping sessions. Although consciousness is commonly impaired in epileptic seizures, limited literature is available on loss of consciousness induced by electrical cortical stimulation (ECS) in humans undergoing intracranial EEG evaluations for localization of epileptic focus. One theory advocates the presence of consciousness ‘switch’ in subcortical structures. While this model is novel and simplistic, it has its inherent limitations. In this case study, we propose an alternative approach on the entity and discuss the complex circuits underlying it and correlate that with the electrophysiological findings and the pathophysiology of the phenotype of the disease and discuss potential causes for rarity of reports on the subject.