Watanabe Satsuki, Dubeau François, Zazubovits Natalja, Gotman Jean
Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; National Center Hospital of Neurology and Psychiatry, Tokyo, Japan.
Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
Clin Neurophysiol. 2017 Jun;128(6):986-991. doi: 10.1016/j.clinph.2017.03.041. Epub 2017 Apr 9.
It has been reported that interictal epileptic discharges (IEDs) recorded in temporal regions on scalp EEG are unlikely to originate from mesial temporal structures. However, EEG-fMRI sometimes show mesial temporal activation. We hypothesized that BOLD activation in the temporal neocortex is weaker than in the mesial structures, reflecting the fact that propagated activity has less metabolic demand than the original discharge.
Twelve patients with epilepsy who have BOLD response in mesial temporal structures were selected from our EEG-fMRI database. We searched the temporal lobe ipsilateral to IEDs and checked whether there is positive BOLD response in the neocortex.
All IED types showed a BOLD response in the temporal neocortex ipsilateral to the mesial temporal BOLD response. T-values were higher in mesial temporal structures than in neocortex in 13/16 cases.
Hemodynamic changes were observed in the mesial temporal lobe at the time of IEDs recorded from the temporal region on the scalp. The finding of smaller BOLD changes in the ipsilateral neocortex is in agreement with our hypothesis.
Our study indicates that scalp-recorded temporal lobe spikes are likely to result from mesial temporal spikes propagating neuronally to the neocortex.
据报道，头皮脑电图颞区记录到的发作间期癫痫样放电（IEDs）不太可能起源于颞叶内侧结构。然而，脑电图功能磁共振成像（EEG-fMRI）有时会显示颞叶内侧激活。我们推测颞叶新皮质中的血氧水平依赖（BOLD）激活比内侧结构中的弱，这反映了传播的活动比原始放电的代谢需求少这一事实。
从我们的EEG-fMRI数据库中选取12例在颞叶内侧结构中有BOLD反应的癫痫患者。我们搜索了与IEDs同侧的颞叶，并检查新皮质中是否存在阳性BOLD反应。
所有IED类型在与颞叶内侧BOLD反应同侧的颞叶新皮质中均显示出BOLD反应。在16例中的13例中，颞叶内侧结构中的T值高于新皮质中的T值。
在头皮颞区记录到IEDs时，观察到颞叶内侧叶的血流动力学变化。同侧新皮质中BOLD变化较小的发现与我们的假设一致。
我们的研究表明，头皮记录到的颞叶尖波可能是由颞叶内侧尖波通过神经元传播到新皮质所致。
