Enatsu Rei, Kanno Aya, Ookawa Satoshi, Ochi Satoko, Ishiai Sumio, Nagamine Takashi, Mikuni Nobuhiro
Department of Neurosurgery, Sapporo Medical University, Sapporo, Japan.
Department of Rehabilitation, Sapporo Medical University, Sapporo, Japan.
World Neurosurg. 2017 Oct;106:1-8. doi: 10.1016/j.wneu.2017.06.116. Epub 2017 Jun 21.
The basal temporal language area (BTLA) is considered to have several functions in language processing; however, its brain network is still unknown. This study investigated the distribution and networks of the BTLA using a combination of electric cortical stimulation and diffusion tensor imaging (DTI).
10 patients with intractable focal epilepsy who underwent presurgical evaluation with subdural electrodes were enrolled in this study (language dominant side: 6 patients, language nondominant side: 4 patients). Electric stimulation at 50 Hz was applied to the electrodes during Japanese sentence reading, morphograms (kanji) reading, and syllabograms (kana) reading tasks to identify the BTLA. DTI was used to identify the subcortical fibers originating from the BTLA found by electric stimulation.
The BTLA was found in 6 patients who underwent implantation of the subdural electrodes in the dominant hemisphere. The BTLA was located anywhere between 20 mm and 56 mm posterior to the temporal tips. In 3 patients, electric stimulation of some or all areas within the BTLA induced disturbance in reading of kanji words only. DTI detected the inferior longitudinal fasciculus (ILF) in all patients and the uncinate fasciculus (UF) in 1 patient, originating from the BTLA. ILF was detected from both kanji-specific areas and kanji-nonspecific areas.
This study indicates that the network of the BTLA is a part of a ventral stream and is mainly composed of the ILF, which acts as a critical structure for lexical retrieval. ILF is also associated with the specific processing of kanji words.
颞叶基底语言区（BTLA）在语言处理中被认为具有多种功能；然而，其脑网络仍不清楚。本研究采用皮层电刺激和弥散张量成像（DTI）相结合的方法，对BTLA的分布和网络进行了研究。
本研究纳入了10例接受硬膜下电极术前评估的顽固性局灶性癫痫患者（语言优势侧：6例患者，非语言优势侧：4例患者）。在日语句子阅读、形态图（汉字）阅读和音节图（假名）阅读任务期间，对电极施加50Hz的电刺激，以识别BTLA。DTI用于识别由电刺激发现的起源于BTLA的皮质下纤维。
在6例于优势半球植入硬膜下电极的患者中发现了BTLA。BTLA位于颞尖后方20mm至56mm之间的任何位置。在3例患者中，对BTLA内部分或全部区域进行电刺激仅诱发了汉字阅读障碍。DTI在所有患者中均检测到下纵束（ILF），在1例患者中检测到钩束（UF），它们均起源于BTLA。ILF在汉字特异性区域和非汉字特异性区域均被检测到。
本研究表明，BTLA网络是腹侧通路的一部分，主要由ILF组成，ILF是词汇检索的关键结构。ILF还与汉字的特定加工有关。
