Open AccessIntraoperative dorsal language network mapping by using single‐pulse electrical stimulation
Author(s) -
Yamao Yukihiro,
Matsumoto Riki,
Kunieda Takeharu,
Arakawa Yoshiki,
Kobayashi Katsuya,
Usami Kiyohide,
Shibata Sumiya,
Kikuchi Takayuki,
Sawamoto Nobukatsu,
Mikuni Nobuhiro,
Ikeda Akio,
Fukuyama Hidenao,
Miyamoto Susumu
Publication year - 2014
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.22479
Subject(s) - arcuate fasciculus , white matter , awake craniotomy , language function , medicine , neuroscience , lateralization of brain function , craniotomy , psychology , brain mapping , audiology , anesthesia , tractography , magnetic resonance imaging , radiology , computer science , natural language processing
The preservation of language function during brain surgery still poses a challenge. No intraoperative methods have been established to monitor the language network reliably. We aimed to establish intraoperative language network monitoring by means of cortico‐cortical evoked potentials (CCEPs). Subjects were six patients with tumors located close to the arcuate fasciculus (AF) in the language‐dominant left hemisphere. Under general anesthesia, the anterior perisylvian language area (AL) was first defined by the CCEP connectivity patterns between the ventrolateral frontal and temporoparietal area, and also by presurgical neuroimaging findings. We then monitored the integrity of the language network by stimulating AL and by recording CCEPs from the posterior perisylvian language area (PL) consecutively during both general anesthesia and awake condition. High‐frequency electrical stimulation (ES) performed during awake craniotomy confirmed language function at AL in all six patients. Despite an amplitude decline (≤32%) in two patients, CCEP monitoring successfully prevented persistent language impairment. After tumor removal, single‐pulse ES was applied to the white matter tract beneath the floor of the removal cavity in five patients, in order to trace its connections into the language cortices. In three patients in whom high‐frequency ES of the white matter produced naming impairment, this “eloquent” subcortical site directly connected AL and PL, judging from the latencies and distributions of cortico‐ and subcortico‐cortical evoked potentials. In conclusion, this study provided the direct evidence that AL, PL, and AF constitute the dorsal language network. Intraoperative CCEP monitoring is clinically useful for evaluating the integrity of the language network. Hum Brain Mapp 35:4345–4361, 2014 . © 2014 Wiley Periodicals, Inc .