Table 3.

Intraoperative language network mapping and functional outcome

	Cortical HFES at the frontal stimulus site	CCEPAL→PL N1 latency (ms)		CCEP amplitude decrease (%)	Subcortical HFES at WM stimulus site	SCEP N1 latency (ms)
						SCEPWM→AL		SCEPWM→PL		SCEPWM→AL + SCEPWM→PL	Language disturbance
	Language impairment	Onset	Peak		Language impairment	Onset	Peak	Onset	Peak	Onset/peak	Intraoperative	Postoperative (day 1)
Patient 1	Yes	7.6	30.8	0	No	no response		no response		no response	No	No
Patient 2	Yes	12.8	27.4	12	n.a.	n.a.	n.a.	n.a.	n.a.	n.a.	No	No
Patient 3	Yes	12.8	29.2	0	Yes	5.6	24.6	6.4	19.6	12.0/44.2	No	No
Patient 4	Yes	11.0	25.0	32	Yes	7.2	19.0	4.2	12.0	11.4/31.0	Yesa	Yes
Patient 5	Yes	9.6	32.0	0	Yes	6.2	17.6	4.0	15.8	10.2/33.4	No	Yes
Patient 6	Yes	13.0	33.2	0	No	6.6	22.6	3.2	18.0	9.8/40.6	No	No

All latencies were measured in the awake condition.

HFES = high‐frequency electrical stimulation; AL = anterior language area; PL = posterior language area; WM = white matter; n.a. = not available (no stimulation).

^aLanguage disturbance was already observed before the CCEP amplitude decreased because of the partial cortical resection of the supramarginal gyrus