Table 4.

HDVL grading system.

Variables		Score∫
Lesion-to-eloquence* distance (LED)	>10 mm	1
	5–10 mm	2
	<5 mm	3
Diffuseness†	Yes	1
	No	0
Deep draining veins‡	Yes	1
	No	0
Hemorrhagic history	Yes	0
	No	1

^∫Total score = LED + Diffuseness+ Deep draining veins + Preoperative hemorrhage.

HDVL scores 1–3: operation is recommended.

HDVL scores 4–6: individualized multimodal treatment or conservative management is recommended.

^*Eloquent areas include: sensorimotor, speech, and visual function related brain area identified by fMRI and functional white matter fiber tracts reconstructed by DTI such as cortical spinal tract (CST), optic radiation (OR), and arcuate fasciculus (AF).

^†Diffuseness refers to the inclusion of normal brain tissue in the nidus.

^‡Deep draining veins refer to part (or all) of the draining veins flow into deep veins, such as internal cerebral veins (ICV), basilar veins or precentral cerebellar veins.