A.T. Robertson Commentary Mark 9:26

"And having cried out, and torn him much, he came out: and [the boy] became as one dead; insomuch that the more part said, He is dead." — Mark 9:26 (ASV)

Having torn much (σπαραξας). The uncompounded verb used in verse 20.

Became as one dead (εγενετο ωσε νεκρος). As if dead from the violence of the spasm. The demon did him all possible harm in leaving him.