The day the convulsive (first blast) shatters convulsively

He was rooted to the spot, but convulsive shudders ran down his back his shoulders would heave suddenly.

And instead of getting normal perception, you're getting an anarchic, convulsive stimulation, or release, of all of these visual cells in the inferotemporal cortex.

Footsteps approached, running heavily, the door was pushed open violently, and Marvel, weeping and dishevelled, his hat gone, the neck of his coat torn open, rushed in, made a convulsive turn, and attempted to shut the door.