Thanks for asking.Stroke
is the involvement of the brain with the resultant either bleeding into the brain or reduced blood supply to the brain.both these conditions lead to damage to the brain area.
Brian is not a regenerable organ so the damage to the Brian cells do not lead to new cells making good the loss, only recovery seen in the Brian is because of reduction of the swelling or the formation of the other channels for the blood flow.
It is very hard to predict how much recovery will happen in a predefined period, keep the blood pressure and diabetes( if any) under control,recovery is usually delayed and is incomplete.
And there is no way to hasten the recovery, it is more of a waiting game.