This is a growth pattern called fasciation. It happens pretty often in some kinds of plants. The meristem doubles or becomes broader instead of being a single small cluster of cells. You can see where the spike begins to look like 2 spikes fused together. This can happen if the meristem is damaged somehow, or it can be a genetic tendency. It has nothing to do with the health or vigor of the plant, and it can't hurt the plant in any way. It is really not much different than a branched spike. There is no reason to cut the spike sooner of shorter than you would otherwise if the plant is healthy and mature enough to allow it to flower in the first place.