Are Muscle Spasms in Forehead After Botox Treatment for Migraine Normal?

There are occasions in which the muscles that are not treated try to overcompensate for the activity which the treated muscles can't accomplish. This can cause a Mr. Spock eyebrow in some cases. 

If there are muscles that are treated that are now having episodes of spasm, it may be that the Botox is wearing off and the muscle is trying to do its normal activity from which it had been prevented from doing while the Botox was in effect.

Well if the muscle spasms are occurring in places that weren't injected with the Botox, then yes, that could be normal. These muscles would still be able to move freely, but the muscles around them, which would have been affected by the injected Botox and can no longer move, would then make the others seem more like they are spasms. But really it's just the muscles that are still able to move, while the ones around it can't anymore. I'd suggest maybe next time you have these additional muscles injected, like above the brows a bit.