Vertigo and dizziness are common problems in migraine sufferers.  In general, as a neurologist, I see a lot of patients with dizziness.  The problem tends to be more prominent in migraineurs.  There are several different potential causes of vertigo, and even more in migraineurs.

Vertigo can be present as a part of migraine, is very common after concussion, and can be caused by a host of middle and inner ear disorders, as well as brain disorders.  In some cases, dizziness can be related to dehydration, blood pressure drops, or heart problems.
 
Vertigo can be an associated symptom of migraine (like nausea and sensitivity to light), it can be an aura-type symptom (preceding the migraine in a very distinct episode), it can be the only manifestation of migraine (migrainous vertigo, a variant of migraine) or it can be a symptom in the general life, intermittently and not associated with actual migraine attacks, of a migraineur, but related to the migraine by the genetic underlying sensitivities.
 
Of course, migraineurs can also get vertigo from the more typical and non-migraine related causes, such as inner ear infections, labyrinthitis, benign positional vertigo, menierie’s disease, other ear problems, and even strokes.
 
It is an interesting and common problem.  It, unfortunately, is very difficult to treat.  Keep yourself well hydrated and ask your doctor if any of your medications can be adding to the problem.  Often times it will go away on it’s own, if it is from a benign cause.  In severe chronic cases of vertigo, a special type of rehabilitation can be useful.