I recently had an mri to investigate migraines and was told that i had a small prior lacunar infarct within the right inferior cerebellar pica territory. can migraines cause this? how serious is this?

Possibly: Small stroke possibly related to migraine (if with "aura") but best prevention is to correct all stroke risk factors including hypertension (how well controlled?), smoking, + high cholesterol. Your doc probably put you on Aspirin and probably checked carotid arteries for blockage and checked the heart for any source of blood clots (most commonly the irregular heartbeat from atrial fibrillation.

See your PCP .: Migraines does not cause lacunar infarcts. With your hypertension, make sure you did not have an undetected cva (stroke). The pain in your neck and back maybe a symptoms of hypertension which your migraine may have obscured. I suggest you see your pcp.

Need to evaluate: Most strokes associated with migraine are in females with migraine auras, who take birth control pills, smoke, and have familial risk factors. The location of your stroke is troublesome implicating vertebro-basilar circulation, and risk factors need assessment. Would totally avoid triptans, and would likely use an anti-platelet and perhaps a statin. This is not due to migraine per se.