After 6 days of mild ataxia (starting w/ 10 sec inability to stay standing), neg mra brain, mri says "multiple old bilateral basal ganglia lacunar infarcts" should i be worried?

You have had multiple small strokes in the brain area that deals with motor function and this would explain your symptoms. Based on your MRI report, there is nothing acute. You need to discuss this with your doctor to prevent future strokes.

You do need to start a preventative medication program, as the small strokes could lead to dementia and/or a larger event which could be profoundly disabling. Contact your doctor today and commence appropriate medication. Do NOT delay.