My 13 Year Old Dog Vomited Earlier (no Food Intake

My 13 year old dog vomited earlier (no food intake since yesterday), urinated and had back leg weakness, followed by confused walking (in circles for a couple of minutes), unstable back legs. Took him to vet and assume that he may have had a mini stroke as health is otherwise good. He just threw up again (yellow bile)and is tired and weak.
Should I take him back to the vet or continue to watch him?