From what you have described, it seems that there are stress of brain damage due to blockage of blood supply. There are 2 types of circulation in the brain. Anterior and posterior circulation. From the areas of damage, it seems like a posterior circulation Stroke. The blockage could be due to several reasons. To prevent such blockage from happening again, the reason for the blockage needs to be found and treated. A thorough evaluation under supervision of a Neuro Specialist find out the reason - eg. High lipids, clot in the heart, clot in the neck etc.
Next Steps
Consult a Neuro Specialist.