Issue with diziness , lightheadedness.

Dear docs I have been facing these episodes of dizziness and lightheadedness and the episodes spin my head and bearing . The reasons unknown . Have got my cervical.mri which says cervical.spodolysis c6-7 with no bulges but nerve root compression. MRI brain is normal ECG was normal 2 D echo was normal in Feb this year Cartiod doppler neck was normal ENT doc has cleared me too My lipids have been high always in range of 280-310. Rest blood report is normal. I also get these headache accompanying this dizziness at times . The dizziness gives a blurred vision at times and a feeling of my above shoulder body spinning . Offlate do have a feeling of nausea Kindly help me with any specific test I can go for Will be a great help Santosh