Pulse-like severe pain in lower back

Hello. I am experiencing periodic severe pulse-like pain in my lower back usually lasting 30 seconds - 1 min. My Dr. doesn't know what the cause could be. He said he isn't informed enough about CM/SM to help. ???

My health history:

Hashimoto's Thyroiditis - Graves Disease (94-Current)

Exopthalamus (97-Current)

Endometriosis (06)

Hypoglycemia (08)

Posterior Disk bulging & disk degeneration @ C4-5, C5-6

Chiari I Malformation (08-Current)

Syringomyelia/Syrinx (08-Current)

Breast Cancer diagnosis (12/10)

Hypertension & Tachycardia (1/12)

Severe Complex Migraines (91-Current)