What Causes A Synovial Cyst?

I have had lower back pain for 8 months now. I was sent to and exercise therapist, chiropractor, and physiotherapist. After 7 months my conditioned worsened terribly. I finally asked for an MRI from my GP. It showed that I have a synovial cyst in my spine measuring 1.5 x 1 x 0.8 cm. at the L4-5 level displacing the right L5 nerve root to the left and compressing the exiting right L4 nerve root. In the last few months my pain has greatly increased from my lower back through the the buttocks down to my toes to the point now where I am in a wheel chair. I cannot stand for more that a minute if so the pain is so excruciating that I cannot cope. If I sit all day in one position I can feel relief, even laying down now is terrible. I am to see a Neurosurgeon but might have to wait for another 7 months since there is a long waiting list and I am not dying. I have just started Lyrica as of yesterday and hoping it shall work. Can you tell me anything encouraging as far as treatment or pain relief?