Nerve compression symptoms and conditions

I have been taking Zocor for 6 months. In the past 3 weeks I have developed intense tingling and burning in both legs from my feet to my knees. I also have a feeling of numbness in my right foot that at times is in the whole ball of my foot but will move to the side of the ball of my foot. I have been to the ER twice and all my neuro checks were normal even though my legs felt like they were on fire. I just this past week had a MRI of cervical and lumbar spine. My doctor is thing the symptoms may be related to the significant arthritis I have in my neck and may be due to nerve compression at one of the discs but I don't think so. I was worried about MS and Guillian Barre as these can be symptoms of those diseases as well but I didn't have any other symptoms of those diseases. At my last ER visit the doctor put me on Neurotin for the burning in my legs. I just happened to think to look on line for med interactions and side effects of the meds I am on and would have never expected that Zocor could be the culprit. I was astounded to find that the tingling and burning was more than likely due to the zocor. I stopped taking it about 4 days ago and am showing some improvement but I am still taking the neurotin. Does anyone know how long it takes Zocor to get completely out of your syste.? I also have nerve conduction studies scheduled.