  The patient is a 46-year-old right-handed gentleman with a past medical history of a left L5-S1 lumbar microdiskectomy in 1998 with complete resolution of left leg symptoms, who now presents with a four-month history of gradual onset of right-sided low back pain with pain radiating down into his buttock and posterior aspect of his right leg into the ankle.  Symptoms are worsened by any activity and relieved by rest.  He also feels that when the pain is very severe, he has some subtle right leg weakness.  No left leg symptoms.  No bowel or bladder changes.