Complex Bilateral Pelvic and Lower Extremity Pain Syndrome

In this example, we examine a patient who was referred for complex bilateral pelvic and lower extremity pain syndrome.

Background: This is a 35-year-old, right-handed female with reports of constant tingling, pain and stabbing to the radial and rectal area with swelling for an ankle pain sensation for the past two years. The patient notes that initially she presented with patch dermatitis of the vulva. Two years ago she began with minor symptoms, following a series of heavy lifting while helping a nearby neighbor care for her husband. She was seen by the OB/GYN who ruled out yeast; however, did start her on Diflucan with no relief. She has tried various topical medications, which have caused increased pain. She was seen by a pelvic pain specialist that diagnosed her with contact dermatitis for which he instituted changes in her soap and detergent, which has helped significantly with the swelling; however, has not had any effect on the burning. She also presented with some bumpiness, which were diagnosed as staph bumps by her primary doctor. In January 2009 she underwent a pudendal block with cortisone, which provided her with 40% relief for two weeks. She then underwent a second injection with no significant relief; however, this caused renal insufficiency resulting in a two-week visit with the Mayo Clinic. Her symptoms over time have been increasing in severity. She notes that her pain is constantly at 10+ levels as well.

MR Neurography: These images (depicted below) demonstrate the course and caliber of the lumbar and sacral spinal nerves, the lumbosacral plexus and pudendal nerves and proximal sciatic nerves. The visualized lumbar and sacral spinal nerves are generally normal in course, caliber and contour as they traverse the proximal and distal foramina. There is no significant sacroiliac joint inflammation. There is no significant hip joint inflammatory or degenerative change. The psoas muscles are symmetric in size and shape. The piriformis muscles are slightly asymmetric being larger right than left and the obturator internus muscles are slightly asymmetric being slightly larger, left than right. A split muscle, split nerve configuration is noted for the piriformis and sciatic nerve on the right side; although on the left there does not appear to be a split muscle or nerve. There is mild-to-moderate irritation demonstrated by increased image intensity affecting the sciatic nerve bilaterally as it exits the sciatic notch. This is accentuated more on the right side with the focus of the point of reconnection of the two components of the sciatic nerve as they exit from the split muscle portion of the piriformis muscle. On the medial aspect of the obturator internus muscle, there is some irritative affect on the pudendal nerve commencing near the level of the ischial spine. This actually commences above the ischial spine level. There is only minimal venous dilatation.

Interventional MRI sets the plan for surgery: Physical exam and MR Neurography imaging have indicated involvement of the piriformis muscle, the obturator internus muscle, the nerve to the obturator internus, the pudendal nerve, and the superior gluteal nerve as well as the sciatic nerve. Based on this history, exam, data and findings, this case is very likely a significant and severe bilateral pudendal syndrome. She clearly has both severe obturator internus muscle involvement, but also piriformis involvement. The patient will proceed with an MRI-guided injection for piriformis and obturator internus muscle. We carried out a complex series of MRI-guided injections, which involved a piriformis muscle, the obturator internus muscle, superior gluteal nerve and the pudendal nerve. The patient had for approximately one day, complete relief of symptoms along with significant numbness, but progressively the symptoms have completely recurred. The patient is interested to proceed with the surgery. She will need a right and a left sided approach for piriformis, superior gluteal nerve, sciatic nerve, nerve to the obturator internus and pudendal nerve. The interventional MRI procedure has confirmed the MR Neurography diagnosis and provides real time images for planning the surgical approach.

Post Surgery: The patient is about four weeks out from her surgery, which was a bilateral operation involving piriformis resection and neuroplasty of the sciatic, pudendal and obturator internus nerves, the superior gluteal nerve. She is happy to report that she is doing extremely well. She is having some days with absolutely zero pain; whereas, prior to surgery she had level 10 pain, reflecting major improvement. Over the next month she should be able to increase her activity and hopefully she will have a complete resolution of all of her symptoms and no need for any additional medications at this time.