Sciatic nerve endometriosis is one of the most unusual forms of involvement by endometriosis and is seen very rarely. When all endometriosis cases are considered, its probability of occurring is rather low. However, when this situation arises it causes serious complaints and loss of function relating to walking, and can naturally affect the person’s quality of life very negatively. Sciatic nerve endometriosis, a very rare form of the chocolate cyst disease, which is seen in about 10% of women of reproductive age, refers to the involvement by the chocolate cyst of the nerve that lies within the pelvis. It is a problem characterised by very severe hip and leg pain on the affected side.
WHAT IS SCIATIC NERVE ENDOMETRIOSIS?
The sciatic nerve can be described as the longest and thickest nerve in the human body. The sensations that arise in areas such as the back of the thigh, the knee, the back of the calf and the sole of the foot are carried by the sciatic nerve. Some foot and leg muscles are also stimulated by this nerve. Endometriosis formations, or the chocolate cyst as it is better known, can rarely involve the part of this nerve that lies inside the abdomen. As a result of this attachment, problems arise from the pressure created on the sciatic nerve. If the patient’s history cannot be taken carefully and examined in detail, it is very difficult to understand that the problem is caused by endometriosis.
WHAT ARE THE SIGNS OF SCIATIC NERVE ENDOMETRIOSIS?
Sciatic nerve endometriosis can cause signs resembling both the chocolate cyst and a lumbar disc herniation. Involvement of the sciatic nerve can lead to symptoms such as pain in the legs, a sensation of numbness, pain from the sole of the foot, tingling and muscle weakness, as in a disc herniation. Foot drop can be seen especially if the diagnosis is delayed. However, the most important detail to note here is that the pain, tingling and numbness in the legs and feet become more severe during menstruation. This is because during menstruation, as a result of the increased inflammation in the endometriotic tissue, the pressure on the sciatic nerve also increases, so the signs are expected to appear far more severely. While at the beginning there is pain only during menstruation, as the disease progresses severe pain begins to be felt continuously.
HOW IS SCIATIC NERVE ENDOMETRIOSIS DIAGNOSED?
In a significant proportion of these patients the absence of endometriosis in the genital area causes the diagnosis to be delayed even further. First of all, the possibility that this situation may be due to the sciatic nerve must be brought to mind. A comprehensive neuropelveological examination is carried out. The affected area and the calf and leg muscles and nerves on that side are assessed in detail. For an even more definite diagnosis, detailed MRI imaging (MR neurography) is requested. In patients whose muscle strength is affected, electromyography (EMG) is added to the assessment. As a result of surgery performed by neuropelveologists specialised in surgery of the sciatic nerve and other pelvic nerves, almost all of the signs the person experiences can be eliminated and the person returns comfortably to normal life. Nerve monitoring can also be used during these operations. One of the important points after surgery is that, although not in all patients, especially in patients whose diagnosis was delayed, the patient must also be prepared for a long rehabilitation programme under the supervision of physical medicine and rehabilitation specialists experienced in this field.