What Is A Cluneal Nerve Block?

medial cluneal nervesA cluneal nerve block is a specialized treatment method for chronic lower lumbar back pain. Pain in this region of the back often spreads to the upper buttocks. Furthermore, lower back problems are among the main health issues that afflict people in the United States. Moreover, back problems are the leading cause for missed time from work.

The condition that is responsible for lumbar pain is not always easy to diagnose. Furthermore, research shows that many clinical cases related to back pain are not properly diagnosed even after a thorough assessment. Certain injuries and conditions, however, are frequently associated with this type of chronic pain. These include spinal stenosis, osteoarthritis, bulging discs, herniated discs, and additional conditions that can become disabling.

Diagnostic tools that are typically used to help pinpoint the reason for a patient’s back pain include a medical history assessment, a spinal exam, or an imaging screening. However, if the results from these diagnostic techniques are inconclusive, a clinician may evaluate whether nerve damage or inflammation in the upper buttocks may be responsible for the pain. This type of nerve damage is known as cluneal neuropathy and this is a condition is often misdiagnosed.

How Is A Cluneal Nerve Block Performed?

Preparation for the cluneal nerve block procedure involves having a patient lie facedown on a table that is equipped with X-ray machinery. The skin is then sterilized and, if an intravenous anesthetic is necessary (an IV), it is set up along with a monitor that records vital signs (e.g., heart rate, blood pressure, and breathing). Topical anesthesia is applied to the lumbar region before the procedure begins if the patient does not need intravenous anesthesia.

The clinician uses the X-ray to guide the injection needle into the lower back. The X-ray is called a fluoroscope and it provides an image of what is occurring in real-time. Once the needle has been correctly positioned, a dye is administered so that the region it circulates to can be observed. This step ensures that the steroid and anesthetic that are to be injected will be delivered as closely as possible to the affected cluneal nerves. The cluneal nerve roots are the target of the block procedure. The steroid targets the inflamed nerves and the anesthetic relieves the persistent pain.

A recently reported study described the effect of nerve block procedures that were performed to treat painful cluneal nerve entrapment. The nerve blocks were administered to 25 individuals who presented medial and superior cluneal nerve entrapment symptoms. All of the patients were treated with a single nerve block consisting of a steroid and an anesthetic. At a one-year check-up examination, each patient was asked about their level of pain and they all stated that they experienced pain relief.

As with other forms of treatment, this type of nerve block may result in certain complications although the occurrence is rare. Possible complications that may occur include tingling and numbness in the extremities, bleeding, an infection, and the possible puncturing of a nerve during the needle insertion.

Conditions Related To Cluneal Nerve Blocks

superior cluneal nervesIn order to better understand how cluneal nerve blocks can be used to treat certain conditions, the function and location of nerves located in the middle and superior cluneal regions of the back will be described. The middle cluneal nerves can be found between positions S1 and S3 in a structure called the dorsal rami. The dorsal rami is located in the lumbar back and it regulates sensory, motor, and visceral signal transmission between cluneal nerves. Middle cluneal nerves are also embedded in the posterior superior iliac spinal region, which refers to the buttocks.

Superior cluneal nerves can be found between positions L1 and L3 along the dorsal rami. This is the upper buttock region. These nerves are at the very tail end of the lower spine and they regulate the transmission of sensory signals in this area.

Lower back pain that extends into the upper buttock region may be the result of cluneal nerve entrapment. This condition is called medial superior cluneal nerve entrapment (MSCNE) and the symptoms it causes are quite similar to those that are reported by people who have facet syndrome. Cluneal nerve entrapment is different, however, because it is characterized by nerves that become pinched in the tunnel-like iliac crest. In order to determine if this condition is present, a clinical examination may be performed to determine if a patient struggles to sit for prolonged periods, if pain in the buttocks is more intense on one side, and if there is a painful trigger point on the buttocks.

Cluneal nerve blocks offer therapeutic advantages for patients suffering from nerve entrapment. However, in addition to the therapeutic benefits, cluneal nerve blocks are also valuable diagnostic tools. This is because if the nerve block effectively alleviates the pain in the buttocks and lower back, it also shows a doctor that the correct diagnosis was made. After undergoing a nerve block procedure, many patients report pain relief that is almost immediate. Furthermore, a cluneal nerve block that is effective can prevent a patient from enduring unnecessary back surgery.

Conclusion

A cluneal nerve block is a specialized treatment method that effectively reduces chronic pain in the lower back and buttocks for most patients. It is often used as a therapeutic tool and a diagnostic technique as it can both relieve pain while identifying the actual cause of the back pain. Cluneal nerve entrapment may cause pain in the upper buttocks, but it is often underdiagnosed. A cluneal nerve block that is successful usually provides an indication that this condition is responsible for a patient’s chronic pain. Some patients can avoid undergoing surgery if they receive a nerve block and most report almost immediate pain relief after the procedure.

References

  1. Ermis M, Yildrum D, Duraknasa M, Tanam C, Ermis O. Medial superior cluneal nerve entrapment neuropathy in military personnel; diagnosis and etiologic factors. J Back Muscul Rehab. 2011;4:137-144.
  2. Herring A, Price D, Nagdev A, Simon B. Superior cluneal nerve block for treatment of buttock abcesses in the emergency department. 2009;39(1):83-85.
  3. Talu G, Suleyman O, talu U. Supeior cluneal nerve entrapment. Regional Anesthesia and Pain Medicine. 2000;25(6):648-650.
  4. Wisotzky E, Cocchiarella A. Cluneal neuropathy – An underdiagnosed cause of low back pain: A case series. PM&R. 2010;2(9):73-74.