What Is A Sciatic Nerve Block?
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The sciatic nerve is the largest nerve in the body, running from the pelvis through the hips and buttocks and down the back of each leg. The sciatic nerve transmits sensory information from the legs to the spinal cord. It also provides motor control for the lower extremities. The sciatic nerve is comprised of multiple bundles of nerves. When these nerves become compressed, it can result in:
- Lumbar spine pain
- Leg and foot pain
- “Pins and needles” sensations
- Muscle weakness
A sciatic nerve block is a minimally invasive procedure that can be offered to patients who suffer from severe, debilitating sciatic nerve pain or to those who continue to suffer from unrelenting pain despite attempting conservative treatment methods. A sciatic nerve block helps to block the transfer of sensory information from the lower extremities to the spinal cord and brain. Blocking the transfer of information helps to reduce or eliminate sciatic nerve pain.
What Is Sciatica?Sciatic nerve pain is also known as sciatica or lower extremity radiculitis or radiculopathy. In its most severe form, it’s known as cauda equina syndrome, and is treated as a true medical emergency. Sciatica is characterized by weakness or sensory changes down the sciatic nerve, typically only affecting one side of the body. The hallmark sign of sciatica is pain that radiates from the lower back, into the buttocks, and then down the back of the leg.
Sciatica commonly occurs when a herniated disc compresses part of the nerve. Separating each vertebra in the spine are discs that cushion and reduce any impact the spine receives. These soft, supportive discs have a tendency to herniate, or extrude, backwards through the outer disc segment and nearby ligaments. This most often occurs as a degenerative condition, through aging. While a herniated disc may not cause symptoms, it can irritate adjacent nerves by physical contact or by leaking caustic substances directly onto the nerves.
Sciatica can also be caused by other conditions that affect the spine including:
- Bone spurs
- Spinal stenosis, or a narrowing of the spinal canal
- Arthritis, another degenerative pain condition
- Nerve root compression
In rare cases, the nerve may become compressed by a tumor and cause pain. Pregnancy may also result in sciatic nerve pain.
The pain that is associated with sciatica varies in severity and can range from mild to severe. In severe cases, sciatica can lead to:
- Severe nerve impingement
- Bladder incontinence
- Bowel incontinence
- Lower extremity weakness
- A profound loss of sensation
Most cases of sciatica resolve with conservative treatment methods including cold and hot packs, physical therapy, sciatica exercises, and over-the-counter medications. However, some patients continue to suffer from sciatic nerve pain even while receiving conservative treatment.
The following video from PainDoctor.com goes into more detail about sciatica and its potential treatment options.
How Is Sciatica Diagnosed?Sciatica is diagnosed by a medical physician, such as a pain doctor. The physician will perform a physical examination to estimate tenderness over certain areas of the spine as well as assess the various limitations in movement of the lower extremities.
The pain doctor may also order radiological imaging to confirm her diagnosis. This may include:
- CT scans
- Bone scans
Currently MRIs are the preferred imaging technique to visualize chronic back pain. They are especially useful before any procedures are undertaken.
How Is A Sciatic Nerve Block Performed?Pain doctors have several methods that they can use to target the bundle of sciatic nerves due to its large size. These methods include the:
- Lateral popliteal approach
- Midfemoral approach
- Subgluteal approach
- Posterior popliteal approach
Sciatic nerve block procedures focus on injecting a corticosteroid adjacent to a peripheral nerve as opposed to injecting the medication directly into the nerve root.
Prior to the procedure, a local anesthetic is used to numb the injection site tissue. Once the area is sufficiently numb, the pain doctor inserts a small needle into the desired area using fluoroscopic guidance. Contrast dye is then injected to ensure proper needle placement and proper medication distribution. Once proper needle placement is confirmed, the physician will inject the anesthetic medication. Corticosteroids may be added to the injection in areas where there is significant inflammation.
Sciatic nerve blocks are relatively quick to perform and the pain relief effects you experience can begin almost immediately after the injection. After the procedure is complete, patients are moved to a recovery area where they are monitored for adverse reactions for one to two hours. For patients who do not have a significant reduction in pain levels following the procedure, effects may be enhanced after a few repeat injection procedures.
Sciatic nerve block procedures are considered a safe and effective treatment option for sciatic nerve pain; however, as with any medical procedure, there are risks associated with this treatment. The most common side effects are:
- Injection site tenderness following the procedure
Rare side effects include bleeding and infection. If you experience any symptoms of an infection–a fever or severe unremitting pain–talk to your doctor immediately.
Conditions Related To Sciatic Nerve BlocksSciatic nerve blocks can be an effective treatment option for patients suffering from chronic, severe sciatic nerve pain that is non-responsive to conservative treatment methods. Sciatica is often difficult to diagnose as the symptoms often overlap with other low back injuries. Oftentimes patients are able to identify an event that occurred which may have triggered their sciatic nerve pain. These events can include a slip and fall, a motor vehicle accident, or other acute traumatic events.
However, it should be noted that acute events are not responsible for all cases of sciatic nerve pain. Research has found that there are a number of characteristics that increase an individual’s risk of suffering from sciatic nerve pain, including:
- Increasing age
- Occupations that involve repetitive twisting, heavy lifting, or prolonged driving
- Prolonged sitting
Before undergoing a sciatic nerve block it is recommended that patients attempt conservative home treatment options including ice, heat, specific exercises, and over-the-counter pain and anti-inflammatory medications. If these treatments fail, a sciatic nerve block may be an ideal treatment option as they have been shown to be effective for reducing sciatic nerve pain in the lower extremities. Sciatic nerve blocks may also be beneficial for patients who experience undesirable side effects from traditional pain management medications.
ConclusionA sciatic nerve block is an effective treatment option for patients who are suffering from chronic, severe sciatic nerve pain that is non-responsive to conservative treatment methods. Sciatic nerve blocks are non-surgical and carry few risks. In addition they also provide patients with almost immediate pain relief. Sciatic nerve blocks are an ideal option to offer to patients prior to considering surgery for sciatic nerve pain relief.
If you’re suffering from pain that’s related to sciatica and have exhausted other treatment options, a sciatic nerve block may be a great option for reducing your pain and helping you get back to your life. To find a pain doctor in your area who performs sciatic nerve blocks, click the button below.
- Chen L, Wang Q, Shi K, Liu F, Liu L, Ni J, Fang X, Xu X. The effects of lidocaine used in sciatic nerve on the pharmacodynamics and pharmacokinetics of ropivacaine in sciatic nerve combined with lumbar plexus blockade: a double-blind, randomized study. Basic Clin Pharmacol Toxicol. 2013;112(3):203-8.
- Cuvillon P, Reubrecht V, Zoric L, Lemoine L, Belin M, Ducombs O, Birenbaum A, Riou B, Langeron O. Comparison of subgluteal sciatic nerve block duration in type 2 diabetic and non-diabetic patients. Br J Anesth. 2013;110(5):823-30.
- Luo D, Wang X, He J. A comparison between acute pressure block of the sciatic nerve and acupressure: Methodology, analgesia, and mechanism involved. J Pain Research. 2013;6:589-593.
- Ponde V, Desai AP, Shah D. Comparison of success rate of ultrasound-guided sciatic and femoral nerve block and neurostimulation in children with arthrogryposis multiplex congenita: a randomized clinical trial. Paediatr Anaesth. 2013;23(1):74-8.
- Sala-Blanch X, de Riva N, Carrera A, López AM, Prats A, Hadzic A. Ultrasound-guided popliteal sciatic block with a single injection at the sciatic division results in faster block onset than the classical nerve stimulator technique. Anesth Analg. 2012;114(5):1121-7.
- Seidel R, Natge U, Schulz J. Distal sciatic nerve blocks: randomized comparison of nerve stimulation and ultrasound guided intraepineural block. Anaesthesist. 2013;62(3):183-88,190-2.
- Tammam TF. Ultrasound-guided infragluteal sciatic nerve block: A comparison between four different techniques. Acta Anaesthesiol Scand. 2013;57(2):243-8.