Selective Nerve Root Block

A selective nerve root block (SNRB) is a minimally invasive procedure where a local anesthetic and steroid are injected around a specific nerve root in the spine. This procedure is both diagnostic, helping to identify which nerve is causing pain, and therapeutic, providing relief from inflammation and pain.

While an epidural steroid injection spreads medication over a larger area around the spine, an SNRB targets a single, specific nerve root. This makes it more accurate for diagnosing which nerve is responsible for your pain and helps to limit the spread of medication to nearby nerves.

After the skin is numbed with a local anesthetic, the doctor inserts a needle under fluoroscopy (X-ray) or CT guidance to ensure it reaches the correct nerve root. Once positioned, a contrast dye may be injected to confirm placement before administering the anesthetic and steroid.

The procedure itself usually takes about 15 to 30 minutes. Most of the time is spent positioning the needle correctly under imaging guidance.

SNRBs are commonly used to treat radicular pain from conditions such as herniated discs, spinal stenosis, sciatica, and post-surgical complications. They are also helpful in managing failed back surgery syndrome (FBSS) and radiculopathy due to osteophytes (bone spurs).

After an SNRB, you may experience immediate pain relief from the local anesthetic. However, it can take 2 to 3 days for the steroid to reduce inflammation and provide longer-lasting relief. Some soreness at the injection site is normal.

Not everyone requires multiple injections. If pain relief is significant, you may not need additional injections. If the pain returns or is only partially relieved, follow-up injections may be considered.

Pain relief varies between individuals. Some patients experience relief for weeks or even months. The duration of relief depends on the underlying condition and how the patient responds to the steroid.

While complications are rare, potential risks include infection, allergic reactions, bleeding, temporary numbness or weakness in the affected limb, increased pain, or in very rare cases, nerve damage. Pneumothorax (collapsed lung) is a risk with thoracic nerve root blocks.

Some patients experience an increase in pain for 24 to 48 hours after the injection due to the steroid’s effect. This usually subsides, but if the pain becomes severe or persists, you should contact your doctor.

You can usually resume light activities the same day, but it is recommended to avoid strenuous activities for 24 to 48 hours after the procedure. Your doctor will give you specific instructions based on your condition.

Unlike surgery, SNRBs are minimally invasive, don’t require anesthesia, and have a much shorter recovery time. They are often used as a diagnostic tool or to provide temporary relief while exploring non-surgical treatments. Surgery is typically reserved for cases where conservative treatments fail.

Yes, most patients will have undergone diagnostic imaging such as an MRI or CT scan to identify potential problem areas in the spine. This imaging helps guide the SNRB procedure by identifying which nerve root is likely causing the pain.

Nerve root pain, or radicular pain, often radiates along the path of the nerve into the limbs. For example, nerve pain from the lumbar spine may travel down the leg (sciatica), whereas muscle or joint pain tends to be localized and doesn’t travel far from its source.

SNRBs are highly successful in diagnosing the source of nerve pain and have a positive predictive value of around 95% for surgical success if surgery is ultimately needed. For therapeutic purposes, SNRBs provide temporary pain relief in a significant number of patients.

SNRBs can be performed in the cervical spine (neck), thoracic spine (mid-back), and lumbar spine (lower back). Cervical SNRBs are used for conditions like cervical radiculopathy, where pain radiates from the neck into the arms.

A local anesthetic such as lidocaine or bupivacaine is typically used, along with a steroid like triamcinolone (Kenalog) or betamethasone (Celestone). The local anesthetic provides immediate relief, while the steroid reduces inflammation over time.

Most patients tolerate SNRBs well. You may feel pressure or a mild ache during the procedure, but the area will be numbed with a local anesthetic to minimize discomfort. Some patients may experience brief pain as the needle approaches the nerve root.

Yes, SNRBs are commonly used to treat sciatica, which is caused by compression of the sciatic nerve in the lower back. The injection targets the affected nerve root to reduce inflammation and alleviate leg pain.

Temporary numbness or weakness in the affected limb is normal due to the local anesthetic. This typically resolves within a few hours. However, if the numbness or weakness persists, contact your doctor.

Most insurance plans, including Medicare, cover SNRBs if they are deemed medically necessary. However, coverage can vary, so it’s important to check with your insurance provider about specific requirements or prior authorizations.

Yes, SNRBs are typically performed on an outpatient basis. The procedure is quick, and you can return home the same day, though you’ll need someone to drive you.

SNRBs are performed by various specialists, including orthopedic surgeons, pain-management anesthesiologists, interventional radiologists, and sometimes neurologists, depending on the practice. The key is that the physician is skilled in image-guided needle placement.

If an SNRB provides only partial relief or fails to alleviate your pain, it may suggest that multiple nerves are involved, or the pain is originating from another source. Your doctor may recommend additional diagnostic procedures, such as further nerve blocks or discography, to pinpoint the pain source.

Imaging, such as fluoroscopy or CT, is crucial for accurately guiding the needle to the targeted nerve root. This reduces the risk of complications and ensures the medication is delivered to the correct location.