Patients may or may not obtain pain relief in the first few hours after the injection, depending upon whether or not the medial branch nerves targeted are the ones carrying signals for their pain. If the joint or joints being targeted are not causing the pain, a patient will not obtain relief from the medial branch nerve block.
See Facet Joint Injections and Medial Branch Blocks
The patient will discuss with the doctor any immediate pain relief. Ideally, patients will also record the levels of pain relief during the next several hours in a pain diary. A pain diary is helpful to clearly inform the treating physician of the injection results and in planning future tests and/or treatment, as needed.
Patients may continue to take their regular medications after the procedure, with the exception of limiting pain medicine within the first 4 to 6 hours after the injection so that the diagnostic information obtained is accurate.
On occasion, patients may feel numb or have a slightly weak or odd feeling in their neck or back for a few hours after the injection.
4 to 6 Hours after the Injection
The medial branch nerve block is designed to interrupt the pain signal being carried by the medial branch nerves supplying a specific facet joint. Because of this, patients may feel complete or partial pain relief during the first 4 to 6 hours after an injection. They may also feel no pain relief during this time (anesthetic phase).
See Pain Signals to the Brain from the Spine
Depending on the amount of pain relief the patient has during the first 4 to 6 hours after the injection, the patient may be a candidate for a radiofrequency neurotomy (radiofrequency ablation) procedure to try and provide longer term pain relief.
Generally, a patient must report at least 80% improvement in their pain during the first 4 to 6 hours after the injection to be considered a candidate for radiofrequency neurotomy.
See Radiofrequency Ablation (RFA) Side Effects and Risks
Days after the Injection
If the area is uncomfortable in the first two to three days after the injection, applying ice or a cold pack to the general area of the injection site will typically provide pain relief.
On the day after the procedure, patients may return to their regular activities. When the pain is reduced, it is advisable to start regular exercise and activities in moderation.
The goal of a medial branch nerve block is diagnostic, not therapeutic, so patients should expect their original pain to return after anesthetic phase.
