What Are Nerve Blocks?
A nerve block is an injection of local anesthetic, corticosteroid, or other therapeutic medication directly adjacent to a specific nerve or nerve cluster to interrupt pain signal transmission. Nerve blocks are among the most versatile tools in interventional pain medicine — they serve dual purposes as both diagnostic procedures (confirming which nerve or structure is generating pain) and therapeutic treatments (providing direct pain relief that can last from hours to months). Dr. Qureshi performs all nerve blocks under fluoroscopic (X-ray) or ultrasound guidance to ensure precise placement and maximize clinical outcomes.
The diagnostic value of nerve blocks is particularly powerful in complex pain presentations. When multiple structures could plausibly be generating pain — for example, the difference between facet joint pain, SI joint pain, and myofascial pain in a patient with chronic low back pain — a targeted diagnostic block temporarily numbs one structure at a time and measures the response. A 50–80% reduction in pain following a specific nerve block provides strong evidence that the blocked nerve or joint is the primary pain generator, directing subsequent definitive treatment accordingly.
Types of Nerve Blocks Performed
Medial Branch Blocks
The medial branch nerves are the small sensory nerves that supply the facet joints of the lumbar and cervical spine. Medial branch blocks are the essential diagnostic step before radiofrequency ablation — two separate positive blocks (achieving 50%+ relief each) are required to confirm facet-mediated pain and qualify for RFA. They also provide direct therapeutic relief lasting days to weeks. Dr. Qureshi performs medial branch blocks at lumbar (L1–L5), cervical (C3–C7), and thoracic levels under fluoroscopic guidance.
Selective Nerve Root Blocks
Selective nerve root blocks (SNRBs) place medication immediately adjacent to a specific spinal nerve root as it exits the foramen, before it joins the main spinal nerve plexus. They provide more targeted diagnostic information than interlaminar epidural injections and are particularly valuable when imaging shows abnormalities at multiple levels — identifying which level is actually symptomatic. SNRBs are performed under fluoroscopic guidance with contrast confirmation.
Occipital Nerve Blocks
The greater and lesser occipital nerves supply sensation to the back and top of the skull. Occipital neuralgia and cervicogenic headaches originating from upper cervical facet pathology frequently respond dramatically to occipital nerve blocks. The injection is performed at the occipital ridge, typically providing rapid relief for headaches that have not responded to medications.
Sympathetic Nerve Blocks
The sympathetic nervous system plays a key role in certain chronic pain conditions, particularly complex regional pain syndrome (CRPS). Sympathetic nerve blocks — including stellate ganglion blocks and lumbar sympathetic blocks — interrupt the abnormal sympathetic contribution to pain in these conditions. They are both diagnostic (confirming sympathetically maintained pain) and therapeutic.
Peripheral Nerve Blocks
Ultrasound-guided peripheral nerve blocks target specific peripheral nerves causing focal pain — including the suprascapular nerve for shoulder pain, the genicular nerves for knee pain, the lateral femoral cutaneous nerve for meralgia paresthetica, and others. These precisely targeted procedures provide relief localized to the distribution of the blocked nerve.
How Nerve Blocks Work
Local anesthetic nerve blocks work by reversibly blocking sodium channels in the nerve membrane, preventing the generation and propagation of electrical action potentials that carry pain signals. This block is temporary — duration depends on the anesthetic used, ranging from 4–8 hours for pure diagnostic blocks to weeks or months when combined with corticosteroid for anti-inflammatory benefit. The temporary nature of diagnostic blocks is actually an advantage: it allows precise, reversible testing of specific pain generators without any permanent effect.
What to Expect
The procedure is performed in our fluoroscopy or procedure suite. The skin is cleaned and numbed with local anesthetic. Under real-time image guidance, Dr. Qureshi advances the needle to the target location, confirms position with contrast or nerve stimulation, and delivers the medication. The procedure typically takes 15–20 minutes. You may notice immediate relief from the local anesthetic — this is diagnostic confirmation that the targeted nerve was reached. A driver is required home if sedation is used.