Nerve blocks at PHI are performed by board-certified physicians Dr. Faisal Lalani and Dr. Nadiv Samimi in our affiliated surgical suite at 455 N Roxbury Drive, Suite B, Beverly Hills, under fluoroscopic guidance. They interrupt specific pain pathways, both to diagnose the source of pain and to treat it, and include genicular, stellate ganglion, ganglion impar, and sympathetic blocks.
What Nerve Blocks Do
A nerve block is a precisely targeted injection that interrupts the transmission of pain signals along a specific nerve or group of nerves. Unlike steroid injections that reduce inflammation, nerve blocks act directly on the nerve itself, either temporarily numbing it with local anesthetic or disrupting its pain-signaling function.
Diagnostic. A successful block confirms that the targeted nerve is the source of your pain. This is critical information when the pain pattern is unclear or when imaging does not point to a single cause.
Therapeutic. Many nerve blocks produce sustained relief that lasts long after the local anesthetic wears off. The mechanism involves resetting overactive nerve signaling rather than just temporarily numbing.
Bridge to definitive treatment. Some nerve blocks are used as a step toward a longer-lasting procedure such as radiofrequency ablation, peripheral nerve stimulation, or sympathetic nerve interventions.
PHI offers four primary nerve block procedures, each indicated for a different clinical situation.
Genicular Nerve Block
The genicular nerves carry pain signals from the knee joint to the brain. A genicular nerve block delivers local anesthetic to these nerves to temporarily interrupt knee pain signaling, used both diagnostically and therapeutically.
Genicular blocks are most often used for patients with chronic knee pain, particularly knee osteoarthritis, who:
- Have not responded adequately to conservative treatments
- Are not surgical candidates due to age, medical conditions, or personal preference
- Want to explore non-surgical options before considering joint replacement
- Have already had knee replacement and continue to experience pain
The procedure is performed under image guidance. The physician identifies the three primary genicular nerves around the knee and delivers local anesthetic to each. It typically takes 15 to 20 minutes, and most patients experience pain reduction within the first hour. A successful response often qualifies the patient for genicular ablation, a longer-lasting next step.
Stellate Ganglion Block (SGB)
The stellate ganglion is a cluster of sympathetic nerves in the front of the neck, near the spine, central to the body’s fight-or-flight response. A stellate ganglion block delivers local anesthetic to this cluster, temporarily interrupting sympathetic signaling. It has expanded well beyond its original use for upper-extremity pain syndromes.
SGB is used for several distinct conditions, including complex regional pain syndrome (CRPS) of the upper extremity, post-traumatic upper-extremity pain, phantom limb pain, and sympathetic-mediated facial pain. PHI also uses SGB for post-traumatic stress disorder (PTSD), where growing evidence, including studies in military veteran populations, shows meaningful symptom reduction. For PTSD, SGB is adjunctive to mental health care, not a replacement for it.
The procedure is performed under image guidance with the patient awake and typically takes 10 to 20 minutes. Patients often experience immediate, expected effects on the treated side, including a temporary droopy eyelid, slight redness, and warmth, which resolve within several hours. For chronic pain indications, patients often receive a series of blocks. PHI performs one side at a time, not both sides on the same day.
Ganglion Impar Block
The ganglion impar (also called the ganglion of Walther) is a small cluster of sympathetic nerves at the very base of the spine, just in front of the tailbone. It receives sympathetic signals from the pelvic organs and perineal region.
Ganglion impar blocks are used for chronic pelvic and perineal pain that is often poorly served by other treatments, including:
- Chronic perineal pain
- Coccydynia (tailbone pain) that has not responded to conservative treatment
- Cancer-related pelvic pain, including rectal, anal, or gynecologic cancers
- Post-surgical pelvic pain
- Pudendal neuralgia in selected patients
- Post-radiation pelvic pain
The procedure is performed under image guidance with the patient face down. The physician advances a thin needle to the ganglion impar location, confirms placement with imaging, and delivers local anesthetic with or without a small amount of corticosteroid. It typically takes 15 to 20 minutes. If the response is positive but short-lived, a longer-lasting procedure such as neurolysis or radiofrequency ablation of the ganglion impar may be considered.
Sympathetic Nerve Block
Sympathetic nerve blocks target the sympathetic nervous system at various levels along the spine, depending on the location of pain. The stellate ganglion block is one type. Two other common targets are the lumbar sympathetic block, for sympathetic-mediated pain in the leg, and the celiac plexus block, for severe upper-abdominal pain such as pain related to pancreatic cancer or chronic pancreatitis.
The unifying feature of conditions treated with sympathetic blocks is overactive sympathetic signaling that maintains pain or vascular symptoms even after the original injury has healed. Common indications include:
- Complex regional pain syndrome (CRPS) of the lower extremity
- Vascular insufficiency pain in the leg
- Phantom limb pain in the lower extremity
- Severe abdominal pain from pancreatic cancer or chronic pancreatitis
- Pelvic pain syndromes with sympathetic features
The procedure is performed under image guidance, with positioning according to the specific block. It typically takes 15 to 30 minutes depending on the complexity of the target. For chronic pain indications, patients often receive a series of blocks, and successful diagnostic blocks may qualify patients for longer-lasting procedures including radiofrequency neurolysis in selected cases.
Why Patients Choose PHI for Nerve Blocks
Covenient surgery center
Nerve blocks are precise procedures with anatomic risk profiles that vary by block type. PHI performs every block in our affiliated surgery center, with full monitoring and emergency-trained staff present.
Image-guided every time
Every block is performed under fluoroscopic guidance with an imaging specialist. Nerve blocks without imaging are less accurate and carry meaningfully higher risk.
Two board-certified physicians
Dr. Faisal Lalani and Dr. Nadiv Samimi, both trained in interventional pain at Cedars-Sinai, where Dr. Lalani is on the faculty.
Diagnostic and therapeutic continuity
A nerve block at PHI is not a one-off. Your physician tracks your response, evaluates whether the block confirms a clinical hypothesis, and recommends a definitive next step when one is available.
Concierge model
Single-physician continuity from consultation through follow-up, with direct access to your physician.
Concierge, coordinated care
Single-physician continuity from consultation through treatment and return to activity. Patients receive clear guidance and transparent pricing at consultation.
What to Expect: Before, During, and After
Consultation and prep
Your physician reviews your imaging, history, and current medications at consultation. Some medications, including certain blood thinners, may need to be paused; you will receive specific instructions.
The block
The procedure typically takes 10 to 30 minutes depending on the specific block. Local anesthetic is used to numb the skin, and PHI offers sedation options including nitrous oxide, conscious sedation (Versed), and deep sedation (Propofol). You remain able to communicate with your physician as needed.
Recovery
You rest in our recovery area for about 30 to 60 minutes while your physician confirms you are stable. Some blocks, particularly stellate ganglion blocks, produce expected temporary effects that take a few hours to resolve. You will need transportation home from any nerve block and should not drive yourself the same day.
The diagnostic window
The local anesthetic produces immediate relief that typically lasts several hours. After this initial period, your physician tracks your symptom pattern carefully. This diagnostic and prognostic information determines next steps.
Response
Response duration varies significantly by block type, indication, and individual patient. Your physician will set expectations specific to your situation.
Frequently Asked Questions
A steroid injection reduces inflammation in or around a structure such as a joint, the epidural space, or soft tissue. A nerve block targets a specific nerve to interrupt pain signaling directly. They serve different purposes and treat different pain mechanisms, and some procedures combine both.
For diagnostic blocks, working means a clear reduction in your typical pain within the timeframe the local anesthetic is active, and this information is valuable whether the result is positive or negative. For therapeutic blocks, response varies by individual and indication. Your physician will set realistic expectations for your situation.
Most patients describe the procedure as briefly uncomfortable rather than painful. The local anesthetic numbs the skin and tissue along the needle path. Some blocks, particularly the ganglion impar, involve sensitive areas that may feel more prominent during the procedure.
No. You should not drive yourself home from any nerve block. Local anesthetic effects, any sedation used, and the temporary signs of a successful block make driving inadvisable for at least 24 hours, so arrange transportation in advance.
This varies by block type and indication. Some blocks are performed once for diagnostic purposes; others are performed in a series of two or three. Therapeutic blocks for chronic pain may be repeated periodically. Your physician will recommend a specific protocol.
Nerve blocks have low complication rates when performed by experienced physicians under image guidance. Risks vary by block type and may include temporary increase in pain, bleeding, infection at the injection site, and rare complications related to needle placement near critical structures. Your physician will review the specific risk profile for the block they recommend.
Yes. PHI offers stellate ganglion blocks for both pain and PTSD, following physician evaluation. For patients pursuing SGB for PTSD, our physicians work alongside your existing mental health treatment team. SGB is not a replacement for psychotherapy or psychiatric care; it is an adjunctive procedure that may help patients respond more effectively to other treatments.
Yes, frequently. A successful diagnostic block often qualifies you for a definitive procedure, such as radiofrequency ablation following a successful diagnostic block, peripheral nerve stimulation following a successful trial, or longer-acting neurolytic procedures in selected cancer pain cases. Your physician will discuss these pathways during consultation.
Insurance coverage and payment options may vary. We provide documentation for you to seek reimbursement through your out-of-network benefits, which may apply to certain services. All pricing is disclosed at consultation.
Yes. PHI regularly treats patients from outside Los Angeles, including Las Vegas, Palm Springs, London, and other international locations. For patients traveling specifically for nerve block evaluation and treatment, we coordinate consultation, imaging review, the procedure, and any follow-up within a single visit when possible.