Adam Sewell MD


Radiofrequency Ablation (RFA) is a minimally invasive out-patient procedure and treatment for a range of conditions and pain syndromes. This cutting-edge procedure uses a specialized device that uses radiofrequency heat energy to stop nerve signals from transmitting pain to the brain.

RFA is often used in pain management to treat chronic back pain, neck pain and muscle pain. During RFA, a radiofrequency probe is inserted through a small needle into the skin. Controlled and targeted heat is delivered through the probe. RFA may be used to destroy the irritated nerve through targeted heat, eliminating pain signals. Pulsed-RFA is used to interrupt painful nerve impulses.


An understanding of spine anatomy and its physiological function is a critical piece in the evaluation of a person with spine-related pain.

The spine consists of individual vertebrae (spinal bones). The vertebrae create a flexible support structure and protect the spinal cord. Facet joints are on the top and bottom of each vertebra and connect the vertebrae to one another. Facet joints hold the spine together and assist with spinal stability. The facet joint structure has lubricating fluids, which allows for ease in a range of back movement. Each vertebra has two facet joints.

Facets are supplied by the medial branch nerve, small nerves which branch out from the vertebra, at the facet joint. They provide sensations to the joints. The facet joints may become arthritic, damaged or irritated, causing severe pain with movement.

When the facet joints are compromised, the medial branch nerves send pain signals to the brain. The nerve is located at the junction of the transverse process and superior articular process of the facet joint.

A recent study found that Medial Branch Radiofrequency Ablation is a minimally invasive outpatient procedure that reduces back pain by interrupting the nerve supply from painful facet joints in the neck or back (Murtagh 2006).

Sphenopalatine Ganglion

A ganglion is a structure containing a bundle of nerve cell bodies. The sphenopalatine ganglion provides sensations to the face and head region. It’s located at the back of the nose. Often times face pain or headaches are treated successfully with a sphenopalatine ganglion blockade or ablation. A recent article showed that the ganglion can be targeted with radiofrequency for chronic headaches or other conditions causing atypical facial pain (Bayer 2005).

Pain conditions commonly treated with RFA:

  • Peripheral Neuropathies
  • Sympathetically Mediated Pain
  • Complex Regional Pain Syndrome
  • Trigeminal Neuralgia
  • Headaches
  • Neck pain
  • Back pain
  • Some Stroke Related Pain
  • Other RFA Techniques
  • IDET
  • Disc Dennervation


The skin area is sterilized and a local-numbing agent is administered through a needle. IV sedation is available and administered if needed. Another needle is placed through the numb tissue and the entire procedure is performed using an imaging device such as a fluoroscopic (X-Ray) to guide the needle placement.

To ensure proper needle placement, an electrode is passed into the center of the needle. First stimulation is verified with sensory stimulation and then with motor stimulation. When the needle position is correct, local anesthetic and sometimes a steroid medication are injected.

The radiofrequency probe produces a lesion created by localized and targeted heat. When the lesion is created over a painful nerve, pain signals are interrupted to the brain.

Radiofrequency thermo-coagulation – The electrode is heated to 50-80°C and kept at that temperature for several minutes. The generated electro-thermal heat allows for destruction of surrounding nerve tissue, thus eliminating or decreasing pain.

Pulsed Radiofrequency – This is similar to thermo-coagulation RFA, except that the electrode is heated at a lower temperature. This lower temperature doesn’t destroy the nerve tissue, but instead stuns the nerve. During the procedure, this technique is generally more comfortable, with often only a mild-pulsating sensation.

After a brief recovery period, patients are typically allowed to go home. Patients may experience mild discomfort following the RFA.


In a recent clinical research study for patients treated with radiofrequency therapy, 21% had complete pain relief, and 65% reported mild to moderate pain relief.

The majority of the patients in this study reported reductions in their pain medication usage. None of the patients developed significant infection, bleeding, hematoma formation, or numbness as complications from the procedure. (Bayer 2005).

RFA has been used for many years, and continues to evolve with better results and fewer risks. It offers patients a long-term and significant pain relief treatment, with a minimally invasive out-patient procedure


RFA is considered a safe minimally invasive option for many patients who have chronic pain. However, like any procedure there are possible complications and risks.

Potential complications include:  bleeding, infection, worsening of pain symptoms, discomfort at the point of injection, and rarely motor nerve damage. Radiofrequency therapy averages three to six months pain relief.


Radiofrequency treatment is an extremely safe and widely accepted technique to treat many chronic pain causes (Menno). If a patient has pain relief from an initial treatment, a second treatment may be beneficial. There is strong clinical evidence that RFA has “an important role in the management of trigeminal neuralgia, nerve root and spinal pain” (Lord 2002).

In a large study, 92.5% of the participants reported excellent or good pain relief with radiofrequency thermo-coagulation for the symptoms of trigeminal neuralgia (Chen 2001).

A group of 100 patients suffering from trigeminal neuralgia were treated by radiofrequency thermo-coagulation. The study concluded that RFA is the treatment of choice for trigeminal neuralgia when other medical treatments are no longer effective, or the side-effects of medications contraindicate their usage (Motta).

Another study evaluated 39 patients with trigeminal neuralgia and 92.3% received satisfactory pain relief (Sengupta).

A large evidence-based practice guideline (developed by the American Society of Interventional Pain Physicians) provided recommendations to clinicians and patients in the United States.

It states “for medial branch blocks, repeated injections at defined intervals provided long-term pain relief. For medial branch radiofrequency neurotomy, short-term pain relief was defined as relief lasting less than three months and long-term relief as lasting three months or longer. The evidence for pain relief with radiofrequency neurotomy of cervical and lumbar medial branch nerves is moderate for short and long-term pain relief,” (Boswell 2007).

For more information about RFA, or other items mentioned, please see your pain physician.


Adam Sewell MD


Adhesiolysis or Epidural Lysis of Adhesions is also known as the RACZ Procedure. The procedure’s name comes from “Adhesion” meaning scar tissue and “Lysis” meaning to dissolve or destroy. The Racz Procedure is a minimally invasive procedure that was developed in the late 1980′s by Dr. Gabor Racz. The procedure has proven effective treating chronic back and neck pain due to scar tissue formation. Scar tissue can form around nerve roots causing constant unrelenting pain. Adhesions are typically formed due to inflammation and irritation in the epidural space (the membrane that surrounds your spinal cord). These adhesions can aggravate nearby nerve roots causing intense pain (Manchikanti 2007). Scar tissue can frequently result in irritated and inflamed nerves, which can cause pain that radiates from the lower back into the legs. Most commonly, people who present with neck or back pain due to scar tissue formation have had prior surgeries or prolonged neck or back pain. After spinal surgery, adhesions develop and are thought to be the cause of recurrent pain.


Before performing a procedure your pain physician will review your MRI in order to identify which nerves are likely affected and are responsible for your pain. Initially a series of epidural steroid injections are often performed to localize and treat your pain. If scar tissue is the cause for your pain then there may not be much of a response to the epidural steroid injections. Once scar tissue is thought to be the cause of your pain you will be schedule for the Racz Procedure. This procedure is performed by injecting a local anesthetic with a small needle into the skin above your buttock. Once the area is numb, then using a larger needle a catheter/guide wire is placed into the epidural space using X-Ray guidance for proper placement. Once the catheter is in the proper location where the scar tissue is affecting the nerve root, multiple medications (omnipaque, hypertonic saline, hyaluronidase, local anesthetics, and steroids) are injected into the space in order to dissolve the scar tissue and reduce the inflammation and irritation on the nerve. This procedure can be performed over a two-day period with another injection of materials through the catheter the following day to ensure lysis (disintegration) of scar tissue has been achieved. The entire procedure typically is finished in less than an hour and is performed on an outpatient basis, so typically you are able to go home within a few hours of the procedure. Immediately after the injection you may notice that your legs feel heavy and you may have some sensory changes, but these are temporary. The local numbing anesthetic wears off in a few hours so you may feel some discomfort once that wears off at the injection site. The inflammation-reducing steroid generally starts working at about forty-eight hours.


The Racz procedure is considered safe and effective. The purpose of the procedure is to minimize the damaging effects of epidural scarring, which can physically prevent direct application of drugs to nerves (epidural steroid injections) and other tissues in the treatment of chronic back pain. It is designed to dissolve scar tissue therefore reducing pressure on irritated nerves (Boswell 2007). There is strong evidence for short term and moderate evidence for long-term effectiveness of adhesiolysis and most people who receive the treatment experience significant pain relief, 50% or more reduction in pain (Trescot 2007).


As with all medications and interventions, there are potential risks of complications. The Racz Procedure is considered an appropriate treatment for many patients who suffer from back pain, but it does have risks (Boswell 2007). The most common complaint is mild to moderate back pain at the injection site shortly after the procedure. Other more serious and far less common complications include spinal cord compression, excessive intracranial pressure, bleeding, subdural injection, hematoma, or infection. These particular risks are decreased by the use of X-Ray imaging, sterile technique and adequate training. The results of a large study show that the Racz Procedure with hypertonic saline is safe and effective in managing chronic low back and lower extremity pain in patients who failed to respond to other conservative modalities of treatments, including epidural steroid injections (Boswell 2007).


The American So ciety of Interventional Pain Physicians developed a large evidence-based practice guideline for the management of chronic spinal pain with interventional techniques. In regards to adhesiolysis, the guidelines state that there is strong evidence to indicate effectiveness of adhesiolysis with epidural steroids for short and long term pain control in difficult or unresponsive pain and radiculopathy (where the nerves do not work together properly). One of the large retrospective studies showed at less than three months 100% of the patients treated had pain relief (Boswell 2007). Further long-term observation showed these results: the percentage of patients who achieved pain relief in less than three months were 100%. In three to six months, 90% still had relief. In 12 months, 72%-52% had relief. Another study indicated that overall health status improved significantly in the patients treated with the Racz Procedure. Patients stated that their pain and pain medication use were decreased and their physical health, mental health, functional status, and psychological states were all increased after undergoing adhesiolysis therapy (Manchikanti 2001). Drs Lynch and McJunkin trained under Dr. Gabor Racz the inventor of the Adhesiolysis Procedure (Racz Procedure) and learned this safe innovative technique from him first-hand. If you are suffering from chronic back or neck pain that has been refractory to other treatments contact Arizona Pain Specialists today to see if you can benefit from this innovative treatment.

Journal Articles

Adam Sewell MD


Peripheral Nerve or Peripheral Field Stimulation procedures are becoming increasingly popular for the treatment of many causes of nerve related pain and peripheral neuralgias. This revolutionary treatment works by placing electrodes along the course of painful peripheral nerves to control pain. The stimulation blocks pain perception from traveling from the nerve to the brain. It involves a small device that is placed near the involved nerve that delivers low-level electrical impulses that interfere with the perception of pain, especially chronic nerve pain. One of the main functions of peripheral nerves is to communicate signals from the periphery to the spinal cord to the brain and the rest of the body. Peripheral neuropathy is a disorder involving the peripheral nervous system (PNS). The central nervous system (CNS) includes your brain and spinal cord. The PNS includes all of the nerves from your spinal cord to the rest of your body. Peripheral neuropathy may be caused by many conditions including vitamin deficiencies, alcoholism, autoimmune diseases, certain medications, trauma, unknown causes, and diabetes. When your peripheral nerves become damaged, they do not function properly, and can eventually produce symptoms of pain, tingling, or numbness. The syndromes that may benefit from peripheral nerve or field stimulation include:

  • Complex Regional Pain Syndrome
  • Diabetic Peripheral Neuropathy
  • Lateral Femoral Cutaneous Neuropathy
  • Back and Neck Pain
  • Post-Surgical Pain
  • Occipital Neuralgia
  • Trigeminal Neuralgia
  • Traumatic Nerve Injuries
  • Peripheral Vascular Disease Neuropathy
  • Post-Amputation Pain
  • Herpetic Neuralgia
  • Trigeminal Neuralgia
  • Reflex Sympathetic Dystrophy (RSD)
  • Complex Regional Pain Syndrome (CRPS)
  • Refractory Angina
  • Other conditions that have failed conventional therapies.


Peripheral Nerve or Field Stimulation uses an innovative technology that works by introducing an electrical current to the source of chronic pain. Under local anesthetic (numbing agent) and IV sedation your pain physician will place a stimulator lead along the painful nerves. Patients typically undergo a trial for seven days to see if they feel better and have increased activity with the device. If pain improves, a permanent electrode and battery can be placed. If the permanent device is in place, soft thin wires with electrical leads on their tips are placed through a needle under the skin. A small incision is made and the battery is placed under the skin. This device is turned on and releases electrical stimulation to the affected nerves. You pain will be replaced by a tingle instead of the pain originally felt. The entire procedure takes less than a couple of hours to complete, and is done as an outpatient. The stimulator is so small that you can wear bathing suits and continue normal activities without an inconvenience. The stimulator is not visible and lies under the skin. It is a self-contained system much like a pace-maker.


The implanted device produces a low voltage current which creates a sensation that blocks the brain’s ability to sense the pain. It interferes with the perception of pain by creating a pleasant sensation that replaces the pain. The intensity of the stimulator can be changed, and the system can be turned on and off as necessary to provide optimal pain relief as experienced by the patient. Treatment of chronic neuropathic pain in the region of the face, neck, and head are challenging for pain specialists to treat. The pain is typically refractory, meaning difficult and not responsive, to many of the conventional treatment options. Recently peripheral nerve stimulation has become increasing common in difficult-to-treat neuropathic facial pain.


Most peripheral nerve stimulation procedures are performed on an outpatient basis. As expected with any surgical procedure, there are potential risks. Side effects that may occur include bleeding, infection, scar tissue, electrode failure, inadequate pain surface area coverage, and nerve damage. While the incision is healing it is important to keep it dry and clean so an infection does not occur. If there is any drainage or redness at the site then you may have developed an infection and your pain specialist must evaluate you. Patients with the following conditions should not receive peripheral nerve stimulation and should talk to their pain specialist about other options:

  • Cardiac pacemaker
  • Systemic infection
  • Pregnancy or lactating


Peripheral nerve stimulation is reported to be an effective pain treatment because it inhibits the perception of pain by the brain, and pain from the peripheral nervous system (Ristic 2007). In a medical study of people receiving peripheral nerve stimulation treatment for craniofacial pain, three out of four of the patients experienced significant improvement in pain intensity (Konstantin 2006). With the improvement of pain symptoms after treatment, you may be able to decrease pain medications and increase your daily activities. The number of centers using peripheral nerve stimulation for craniofacial pain and other peripheral nerve syndromes is increasing. In the future there will be a wider acceptance of this treatment because it is minimally invasive, can be tested, is reversible in effect, and has adjustable settings. These unique qualities may eventually make peripheral nerve stimulation the preferred treatment for otherwise unresponsive conditions (Konstantin 2006). Peripheral nerve stimulation can be very effective in reducing chronic pain from certain painful conditions, however it does not work for everyone. A trial with a temporary device is usually done before you have a permanent device placed, which ensures good response to therapy. For those that it does help it is an innovative treatment that brings significant relief. You should contact Arizona Pain Specialists now to speak with a physician to see if this treatment can benefit you. We are happy to offer this service as a pain management tool for patients in the Phoenix area.

Journal Articles:

Adam Sewell MD


Percutaneous Discectomy, also known as Dekompressor (Stryker) is a non-percutaneous-discectomysurgical effective treatment for back and neck pain associated with herniated disc disease. The pain relief associated with this therapy is due to taking the pressure off of the spinal discs and facet joints. This reduces the pressure exerted onto the spinal cord and nerve roots, which is causing the pain (Boswell 2007). Separating each individual spinal vertebrae are discs that act as cushions to minimize the impact that the spinal column receives. Since the discs are designed to be soft and provide support, they have a tendency to herniate (bulge) backwards through the outer disc segment and ligaments. These bulging discs can cause irritation to the adjacent nerves. Disc disease is one of the most common causes of chronic neck and back pain and accounts for approximately 10% of all lower back pain complaints. Disc disease may be acute, it may be herniation resulting from trauma, or more commonly, from chronic disease. Degenerative disc disease is a process, which is due to a thinning and degeneration of the discs over time. Commonly seen, neck and back pain may go into painless remission with periods of decreased or absent symptoms, however, the pain often returns causing a chronic pain syndrome. If your pain has lasted longer than four weeks or is severe in nature you should see a pain specialist about treatment options. Ongoing research has hinted that early intervention decreases the incidence of developing chronic pain. Decompression therapy is often considered when the pain has not improved after a month and is radiating, resulting from irritation of the nerve roots.


Percutaneous Discectomy uses a single-use probe called the “Stryker Dekompressor,” which is placed using X-Ray guidance. You will be pre-treated with a sedative that will help you to relax, but you will remain awake for the procedure. Before the treatment begins, you will be comfortably positioned on your stomach, with your knees supported on the table. Your physician will inject a local anesthetic with a small needle to numb the area. Once the area is numb, a larger needle is placed into the affected disc with X-Ray guidance. The probe is placed through this needle and the procedure is initiated. You may feel pressure during this part of the procedure, but should not experience pain. The Dekompressor uses a pump method to remove excessive disc material from bulging or contained herniated discs, thus reducing pressure in the disc and providing pain relief.


A discectomy using the Dekompressor is a lower-risk treatment option for neck and back pain. The procedure may decrease pain, increase mobility, and eliminate the need for traditional surgery. This treatment is designed to correct the underlying problem, not just relieve the symptoms. The procedure is a minimally invasive procedure that causes much less scarring and fibrosis that is commonly associated with other interventions. A study reported in 2007  stated that “discectomy is minimally invasive, safe and effective for treating disc herniations and that 89% of patients treated by this method stated they achieved successful outcomes from the therapy“ (Tzaan 2007).


As with all medications and surgical procedures, there is always a risk of complications. With lower risks than traditional back surgery, discectomy is considered an appropriate treatment for many patients who suffer from back pain (Boswell 2007). The most common complaint is mild back pain at the injection site shortly after the procedure. Other more serious and far less common complications include spinal cord compression, excessive intracranial pressure, bleeding, hematoma, or infection. These particular risks are decreased by the use of X-Ray and sterile technique.


The American Society of Interventional Pain Physicians developed a large evidence-based practice guideline for the management of chronic spinal pain with interventional techniques. The 2007 article stated that for percutaneous discectomy using the Dekompressor resulted in greater than 70% improvement in pain in 79% of patients undergoing the treatment for postero-lateral disc herniations. (Boswell 2007). The reduction in pain allows patients to experience enough relief to become active again. Often patients regain the ability to resume their normal daily activities. If you are suffering from chronic back or neck pain contact Arizona Pain Specialists today to see if you can benefit from this advanced treatment.

Journal Articles

Adam Sewell MD


Performed By Top Pain Management Doctors in Fort Smith, Arkansas 


Just beneath the scalp, in the back of the head, are the greater and lesser occipital nerves. The greater nerve arises through the top two vertebrae, the cervical vertebrae, and comes from the cervical nerve root deep into the paraspinous musculature (literally, muscles next to the spine). The nerve comes closer to the surface just below the superior nuchal line (muscular line that divides the back of the skull). It goes next to the occipital protuberance of the skull, which is next to the occipital artery. Basically, the nerve starts in the top vertebrae, and goes up towards the surface near the mid-line of the back of the skull.

The lesser occipital nerve arises through the second and third cervical nerve roots in the upper vertebrae. It travels through the cervical paraspinous musculature (muscles next to the spine), and comes close to the surface over the inferior nuchal line of the skull (muscular line that divides the back of the skull). Basically, the nerve starts in the top vertebrae and goes up towards the surface near the lower line that divides the back of the skull.

These two nerves, the greater and lesser, help give sensation to the back of the scalp. These nerves are commonly involved in patients suffering from Cervicogenic headaches and Occipital Neuralgia.


Essentially an Occipital Nerve block is the numbing of the greater and lesser occipital nerve. The block is an injection composed of an anesthetic and a corticosteroid next to the greater and lesser occipital nerves. It is most often used in the diagnosis and treatment of Occipital Neuralgia and Cervicogenic headaches (Afridi 2006). Occipital Neuralgia will typically follow a trauma to the nerves over the occiput (back of the head) and is characterized by an acute onset of pain in the the occipital nerves.  A Cervicogenic headache is more chronic, it comes on slowly. It is characterized by pain in the same area. Most patients with Cervicogenic headaches have associated spondylosis, or problems of the cervical facet joints in the neck, and therefore may need an additional block in the cervical facet joint to completely alleviate their symptoms. In one medical study, a group of people suffering from Cervicogenic headaches was split into two categories, one of which received the Occipital Nerve Block. The study found that the taking of pain relievers such as aspirin, duration of headache and its frequency, nausea and vomiting, light and sound sensitivity, decreased appetite, and limitations in functional activities were significantly less in the blocked group compared to control group. In other words, the people who had the Occipital Block fared better in all areas than their counterparts who did not have the block.  The study therefore concluded “the nerve stimulator-guided occipital nerve blockade significantly relieved cervicogenic headache and associated symptoms at two weeks following injection.” (Naja 2006).

The procedure involves inserting a small fine needle through the skin beneath the scalp in order to get the anesthetic and corticosteroids around the area of the nerve. In order to minimize this discomfort your pain specialist may numb the skin in the injection area with an even smaller needle with a local anesthetic before inserting the block needle. The injection blocks both the greater and lesser occipital nerves. There are two major benefits to using this block. Not only is it useful in treating Occipital Neuralgia, relieving or reducing pain in the back of the head in the scalp, but if symptoms improve after the injection then the block is also useful in diagnosing Occipital Neuralgia. Typically if you respond well to the injection and have pain relief then it is recommended that you return and receive repeat injections. Usually, a series of block injections is needed to treat the problem adequately, however the response to the block varies from patient to patient. Also, if you respond well to the Occipital Nerve block then you will most likely benefit even more with the addition of Occipital Nerve Stimulation. A 2006 study reported that if a patient receives repeated nerve stimulator guided Occipital Nerve blockade for the treatment of Cervicogenic headache, the patients experienced significant reduction of symptoms with no recurrence for at least six months in addition to alleviation of associated symptoms. Eighty-seven (87%) of the patients who experienced relief required more than one injection to achieve a six-month period of pain relief (Naja 2006).


Occipital Nerve Block injections are considered safe, however, with every procedure there are associated risks, side effects, and possible complications. With nerve blocks in general, the most common is the superficial pain from the scalp where the needle was inserted. This pain comes after the local anesthetic wears off, but this pain is temporary and typically mild. Another frequently seen occurrence is bleeding, since the scalp is highly vascular (there is an abundance of tiny blood vessels near the surface of the skin). Bleeding is common but is easily stopped and temporary. This risk is significantly reduced if ice is placed at the injection site immediately after the procedure. The other less common risks involve excessive bleeding, infection, and nerve damage. Patients with an allergy to any of the anesthetics used, are on blood thinning medications, have an active infection, or are pregnant should consult with your pain physician before receiving the procedure.

Journal Articles

Adam Sewell MD


Performed By Top Pain Management Doctors in Fort Smith, Arkansas 

Description of Procedure

The facet joints are the small joints that help stabilize each vertebrae. Medial Branch pain is inflammation arising from the facet joints. There are even smaller nerves stimulating the facets of the spine.  When these nerves are inflamed and irritated, signals of pain are sent to the brain. This is a common cause of mid-to-lower back and neck pain. A procedure that has become more popular is called a Medial Branch Block (MBB). An MBB temporarily reduces or stops those pain signals from reaching the brain.

An MBB is a medical (nerve) block.  It is an injection that disrupts pain and keeps those impulses from reaching the brain. A nerve block helps diagnose the source of a patient’s pain. It may provide temporary relief, and is often used to determine the outcome of a surgery that is meant to permanently block the activity of certain nerves.

When oral medications and physical therapy fail to work, it is often recommended that the patient receive an MBB for facet joint related pain. Medial branch nerves near the facet joints are responsible for small muscles in the neck, mid and lower back. These nerves often cause chronic neck and lower back pain, in addition to having the brain misinterpret the source of the pain and cause referred head pain.

MBB is a minimally invasive treatment and is commonly used to treat lower back pain. The facet joints that are located around the groove of the lower back are called the Lumbosacral medial branch nerves. These nerves are often associated with lower back pain. Up to 45% of patients suffering from lower back pain have inflammation or irritation of their facet joints (Boswell et al, 2007). In one clinical study, 57 patients with lower back pain were given an MBB. After eight weeks, 30 of those patients had relief. Upon reevaluation six months after the initial injection, the number of patients who had relief increased to 39 (Anand et al, 2007).

MBB is also used to treat neck pain.  There are cervical facet joints that are located at the back or side of the head. There has been a recent study that states that up to 67% of patients suffering from head and neck pain can attribute that pain to irritated or inflamed facet joints (Boswell et al, 2007).


MBB treatment is minimally invasive. It gives relief immediately. It is a non-surgical injection that takes an average of 15 to 30 minutes to perform.

After being numbed with a local anesthetic, the site of the MBB is injected with a long-lasting steroid and a local anesthetic. This injection is guided by a live X-Ray (fluoroscopy). This type of injection uses the anesthetic to numb the medial nerve branch. The impulses that caused so much pain are blocked. The steroid reduces inflammation and irritation. It is important for the patient to rest for 20-30 minutes after the injection (Baker). This treatment is considered a success if the patient has a significant decrease in pain. The MBB may be repeated at least two months after the initial injection.  Patients should not receive more than six per year (Manchikanti et all).

When using the MBB to diagnose, patients should not receive more than four injections per year (Manchikanti et al). When the MBB is successful, the patient may be a candidate for radiofrequency ablation, which is a longer-lasting treatment for pain management (Baker). Radiofrequency ablation uses heat to deaden a nerve. This heat is produced by electric currents (RF currents) and creates a lesion on the nerve. This prevents pain signals from reaching the brain.


One of the greatest benefits of having MBBs are that not only do they relieve pain immediately, they are low-risk and minimally invasive. They are very effective with prognostic and diagnostic treatment (Manchikanti et al). Traditional therapy is not very effective when trying to diagnose lumbar and cervical facet joint pain. MBBs have greatly improved diagnosing whether or not the facet joints are causing the patient’s pain. The American Society of Interventional Pain Physicians created a guideline for chronic spinal pain management. They specifically stated that MBBs are extremely beneficial for diagnosing lumbar and cervical facet joint pain (Boswell et al, 2007).

When used as a pain management procedure, an MBB provides pain relief very rapidly. This pain relief will often last from one month up to a year (Boswell et al, 2007). The patient may also be a candidate for radiofrequency ablation if the MBBs are successful.


MBBs are considered a safe procedure, but as with all medical procedures there are associated risks, possible side effects and complications that vary with each patient.

Pain at injection site. The patient might experience tenderness at the injection area for a short period of time as the local anesthetic wears off.

Minor infection. In less than 1% to 2% of patients, minor infections occur.

Increased pain. The patient might experience a worsening of pain symptoms.

Excessive bleeding, or infection. The patient might suffer excessive bleeding, infection and nerve damage as a result of undergoing an MBB treatment while on blood thinning medications, pregnant, allergic to any of the anesthetics used or they have an active infection.

Nerve or spinal cord damage. Very rarely, a patient suffers from nerve or spinal cord damage or paralysis resulting from direct trauma from the needle, from an infection, bleeding resulting in compression or injection into an artery causing blockage (Baker).


When a patient suffers from chronic neck, back and lower back pain, the Medial Branch Block is a very effective treatment for management of that pain. Not only does relief take place very quickly, MBBs are excellent tools that may be used in the prognosis and diagnosis of the patient’s pain. They will also determine if radiofrequency ablation is a worthwhile treatment. Having an MBB is a very low-risk procedure, with very little recovery time. This makes this a very popular pain management solution.


Adam Sewell MD


Performed by top pain management doctors in Fort Smith, Arkansas.

Kyphoplasty, which is very similar to Vertebroplasty, is a minimally-invasive procedure that is designed to help people suffering from severe back pain most likely caused by cracked, fractured, compressed or collapsed vertebrae. Kyphoplasty is a surgical procedure that is used when other treatments fail to relieve pain.  (DeNegri 2007.)


The backbone consists of individual bony structures called vertebrae that interlock together to give strength and structure to the spine.  These vertebrae allow us to move and also protect the spinal cord. The vertebrae may develop fractures, compress or collapse. Bone fragments may then irritate the nerves of the spine or the spinal cord.

Conditions commonly treated with Kyphoplasty and Vertebroplasty include:

  • Osteoporosis
  • Trauma or Injury
  • Bone cancer metastasis


The patient lies on his or her stomach.  After the back is sterilized, a local numbing cream is applied. The patient may also take sedatives in order to relax. An X-Ray or other such guiding machine is used to ensure correct placement of small needles that are carefully placed into the vertebral body.

In balloon-assisted Vertebroplasty, a strong inflatable balloon is inserted through a tube in into the vertebral body.

The small balloon is slowly inflated. The balloon fills the center of the vertebrae. Using low pressure, the balloon later is filled using special bone cement.


Kyphosis is a condition that is known to give the patient a pronounced curve or hump on his or her upper back. The most common cause is from compressed fractures of the vertebrae. Severe Kyphosis may cause debilitating pain and is a serious medical condition.

The benefits of having Kyphoplasty is that one’s height may be restored, pain is relieved and vertical alignment is improved. In a 2006 study, after having this procedure, 80% of patients recovered their height. 90.7% of patients had fracture improvement.  (Shindle 2006). If height recovery is a goal, then the Kyphoplasty procedure may have some added benefits from Vertebroplasty.


Kyphoplasty is considered a generally safe procedure. There are some risks, but it is considered appropriate to alleviate the pain of vertebral compressed fractures. The potential risks include the slight chance that there may be cement leakage out of the vertebral body. Serious complications are rare; but may include: infection, bleeding, numbness, tingling, headache, and paralysis from improper placement of the needle or cement. The risk of improper needle placement is decreased by using an imaging device, during the procedure.

Studies have shown that Kyphoplasty is a very safe treatment for debilitating and painful fractures of the vertebra, with only rarely having complications. (DaFonseca 2006)(Hiwatashi 2007).


Kyphoplasty and Vertebroplasty are procedures that have significant benefits to those suffering the severe pain of Kyphosis. Patients experience immediate relief, improved movement and mobility, and 95% of patients reporting partial or complete pain relief (Hiwatashi 2007).

Fracture Prevention

Good general health is the best prevention; and includes a balanced diet, regular exercise, weight lifting, calcium and vitamin D supplements. Bisphosphonates medications (Aredia and Fosamax) for Osteoporosis treatment may prevent future compression fractures. These types of medications improve bone strength and bone density. Individuals with compression fractures may be good candidates for proven minimally invasive, including Kyphoplasty (Old 2004).

There is a guideline available to people who experience chronic spinal pain that was written by the American Society of Interventional Pain Physicians. It is a practice guideline for management with surgical techniques. The evidence suggests that vertebral augmentation procedures such as Kyphoplasty and Vertebroplasty give relief (Boswell 2007).

For more information about Kyphoplasty or Vertebroplasty, or other items mentioned, please see your pain physician.

Resources/Journal Articles:

Adam Sewell MD


Intrathecal Pumps (ITPs) are devices used in the treatment of many chronic pain states. The pumps have shown effective in treating cancer pain, severe back pain, neuropathic pain, and muscle spasticity. ITPs are an automated piece of equipment that are programmed to deliver medication into the spinal fluid through a small catheter. This exciting pain relief technique has been shown to be both safe and effective

The purpose of the pump is to interrupt pain signals that travel through the spinal cord. Pain signals which normally travel to the brain are lessened and pain relief is perceived. Medication is delivered into the intrathecal space surrounding the spinal cord. The ITP delivers pain medication directly to the pain receptors in the spinal cord and smaller doses of medication are required to gain relief.

ITP implants are considered when oral pain medications and other methods of pain control have been exhausted or proven ineffective.


Before an ITP is placed, an intrathecal medication trial is performed. Medication is placed in the spinal fluid. If pain relief is adequate, an ITP can be permanently placed to control your pain.

Placement of the ITP can be performed in an outpatient setting or in the hospital. The implantation of the device is done with local anesthesia and sedation (general anesthesia is usually not required). After a sterile scrub, local anesthesia is used to numb the needle entry location. Once the area is numb, a larger needle and catheter are placed into the intrathecal space using x-ray guidance.

Once the catheter is in the proper location, the pump is then connected and placed under the skin on the lower part of your abdomen. The catheter and pump are tunneled under your skin and all wounds are surgically closed.

The pump delivers pain medication (opiates, local anesthetics, and/or muscle relaxants) directly into the intrathecal space around the spinal cord. The medication reservoir in the pump is refilled periodically (every four to six weeks) by your pain physician by injecting the medication through your skin into the pump.

The entire procedure typically takes one to two hours and may be performed on an outpatient or in-patient basis.


ITPs can be used to treat a variety of painful conditions. Nociceptive pain, or pain from tissue irritation can usually be effectively treated with uploads like morphine. Nociceptive pain transmission is interrupted at the spinal cord and pain relief is experienced.

Neuropathic pain, peripheral or central nervous system pain, tends to be receptive to treatments with local anesthetics more than opioids. Examples of neuropathic pain syndromes include CRPS (complex regional pain syndrome or reflex sympathetic dystrophy), cancer pain, phantom limb pain, post herpetic neuralgia (shingles), carpal tunnel syndrome, failed back surgery syndrome, and peripheral neuropathy (Diabetes Mellitus, vitamin deficiencies).

Spasmodic pain can also be successfully treated by ITPs. This type of pain is effectively treated with anti-spastic muscle-relaxing medications like Baclofen. Spasticity may be caused by impairment in the brain or spinal cord and is seen in several conditions, such as stroke, brain injury, spinal cord injury, cerebral palsy, and multiple sclerosis (Rawlins 2004). Spasticity is an abnormal increase in muscle tone and tightening of the muscles.


Intrathecal pump implants are effective and safe devices used for pain management. The complications associated with implants are mostly pharmacological and transient (Kamran). Some of the common side effects due to the medications that are dispersed through the pump are:

  • Nausea & Vomiting
  • Itching
  • Weakness
  • Facial flushing
  • Constipation
  • Sleepiness
  • Respiratory Depression

More serious complications that can ensue are:

  • Hematoma
  • Bleeding
  • Infection
  • Infection/Meningitis
  • Catheter malfunction

ITP implants are considered an appropriate treatment for many patients who suffer from chronic difficult to control pain. As with any medication taken, there are always risks and potential side effects that may occur. All patients receiving a pump implant should be evaluated by their physician and risks of ITPs should be discussed.


A large clinical study involving twenty four European centers showed that intrathecal pump implant therapy is clinically effective, well tolerated and may offer improvements in pain relief and function. Muscle tone, spasm levels, and pain intensity reductions were observed. Also cognition and motor function showed improvements (Guillaume 2005).

Intrathecal Baclofen therapy is considered safe and so effective that it has evolved into the standard treatment for severe spasticity (Rawlins 2004). Most patients and caregivers express satisfaction with the therapy and would recommend it to other patients. Spasm frequency appears to be the single most common variable positively affected by therapy (Vender 2006). Another study showed excellent long term efficacy in the treatment of lower extremity spasticity (Ethans 2007).

Another study observed the effects of intrathecal Morphine when delivered to patients with painful cancer. In this study all patients and their families reported an improved quality of life with an increased level of activity, and it was deemed “efficacious and safe” (Gilmer-Hill 1999). Another benefit with ITPs in terminal cancer is that continuous intrathecal narcotic infusion is a very effective method to control terminal cancer pain and enables treatment in an outpatient setting (Motsch 1988).

Pain can be a debilitating condition physically, as well as emotionally. ITPs can dramatically help those with painful conditions that are unrelieved by other therapies. Call Arkansas Pain today and see what they can do to relieve your pain.

Journal Articles:

Adam Sewell MD


IDET therapy is a relatively new technique for the treatment of back pain that originates from the intervertebral discs. IDET essentially is administered by inserting a probe into the irritated disc and applying heat to it through a catheter. This causes the collagen in the disc to thicken and change form, destroying painful nerves located nearby the disc (Wang 2005).

The spine is positioned so that individual vertebrae (bones of the spine) provide a flexible support structure for the spinal cord. Separating individual vertebrae, are discs that act as cushions that absorb the physical impact that the spinal column receives. These are not as firm as the surrounding bone and have a tendency to herniate backwards through the outer segment. This can cause irritation to adjacent nerves. Discs are made of concentric layers of collagen, one on top of the other. Sometimes, the layers tear, and disc material can leak outside of the disk. This causes nerve irritation. Small pain fibers can grow inside discs, causing pain, and even simple everyday activities can become impossible to complete. Disk disease is one of the most common causes of chronic back pain in the world, and it accounts for approximately 10% of all low back pain complaints.


The IDET (intradiscal Electro-Thermal) Annuloplasty, is an innovative technology that generates heat in order to destroy the painful nerves that are causing you low back pain. The procedure uses only a local anesthetic (numbing agent) and a sedative. Using a small needle, your pain physician will inject the area with a local anesthetic, first, to numb the area. When numbness is achieved, a larger needle is placed in the affected disc, and a catheter is advanced to the inside of the disc using x-ray guidance.

The procedure lasts less than an hour and is done on an outpatient basis. After the procedure is completed, the catheter and needle are removed and a small bandage is placed over the needle insertion site.


Discogenic pain (pain caused by the disc) is an extremely common cause for back pain complaint. IDET therapy has several advantages over other disogenic pain treatments. It is minimally invasive, has a high success rate, requires no hospitalization, and is performed under a local anesthetic rather than general. Additionally, there is hardly any post-procedure discomfort, and normal activities are quickly resumed. Another advantage to IDET is that this is a highly controlled procedure, making the risk of damaging adjacent structures, very slim. Most often, IDET provides immediate, long lasting relief, but if it doesn’t, it can be repeated as many times as are needed to achieve proper pain relief.


As with all medications and surgical procedures, there is risk. However, the risks presented by IDET are very minimal. It is considered an appropriate treatment for many patients who suffer from back pain. The most common complaint is mild irritation at the needle site after the procedure anesthetic has worn off, as there is with any procedure utilizing needles. Other, more serious and far less common, complications include: Bleeding, nerve damage, or infection. Many of these risks are decreased with proper sterilization, temporarily stopping any blood-thinning medications, and using x-ray guidance during the procedure.


Although there are many surgical, and other, options for back pain, the most commonly recommended methods are conservative ones. These methods include interventional procedures, medications, physical therapy, cognitive behavioral therapy, biofeedback, diet, exercise, and many other alternative techniques and procedures (Manchikanti 2007). Sometimes, a patient’s back pain is so intense and unrelenting, that more advanced interventions like the IDET are required to control pain.

In a large study, patients that had low back pain for, at least, three months, and failed to respond to conservative care, responded well to IDET. The patients demonstrated an increase in physical function and decreased levels of back pain. The study concluded that pain resulting from disc disease may, not only be reduced, but be ended by IDET (Wetzel 2002). This is an extremely encouraging news for people dealing with chronic back pain and, more specifically, disc-related pain. IDET provides, both, temporary and long-term pain relief.


Adam Sewell MD


Performed by top Pain Management doctors in Merritt Island & Melbourne, Arkansas

A ganglion impar block is an excellent treatment for chronic, neuropathic perineal pain from visceral and/or sympathetic pain syndromes, especially if they arise due to malignancy.

If you have vague, perineal pain that is hard to pinpoint, and is frequently accompanied by sensations of burning or urgency, you may benefit from a gangliar impar block. However, since the symptoms of burning and urgency, especially if their associated with urination or defecation, may be due to a secondary medical issue, it is imperative that you, first, consult your general practitioner to make certain you are not experiencing perineal area pain from one of these other causes.

Since the ganglion impar receives afferent pain fibers from the perineum, distal rectum, anus, distal urethra, vulva, and distal third of the vagina, this block has the potential to alleviate pain that originates from the regions mentioned above. The most recent literature shows that ganglion impar blocks have, also, been used successfully to treat non-malignancy-associated perineal pain from various conditions, including sacral post herpetic neuralgia, spinal cord malformations, and failed back surgery syndrome, etc… Emerging evidence also suggests that, due to its sympathetic nerve irritation, a ganglion impar block may provide relief to patients with perineal hyperhidrosis (excessive sweating).

Perineal Pain originating from:

  • Perineum
  • Distal rectum
  • Anus
  • Distal urethra
  • Vulva
  • Distal third of the vagina

Perineal Pain secondary to:

  • Cancer that metastasized to perineum (cervical, prostate, testicular, colorectal etc.)
  • Sacral post herpetic neuralgia
  • Postsurgical thrombosis of perineal veins
  • Spinal cord malformations
  • Vaginal protrusion
  • Failed back surgery syndrome
  • Testicular ablation


  • Perineal hyperhidrosis


The ganglion impar is the only unpaired autonomic ganglion in the body. It marks the end of two sympathetic chains. It is located in front of the sacrococcygeal joint in the retro peritoneum. However, research has revealed that the location, shape, and size of the ganglion impar are variable (Oh et al. 2004). After performing anatomical dissections on 50 sacra and coccyges, it has been discovered, that the location of the ganglion impar can range from the sacrococcygeal junction to approximately 10mm in front of the tip of the coccyx. The majority of the ganglia impar are located approximately 25-30mm in front of the tip of the coccyx .This anatomical variation may contribute to the possible inefficacy of the ganglion impar nerve block in some patients.

The ganglion impar receives pointed pain fibers from the perineum, distal rectum, anus, distal urethra, vulva, and distal third of the vagina. This block can potentially alleviate pain originating from the above mentioned regions. The impar ganglion’s postganglionic fibers pass along the gray rami communicantes to the sacral and coccygeal spinal nerves.


Since its first implementation, via the horizontal approach, researchers continue to introduce modified techniques that attempt to maximize the ease of performing this block, while maintaining patient safety and increasing the chance of maximal pain alleviation for their patients (Plancarte et al. 1990).

Some of these modified techniques include: techniques using fluoroscopic guidance or ultrasound guidance, approaches using the transsacrococcygeal ligament approach, the transcoccygeal joint approach, the paramedial approach, the paracoccygeal corkscrew approach, and using a curved needle technique, or needle-inside-needle technique. Of the many approaches, the transsacrococcygeal approach remains the most popular.

With this technique, your lower back and intergluteal cleft and will be prepped and sterilized before local anesthesia is administered. When your skin is adequately anesthetized, the needle will be advanced under fluoroscopy guidance. This will give the physician correct needle placement. Its correct placement will also be confirmed by a contrast dye. Once positioned properly, either a diagnostic block (to determine if your perineal pain is visceral or somatic), or a therapeutic block, will be performed. When profound pain relief has been achieved, the block is considered successful.

Local anesthetic is usually administered for diagnostic ganglion impar blocks. This is the same for patients that do not have cancer-related pain. For patients who have a documented response to the administration of local anesthetic onto the ganglion impar, a therapeutic block is administered with a neurolytic agent like phenol. Radioablation of the ganglion impar is another treatment that can offer longer-lasting pain relief.

The procedure usually takes less than 15 minutes. Your physician will, sometimes, recommend intravenous sedation to make the procedure more comfortable. Your physician will monitor your pain, and vital signs (pulse, blood pressure, temperature) during and after the procedure.


Ganglion impar block is a short, minimally invasive procedure treating, neuropathic perineal pain from visceral and sympathetic pain syndromes. This is especially true if they are secondary to malignancy. Published literature also highlights significant pain relief. This can also be achieved if the pain is of nonmalignant origin and originates from one of the organs, sending afferent fibers to the ganglion impar.


There are very few risks associated with this procedure. In fact, current literature doesn’t note any major complications reported from this block (Plancarte, et al. 1993). Only one case of epidural contrast spread within the caudal canal. However, needle repositioning quickly resolved the problem without any harm to the patient (Plancarte et al. 1990).

Despite these published statistics, the theoretical risk of this procedure exists and includes: Bleeding with needle displacement, especially into your retroperitoneal space, nerve injury and/or paralysis, puncture of surrounding organs (including rectum) and puncture of adjacent vessels. Risks resulting from the anesthetic include – drug allergy and seizure (if the medication is injected into a blood vessel). Additionally, there always exists a risk of infection with any penetration of skin and soft tissues.

Finally, due to where the impar ganglion is situated, an ineffective block is, also, a risk in some patients. If no relief is obtained after your physician has placed the block through the transsacrococcygeal approach, he or she may decide on another approach to best accommodate your anatomy (transcoccygeal joint approach, paramedial approach etc.)


Ganglion impar block is an excellent treatment for chronic, neuropathic perineal pain from visceral and sympathetic pain syndromes stemming from malignancy.

In 1990, Plancarte et al. not only described the ganglion impar technique, but also demonstrated its helpful results in cancer patients. Patients with advanced cancer (cervical, endometrial, bladder, colon, and rectal) with perineal involvement, who had little response with pharmacotherapy, received a neurolytic ganglion impar block. After the block, nearly eight patients experienced total relief of pain, and the remaining patients reported a 60-90% reduction in their pain.

Agarwal-Kozlowski et al. (2009) evaluated the efficacy of the ganglion impar block on various types of perineal pain (including malignancy, post-surgical thrombosis of perineal veins, postherpetic neuralgia, spinal cord malformations, vaginal protrusion, failed back surgery syndrome, testicular ablation, and what was deemed as perineal pain of unknown origin) in 43 patients. Many of the patients reported immediate and lasting pain relief through the 4-month follow up. This success has continued through subsequent patient observation and experiences.

For some people, the benefits of a ganglion impar block can be temporary, and the extent and duration of pain relief can vary from person to person. Some tend to have relief for weeks, while others, experience a complete remission of pain for years at a time.  Fortunately, this is a low risk procedure, and if the first attempt is not successful, it can be repeated.

If you are suffering with chronic perineal pain or pain that you or physician believe is originating from the perineum, distal rectum, anus, distal urethra, vulva, and distal third of the vagina, the ganglion impar block may be an excellent alternative treatment for you.

Journal Articles:

  1. Agarwal-Kozlowski K, Lorke DE, Habermann CR, Am Esch JS, Beck H. CT-guided blocks and neuroablation of the ganglion impar (Walther) in perineal pain: anatomy, technique, safety, and efficacy. Clin J Pain. 2009 Sep;25(7):570-6.
  2. Başağan Moğol E, Türker G, Kelebek Girgin N, Uçkunkaya N, Sahin S. [Blockade of ganglion impar through sacrococcygeal junction for cancer-related pelvic pain] Agri. 2004 Oct;16(4):48-53.
    de Leon-Casasola OA. Critical evaluation of chemical neurolysis of the sympathetic axis for cancer pain. Cancer Control. 2000 Mar-Apr;7(2):142-8.
  3. Eker HE, Cok OY, Kocum A, Acil M, Turkoz A. Transsacrococcygeal approach to ganglion impar for pelvic cancer pain: a report of 3 cases. Reg Anesth Pain Med. 2008 Jul-Aug;33(4):381-2.
    Foye PM, Patel SI. Paracoccygeal corkscrew approach to ganglion impar injections for tailbone pain. Pain Pract. 2009 Jul-Aug;9(4):317-21. Epub 2009 May 29.
  4. Foye PM. New approaches to ganglion impar blocks via coccygeal joints. Reg Anesth Pain Med 2007; 32:269.
  5. Foye PM, Buttaci CJ, Stitik TP, Yonclas PP. Successful injection for coccyx pain. Am J Phys Med Rehabil 2006; 85:783-784.
  6. Gupta D, Jain R, Mishra S, Kumar S, Thulkar S, Bhatnagar S. Ultrasonography reinvents the originally described technique for ganglion impar neurolysis in perianal cancer pain. Anesth Analg. 2008 Oct;107(4):1390-2.
  7. Hong JH, Jang HS. Block of the ganglion impar using a coccygeal joint approach. Reg Anesth Pain Med. 2006 Nov-Dec;31(6):583-4.
  8. Kabbara AI. Transsacrococcygeal ganglion impar block for postherpetic neuralgia. Anesthesiology. 2005 Jul;103(1):211-2.
  9. Kim ST, Ryu SJ. Treatment of Hyperhidrosis Occurring during Hemodialysis: Ganglion Impar Block: A case report. Korean J Anesthesiol. 2005 May;48(5):553-556.
  10. Kuthuru M, Kabbara AI, Oldenburg P, Rosenberg SK: Coccygeal pain relief after transsacrococcygeal block of the ganglion impar under fluoroscopy: A case report. Arch Phys Med Rehabil 2003; 84:E24.
  11. Loev M, Varklet VL, Wilsey BL, Ferrante M: Cryoablation: A novel approach to neurolysis of the ganglion impar. Anesthesiology 1998; 88:1391–3.
  12. McAllister RK. Paramedial approach to the ganglion impar. Reg Anesth Pain Med. 2007 Jul-Aug;32(4):367.
  13. McAllister RK, Carpentier BW, Malkuch G: Sacral postherpetic neuralgia and successful treatment using a paramedial approach to the ganglion impar. Anesthesiology 2004; 101:1472-4
  14. Munir MA, Zhang J, Ahmad M. A modified needle in needle technique for the ganglion impar block. Can J Anaesth 2004;51:915-917.
  15. Nebab EG, Florence IM: An alternative needle geometry for interruption of the ganglion impar. Anesthesiology 1997; 86:1213–4.
  16. Oh CS, Chung IH, Ji HJ, et al. Clinical implications of topographic anatomy on the ganglion Impar. Anesthesiology. 2004;101:249–250.
  17. Plancarte R, Velazquez R, Patt RB: Neurolytic blocks of the sympathetic axis. In Patt RB (ed): Cancer Pain. Philadelphia, Lippincott-Raven, 1993, pp 419-442.
  18. Plancarte R, Amescua C, Patt RB: Presacral blockade of the ganglion of Walther (ganglion impar). Anesthesiology 1990; 73: A751.
  19. Reig E, Abejón D, del Pozo C, Insausti J, Contreras R. Thermocoagulation of the ganglion impar or ganglion of Walther: description of a modified approach. Preliminary results in chronic, nononcological pain. Pain Pract. 2005 Jun;5(2):103-10.
  20. Toshniwal GR, Dureja GP, Prashanth SM. Transsacrococcygeal approach to ganglion impar block for management of chronic perineal pain: a prospective observational study. Pain Physician. 2007 Sep;10(5):661-6.
  21. Wemm JR, K, Saberski L: Modified approach to block the ganglion impar (ganglion of Walther) (letter). Reg Anesth 1995; 20:544–5.