Below is a list of some frequently asked questions, but please feel free to contact us if you need additional information. We are always pleased to assist you.
Facet Injection and Nerve Root Blocks
Spinal procedures include myelograms, discograms, and facet injections. These procedures are performed to diagnose, and occasionally treat, the causes of back pain.
Who performs and interprets these procedures?
Myelograms, discograms, facet injections and nerve root blocks are performed by specialty-trained physicians. Board certified radiologists are physicians with specific training in performing these procedures and in the safe and efficient utilization of the imaging equipment. A radiologist is a doctor that specializes in radiology (X-ray) along with the other imaging modalities of MRI, ultrasound, and CT. A radiologist specializes in the imaging and diagnosis of disease. Radiographs and ultrasounds are two-dimensional displays of a three-dimensional object. Both MRI and CT use axial cross-sectional imaging and 3D displays of the body. Interpretation of a radiograph MRI, CT or ultrasound examination requires expertise in pattern recognition and in the identification of potential artifacts that may otherwise be mistaken for pathology. Radiologists are trained in the variable sensitivity and specificity of each imaging technique, and in the potential for hazards related to the examination that could cause harm and must be avoided. All the radiologists at Hospital for Special Surgery are board certified by the American Board of Radiology, have years of experience in the imaging of musculoskeletal disorders, and the majority have additional formal fellowship training beyond residency in musculoskeletal or body imaging.
What should I do to prepare for the procedure?
A board certified radiologist will generate a written report, which will be sent to the doctor who referred you for the examination. The report becomes part of your medical record. All removed fluid, including cerebral spinal fluid (CSF), is sent to the laboratory for analysis. The results may take several days and will be sent to your referring physician. Copies of the report can be obtained through your referring physician's office. Your physician can call the file room at 212.606.1015 and a copy of the report can be faxed or mailed free of charge to their office. The radiographs are the property of the institution as are biopsy slides or blood samples. Copies of the radiographs can be obtained by contacting the file room. There is a charge for obtaining film copies and mailing them to your physician.
A myelogram is a procedure that involves placing a needle into the spinal canal and injecting an iodine containing contrast agent into the sac that contains the spinal cord and nerve roots, and then taking images.
Why has my doctor ordered a myelogram?
A myelogram provides detailed information about the spinal cord and the nerve roots. This information is valuable in helping your doctor make a diagnosis or plan the appropriate treatment to help relieve your symptoms.
A needle is placed in their lower back (lumbar and lumbosacral region) or occasionally in the neck (cervical region). The area for needle placement is localized using imaging guidance. The radiologist will administer local anesthesia. Since the needle tip is in a location near the nerve roots, you may briefly experience symptoms such as pain or an electric shock sensation down the leg; if this happens, the needle position will be adjusted. Contrast is injected, multiple X-ray images are obtained, and the needle is removed. A series of X-ray pictures are obtained. A CT scan is routinely performed after the myelogram in order to provide additional information. Much of the procedure is performed with you lying prone (face down). The entire procedure from start to finish lasts approximately one hour; the needle is removed at the very beginning of the procedure. You will be awake during the procedure and can ask questions.
Routine radiographs are usually performed prior to myelograms. Your doctor may order additional studies such as Mifi to further evaluate your condition.
What should I do to prepare for a myelogram?
Certain medications are contraindicated and should be withheld because they lower the seizure threshold. Seizure is an uncommon complication. If you are on any medications that lower the seizure threshold, please consult your physician in advance of the procedure. If you are taking any antidepressant medications, such as phenothiazines, MAO-inhibitors, tricyclic antidepressants, Zyban (for smoking cessation), antipsychotic medications, CNS stimulants, muscle relaxants or any other medication that lowers the seizure threshold, please inform your doctor in advance of the procedure so that these medications can be stopped at least 48 hours before the procedure and resumed no earlier than 24 hours after the procedure. A nurse will call you three days before the procedure to check if you are on any of these medications and to give you instructions for the procedure. Your physician will decide if it is alright for you to stop these medications and how long they should be withheld.
Sometimes, additional medication must be given at the time of the procedure. Do not eat any solid food after midnight. Take any of your medications that are not contraindicated on the day of the procedure. Do not have any caffeine or alcohol on the day of the procedure. On the day of the procedure, a nurse will take your vital signs, start your intravenous line and answer any questions you may have.
MRI can provide much of the same information as a myelogram without an injection of contrast. The myelogram with CT offers certain advantages including detail of the bony structures. Some individuals cannot tolerate MRI scanning because of claustrophobia or contraindications such as a pacemaker. In certain instances your physician may recommend both tests (a myelogram and an MR examination) be performed.
What can I expect after the procedure?
You will be placed on bed rest with your head elevated (about 30 degrees) for 24 hours to decrease the risk of headache. You will be encouraged to drink plenty of fluids throughout the day of the procedure. Mild soreness at the site of the lumbar puncture is expected and usually lasts only hours or on rare occasions 1 to 3 days. You will be observed several hours after the contrast is injected and then discharged if there are no immediate complications. Please have someone accompany you on your travel home. Headache is not an uncommon complication and may occur immediately after the procedure or within hours, lasting from hours (usually) to days. NSAIDs are usually used for treatment.
A discogram is an X-ray procedure to evaluate the intervertebral disc and to determine if your pain or other symptoms are specifically related to an abnormality of the disc. The intervertebral disc is a structure that is located between the spinal vertebrae and acts as a cushion. It is composed of fibrocartilage (annulus fibrosis) surrounding a rubbery center (nucleus pulposus).
Why has my doctor ordered a discogram?
The discogram can be helpful in determining if your symptoms are specifically related to an abnormality of the disc and if so, which disc.
A discogram is a procedure in which a needle is placed into the nucleus pulposus of an intervertebral disc and a small amount of iodinated contrast is injected. The radiologist will localize the site for needle placement using fluoroscopic guidance. In addition to the pain control administered by an anesthesiologist, the radiologist will administer local anesthesia at the site of needle placement. Since the needle tip is in a location near the nerve roots, you may briefly experience symptoms such as pain or an electric shock sensation down your leg. A small amount of iodinated contrast agent is injected into the disc. At the time of the injection, you will be asked if the injection reproduces your pain or other symptoms. A series of radiographs are obtained after the injection to evaluate the condition of the disc. In most cases, multiple disc levels are injected. Pain and discomfort at the time of the injection are common since one of the goals of this test is to determine if your symptoms are coming from irritation or compression of nerve roots by the disc. The pain may be as bad as the worst pain your back or spine trouble usually gives you. This pain generally subsides to your baseline level following the injection.
You are conscious in light sleep during the procedure and can ask questions at any time. After the needle is removed, a CT scan is performed to provide further information. Occasionally, needle placement must be made from the midline with the needle crossing the sac that contains the nerve roots. In that instance, you may experience a headache after the procedure. If this approach is required, you will have to be observed in the hospital for several hours after the needle placement.
A discogram is often used in conjunction with other examinations such as routine radiographs, an MRI examination or a myelogram and CT examination.
What should I do to prepare for the discogram?
Do not take solids by mouth after midnight before the procedure. Fluids and medications are all right to have on the morning of the examination. If the procedure is scheduled for the end of the day, it is okay to have breakfast. You will undergo an evaluation by the anesthesiologist for what is known as conscious sedation. Please follow the instructions of the anesthesiologist. On the day of the procedure you will be seen by a nurse, who will take your vital signs, start your intravenous line (if necessary), and answer any questions you may have.
Other tests such as routine radiographs, myelogram CT or MRI can give information about disc degeneration or herniations. However, these tests cannot always specifically localize the level producing your symptoms.
What can I expect after the procedure?
Soreness at the injection site(s) may occur and usually lasts hours or a few days. After the procedure you can expect your usual spine related symptoms.
Facet joints are paired joints on the side of the midline at each level of the spine. A facet injection is a procedure in which a needle is placed into the facet joint under imaging guidance for the nerve root block injection of a local anesthetic and/or steroid. A facet joint injection may be performed at one or multiple levels and on one or both sides of the spine (right or left).
A nerve root block is the placement of a needle near a nerve root and injecting a combination of local anesthetic and steroid.
Why has my doctor ordered this?
These procedures are diagnostic tests to localize the source of your pain by determining if your pain responds to the injection of medication. Alternatively, these procedures are used to treat symptoms arising from facet joint arthritis, or from irritation or inflammation of the nerve roots.
How are the procedures performed?
The precise location for the needle placement is determined with imaging guidance. You may experience brief, temporary sensations of pain or an electric shock sensation down the leg. Iodinated contrast is injected to confirm the location of the needle tip.
Routine radiographs, CT, a myelogram, or MRI are often necessary.
Conservative treatment (such as a combination of physical therapy, exercise regimens and NSAIDs) is often used first. Surgery is a possible alternative, however, these procedures may be an adequate treatment, providing temporary relief. These procedures can help determine if surgery would be of benefit by more precisely localizing the source of your symptoms.
What should I do to prepare for the facet injection and nerve root block?
What can I expect after the procedure?
Some patients get immediate relief of symptoms related to the injection of the local anesthetic in the facet joint or around the nerve root. Others have relief beginning hours or days after the procedure related to the long acting local anesthetic or the steroid compound. Relief may last from hours to months and in some cases indefinitely. Some patients experience no relief either because of a lack of response to the medication or because their symptoms are coming from a different source.
Department of Radiology and Imaging
Hospital for Special Surgery