Home » Spinal Pain Diagnostic Center » The Diagnosis of Spinal Problems

The Diagnosis of Spinal Problems

This is how I go about diagnosing a spinal pain problem. What are nerve blocks and how are they done? What do they tell us? And how do we use them to treat the pain?

The HISTORY is extremely important when assessing spine pain.  The descriptions of the pain and the history of how the pain began, what worsens it, what makes it better, and what treatments have helped is usually much more important than the physical examination.  It is very helpful to know exactly where the pain is located, if it radiates, and where it goes specifically.  Whatever loss of function the patient suffers in also extremely important to know.

PHYSICIAL EXAMINATION is less valuable.  A general examination is rarely needed.  This is because it rarely helps in the diagnosis, although it does serve to determine how seriously the patient is disabled. 

THE SPINAL EXAMINATION is very important.  The spinal examination is to determine specific spinal and neurological abnormalities.  Most patients are surprised by how simple the focused examination of the spine really is.  A complete spinal examination takes no more than a few minutes.  It is unusual that the examination makes a diagnosis.  Its principal purpose is to determine what the patient’s functional status is.  Paralysis, loss of sensation, and loss of normal bowel, bladder, and sexual function are the most important along with ability to walk and reports of the activities of daily living.  The patient usually reports these as accurately as any examination can determine.

IMAGING is key in spinal diagnosis.  Plain spine x-rays are frequently done with motion – that is bending forward, bending back, and sometimes bending side wards.  Movement of the spine can be assessed in this way and many abnormalities of the bone and related spinal structures are seen.  CT is a more advanced way to examine the bony structures of the spine.  Soft tissues are less well seen.  MRI is superior to examine the soft tissues.  These include muscle, nerve, spinal cord, and such surrounding structures as blood vessels, fat, and internal organs.  A combination of these imaging studies will give a great deal of information about the status of the spine and all of its related structures.  Unfortunately, it often does very little to determine exactly what is the cause of the pain in most patients.  Sometimes patients will have an obvious abnormality that immediately explains the problem, but that is relatively unusual.  (Some studies say about 10%.)  In 90% of patients the cause of the pain may not be certain after examination and imaging.

Early Therapy of Spine Pain

When there is no serious muscle paralysis, loss of important sensations, or impairment of bowel, bladder, or sexual function then symptomatic treatment is adequate for most complaints of spinal pain and should be the first step.  These treatments include pain medication which gives satisfactory relief.  Then there are many local measures that may help.  Several medications can be applied through adhesive patches put over the area of pain.  Heat, massage, ultrasound, and manipulation treatments can be very valuable.  An active exercise and therapy program can often begin immediately.  Manipulation treatments can be very helpful.  There are several kinds of therapeutic nerve blocks that can be employed early for immediate relief of pain.  They are discussed more in the nerve block section to follow.

A small number of patients need to go directly to surgery.  These will be chosen because of severe pain which does not respond to treatment, paralysis, loss of important skin sensations, or bowel, bladder, and sexual function loss.  Sometimes a problem is present which has not caused these yet, but might if left untreated.  Therefore, it is extremely important to have thorough early evaluation to be certain that immediate surgery is not needed.  Otherwise, most patients can be treated to relieve symptoms and most will recover spontaneously.  Treatments are mostly meant to speed that spontaneous recovery and relieve acute pain. 

Diagnostic and Therapeutic Nerve Blocks

Most patients with pain that persists do not have an obvious cause which can be determined by the history, the physical examination, or the imaging.  Then we use diagnostic techniques called nerve blocks to try to determine what structures in the spine are causing the pain.  The spinal joints are one common cause.  They usually cause back pain without significant leg pain.  Nerve roots are another common cause of pain when they are compressed by some abnormality.  Root compression usually causes leg pain which follows the major nerves in the leg.  The most common goes down the back of the leg to the foot and is called sciatica.  The sacroiliac joints,  large  joints binding the tail bone to the pelvis, are another common cause of pain.  The discs themselves can cause pain.  All of these are diagnosed by the same technique of nerve block.  This is like a dentist anesthetizing a tooth to work on it.  When the tooth is numb, the pain is gone.  We use the same principle to determine what is hurting in the spine.  Using CT or fluoroscopic control, the structures are visualized and then a needle is passed to the specific structure which is to be blocked.  Then a local anesthetic is injected.  If the structure blocked is the cause of a pain, the local anesthetic should relieve that pain for a period of time and should allow the patient to carry out activities without pain that would otherwise be painful.  It is often necessary to block each of these different structures separately to see what the effect will be.  By combining the results of all the blocks, it is often possible to determine the most likely cause of the pain.

Painful discs are identified in a somewhat different way.  This technique is called provocative discography.  Using the same imaging control (CT or fluro), needles are passed into the discs which are questionable, and into at least one normal disc.  Injections are made to increase the pressure in the disc.  This should cause the typical pain which the patient suffers if that disc is the culprit.  Normal discs are not painful when injected.  Neither are many abnormal discs, so a positive test occurs when the usual pain can be precipitated by the injection.  Then small amounts of local anesthetic can be injected and the pain relieved temporarily.

Studying these various structures by blocks, along with the history and imaging studies, has a good chance of defining the cause of the pain and also defining what is not causing the pain.

Therapeutic blocks – that is those designed to actually treat the pain rather than just diagnose its cause – are done in exactly the same way.  They are usually done on the basis of history, physical examination, and imaging studies if an obvious abnormality is found, or when the diagnostic blocks make the cause of the pain apparent.

With these blocks, which are done for treatment, the injection includes the local anesthetic as well as a potent anti-inflammatory medication called steroid.  Injections around herniated discs, inflamed and compressed nerves, or arthritic joints can often result in excellent pain control and greatly reduce the waiting period for recovery.  One to three blocks are often needed for best relief.

Once the cause or causes of the pain is known, then more specific treatments are possible.  Sometimes those treatments are just the injections which I have described.  Sometimes nerves can actually be interrupted by a technique called denervation or rhizotomy.  This technique uses radiofrequency current to kill small nerves carrying pain.  It is a needle technique done on an outpatient basis and is more permanent than the injections.  Sometimes the diagnostic blocks lead to surgery.  For instance, there is good evidence that an injured sacroiliac joint can be treated by injection , denervation, and even surgical fusion when needed.  A herniated disc may respond to simple discectomy, and a new disc replacement surgery with artificial discs is now possible.  Patients with abnormal facet joints who are not relieved by the simple block techniques can sometimes be candidates for surgery as well.

In general, our approach is to do nothing in the acute phase of a spinal pain problem other than provide satisfactory symptomatic relief.  Red flags may lead to early treatment.  Once it becomes obvious the problem will not disappear spontaneously, then the diagnostic procedures outlined here are indicated.  The goal is to identify the causes of the pain to allow the best therapies to be chosen which have the highest chance of success.  Our usual approach is to do the least possible to get the best possible result, and, except in rare instances, surgery is and should be the last resort.