Ms. L.G. is a 42-year old female in previously excellent health who presented to our office with a two-week history of low back pain. The patient developed pain after raking leaves on a Monday, then running her daughter’s birthday party on Tuesday afternoon. She developed central achiness of the back, which then increased and began to be felt in her left buttock. The pain intensified and the patient was unable to assume an erect posture. She felt shifted to the right when attempting to stand. Arising out of a chair became intolerable in terms of pain. The patient began to have pain down the leg into her anterior shin and noted a tingling feeling in her left big toe. The patient noted increasing pain when attempting to have a bowel movement and when coughing or sneezing.

On examination Ms. L.G. was noted to have partial foot drop on the left she was unable to heel walk on the left without loss of dorsiflexion in midstance. There was decreased sensation in an L5 distribution. Straight leg raise was positive at 40 degrees. The patient was unable to tolerate lying flat on either stomach or back and was most comfortable sitting bent toward the right.

Does Ms. L.G. require surgery? If so, how urgent is this situation?

Indications for surgery

Basically, the indications for surgical decompression in radicular pain, when associated with a slipped disc, fall into two categories. First, there is a very small population of patients in whom there is a clear medical necessity, and indeed urgency, for surgical treatment. These patients are those in whom there is bowel or baldder dysfunction, since this is evidence of cauda equina dysfunction and can lead to permanent incontinence, paralysis, and is reversible only if attended to on an emergent basis. Those patients who have progressive neurological deficits despite treatment usually will require surgical management as well; although they require surgery, the need is not quite as urgent. At times, the patient can be followed very closely, as long as surgical intervention is available should things continue to progress.

The second population who benefits clearly from surgery are those patients whose condition has failed to respond to aggressive conservative measures. These patients do best when decompressed within the first three to six months of initial onset of radicular symptoms. Likewise, if the degree of discomfort and/or rate of recovery are not adequate, the patient may benefit from an elective laminectomy/discectomy. To some extent this depends upon the patient’s psychological state and social milieu; some patients cope better socially, financially, and emotionally with persistent pain and dysfunction than others.

The populations discussed comprise only a small percent of all patients who present with disc disease. The vast majority of patients, followed closely, given aggressive conservative treatment, and given psycho-social support, will gradually improve symptomatically and functionally without need for surgery.

Often people, and indeed many doctors, focus on the appearance of the MRI or CAT Scan in determining the need for surgery, the size of the HNP (Herniated Nucleus Pulposis) is not by any means an indication for surgery! The main determining factor is the amount of room left in the forarmen for the nerve root. For example, a mere disc bulge in an already narrowed (stenotic) canal could create more resistant and irreversible symptoms than a huge disc herniation in a canal with ample dimension. Similarly, a small HNP in the foramen (laterally) is much more resistant and difficult to treat than a central large HNP.

Role of MRI/CAT

Should everyone with disc symptoms immediately go for MRI or CAT Scan to determine size and location of disc? The answer is a qualified no! Unless the patient has symptoms which raise concerns about causes other than disc, an MRI or CAT Scan are rarely firstline diagnostic information. Of course, if the patient’s pain is persistent, progressing, nocturnal, widespread, associated with weight loss or other constitutional symptoms, then our antennae are raised and more comprehensive diagnostic tests including MRI must be considered. However, in most patients, this is not the presenting history.