The patient who presents with sciatica and with a clinical radicular pattern of pain needs careful attention. Especially in an era when there is a tendency to "lump" and set up "clinical protocols," it becomes imperative that the initial diagnostic impressions be sharpened as much as possible.

Fortunately, in lumbosacral radiculopathy, sharpening one’s acumen can bear fruitful results. As goes the accuracy of the initial diagnosis... so goes the success with treatment.

As Sir William Osler stated at the turn of the century, "Eighty percent of diagnoses are made on the basis of an accurate medical history." Generally, clinical examination is useful for confirming one’s suspicion’s and ruling out more definitively one’s peripheral concerns.

What then are the crucial components of medical history in the patient with lumbosacral radiculopathy which must be distinguished.

Classical discogenic history

First, the description of the classical discogenic history is crucial since all other conditions will vary from that history and should therefore be able to be distinguished from it. In the classical discogenic history, the patient has generally begun with back pain weeks to months before the acute episode. This pain is often described as an ache. Depending upon the degree of pressure on the nerve root, the low back pain may even subside as buttock and leg pain intensify. The factors which worsen the pain include activities of flexion. Therefore, sitting is worse than standing which is worse than lying. This has been proven to correlate with disc pressure mechanics, by Alf Nachemson, MD, in his elegant study in 1973 in which he measured pressure in the disc space in different body positions. Other activities which increase pressure upon the disc and therefore exacerbate discogenic pain include twisting/rotation activities as well as bending at the waist. In addition, coughing, sneezing and straining (Valsalva maneuver) increase disc pressure and exacerbate radicular pain as well. Arising from a seat after sitting for a period of time often exacerbates pain; it is believed that the disc has been allowed to migrate posteriorly and is now "caught" or "squeezed" as one attempts to straighten up. In what often seems a paradox to the patient, getting from sitting to standing position may be excruciatingly painful, yet once upright, the patient feels almost no pain. Robin McKenzie has posited that this is the result of centralization of bulging or herniated disc material. Centralization techniques have in fact been proven to reduce radicular symptoms. In addition, most patients with discogenic pain complain of increased pain for the first 30 minutes or so of their waking hours, a phenomenon attributed to central pooling of interstitial fluid and resultant "swelling" of the disc upon first awakening. After the patient has been up and around for several minutes, and the disc has partially "desaturated", the patient often feels quite well comparatively.

Lumbar stenosis

Compared to the above classical discogenic history, patients with lumbar stenosis have a significantly contrasting history. Unlike patients with discogenic radiculopathy, lumbar stenosis is uncommon in the 30s and 40s. It is, in fact, uncommon before approximately age 55. There is often a history of significant prior disc or facet joint disease. The onset of pain is spontaneous or insidious, with gradual progression. Sudden changes in symptoms require an explanation other than simple lumbar stenosis,e.g., superimposed disc disease or tumor.