Clinical syndrome of lumbar disc herniation The fully developed syndrome of the common herniated (the terms ruptured and prolapsed are used equivalently) intervertebral lower lumbar disc consists of (1) pain in the sacroiliac region, radiating into the buttock, thigh, and the calf, a symptom termed sciatica; (2) a stiff or unnatural spinal posture; and often (3) some combination of paresthesia, weakness, and reflex impairment.
The pain of herniated intervertebral disc varies in severity from a mild aching discomfort to severe knife-like stabs that radiate the length of the leg and are superimposed on a constant intense ache. Sciatic pain is perceived by the patient as originating deep in the buttock and radiating to the posterolateral thigh; it may progress to the calf and ankle—to the medial malleolus (L4), lateral malleolus (L5), or heel (S1). Distal radiation to the foot is infrequent and should raise concern of an alternative process. Abortive forms of sciatica may produce aching discomfort only in the lower buttock or proximal thigh and occasionally only in the lower hamstring or upper calf. With the most severe pain, the patient is forced to stay in bed, avoiding the slightest movement; a cough, sneeze, or strain is intolerable. The most comfortable position is lying on the back with legs flexed at the knees and hips and the shoulders raised on pillows to obliterate the lumbar lordosis. For some patients, a lateral decubitus position is more comfortable. Free fragments of disc that find their way to a lateral and posterior position in the spinal canal may produce the opposite situation, one whereby the patient is unable to extend the spine and lie supine. Sitting and standing up from a sitting position are particularly painful. It is surprising to patients that a lumbar disc protrusion may cause little or no back pain. As a corollary, the presence of lumbar disc disease, even frank rupture, bears an inconsistent relationship to low back pain, as already emphasized.
In cases of root compression, pain is also characteristically provoked by pressure along the course of the sciatic nerve at the classic points of Valleix (sciatic notch, retrotrochanteric gutter, posterior surface of thigh, and head of fibula). Pressure at one point may cause radiation of pain and tingling down the leg.
Elongation of the nerve root by straight-leg raising or by flexing the leg at the hip and extending it at the knee (Lasègue maneuver discussed earlier) is the most consistent of all pain-provoking signs. During straight-leg raising, the patient can distinguish between the discomfort of ordinary tautness of the hamstring and the sharper, less-familiar root pain, particularly when asked to compare the experience with that on the normal side. Many variations of the Lasègue maneuver have been described (with numerous eponyms), the most useful of which is accentuation of the pain by dorsiflexion of the foot (Bragard sign) or of the great toe (Sicard sign). The Lasègue maneuver with the healthy leg may evoke sciatic pain on the contralateral side), but usually of lesser degree (Fajersztajn sign). However, the presence of the “crossed straight-leg-raising sign” is highly indicative of a ruptured disc as the cause of sciatica (Hudgkins). With the patient standing, forward bending of the trunk will cause flexion of the knee on the affected side (Neri sign). Sciatica may be provoked by forced flexion of the head and neck, coughing, or pressure on both jugular veins, all of which increase the intraspinal pressure (Naffziger sign). Marked inconsistencies in response to these tests raise the suspicion of psychologic factors or of referred muscular pain.