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Acute lumbosacral radiculopathy: Pathophysiology, clinical features, and diagnosis

Philip S Hsu, MD
Carmel Armon, MD, MHS
Kerry Levin, MD
Section Editor
Jeremy M Shefner, MD, PhD
Deputy Editors
John F Dashe, MD, PhD
Susanna I Lee, MD, PhD


Lumbosacral radiculopathy is a condition in which a disease process affects the function of one or more lumbosacral nerve roots [1]. The clinical aspects of lumbosacral radiculopathy will be reviewed here.

The treatment of lumbosacral radiculopathy and other disorders of the lower spine are discussed separately. (See "Acute lumbosacral radiculopathy: Treatment and prognosis" and "Lumbar spinal stenosis: Pathophysiology, clinical features, and diagnosis" and "Evaluation of low back pain in adults" and "Subacute and chronic low back pain: Nonpharmacologic and pharmacologic treatment" and "Subacute and chronic low back pain: Nonsurgical interventional treatment" and "Subacute and chronic low back pain: Surgical treatment".)


The lumbar spine consists of five movable lumbar vertebral bodies, numbered L1 to L5 (figure 1). The sacrum is made up of five developmentally fused vertebral levels (S1 to S5), followed by a terminal bony prominence, the coccyx. The entire region is commonly described as the lumbosacral spine.

Directly beneath each lumbar and sacral vertebra, there is a pair of neural foramina with the same number designation, such that the L1 neural foramina are located just below the L1 vertebral body. Neural foramina are bounded superiorly and inferiorly by pedicles, anteriorly by the intervertebral disc and vertebral body, and posteriorly by facet joints (figure 1).

Through each neural foramen passes the same numbered spinal nerve root, recurrent meningeal nerves, and radicular blood vessels. On each side there are five lumbar, five sacral, and one coccygeal spinal nerve roots.

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Literature review current through: Oct 2017. | This topic last updated: May 31, 2017.
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