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Chapter 7 covered a general approach to and a detailed examination of the patient with back or neck pain. In this chapter, a more extensive discussion of specific conditions of the spine is presented. For a review of seronegative spondyloarthropathy (e.g., ankylosing spondylitis), the reader is referred to Chapter 3. Fractures of the spine are addressed in Chapters 9 and 10.
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It should be noted that in an unselected emergency department (ED) population presenting with back pain, between 1 and 5 patients will have a specific diagnosis and approximately 1 in 200 patients will need surgery. The challenge for the clinician is to identify these small patient populations from among the larger group with a complaint of "back pain." The clinician, armed with a history and physical examination, must frequently decide who needs further emergent workup and who can be safely observed. Further challenges the clinician faces are that spinal syndromes can present in a subtle fashion and that a great deal of clinical overlap occurs between many of the pathophysiologic processes.
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The imaging of most patients presenting with spinal disorders is driven by the search for "red flags" in the history or physical examination. Generally, there is higher concern and hence a lower threshold to image those younger than 18 and those older than 50. Also included in this group are those with immunocompromise, those who use IV drugs, those with histories of primary cancers known to metastasize to the spine, those with recurrent infections (e.g., GU infections), those with significant trauma, and those exhibiting neurologic dysfunction. Regarding the search for red flags, a recent systematic review of the literature found that there were currently 26 different "red flags" identified in the literature, and there was very little evidence for any of them beyond common sense and anecdote. The review noted that of the 26 possible red flags, the 3 that were the most likely to predict pathology were older age, prolonged steroid use, and a history of malignancy.1 In the absence of red flags, it is generally recommended that imaging be avoided in the first 4 to 6 weeks of the back pain syndrome, as the vast majority of patients will resolve within this time frame.
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CAUDA EQUINA SYNDROME
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Cauda equina syndrome refers to nerve compression within the spinal canal that occurs below the L1-L2 interspace after the termination of the spinal cord. The clinical picture is that of a lower motor neuron lesion with weakness or paralysis, loss of rectal tone, sensory loss in a dermatomal pattern, decreased deep tendon reflexes, and bladder dysfunction. The classic sensory description is "saddle" anesthesia, with loss of sensation in the buttocks and perineal areas. It should be noted that within the first few days, a complete cord syndrome may present similarly until upper motor neuron symptoms develop.
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The most common cause ...