Analgesic medications, either NSAIDs or opioids, may be required for a few days. In a few patients with severe sciatica we have been impressed with the temporary relief afforded by administration of oral dexamethasone (4 mg every 8 h) for several days, although this approach has uncertain effects according to several systematic surveys summarized by Ropper and Zafonte. The treatment of nerve root compression with repeated epidural injections of corticosteroids has enjoyed periods of popularity, but controlled studies have failed to confirm a sustained efficacy (White et al; Cuckler et al), and it is not without complications. As with many similar studies, Carette and colleagues (1997) found short-term improvement with epidural steroid injection and the ultimate need for surgery was not altered. Nevertheless, we and many other neurologists and pain clinics have not discarded this form of treatment in view of notable success in selected patients, even if short-lived and only aiding in mobilizing the patient and relieving discomfort.
Surgical relief of lumbar disc disease Urgent surgery is generally required for an acute compression of the cauda equina by massive disc extrusion, causing bilateral sensorimotor loss and sphincteric paralysis. Although not the recommended course, it should be pointed out that there are infrequent instances where even a dramatic syndrome of cauda equina compression has resolved after several weeks of bed rest.
If the pain and neurologic findings do not subside in response to conservative management or the patient suffers frequent disabling acute episodes, surgical treatment must be considered. Useful information regarding surgery and its timing can be ascertained from a recent randomized Dutch trial conducted by Peul and colleagues and from the Spine Patients Outcomes Research Trial (SPORT) conducted by Weinstein and coworkers (2006). In the first mentioned trial, a large proportion of patients assigned to treatment with physical therapy and pain medications nonetheless had enough pain that they required surgery after several months. Patients assigned initially to surgery by microdiscectomy also had considerably faster relief of back and sciatic pain, but at the end of a year, both groups had minimal disability and similar degrees of minor pain. The implications of this study are that avoiding surgery initially does not have adverse consequences but if rapid pain relief and mobilization is the aim, surgery is preferable. In the second cited study there was even greater crossover between conservative and surgically assigned groups but there was a slightly more favorable outcome in those who underwent early surgery.
The surgical procedure most often indicated for lumbar disc disease is one of the variants of a hemilaminectomy with excision of the disc fragment. Questions relating to the relative merits of limited (“microdisc”) excision of the lamina are often raised by patients but no clear answer can be given except that individual surgeons excel at one or another technique and a minimal procedure is currently favored but the short-term outcomes are similar for most approaches. Eighty-five to 90 percent of cases with sciatic pain because of L4-L5 or L5-S1 disc ruptures are relieved by operation, are home in days or less, and resume activities within weeks. Rerupture occurs in approximately 5 percent or fewer operated cases according to Shannon and Paul. Fusion of the involved segments may be indicated in cases in which there is substantial spondylolisthesis or instability. It is not known if delaying surgery in patients with foot or leg weakness from disc herniation risks irreversible damage. Similar issues pertain to surgical to the more complex issue of decompression of lumbar stenosis, discussed in a later section. It is of interest that the findings on follow up at a year or so after laminectomy for disc removal do not correspond to the clinical outcomes according to Barzouhi and coworkers.
In our experience and that of our neurosurgical colleagues, the features that are predictive of better outcome from decompressive surgery are the presence of radicular leg pain, younger age, a clear precipitating event for the back and sciatic pain, clinical features that are restricted to compression of a single nerve root, and the absence of chronic or recurrent back pain. Psychological problems of various types and chronic smoking, because of poor bone structure, are risks for poorer outcomes.