Acute lumbosacral radiculopathy: Treatment and prognosis

INTRODUCTION — Lumbosacral radiculopathy is a condition in which a disease process causes functional impairment of one or more lumbosacral nerve roots. The most common cause is structural (ie, disc herniation or degenerative spinal stenosis) leading to root compression. The acute time period starts at the time of symptom onset and extends up to four or six weeks.

Other clinical aspects of lumbosacral radiculopathy and the management of lumbar spinal stenosis are discussed separately. (See "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis" and "Lumbar spinal stenosis: Treatment and prognosis".)

The management of subacute and chronic low back pain is reviewed elsewhere. (See "Subacute and chronic low back pain: Nonsurgical interventional treatment" and "Subacute and chronic low back pain: Nonpharmacologic and pharmacologic treatment" and "Subacute and chronic low back pain: Surgical treatment".)

GOALS OF ACUTE MANAGEMENT — For patients with acute lumbosacral radiculopathy, the objectives of management are twofold:

●To identify patients who require urgent evaluation and to treat specific underlying processes that expose such patients to the risk of progressive or permanent neurologic impairment (mechanism-specific treatment) (see 'Identifying patients who need urgent diagnostic evaluation' below)

●To ameliorate pain (symptomatic treatment) (see 'Symptomatic management in other patients' below)

Refer also to the algorithm (algorithm 1).

The most common cause of lumbosacral radiculopathy is nerve root compression from intervertebral disc herniation or spondylosis, producing painful symptoms but often a self-limiting course. However, patients should be evaluated for less common mechanisms associated with permanent and progressive neurologic disability, as prompt diagnosis and treatment may improve outcome.

The diagnosis and evaluation of suspected lumbosacral radiculopathy is discussed in detail elsewhere. (See "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis", section on 'Evaluation and diagnosis'.)

IDENTIFYING PATIENTS WHO NEED URGENT DIAGNOSTIC EVALUATION — Based on history and examination, patients with acute lumbosacral radiculopathy should be evaluated promptly for specific high-risk underlying structural or inflammatory mechanisms (algorithm 1):

●Cauda equina syndrome – Patients with cauda equina syndrome present with bilateral lower extremity radicular pain, often with weakness and numbness with or without new urinary retention. Though rare, cauda equina syndrome represents a true surgical emergency where decompression should be performed within 24 hours, and within 12 hours if possible. (See "Clinical features and diagnosis of neoplastic epidural spinal cord compression", section on 'Cauda equina syndrome'.)

●Other high-risk structural lesions – Specific underlying causes in patients with acute lumbosacral radiculopathy should be excluded if history or examination suggests a mechanism with high risk for progressive or permanent neurologic disability. Features concerning for a high-risk mechanism include:

•Fever

•Night sweats

•Nocturnal pain

•Pain that does not remit with positional changes

•Unintentional weight loss

•Treatment with an anticoagulant

•Immunosuppressed state

•Active/prior malignancy

•Age greater than 60 years

Neoplastic, hemorrhagic, inflammatory, or infectious etiologies of radiculopathy require prompt mechanism-specific treatment. (See "Spinal epidural abscess" and "Treatment and prognosis of neoplastic epidural spinal cord compression" and "Disorders affecting the spinal cord", section on 'Spinal epidural hematoma' and "Disorders affecting the spinal cord", section on 'Vascular malformations' and "Transverse myelitis: Treatment and prognosis", section on 'Idiopathic transverse myelitis'.)

●Severe disc herniation or foraminal stenosis – With radiculopathy caused by disc herniation or foraminal stenosis, symptomatic treatment is used during the acute period. However, surgical treatment is indicated if there is progressive neurologic compromise or severe weakness unresponsive to conservative measures. (See 'Management for patients with persisting symptoms' below.)

SYMPTOMATIC MANAGEMENT IN OTHER PATIENTS — In patients who do not have an indication for urgent treatment, conservative symptomatic treatment is used during the acute period. While acute lumbosacral radiculopathy is often extremely painful, symptoms may spontaneously improve in many cases. As examples, the clinical course may variably wax and wane when due to lumbar spinal stenosis from degenerative arthritis and may be self-limited when due to disc herniation.

Initial conservative treatment — Analgesic medications such as nonsteroidal antiinflammatory drugs (NSAIDs) or acetaminophen and activity modification are the mainstays of treatment. Patients should avoid pain-producing activities. However, engaging in a regimen of progressive mobilization of the impacted limb(s) may further reduce pain and duration of symptoms.

For patients managed with initial conservative treatment, we suggest a one- to two-week trial of NSAIDS or acetaminophen and activity modification before reassessing whether or not continued conservative treatment or adjunctive treatments are warranted. Inadequate clinical response to initial treatment over time guides decision-making.

Nonopioid analgesics — Clinical experience suggests that short-term treatment with either an NSAID or acetaminophen is useful for patients with acute lumbosacral radiculopathy. For most patients, we start with a one- to two-week course of either ibuprofen 400 to 800 mg orally every eight hours or acetaminophen 650 mg orally every six hours. NSAIDs may be preferred for patients without significant renal, gastric, or cardiovascular comorbidity, while acetaminophen can be used for patients without hepatic compromise who cannot tolerate NSAIDs. Nonopioid analgesics are discussed in further detail separately. (See "Pharmacologic management of chronic non-cancer pain in adults", section on 'Nonopioid analgesics'.)

However, the effectiveness of NSAIDs and acetaminophen for acute lumbosacral radiculopathy has not been firmly established. As an example, a 2016 meta-analysis included 10 randomized controlled trials with over 1600 participants that evaluated NSAIDs versus placebo or other medications for sciatica; seven of the trials enrolled only patients with acute sciatica of <3 weeks duration [1]. There was no significant effect of NSAIDs for pain reduction, but NSAIDs led to a better global improvement compared with placebo. The quality of the evidence in this analysis was low. Other studies reached similar conclusions [2-4].

Activity modification — Activity modification is as important as analgesic treatment in the management of acute radiculopathy. The goals are to lessen nerve root impingement and to avoid activities that exacerbate pain.

We advise patients to reduce exacerbating physical activity, typically during the first week after symptom onset. Patients often identify pain-relieving positions for themselves. Some individuals report that crouching, reclining, or lying in certain positions in bed provide meaningful pain relief. Others find that recumbency in bed is associated with increased pain. Such patients may prefer to be up and around, even going about light work duties.

Modification or avoidance of activity does not imply prolonged complete bed rest. After the first week or otherwise when the acute symptoms decrease, we recommend resuming modest physical activity as tolerated. Randomized trials of patients with acute lumbosacral radicular syndromes have found no significant difference in outcome for treatment with bed rest versus watchful waiting [5] or bed rest versus physical therapy [6]. Similarly, a systematic review of these studies found no benefit with bed rest [7].

Adjunctive treatments if initial therapy fails — For patients whose symptoms persist or who report inadequate response to initial conservative treatment, we suggest continuing initial conservative treatments and adding adjunctive treatments, including a trial of physical therapy. Selection of other modalities depends upon severity of symptoms and patient preferences.

Physical therapy — Physical or manual therapies are often tried for patients with persistent symptoms that are mild or moderate in nature. The optimal timing of referral to physical therapy remains unclear, as does the optimal frequency of visits and duration of therapy. In general, physical therapy in the first one to two weeks is not recommended because patients with mild symptoms are likely to improve on their own while patients with very severe symptoms cannot participate in exercise therapy. Given the generally favorable natural history of acute lumbosacral radiculopathy, it is reasonable to delay physical therapy until symptoms have persisted for three weeks.

Although many patients report benefit with physical therapy, data supporting its use are limited. In one trial, patients assigned to physical therapy plus usual care, including advice regarding activity modification, reported greater symptomatic improvement at six months than those assigned to usual care alone [8]. Physical therapy also provided greater symptom relief at one year without higher rates of health care utilization, need for advanced imaging with magnetic resonance imaging, or surgery. (See "Treatment of acute low back pain", section on 'Nonpharmacologic therapies'.)

Systemic glucocorticoids — In the clinical experience of some experts, systemic glucocorticoid treatment may provide partial pain relief for select patients with acute lumbosacral radiculopathy. Acknowledging that any benefit is likely modest, one author of this topic employs a course of oral prednisone (60 to 80 mg daily) for five to seven days for patients with acute lumbosacral radiculopathy who do not respond well to analgesics and activity modification. This is followed by a rapid taper to discontinuation over the following 7 to 14 days. However, the other authors generally do not use systemic glucocorticoids in this setting.

The available evidence suggests that systemic glucocorticoid therapy has either limited benefit or no benefit [9-15]. A 2022 systemic review of clinical trials on systemic glucocorticoids for low back pain that included data on three trials of patients with acute lumbosacral radiculopathy found modest improvements in pain but not function in short-term follow up [16]. Similarly, a 2017 systematic review and practice guideline from the American College of Physicians evaluated six randomized trials of moderate quality and concluded that systemic glucocorticoids have no benefit on pain and minimal or no functional benefit in patients with radicular low back pain [17]. In one of the larger randomized controlled trials included in the systematic review, 269 patients who had radicular pain for three months or less were randomly assigned in a 2:1 ratio to oral prednisone (five days each of 60, 40, and 20 mg per day) or placebo [14]. At 3 and 52 weeks, the improvement in disability scores was modestly higher in the prednisone group, a result that was statistically significant but of marginal clinical importance. There was no difference between the groups in pain scores during follow-up and no difference in the rate of lumbar spine surgery at 52 weeks.

Major side effects associated with systemic glucocorticoids include elevated blood pressure, mood disorders, psychosis, insomnia, gastritis, ulcer formation, gastrointestinal bleeding, hyperglycemia, bone loss, and heightened risk of infections. Some of these side effects are both dose and duration dependent and are more likely to occur with long-term glucocorticoid use. Patients taking glucocorticoids in combination with NSAIDs may require prophylaxis against gastrointestinal bleeding. (See "NSAIDs (including aspirin): Primary prevention of gastroduodenal toxicity".)

Options of limited utility

●Opioids – We generally do not give opioids to most patients with acute lumbosacral radiculopathy except for those with severe intractable pain unresponsive to other therapies and who are awaiting mechanism-specific treatment. (See 'Patients with disc herniation or spinal stenosis' below.)

Opioid therapy is commonly considered for patients with severe pain that is inadequately controlled with NSAIDs and acetaminophen. However, no high-quality trials have evaluated opioids specifically for acute lumbosacral radiculopathy. We and many experts oppose the use of opiates for acute radiculopathy given the lack of proven efficacy, the potential for serious side effects, and the potential for misuse and abuse.

However, if opioids are used, measures to reduce the risk of dependency and addiction include the following [18,19]:

•Using short-acting opioid analgesics for the treatment of acute pain only when the severity of the pain is reasonably assumed to warrant their use

•Starting with the lowest possible effective dose

•Prescribing no more than a short course of opioid analgesics for acute pain or no more than three days (some would allow for up to two weeks)

•Avoiding initial treatment with long-acting or extended-release opioid analgesics

Adverse effects of opiates include sedation, confusion, nausea, and constipation. Respiratory depression is an issue at higher doses but rarely at the doses used for acute low back pain. As with other medications, older patients are more susceptible to these adverse effects.

The use of opioids for treatment of non-cancer pain is discussed in greater detail separately. (See "Use of opioids in the management of chronic non-cancer pain", section on 'Indications for opioid therapy'.)

●Benzodiazepines and antispasmodic agents – We generally do not use benzodiazepines or antispasmodic agents (classified as muscle relaxants) for acute lumbosacral radiculopathy. In our clinical experience, muscle relaxants do not provide a significant benefit over nonopioid analgesic medications. Their efficacy has not been demonstrated, and they would be expected to have little benefit for pain arising from the compressed nerve root [17].

●Epidural glucocorticoids – Epidural glucocorticoid injections may provide modest transient benefit for amelioration of back and leg pain in patients with acute lumbosacral radiculopathy. In a trial of 141 patients with acute lumbosacral radiculopathy, patients assigned to glucocorticoid injections had more reduced leg pain at three months than those assigned to placebo, but outcomes between groups were similar for leg pain at six months as well as back pain and physical functioning at all time points [20]. Given the usually self-limited natural history of acute lumbosacral radiculopathy and the availability of alternatives, epidural glucocorticoid injections are generally not recommended during the first four weeks of symptoms of lumbosacral radiculopathy. After weighing risks and benefits, their use may be reasonable for selected patients with lumbosacral radiculopathy who have not improved with conservative treatment over six weeks. However, they provide no benefit beyond three months [21-23]. The risks and benefits of this approach are discussed separately. (See "Subacute and chronic low back pain: Nonsurgical interventional treatment", section on 'Glucocorticoid and other injections'.)

Management for patients with persisting symptoms

Neuroimaging evaluation — Patients whose symptoms persist or worsen during acute treatment should undergo diagnostic testing with neuroimaging. Magnetic resonance imaging (MRI) of the lumbar spine is preferred but computed tomography (CT) with CT-myelography is an alternative modality. (See "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis", section on 'Neuroimaging'.)

Additional testing when neuroimaging is nondiagnostic — Patients whose acute symptoms persist or inadequately respond to symptomatic treatment options used and in whom neuroimaging is nondiagnostic should be reevaluated clinically (typically four to six weeks after symptom onset). This can help verify the diagnosis and provide objective assessment of response to therapy. Reevaluation can help guide whether or not additional time with symptomatic treatment or additional diagnostic testing is warranted. The decision to continue the same symptomatic treatments or change to alternative options is individualized and based on degree of response to initial therapies, severity of symptoms, and patient preferences. For patients in whom a primary neurologic cause is suspected based on symptoms, findings, or clinical course, additional testing may include:

●Lumbar puncture (see "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis", section on 'Cerebrospinal fluid analysis')

●Nerve conductions studies with electromyography (see "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis", section on 'Nerve conduction studies and electromyography')

●Somatosensory evoked potentials (see "Acute lumbosacral radiculopathy: Etiology, clinical features, and diagnosis", section on 'Somatosensory evoked potentials')

It is not known whether four additional weeks of the same symptomatic treatment would be as beneficial as alternative pharmacologic, interventional, or surgical options. Interpretation of the available treatment data is confounded by several issues, which include the benign or self-limited course of lumbosacral radiculopathy, the role of placebo effect, and social factors. These issues impede the selection of effective treatments, particularly for patients who fail to gain complete relief despite a four-week course of analgesic medication, activity modification, and physical treatments.

The management of subacute and chronic lumbosacral radiculopathy is discussed in detail separately. (See "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".)

Patients with disc herniation or spinal stenosis — Surgery for disc herniation and lumbar spinal stenosis is most commonly performed because of progressive neurologic impairment or because of persistent, severe symptoms recalcitrant to conservative measures. The purpose of surgery for symptomatic lumbar disc herniation is to relieve symptoms due to compression or inflammation of affected nerve roots. The surgery involves either partial or complete removal of the herniated disc.

In the setting of progressive neurologic impairment, we recommend urgent surgical consultation. For patients without progressive neurologic impairment but with persistent severe symptoms, the decision to have surgery requires assessing whether a clinically meaningful reduction in pain and/or disability is more likely to occur spontaneously or with surgery. Clinical improvement in pain and neurologic deficits over time will help inform the final decision.

Specific clinical considerations impact utility of surgery for selected symptomatic patients due to acute lumbar disc herniation:

●It is unclear whether early referral for surgery improves outcome in patients with lumbar disc herniation and radiculopathy who do not have severe or progressive neurologic deficits. (See "Subacute and chronic low back pain: Surgical treatment".)

●Guidelines from the American Pain Society recommend that clinicians discuss risks and benefits of surgery with patients who have persistent, disabling radiculopathy due to a herniated lumbar disc [24]. The guidelines note that benefits are moderate on average and decrease over time compared with patients who do not choose to have surgery.

●There is no clear correlation between the size of disc herniation or nerve compression and the amount of spinal nerve root injury. Small compressive lesions can at times produce severe, irreversible nerve damage if they affect arterial blood supply to the nerve. An ischemic nerve lesion, though severe, would not be likely to improve after removal of the compressive lesion.

●The indications for surgical treatment in radiculopathy and spinal stenosis are discussed in detail elsewhere. (See "Subacute and chronic low back pain: Surgical treatment", section on 'Indications for spinal surgery'.)

Patients with other etiologies on neuroimaging

●Neoplasm – The treatment of neoplastic spinal cord lesions is discussed separately. (See "Treatment and prognosis of neoplastic epidural spinal cord compression".)

●Epidural abscess – The treatment of epidural spinal abscess is discussed separately. (See "Spinal epidural abscess", section on 'Management'.)

●Epidural hematoma – The treatment of spinal epidural hematomas is discussed separately. (See "Disorders affecting the spinal cord", section on 'Spinal epidural hematoma'.)

●Transverse myelitis – The treatment of transverse myelitis is discussed separately. (See "Transverse myelitis: Treatment and prognosis", section on 'Idiopathic transverse myelitis'.)

●Spinal vascular malformations – Vascular malformations of the spinal cord are discussed separately. (See "Disorders affecting the spinal cord", section on 'Vascular malformations'.)

PROGNOSIS — While acute lumbosacral radiculopathy is often extremely painful, the likelihood of spontaneous improvement is high when the cause is disc herniation or lumbar spinal stenosis due to degenerative arthritis [25]. However, natural history data for lumbosacral radiculopathy are limited.

Some insight can be gained from placebo arms of randomized trials. In this regard, a trial of 208 patients with acute L5 and/or S1 radiculopathy found no significant difference in outcome for those assigned to nonsteroidal antiinflammatory treatment or to placebo at four weeks, and most patients had a satisfactory recovery [26]. At three months, approximately 30 percent of patients in both groups still had complaints of back pain.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Radiculopathy".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Herniated disc (The Basics)" and "Patient education: Radiculopathy of the neck and back (including sciatica) (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Definition – Lumbosacral radiculopathy is a condition in which a disease process causes functional impairment of one or more lumbosacral nerve roots. The most common cause is structural (ie, disc herniation or degenerative spinal stenosis) leading to root compression. The acute treatment period is four to six weeks. (See 'Introduction' above.)

●Management objectives in acute period – For patients with lumbosacral radiculopathy, the objectives of acute management are twofold (algorithm 1) (see 'Goals of acute management' above):

•To identify patients who require urgent evaluation and to treat specific underlying processes that expose such patients to the risk of progressive or permanent neurologic impairment (mechanism-specific treatment)

•To ameliorate pain (symptomatic treatment)

●Indications for urgent surgical referral – Urgent surgical referral is indicated if there is cauda equina syndrome, high-risk structural lesions, or progressive neurologic compromise or severe weakness unresponsive to conservative measures. (See 'Identifying patients who need urgent diagnostic evaluation' above.)

●Acute symptomatic management – In patients who do not have an indication for urgent treatment, symptomatic treatment is used in the acute period. While acute lumbosacral radiculopathy is often extremely painful, symptoms may spontaneously improve in many cases. (See 'Symptomatic management in other patients' above.)

•Initial treatment with NSAIDs – Analgesic medications such as nonsteroidal antiinflammatory drugs (NSAIDs) or acetaminophen and activity modification are the mainstay of treatment. We suggest a one- to two-week trial of NSAIDS or acetaminophen (Grade 2C) and activity modification (Grade 2C) before reassessing whether or not continued conservative treatment or adjunctive treatments are warranted. (See 'Initial conservative treatment' above.)

•Physical therapy and additional treatment options – For patients whose symptoms persist or who report inadequate response to initial conservative treatment, we suggest continuing initial conservative treatments and adding adjunctive treatments, including a trial of physical therapy (Grade 2C). Some experts use systemic glucocorticoids in addition to physical therapy. (See 'Adjunctive treatments if initial therapy fails' above.)

•Evaluation and management for patients with persistent symptoms

-Neuroimaging – Patients whose symptoms persist or worsen during acute treatment should undergo diagnostic testing with neuroimaging. Magnetic resonance imaging of the lumbar spine is preferred but computed tomography with CT myelography is an alternative modality. (See 'Neuroimaging evaluation' above.)

Treatment is geared toward the underlying cause when neuroimaging is diagnostic. (See 'Patients with disc herniation or spinal stenosis' above and 'Patients with other etiologies on neuroimaging' above.)

-Further management when imaging is nondiagnostic – Patients whose acute symptoms persist or inadequately respond to symptomatic treatment options used and in whom neuroimaging is nondiagnostic should be reevaluated clinically (typically four to six weeks after symptom onset) to help guide whether additional time with symptomatic treatment or further diagnostic testing is warranted. The decision to continue the same symptomatic treatments or change to alternative options is individualized and based on degree of response to initial therapies, severity of symptoms, and patient preferences. (See 'Additional testing when neuroimaging is nondiagnostic' above.)

●Prognosis – While acute lumbosacral radiculopathy is often extremely painful, the likelihood of spontaneous improvement is thought to be high when the cause is disc herniation or lumbar spinal stenosis due to degenerative arthritis. (See 'Prognosis' above.)