Non-radicular lower back pain and sciatica

Red flags suggestive of cancer causing sciatica

>50yo or <20 with NEW onset pain Gradual onset Severe unremitting pain that remains when the person is supine, aching night pain that prevents or disturbs sleep, pain aggravated by straining (for example, at stool, or when coughing or sneezing), and thoracic pain. Localised spinal tenderness No symptomatic improvement after four to six weeks of conservative low back pain therapy Unexplained weight loss >10kg in 6months Past history of cancer — breast, lung, GI, prostate, renal, and thyroid cancers are more likely to metastasize to the spine.

Causes of sciatica

A herniated intervertebral disc ("slipped disc") in 90% of cases, most commonly at L4/5 and L5/S1 level Spondylolisthesis (when a proximal vertebra moves forward relative to a distal vertebra) Spinal stenosis (spinal canal narrowing) either due to congenital stenosis or spondylolisthesis - lateral recess stenosis and foraminal stenosis tend to cause sciatica - central spinal stenosis tends to cause spinal claudication (bilateral calf pain, paraesthesia, or numbness on walking) Infection e.g. discitis, vertebral osteomyelitis or spinal epidural abscess Cancer (most often mets)

When to suspect non-specific low back pain as cause of low back pain

Absence of features suggestive of another cause Pain varies with posture + time Exacerbated by movement

Pain killers to offer for neuropathic pain

Amitriptyline, duloxetine, gabapentin or pregabalin - do not prescribe more than one at the same time For gabapentin or pregabalin, carefully evaluate for a history of drug abuse before prescribing them and observe for development of signs of abuse/dependence Response to drug treatment is often inadequate, with no more than 40-60% of people obtaining partial pain relief Capsaicin 0.075% cream may be considered for localized neuropathic pain wanting to avoid or not tolerating oral treatments Refer to specialist pain clinic if no response to the 4 neuropathic agents or if pain severe, significantly limits their participation in daily activities Consider prescribing tramadol short-term (controlled drug) whilst awaiting referral https://cks.nice.org.uk/topics/neuropathic-pain-drug-treatment/prescribing-information/

Diagnosing sciatica

Assess for red flag symptoms and signs suggestive of more concerning symptoms of sciatica (see later flashcards) Suspect sciatica if: - unilateral leg pain radiating down back/outside of leg below the knee to the foot or toes - LBP (IF present is often less severe than the leg pain) - numbness, tingling, muscle weakness, muscle spasm and loss of tendon reflexes in the distribution of a nerve root (dermatome) — this suggests nerve root compression Sitting, coughing and straining may aggravate the pain Positive straight leg raising test — with the person lying lying down on their back, raising the leg whilst it is straight causes greater pain radiation below the knee and/or more nerve compression symptoms. Examine hips + knees too, which helps reveal most of the conditions with similar symptoms

Red flags suggestive of cauda equina

Bilateral sciatica Severe/progressive bilateral neurological deficit such as major motor weakness with knee extension/ankle eversion/foot dorsiflexion Difficulty initiating micturition or impaired sensation of urinary flow - if untreated this may lead to irreversible urinary retention with overflow urinary incontinence Loss of sensation of rectal fullness - if untreated this may lead to irreversible faecal incontinence Perianal, perineal or genital sensory loss (saddle anaesthesia or paraesthesia), erectile dysfunction Laxity of the anal sphincter - consider an assessment of anal tone but this does not need to be performed in primary care

Management of non-specific low back pain

Encourage continuing normal activities of daily living and return to work ASAP Normal movements may produce some pain which should not be harmful if activities are resumed gradually and as tolerated Refhelp says increase physical activity progressively over a few days to weeks Local heat may relieve pain + muscle spasm Offer info on simple exercises (see NICE cks page for links) ANALGESIA - 1st line ibuprofen/naproxen - 2nd line codeine +/- paracetamol (paracetamol alone isn't really any good) For muscle spasm, consider offering a short course of benzos e.g. diazepam 2mg max TDS Do not ROUTINELY offer opioids for managing acute low back pain. Do not offer opioids, SSRIs, SNRIs, TCAs, gabapentinoids or antiepileptics for managing chronic low back pain. Consider referral to physio for manual therapy (spinal manipulation, mobilisation or massage) + exercise (in Lothian this is via the integrated back pan service) Consider referral for CBT if significant psychosocial obstacles to recovery Advise patient to seek f/u if no better or worsening in 3-4 weeks

Prognosis of sciatica

Episodes are usually transient with rapid improvement in weeks to months (most cases settle within 4-6 weeks) Recurrence is common

Red flags suggestive of infection causing sciatica

Fever/rigors General malaise TB or recent urinary tract infection Diabetes History of IVDU HIV infection, use of immunosuppressants, or otherwise immunocompromised. Recent disc surgery/discography

Refhelp criteria for suspected axial spondyloarthritis

LBP started before 45yo and lasted for >3 months + 4 or more of the following: Low back pain that started before the age of 35 years (this further increases the likelihood that the back pain is due to spondyloarthritis, compared with low back pain that started between 35 and 44 years). Waking during the second half of the night due to symptoms. Buttock pain. Improvement with movement. Improvement within 48 hours of taking NSAIDs. A first degree relative with spondyloarthitis. Current or past arthritis. Current or past enthesitis (inflammation of a site at which a tendon or ligament attaches to the bone). Current or past psoriasis. Or 3 of the above and a positive HLA-B27 test.

Management of sciatica

Lifestyle modication and self-management as per non-specific low back pain A small firm cushion between the knees when sleeping on the side, or several firm pillows propping up the knees when lying on the back, may ease symptoms Analgesia - as for non-radicular back pain - NICE cks suggests that if symptoms persist or worsening despite the above prescribe a neuropathic agent NICE cks seems to suggest that there is limited evidence of benefit from the use of NSAIDs in sciatica, but then to use analgesia as for non-radicular LBP which recommends NSAIDs first line! Do not offer gabapentinoids, other antiepileptics, oral corticosteroids or benzos for managing sciatica as there is no overall evidence of benefit and there is evidence of harm. Do not offer opioids for managing chronic sciatica. Consider referral to physio for manual therapy (spinal manipulation, mobilisation or massage) + exercise (in Lothian this is via the integrated back pan service) Consider referral for CBT if significant psychosocial obstacles to recovery NICE suggests that people should seek advice in 1-2 weeks if symptoms persist or worsen Back pain service can arrange epidural corticosteroid/LA injections, radiofrequency denervation or spinal decompression

Prognosis of non-specific low back pain

Mostly resolves within 4 weeks with self-care Likely to last longer if avoid work, movement or other activities due to fear of exacerbating the pain Recurrance very common (40-80% within a year) About 5% of those with acute low back pain will develop persistent back pain

When to suspect ankylosing spondylitis (particularly if <40yo male) as the cause of low back pain

Night pain not relieved by being supinne Morning stiffness relieved with movement/exercise Gradual onset of symptoms Symptoms >3months

Definition of low back pain

Pain in the lumbosacral area of the back, between the bottom of the ribs and the top of the legs/buttock creases

Definition of sciatica

Pain/tingling/numbness felt in the distribution of a nerve root(s), arising from impingement of the lumbrosacral nerve roots as they emerge from the spinal canal Symptoms typically extend from the buttocks across the back of the thigh to below the knee, and often to the foot and toes There may be accompanying motor weakness in a corresponding myotomal distribution

Complications of sciatica

Permanent nerve damage with possible sensory deficits and motor weakness, such as foot drop. There is an increased risk of permanent damage to a compressed nerve if there is significant muscle weakness or wasting, and/or loss of tendon reflexes.

Sciatica differential diagnoses

Referred pain from hip OA Sacroiliitis in ankylosing spondylitis and other spondyloarthropathies Intervertebral facet joint pain Trochanteric bursitis Piriformis syndrome (where the sciatic nerve is compressed or irritated where it is covered by the piriformis muscle) Peroneal palsy or other neuropathies — e.g. nerve entrapment at the fibular head Spinal claudication Aseptic necrosis of the femoral head Myelopathy or a higher cord lesion

Nature of neuropathic pain

Shooting, stabbing, electric-shock like, burning, tingling, tight, numb, prickling, itching May also experience: Allodynia — pain caused by a stimulus that does not normally provoke pain (for example, pain in response to light touch/pressure). Hyperalgesia — an increased response to a stimulus that is normally painful. Anaesthesia dolorosa — pain felt in an anaesthetic area or region. Sensory gain or loss.

Causes of low back pain

Specific - sciatica, vertebral fracture, intra-abdominal pathology, ankylosing spondylitis, cancer, infection Non-specific low back pain - diagnosed when the pain cannot be attributed to a specific cause - in many causes it may be related to trauma or musculoligamentous strain

Possible RFs for sciatica

Strenuous physical activity e.g. frequent heavy lifting especially whilst bending, twisting, jogging Whole body vibration e.g. operating heavy machinery Smoking Obesity

Red flags suggestive of spinal fracture causing sciatica

Sudden onset of severe central spinal pain relieved by lying down There may be a history of major trauma (such as a road traffic collision or fall from a height), minor trauma, or even just strenuous lifting in people with osteoporosis or those on corticosteroids Structural deformity of the spine (such as a step from one vertebra to an adjacent vertebra) may be present Point tenderness over a vertebral body may be present

Assessment of someone with low back pain

Type of pain Duration of symptoms Aggravating and relieving factors Associated symptoms Radiation of pain Night pain? Red flags? Observe gait, posture, skin and any bruising, skin changes, rashes, deformity or swelling of the back. Perform a neurological examination looking for loss of sensation, changes to reflexes, limitation of range of movement including straight leg raising, tenderness, and fever. Consider an assessment of anal tone but note that this does not need to be performed in primary care.