Clinical Approach to Back Pain: From Diagnosis to Treatment Strategies (4th Medical student)

Most people will experience back pain at some point in their life, making it one of the most common symptoms.

The most common mechanism of back pain is muscle spasm or muscle strain, occurring with sudden heavy loads or trauma to the back muscles.

Disc degeneration primarily causes leg pain rather than back pain, but is usually associated with facet joint hypertrophy, arthritis, inflammation, and loss of disc height that contribute indirectly to back pain.

Red-flag signs in history include age less than 20 or more than 55 with persisting low back pain, history of malignancy or weight loss, immunosuppression, night pain not improved with rest, and recent trauma.

Cord compression presents with upper motor neuron signs: bilateral lower limb weakness, spasticity, hyperreflexia, and a sensory level corresponding to the compressed cord level.

Cauda equina syndrome presents with a triad of saddle anesthesia or perianal numbness, bladder/bowel dysfunction causing urine retention and overflow incontinence, and sexual dysfunction, along with bilateral sciatica and lower motor neuron signs (weakness, hyporeflexia).

Overflow incontinence in cauda equina occurs when nerve compression to the bladder prevents the patient from feeling the need to urinate, leading to retention and then incontinence when bladder capacity is exceeded; post-void bladder scan shows high volume (at least above 200 mL).

Urge incontinence is a different pathology from cauda equina overflow incontinence; the patient feels the need to urinate but cannot hold urine long enough to reach the toilet due to urethral sphincter weakness.

X-ray is rarely needed for back pain evaluation and has low clinical value for serious back pain, though it is sometimes performed in the emergency department.

CT scan is indicated when bony lesions such as fractured spine or metastatic spine deposits are suspected, and serves as an alternative when MRI is contraindicated.

MRI is the gold standard for back pain investigation, allowing visualization of soft tissue including disc herniation, epidural abscess, and tumors.

According to NICE guidelines, first-line non-pharmacological interventions for back pain include self-management education, exercise (stretching and core muscle strengthening via physiotherapy), manual therapy (massage), and psychological therapy including cognitive behavioral therapy.

Mental health and well-being significantly influence how patients perceive back pain; conditions like fibromyalgia demonstrate this relationship, making psychological interventions effective for chronic back pain.

According to NICE guidelines, first-line pharmacological treatment for low back pain is non-steroidal anti-inflammatory drugs (NSAIDs) such as naproxen or ibuprofen, with proton pump inhibitors given to prevent gastritis.

Second-line pharmacological treatment for low back pain is weak opioids such as oxycodone or co-codamol, not paracetamol.

Paracetamol is not routinely recommended and is not recommended as a standalone treatment for low back pain according to NICE guidelines.

Antidepressants and antiepileptics are not recommended for low back pain according to NICE guidelines.

For neuropathic leg pain, first-line medications include amitriptyline (a tricyclic antidepressant given as a single 10-25 mg dose at night), duloxetine, pregabalin, or gabapentin.

Amitriptyline improves neuropathic pain, helps with sleep, and improves mental health.

Neuropathic pain medications should be started at a low single dose and increased gradually to allow patients to tolerate side effects, with dosing tailored to individual patient response.

Spinal injections (combination of steroids and local anesthetic) are minimally invasive interventions performed under fluoroscopy and X-ray guidance, injected directly to the nerve to address leg pain, not back pain.

Spinal injections use local anesthetic and corticosteroids to decrease inflammation around the nerve and temporarily decrease pain impulses before other treatments take effect.

Radio frequency denervation should be considered for chronic low back pain in patients who show a positive response to medial branch block.

Epidural injection can be used when there is bilateral leg pain to improve the leg pain.

Spinal decompression and discectomy are used for large disc herniation compressing the nerve that does not respond to medical treatment or causes cauda equina syndrome requiring urgent immediate decompression.

Surgical decompression involves removing the herniated portion of the disc and removing part of the bony canal to widen it.

Spinal fusion is indicated for fractured spine with instability; not all fractured spines need fusion, only certain types of instability require fixation, while other cases may be managed with a brace.

Spinal decompression and discectomy primarily address leg pain, not back pain, though back pain may improve indirectly due to improvement in associated pathology such as facet degeneration and ligamentum hypertrophy.

Patients undergoing lumbar decompression should be counseled that the surgery will primarily address leg pain and that back pain may require continued non-pharmacological and pharmacological treatment, though there is a chance back pain will improve.

Back pain that does not improve with exercise is NOT a red flag; pain that improves with exercise typically indicates mechanical back pain and suggests non-serious pathology.

The combination of severe low back pain, bilateral sciatica, saddle anesthesia, and recent onset bladder dysfunction with urinary retention is classic for cauda equina syndrome.

Hyperreflexia below the level of the lesion is the most characteristic sign of spinal cord compression (upper motor neuron lesion) compared to cauda equina syndrome (lower motor neuron lesion).

Imaging studies of the spine should be considered when red flags suggest serious pathology, not routinely for all back pain or based on patient request.