Sciatica & Lumbar Disc Herniation

The most common underlying cause of lumbar disc herniation is age-related disc degeneration. Over time, intervertebral discs lose water content and elasticity, making them less able to absorb mechanical load and more susceptible to tearing. This degeneration can make even everyday activities a potential trigger for herniation.

Common contributing factors include:

• Age-related disc degeneration — discs become drier and more brittle with age, increasing the risk of tearing
• Heavy lifting or improper lifting technique — placing sudden excessive load on lumbar discs
• Repetitive bending, twisting, or stooping — common in manual occupations
• Prolonged sitting — particularly relevant for desk workers and drivers
• Obesity — excess body weight increases the mechanical load on lumbar discs
• Sedentary lifestyle — weakened core and paraspinal muscles reduce spinal support
• Smoking — impairs disc nutrition and accelerates degeneration
• Genetic predisposition — family history of disc disease increases individual risk
• Acute trauma — such as a fall or motor vehicle accident, though this is less common
• Often no cause can be identified

It is important to note that many people have imaging evidence of disc herniation without any symptoms. The clinical significance of a disc herniation depends not just on its size and location, but on whether it is compressing neurological structures and producing symptoms.

Symptoms vary depending on the level of the spine affected, the degree of nerve compression, and individual patient factors. Some disc herniations cause no symptoms at all, while others can be severely disabling.

Pain Symptoms

The hallmark symptom is sciatica — a sharp, burning, or electric-shock-like pain that travels from the lower back through the buttock and down one leg, sometimes reaching the foot. Leg pain is often more severe than back pain and is typically worsened by sitting, coughing, sneezing, or straining. The pain distribution follows the path of the compressed nerve root and can help localise the level of herniation.

Nerve-Related Symptoms (Radiculopathy)

In addition to pain, nerve compression (radiculopathy) can produce:

• Numbness and tingling (paraesthesia) in the leg, calf, or foot
• Weakness of the foot, ankle, or leg muscles
• Reduced or absent reflexes — such as loss of the ankle jerk reflex
• A sensation of heaviness or dragging in the affected limb

Red Flag Symptoms — Seek Urgent Medical Attention

In rare but serious cases, a large disc herniation can compress multiple nerve roots in the cauda equina, causing cauda equina syndrome. This is a surgical emergency. Seek immediate medical attention at your nearest emergency department if you experience any of the following:

• Sudden or progressive weakness in both legs
• Loss of bladder control — inability to urinate or urinary incontinence
• Loss of bowel control
• Numbness or reduced sensation in the saddle region (inner thighs, perineum, and buttocks)
• Rapidly worsening neurological symptoms

Cauda equina syndrome requires emergency surgical decompression and must not be delayed. If in doubt, present to your nearest emergency department immediately.

Accurate diagnosis of lumbar disc herniation requires a combination of clinical assessment and targeted imaging. At One Brain and Spine, our neurosurgeons take a thorough and systematic approach to ensure the correct diagnosis and to tailor treatment to each individual patient.

Clinical Assessment

Your neurosurgeon will take a detailed history of your symptoms — including the onset, character, distribution, and aggravating factors of your pain — as well as a comprehensive neurological examination assessing strength, sensation, and reflexes in the lower limbs. This examination helps localise the level of nerve compression and guides investigation.

Imaging Investigations

• MRI (Magnetic Resonance Imaging) — the gold standard for diagnosing lumbar disc herniation. MRI clearly demonstrates the disc, adjacent nerve roots, and degree of neural compression without radiation exposure.
• CT Scan (Computed Tomography) — useful when MRI is contraindicated or to assess bony anatomy in detail.
• X-ray — does not visualise discs or nerves directly, but is useful for assessing spinal alignment, disc space height, and the presence of instability.
• CT Myelogram — occasionally used when further definition of neural compression is required.
• Nerve Conduction Studies (NCS) and Electromyography (EMG) — may be used to assess nerve function and distinguish between spinal and peripheral nerve pathology.

It is important to interpret imaging findings in the context of clinical symptoms. Disc herniations are common incidental findings in asymptomatic individuals, and treatment decisions are always guided by the patient's clinical presentation, not imaging alone.

Non-Surgical Treatment Options

The majority of patients with lumbar disc herniation will improve with non-surgical management. Research indicates that up to 86% of episodes of sciatica from disc herniation resolve with appropriate conservative treatment, and that many disc herniations will reduce in size over time without surgery.

Non-surgical treatment options include:

• Activity modification — avoiding aggravating activities such as heavy lifting, prolonged sitting, and repetitive bending while remaining as active as tolerable
• Analgesic medications — including paracetamol and anti-inflammatory medications (NSAIDs) to manage pain and reduce inflammation
• Neuropathic pain medications — such as gabapentin or pregabalin, which can be helpful for nerve-related pain
• Physiotherapy — targeted exercises to improve core stability, spinal mobility, and posture
• Pilates and hydrotherapy — low-impact approaches to strengthening the spinal support musculature
• Epidural steroid injections — corticosteroid injected around the affected nerve root to reduce inflammation and provide pain relief
• Nerve root (transforaminal) injections — targeted injection at the specific level of nerve compression
• Referral to a pain management specialist — for complex or refractory cases
• Weight management — reducing body weight decreases the mechanical load on lumbar discs

When is Surgery Required for Lumbar Disc Herniation?

Surgery is considered when non-surgical treatment has been trialled appropriately and has not provided sufficient relief, or when there are signs of significant or progressive neurological compromise. Surgery is not required for all patients with lumbar disc herniation.

Surgical indications include:

• Persistent severe sciatica that has not improved after 6–12 weeks of adequate conservative management
• Progressive neurological deficit — worsening weakness or increasing numbness in the leg or foot
• Significant functional limitation — inability to work or perform daily activities
• Cauda equina syndrome — this is an absolute surgical emergency requiring urgent decompression
• Patient preference — in selected cases where rapid return to function is a priority and the patient is well informed

Surgical Treatment Options

At One Brain and Spine, our neurosurgeons employ the most advanced surgical techniques to achieve optimal outcomes with minimal tissue disruption.

Microdiscectomy (Minimally Invasive)

Microdiscectomy is the gold-standard surgical procedure for lumbar disc herniation. Through a small incision in the lower back, the surgeon uses microscopic magnification to remove the herniated disc fragment compressing the nerve. The procedure preserves the majority of the disc and surrounding structures. Most patients experience significant relief from leg pain immediately following surgery. The procedure is typically performed with an overnight stay.

Endoscopic Discectomy

Endoscopic techniques represent the latest advancement in minimally invasive spine surgery. Using small working channels and a camera, the herniated disc can be removed with even less soft tissue disruption than traditional microdiscectomy. Uniportal and Biportal endoscopic approaches are available at One Brain and Spine, and may be suitable for selected patients seeking the most minimally invasive option.‍

Spinal Fusion

Spinal fusion is rarely required for isolated disc herniation. It may be considered in the uncommon situation where there is associated segmental instability or spondylolisthesis contributing to the patient's symptoms.

Recovery and Prognosis

Outcomes following surgery for lumbar disc herniation are generally excellent. Up to 90% of patients experience significant improvement in leg pain (sciatica) following microdiscectomy.

Recovery milestones:

• Leg pain relief — often experienced immediately or within days of surgery
• Hospital stay — typically one overnight stay
• Mobilisation — patients are encouraged to walk on the day of surgery
• Return to sedentary work — usually within 1–2 weeks
• Return to physical work or sport — typically 4–6 weeks, depending on individual progress
• Back pain — may persist for some weeks following surgery and gradually improves
• Nerve recovery — numbness and weakness may take weeks to months to fully resolve, depending on the duration and severity of compression prior to surgery

Risks and Complications

As with any surgical procedure, microdiscectomy carries a small risk of complications. These are uncommon and your surgeon will discuss them with you in detail prior to proceeding. Potential risks include:

• Recurrent disc herniation — occurring in approximately 5–10% of patients
• Nerve injury — rare, but can result in persistent pain, weakness, or numbness
• Infection — including superficial wound infection or, rarely, discitis
• Dural tear — inadvertent opening of the membrane surrounding the spinal cord (CSF leak), usually managed at the time of surgery
• Bleeding — haematoma formation is rare
• Incomplete symptom relief — some patients may have residual symptoms, particularly if nerve damage was prolonged prior to surgery
• Anaesthetic risks — discussed separately with your anaesthetist