Radiculopathies

🧠 Radiculopathy is dysfunction of a spinal nerve root caused by compression, irritation, or inflammation. This results in a characteristic triad of: 👉 Pain (shooting, dermatomal), 👉 Sensory changes (numbness/tingling), 👉 Motor weakness with or without reflex loss.
The level of the lesion determines the clinical syndrome. Most commonly due to 💿 disc herniation or 🦴 degenerative spondylosis, but trauma, infection, and tumours are also important causes.

🧩 Pathophysiology

• Spinal nerve roots exit through the intervertebral foramina, where they are vulnerable to compression.
• Cervical roots: usually affected by disc protrusion or osteophytes.
• Lumbar roots: commonly affected by herniated nucleus pulposus (especially L4–L5, L5–S1).
• Compression → ischaemia, impaired axonal conduction, and neuroinflammation → pain and neurological deficit.
• Symptoms follow dermatomal and myotomal patterns, aiding localisation.

🩺 General Clinical Features

• ⚡ Radicular pain: sharp, shooting, or burning in a dermatomal distribution.
• 🎯 Paresthesia / numbness: sensory loss in affected dermatome.
• 💪 Weakness: in muscles supplied by the root (myotome).
• 🔔 Reflex loss: reduced/absent reflexes (useful for localisation).
• 🧪 Positive nerve stretch tests:
  • 💡 Straight Leg Raise (SLR): reproduces sciatic pain in lumbar radiculopathy.
  • 💡 Spurling’s Test: neck extension + lateral flexion → reproduces symptoms in cervical radiculopathy.

🦴 Cervical Radiculopathies

👉 C5 Root

• 🩹 Pain: Shoulder radiating to upper arm.
• 💪 Weakness: Deltoid (abduction), external rotation.
• 🎯 Sensory loss: Lateral upper arm.
• 🔔 Reflex: Biceps ↓.
• 💿 Causes: C4–C5 disc herniation, spondylosis, trauma.
• 🧪 Diagnostics: MRI cervical spine, EMG/NCS.
• 💊 Management: Physiotherapy, NSAIDs; decompression if progressive.

👉 C6 Root

• 🩹 Pain radiating to thumb.
• 💪 Weakness: biceps, wrist extension.
• 🎯 Sensory loss: lateral forearm + thumb.
• 🔔 Reflex: Brachioradialis ↓.
• 💿 Causes: Disc herniation at C5–C6 (most common cervical root).
• 💊 Management: Conservative first; ACDF if severe.

👉 C7 Root

• 🩹 Pain radiating to middle finger.
• 💪 Weakness: triceps, wrist flexion.
• 🎯 Sensory loss: index & middle fingers.
• 🔔 Reflex: Triceps ↓.
• 💿 Causes: C6–C7 disc herniation (most common overall).

🦵 Lumbar Radiculopathies

👉 L4 Root

• 🩹 Pain: anterior thigh → medial knee/leg.
• 💪 Weakness: quadriceps, hip flexion.
• 🎯 Sensory loss: medial lower leg.
• 🔔 Reflex: Patellar ↓.
• 💿 Causes: L3–L4 disc herniation, spondylosis.

👉 L5 Root

• 🩹 Pain: lateral thigh/leg → dorsum of foot.
• 💪 Weakness: dorsiflexion → foot drop.
• 🎯 Sensory loss: dorsum of foot, great toe.
• 🔔 Reflex: None reliable.
• 💿 Causes: L4–L5 disc herniation (most common lumbar radiculopathy).

👉 S1 Root

• 🩹 Pain: posterior leg → sole of foot.
• 💪 Weakness: plantarflexion.
• 🎯 Sensory loss: lateral foot + sole.
• 🔔 Reflex: Achilles ↓.
• 💿 Causes: L5–S1 disc herniation, stenosis.

📊 Quick Comparison Table

🧪 Diagnosis

• 🔍 Clinical exam: Localises lesion (dermatomes, reflexes, power).
• 🖥️ MRI spine: Gold standard for herniated disc, stenosis, tumour.
• ⚡ EMG/NCS: Confirms root dysfunction, excludes peripheral neuropathy.
• 🚩 Red flags: bilateral weakness, saddle anaesthesia, bladder/bowel dysfunction → cauda equina syndrome (emergency MRI & surgery).

💊 Management

• 🛌 Conservative: Rest, physiotherapy, NSAIDs, neuropathic agents (gabapentin, pregabalin).
• 💉 Interventional: Epidural steroid injections for persistent pain.
• 🔪 Surgery: Indications = progressive weakness, intractable pain, or cauda equina. Procedures include discectomy, laminectomy, ACDF (cervical).

💡 Tips & Teaching Pearls

• 🔑 Pattern recognition is everything: Thumb → C6, Middle finger → C7, Foot drop → L5.
• 🧪 Reflexes localise: Biceps (C5/6), Triceps (C7), Knee jerk (L4), Ankle jerk (S1).
• ⚡ Most common levels: C6–C7 in cervical, L4–L5 and L5–S1 in lumbar.
• 🚩 Always screen for cauda equina syndrome: urinary retention, incontinence, saddle anaesthesia, bilateral sciatica → red flag for emergency referral.
• 🧘 Patient advice: Most radiculopathies improve within weeks to months with conservative therapy; reassure but safety-net for red flags.
• 🏥 In UK practice: NICE recommends conservative care first, unless neurological deficit or red flag features.