π§ Radiculopathy is dysfunction of a spinal nerve root caused by compression, irritation, or inflammation.
This results in a characteristic triad of:
π Pain (shooting, dermatomal),
π Sensory changes (numbness/tingling),
π Motor weakness with or without reflex loss.
The level of the lesion determines the clinical syndrome.
Most commonly due to πΏ disc herniation or 𦴠degenerative spondylosis, but trauma, infection, and tumours are also important causes.
π§© 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 L4βL5, L5βS1).
- Compression β ischaemia, impaired axonal conduction, and neuroinflammation β pain and neurological deficit.
- Symptoms follow dermatomal and myotomal patterns, aiding localisation.
π©Ί General Clinical Features
- β‘ Radicular pain: sharp, shooting, or burning in a dermatomal distribution.
- π― Paresthesia / numbness: sensory loss in affected dermatome.
- πͺ Weakness: in muscles supplied by the root (myotome).
- π Reflex loss: reduced/absent reflexes (useful for localisation).
- π§ͺ Positive nerve stretch tests:
- π‘ Straight Leg Raise (SLR): reproduces sciatic pain in lumbar radiculopathy.
- π‘ Spurlingβs Test: neck extension + lateral flexion β reproduces symptoms in cervical radiculopathy.
𦴠Cervical Radiculopathies
π C5 Root
- π©Ή Pain: Shoulder radiating to upper arm.
- πͺ Weakness: Deltoid (abduction), external rotation.
- π― Sensory loss: Lateral upper arm.
- π Reflex: Biceps β.
- πΏ Causes: C4βC5 disc herniation, spondylosis, trauma.
- π§ͺ Diagnostics: MRI cervical spine, EMG/NCS.
- π Management: Physiotherapy, NSAIDs; decompression if progressive.
π C6 Root
- π©Ή Pain radiating to thumb.
- πͺ Weakness: biceps, wrist extension.
- π― Sensory loss: lateral forearm + thumb.
- π Reflex: Brachioradialis β.
- πΏ Causes: Disc herniation at C5βC6 (most common cervical root).
- π Management: Conservative first; ACDF if severe.
π C7 Root
- π©Ή Pain radiating to middle finger.
- πͺ Weakness: triceps, wrist flexion.
- π― Sensory loss: index & middle fingers.
- π Reflex: Triceps β.
- πΏ Causes: C6βC7 disc herniation (most common overall).
𦡠Lumbar Radiculopathies
π L4 Root
- π©Ή Pain: anterior thigh β medial knee/leg.
- πͺ Weakness: quadriceps, hip flexion.
- π― Sensory loss: medial lower leg.
- π Reflex: Patellar β.
- πΏ Causes: L3βL4 disc herniation, spondylosis.
π L5 Root
- π©Ή Pain: lateral thigh/leg β dorsum of foot.
- πͺ Weakness: dorsiflexion β foot drop.
- π― Sensory loss: dorsum of foot, great toe.
- π Reflex: None reliable.
- πΏ Causes: L4βL5 disc herniation (most common lumbar radiculopathy).
π S1 Root
- π©Ή Pain: posterior leg β sole of foot.
- πͺ Weakness: plantarflexion.
- π― Sensory loss: lateral foot + sole.
- π Reflex: Achilles β.
- πΏ Causes: L5βS1 disc herniation, stenosis.
π Quick Comparison Table
Root |
Motor Deficit |
Sensory Loss |
Reflex |
Key Clinical Pearl |
C5 |
Deltoid (abduction) |
Lateral upper arm |
Biceps β |
Shoulder pain, not beyond elbow |
C6 |
Biceps, wrist extension |
Lateral forearm, thumb |
Brachioradialis β |
βThumb involvementβ |
C7 |
Triceps, wrist flexion |
Middle finger |
Triceps β |
Most common cervical root |
L4 |
Quadriceps |
Medial leg |
Patellar β |
Think βknee jerkβ |
L5 |
Dorsiflexion (foot drop) |
Dorsum of foot |
None reliable |
Most common lumbar root |
S1 |
Plantarflexion |
Lateral foot, sole |
Achilles β |
Loss of ankle jerk = S1 |
π§ͺ Diagnosis
- π Clinical exam: Localises lesion (dermatomes, reflexes, power).
- π₯οΈ MRI spine: Gold standard for herniated disc, stenosis, tumour.
- β‘ EMG/NCS: Confirms root dysfunction, excludes peripheral neuropathy.
- π© Red flags: bilateral weakness, saddle anaesthesia, bladder/bowel dysfunction β cauda equina syndrome (emergency MRI & surgery).
π Management
- π Conservative: Rest, physiotherapy, NSAIDs, neuropathic agents (gabapentin, pregabalin).
- π Interventional: Epidural steroid injections for persistent pain.
- πͺ Surgery: Indications = progressive weakness, intractable pain, or cauda equina. Procedures include discectomy, laminectomy, ACDF (cervical).
π‘ Tips & Teaching Pearls
- π Pattern recognition is everything: Thumb β C6, Middle finger β C7, Foot drop β L5.
- π§ͺ Reflexes localise: Biceps (C5/6), Triceps (C7), Knee jerk (L4), Ankle jerk (S1).
- β‘ Most common levels: C6βC7 in cervical, L4βL5 and L5βS1 in lumbar.
- π© Always screen for cauda equina syndrome: urinary retention, incontinence, saddle anaesthesia, bilateral sciatica β red flag for emergency referral.
- π§ Patient advice: Most radiculopathies improve within weeks to months with conservative therapy; reassure but safety-net for red flags.
- π₯ In UK practice: NICE recommends conservative care first, unless neurological deficit or red flag features.