What are low back or neck radiculopathies

Radiculopathy is a condition caused by compression, inflammation, or injury to a spinal nerve root, resulting in pain, numbness, tingling, or weakness along the nerve’s path.

What is involved?

Spinal Nerve Roots:

• Cervical (C2-C8)
• Thoracic (T1-T12)
• Lumbar (L1-L5)
• Sacral (S1-S4)

Location

• Cervical Radiculopathy: most commonly C6 and C7 roots
• Thoracic Radiculopathy: rare, T6-T12 most common
• Lumbar Radiculopathy: most commonly L4, L5, and S1 roots

Common symptoms

Cervical Radiculopathy

• Neck pain radiating to shoulder, arm, hand
• Numbness/tingling in specific fingers
• Arm weakness
• Pain worse with neck movement, Valsalva

Lumbar Radiculopathy (Sciatica)

• Low back pain radiating to buttock, leg, foot
• Numbness/tingling in specific dermatome
• Leg weakness
• Pain worse with sitting, bending, coughing, sneezing

Root-Specific Patterns

Root	Pain/Numbness	Weakness	Reflex
C5	Lateral shoulder/arm	Deltoid, Biceps	Biceps
C6	Lateral forearm, thumb, index	Biceps, Wrist extensors	Brachioradialis
C7	Middle finger, posterior arm	Triceps, Finger extensors	Triceps
C8	Medial forearm, ring, little	Hand intrinsics, Finger flexors	None
L4	Anterior thigh, medial leg	Quadriceps, Tibialis Anterior	Patellar
L5	Lateral leg, dorsum foot, great toe	Tibialis Anterior, EHL, Hip abductors	None (or medial hamstring)
S1	Posterior leg, lateral foot, little toe	Gastrocnemius, Hamstrings	Achilles

Onset

• Acute: sudden onset with disc herniation
• Chronic: gradual onset with spondylosis, stenosis
• Can have acute on chronic pattern

Risk factors

• Age (disc degeneration)
• Heavy lifting, poor body mechanics
• Prolonged sitting or driving
• Obesity
• Smoking
• Trauma
• Diabetes (increases nerve vulnerability)
• Occupational factors (vibration exposure)

Exam

Cervical Radiculopathy

• Limited neck range of motion
• Spurling test positive (head extension and rotation to affected side reproduces symptoms)
• Weakness in myotomal pattern
• Sensory loss in dermatomal pattern
• Decreased deep tendon reflex (C5-biceps, C6-brachioradialis, C7-triceps)

Lumbar Radiculopathy

• Limited lumbar range of motion
• Positive straight leg raise (L5, S1)
• Positive femoral stretch test (L2-L4)
• Weakness in myotomal pattern
• Sensory loss in dermatomal pattern
• Decreased deep tendon reflex (L4-patellar, S1-Achilles)

Red Flags (Require Urgent Evaluation)

• Bowel or bladder dysfunction (cauda equina)
• Progressive motor weakness
• Bilateral symptoms
• Saddle anesthesia
• Fever, weight loss (infection, malignancy)

EMG

EMG is excellent for confirming radiculopathy and identifying the involved root level.

Key Principles

• Abnormalities appear 2-3 weeks after symptom onset
• Must sample multiple muscles from same root but different peripheral nerves
• Paraspinal muscles should be examined
• Sensory nerve studies are NORMAL (lesion proximal to DRG)

Findings

• Fibrillation potentials and positive sharp waves in affected myotome
• Reduced recruitment of motor units
• Large, polyphasic motor units (chronic changes)
• Paraspinal denervation helps confirm root level
• Normal sensory nerve action potentials
• H-reflex may be prolonged or absent (S1 radiculopathy)
• F-waves may be prolonged or absent

Muscles to Sample by Root

Cervical: | Root | Muscles | |------|---------| | C5 | Deltoid, Biceps, Infraspinatus, Rhomboids | | C6 | Biceps, Pronator Teres, FCR, Brachioradialis | | C7 | Triceps, FCR, Pronator Teres, EDC | | C8 | FDI, ADM, EIP, FDP |

Lumbosacral: | Root | Muscles | |------|---------| | L4 | Vastus Lateralis, Tibialis Anterior, Adductors | | L5 | Tibialis Anterior, EHL, Gluteus Medius, Tibialis Posterior | | S1 | Gastrocnemius, Gluteus Maximus, Biceps Femoris |

Limitations

• May be normal in early or pure sensory radiculopathy
• May be normal if patient has fully recovered
• Cannot distinguish between disc herniation and other causes

Recommendations

Conservative Treatment (First Line)

• Activity modification (avoid aggravating activities)
• NSAIDs, muscle relaxants
• Physical therapy
• Short course of oral steroids for acute radicular pain
• Most disc herniations improve within 6-12 weeks

Interventional Treatment

• Epidural steroid injections
• Selective nerve root blocks (diagnostic and therapeutic)

Surgical Treatment

Indications:

• Progressive motor weakness
• Cauda equina syndrome (emergency)
• Failure of conservative treatment after 6-12 weeks
• Intractable pain

Procedures:

• Microdiscectomy
• Laminectomy
• Foraminotomy
• Fusion (for instability)

What else could it be?

• Peripheral Nerve Entrapment: different distribution, focal slowing on NCS
• Plexopathy: abnormal sensory potentials, multiple root involvement
• Peripheral Neuropathy: bilateral, symmetric, length-dependent
• Motor Neuron Disease: no sensory symptoms, widespread denervation
• Myopathy: proximal weakness, no sensory symptoms, myopathic EMG
• Hip or Shoulder Pathology: localized joint pain
• Piriformis Syndrome: buttock pain with sciatic symptoms
• Herpes Zoster: dermatomal pain and rash
• Diabetic Amyotrophy: painful, asymmetric proximal leg weakness