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Information

Editors

EBMG

Radiculopathies

Essentials

  • Pain radiating from the spine to the territory innervated by the affected root is the most typical sign of root compression.
  • The most common causes of root compression comprise a prolapsed disc in the lumbar or cervical region and degenerative changes of the spine.
  • Keep in mind emergency situations.
    • Cauda equina syndrome
    • Spinal cord compression symptoms
    • L5-root-related paresis of the peroneus nerve with sudden onset

Symptoms and signs

  • In radiating pain caused by root compression, increased compression intensifies the pain and reduced compression relieves it.
  • In mild cases there may be radiating paraesthesia in the territory innervated by the affected root instead of pain.
  • There are variations and overlap between territories innervated by separate roots. Therefore, even a complete loss of one root may not result in complete sensory loss.
  • Weakness in muscles innervated by a root and muscular atrophy in chronic states. The muscles are, however, innervated by several roots. Chronic root lesions may involve fasciculations.
  • The reflexes innervated by the root become diminished or absent within hours.
  • Clinical findings in nerve root lesions: see table T1

Clinical findings in nerve root lesions

CERVICAL NERVE ROOTS
RootRadiates toAffected musclesReflex
C2-C3Occiput-
C4Neck-
C5Shoulder, upper armShoulder, upper armBiceps
C6ThumbUpper arm, forearmBiceps
C7Middle fingerForearm, handTriceps
C8Little fingerIntrinsic muscles of the handTriceps
THORACIC NERVE ROOTS
RootSensory level
Th1Below the clavicle
Th5Nipples
Th10Navel
Th12Groin
LUMBAR NERVE ROOTS
RootRadiates toWeaknessReflex
L2Base of the thighLumbar flexion
L3Front of the thighKnee extension
L4Front of the thigh and of the lower legKnee extensionPatella
L5Big toeBig toe extension and ankle flexion-
SACRAL NERVE ROOTS
RootRadiates toImpairmentReflex
S1Heel and sole of the footRising on toesAchilles tendon
S2-4Buttock and perianal area"Saddle" denervation, bladder, bowel, sexual functionPerianal

Causes

Compression

  • Prolapsed disc
    • Most common cause in the lumbar region Low Back Pain
    • In root-related conditions with weakness in the lower extremities, pain is usually felt in the lower back and/or radiating pain in the lower limb. If there is no pain associated with the weakness, other causes than radiculopathy should be suspected (spinal cord disorders, see Diseases of the Spinal Cord; or gait disturbances, see Gait Disturbances).
    • Prolapsed disc in the cervical spine Neck and Shoulder Pain
      • The pain radiates down the upper limb and intensifies when the head is inclined toward the side of the pain.
      • The neck is often stiff.
      • The most common site is C5-C6; next most common are C4-C5 and C6-C7.
    • A medial prolapse may compress the spinal cord and cause, depending on the level, weakness in the upper and lower extremities or only lower extremities; in such cases treatment is urgently required.
    • Treatment for mild conditions is conservative. Surgical treatment should be considered if the patient has muscle weakness, severe sensory disturbances in the territory innervated by the affected root or chronic (lasting over 6 weeks) intense pain.
  • Tumours
    • Symptoms progress slowly and usually extend to several roots.
    • If the tumour is located in the neck or the thoracic spine, there are also symptoms of spinal cord compression.
    • Neurinoma causes a widening in the root canal of the nerve, evident in plain x-rays (the C2 root canal is normally wider than the others; thus both sides must be compared).
  • Degenerative changes
    • Especially in the cervical spine region, narrowing of the root canal may cause symptoms of nerve root irritation.
    • It should be considered whether the radiographic and clinical findings indicate the same segmental level.
      • Imaging often reveals asymptomatic narrowed intervertebral foramina.

Inflammation

  • Herpes zoster Shingles (Herpes Zoster)
  • Radiculitis
    • Radiculites affecting one or more roots whose aetiology often remains unknown occur in both the cervical and the lumbar regions. Conditions such as Lyme disease may be a possible cause.
  • Polyradiculitis

Diabetes

  • Diabetic radiculopathy of the thoracic region causes unilateral encircling pain, sensory impairment, and localized muscle weakness Diabetic Neuropathy.

Diagnosis

  • The diagnosis is based on the clinical picture in acute situations where no alarming "red flag" signs are present Low Back Pain.
  • As for further investigations, MRI is the primary imaging mode. Depending on the level of symptoms, either an MRI of the whole spinal canal or of the lumbar spine is performed.
  • ENMG is helpful in differentiating between root and other peripheral nerve disorders and provides information about the duration of the disorder.
  • Denervation does not develop until after 2-3 weeks; therefore ENMG is not helpful in conditions requiring urgent treatment Clinical Neurophysiology in Diagnostics.

Urgency of treatment

  • Emergencies
    • Cauda equina syndrome Low Back Pain
    • Complete L5-root-related paresis of the peroneus nerve with sudden onset
    • Spinal cord compression symptoms (sensory demarcation line on the trunk, bilateral weakness of the lower limbs or tetraplegia)
  • Urgent
    • Nerve root-related paralytic symptoms
    • Intolerable pain

Referral

  • Conservative treatment
    • Primary choice in pain with a duration of less than 6 weeks, provided there are no alarming symptoms
    • If the back pain is prolonged for over 6 weeks, further investigations are usually indicated in order to establish the diagnosis and to draw a rehabilitation plan.
  • Surgical treatment
    • Orthopaedics: lumbar region
    • Neurosurgery: cervical region, thoracic spine, tumours
  • Diagnostics of indistinct conditions
    • Neurology