Cervical Radiculopathy
Quick synopsis
  • C7 radiculopathy: most common root affected by herniated disc. Weak triceps and numb middle finger.
  • C5 radiculopathy: most common root affected by brachial neuritis and spondylosis. Weak biceps & infraspinatus (external rotation of shoulder). Numb over deltoid area.
  • C8T1 radiculopathy: think of pantcoast tumor, thoracic outlet syndrome. Small muscle atrophy of the hand, minimal numbness in hand.
Key exams in upper limbs
  • Deep Tendon Reflexes: biceps/brachioradialis (C5-6), triceps (C6-7)
  • Motor strength: 
    • Finger spread (abduction) C8, T1, Ulnar
    • Extension of fingers at Metacarpal-Phalanx + PIP C7-8, Radial n
    • Adduct thumb against base of index finger C8,T1,Ulnar n
    • Pinch between thumb + little finger C8, T1, Median n
    • Flex thumb C8, Median n 
    • Extend wrist C6-8, Radial n
    • Flex wrist C6-7, Median n
    • Supinate forearm with elbow straight C5-6, Radial n
    • Pronate forearm with elbow straight C6-7, Median n
    • Flex elbow with forearm supinated C5-6, musculocutaneous
    • Extend elbow C6-8, Radial n
    • Hold shoulders abducted C5-6, Axillary n
  • Sensory: 2-point discrimination
    • Web space between thumb + index on back of hand C6, Radial n
    • Palmar side distal middle finger C7, Median n
    • Ulnar side of hand C8, Ulnar n
    • Ulnar side of mid-forearm T1
  • Maneuvers to reproduce or intensify symptoms
    • Forced full flexion of neck - discogenic cervical radiculopathy
    • Foraminal compression (Spurling's maneuver) turn head towards involved side - cervical radiculopathy from nerve root impingement, first R/O fracture
    • Thoracic outlet maneuvers
      • Adson's maneuver (scalenus anticus) head away from involved side, arm up, hold deep inspiration - anterior scalene syndrome
      • Costoclavicular maneuver (press down on shoulders while patient moves shoulders back) - costoclavicular syndrome
      • Hyperabduction (Wright's) maneuver, hands over head - pectoralis minor syndrome
    • Phalen's maneuver - carpal tunnel syndrome
Root (Disk level) Clinical & Electrodiagnosis
C7 

(C6-C7)

  • Pain: neck, medial scapula, down to middle finger
  • Most common cause: Acute disc lesions
  • Motor weakness: triceps, pronator teres, wrist flexors, and finger extensors.
  • Sensory loss: middle finger. 
  • Reflex: decreased Triceps reflex
  • Motor NCV Median & Ulnar normal.
  • Median SNAP normal. Needed to rule out Median nerve dysfunction and middle trunk brachial plexopathy.
  • Needle examination:
    • Best C7 muscle: Triceps
    • Also extensor digitorum communis.
C6 (C5-C6)
  • Pain: lateral forearm, thumb and index finger.
  • Cause: Cervical spondylosis, disc lesions.
  • Motor weakness: biceps and brachioradialis.
  • Sensory loss: thumb and index finger.
  • Reflex: supinator jerk.
  • Motor NCV of median and ulnar nerves are normal. 
  • Radial SNAP will be normal and useful to exclude a radial  neuropathy and upper trunk brachial plexopathy.
  • Needle exam:  Infraspinatus, Supraspinatus.  Biceps, Brachioradialis.
C5

 (C4-C5)

  • Pain: lateral upper arm to elbow, medial scapular border.
  • Cause: brachial neuritis, cervical spondylosis, upper plexus avulsion
  • Motor weakness: Deltoid, Supraspinatus, infraspinatus, Rhomboids.
  • Sensory loss: lateral upper arm and over deltoid.
  • Reflex: biceps reflex
  • Motor NCV of median and ulnar nerves are normal. 
  • The lateral antebrachial  cutaneous SNAP will be normal and useful to exclude a musculocutaneous axonal neuropathy and upper trunk brachial plexopathy.
  • Needle exam: Rhomboids (best). Infraspinatus, Supraspinatus.
C8 

(C7-T1)

  • Pain: neck radiating to the shoulder, ulnar side of forearm and little finger.
  • Cause: rare in spondylosis and disc disease.
  • Motor weakness: thumb flexors, abductors, intrinsic hand muscles, and long finger flexors.
  • Sensory loss: little finger, heel of hand to above wrist.
  • Reflex: finger jerk.
  • Median CMAP and F-response usually normal, presumably because the abductor pollicis brevis receives the bulk of its innervation from the T1 root.
  • Ulnar: CMAP amplitude usually normal. F-response may be prolonged or absent.
  • Ulnar SNAP if abnormal: suggest Ulnar  mononeuropathy or lower trunk brachial plexopathy, rather than radiculopathy.
  • Needle exam:
    • First dorsal interosseus
    • Extensor indicis proprius (helps exclude ulnar mononeuropathy)
T1 (T1-T2)
  • Pain: deep aching pain in shoulder and axilla to olecranon.
  • Cause: cervical rib, pancoast tumor, metastatic carcinoma in deep cervical nodes, outlet syndromes.
  • Motor weakness: Small muscles in hand.
  • Sensory loss: minimal.
  • Reflex: none
  • For any neck problem, always think of cervical myelopathy. 
    • Check the legs too. Patient may complain of gait disturbance.
    • Up going toes, leg spasticity, decreased position sense,  increased knee & ankle reflexes.

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