Peripheral nerve injuries of Brachial plexus

What is Brachial plexus? 

Brachial plexus is the group of nerves of upper extremity arising from cervical to thoracic (C5-T1) nerve root.

What are different cords of brachial plexus?

  • There are different cords of brachial plexus which supplies to different areas upper extremity according to their pathway.
  • Three cords of brachial plexus are- 
  1. Medial cord
  2. Posterior cord
  3. Lateral cord

Medial cord

It is the part of brachial plexus formed by the anterior division of the lower trunk (C8-T1).
Its name comes from that it passes medial to medial side of axillary artery as it passes through axilla.
The medial cord gives the following nerves from proximal to distal in upper extremity-
  • Medial pectoral nerve (C8-T1)
  • Medial cutaneous nerve (C8-T1)
  • Medial head of median nerve (C8-T1)
  • Ulnar nerve (C8-T1)

Posterior cord

It is formed by all the three posterior cord of three trunks of the brachial plexus.
Posterior cord gives following nerves in upper upper extremity-
  • Upper and lower subscapular nerve (C5-C6)
  • Thoracodorsal nerve (C6-C8)
  • Axillary nerve (C5-C6)
  • Radial nerve (C5-C8,T1)

Lateral cord

It is formed by the anterior division of the upper and middle trunk.
Its name suggest that it passes from lateral side of the axillary artery.
Lateral cords gives the following nerves in upper extremity-
  • Lateral pectoral nerve (C5-C7)
  • Musculocutaneous nerve (C5-C7)
  • Lateral head of median nerve (C5-C7)

Causes of peripheral nerve injuries-

1. Axillary nerve injury:-

Causes of Axillary nerve injury

  1. Road traffic accident
  2. Sports injuries- overhead activities
  3. Blunt trauma or excessive stress
  4. Compression- saturday night palsy
  5. Violence-knife injury, cut, gunshot 
  6. Autoimmune disorders- diabetes, GB syndrome, motor neuron diseases.

Symptoms of axillary nerve injury-

  • Tingling sensation or numbness in shoulder region
  • Weakening of the shoulder muscles
  • Difficulty in doing ADLs(activity of daily living)
  • Difficulty in doing overhead activities.

Diagnosis of axillary nerve injury-

  • Diagnosis is based upon the physical examination and the symptoms occurring.
  • Test for pain- VAS scale
  • Test for motor power- MMT
  • Test for sensation- Dermatomes
  • Test for reflexes
  • NCV
  • EMG
  • X-RAY
  • MRI

Treatment of axillary nerve injury-

  • To reduce the pain- analgesics and anti-inflammatory medication are given.
  • In mild compression or stretching physical therapy is the first option.
  • PRICE(prevention, rest, ice, compression, elevation).
  • TENS-(transcutaneous electrical nerve stimulation).
  • US therapy- ultrasound therapy.
  • Immobilization- by orthosis or splinting (aeroplane splint)
  • Strengthening exercises for muscle power.
  • Surgical repair- nerve grafting, neurolysis, tendon grafting.

2. Radial nerve injury-

Causes of radial nerve injury-

  1. Fracture of shaft of humerus
  2. Sleeping in awkward position
  3. Any kind of sudden weight lifting
  4. Trauma
  5. Autoimmune disorders- diabetes, GB syndrome, motor neuron diseases.

Symptoms of radial nerve injury-

  • Wrist drop or finger drop
  • Tingling sensation over the arm and forearm area
  • Griping of the first two finger and thumb is lost.
  • Loss of motor and sensory functions over hand and wrist.

Diagnosis of radial nerve injury

  • Test for motor power-MMT
  • Test for sensory loss-dermatomes
  • Test for pain-VAS
  • Testing of reflexes
  • NCV
  • EMG
  • X-RAY
  • MRI
  • Blood sugar
  • Blood testing

Treatment of radial nerve injury-

  • Analgesics for pain.
  • Immobilization- orthosis or splint(cock-up splint)
  • TENS therapy
  • US therapy
  • IFT therapy
  • Isometric exercises
  • Strengthening exercises
  • Surgical procedures- nerve grafting, neurolysis, or tendon transfer.

Post a Comment