Question

27 years old male patient is admitted to the emergency department following a motor cycle accident. His MR images reveal a C-5 and C-6 spinal nerve injuries.(max 250 words)
a) What kind of motor losses of the upper extremity would you expect in this patient?
(1 point)
b) Which muscles would be affected in this patient?(1 point)
c) Which areas of the upper extremity would be affected in means of sensory functions?
(1 point)
d) Which reflexes would be compromised in this patient? (2 points)

Answer 1

a). C5- C6 injury is called low level nerve injury... It is called Erb's paralysis ...

​​​​​Following manifestations are present -

• C5 injury

  • Person can raise his or her arms and bend elbows.
  • Likely to have some or total paralysis of wrists, hands, trunk and legs
  • Can speak and use diaphragm, but breathing will be weakened

• C6 injury

  • Nerves affect wrist extension.
  • Paralysis in hands, trunk and legs, typically
  • Should be able to bend wrists back
  • Can speak and use diaphragm, but breathing will be weakened

Erb's palsy or Duchenne-Erb paralysis involves the C5 and C6 roots of the brachial plexus. Palsy of C5 and C6 affects the strength of deltoid, biceps, brachialis, infraspinatus, supraspinatus, and serratus anterior muscles. Also involved are the rhomboids, levator scapulae, and supinator muscles. Therefore, this injury causes severe restriction of movement at the shoulder and elbow joints. The patient is unable to abduct or externally rotate the shoulder. The patient cannot supinate the forearm because of weakness of the supinator muscle.....

The classical sign of erb's palsy is called Waiter's tip deformity.

b). There are multiple muscles affected depending upon the location where they are affected...

for eg:- if they both are affected at root then-

• C5, , along with C3 and C4, contributes to the phrenic nerve that innervates the diaphragm that explains the weakened breathing which is due to paralysis of diaphragm muscle....
• Roots C5, C6, and C7 produce the long thoracic nerve, responsible for controlling the serratus anterior.

From trunk - From the upper trunk C5 and C6 give rise to the nerve to the subclavius, and the suprascapular nerve, that supply the subclavius muscle, and the supra- and infraspinatus muscles, respectively....

from cord- From the lateral cord, C5, C6, and C7 supply the pectoralis major and minor muscles, via the lateral and medial pectoral nerves, as well as the coracobrachialis, brachialis and biceps brachii, via the musculocutaneous nerve...

These three roots also form the lateral root of the median nerve that controls most forearm flexors...

• C5 and C6 forms , the upper and lower subscapular nerves supply the upper and lower portions of the subscapularis. The lower subscapular nerve also innervates the teres major.
• Additionally, from C5 and C6, the axillary nerve supplies the motor function of the deltoid and teres minor...

c). Sensory involvement is usually confined along the deltoid muscle and the distribution of the musculocutaneous nerve... As The musculocutaneous nerve provides sensation to the skin of the lateral forearm....axillary nerve also supplies the sensory aspect of the overlying skin, the superior lateral cutaneous nerve of the arm, and the skin of the lateral shoulder and arm......

d). The biceps and brachioradialis reflexes are mediated by the C5 and C6 nerve roots.. so they are lost in erbs paralysis..

Moro' reflex lost on affected side in case of children as It is one of the most common neurological birth injuries and these injuries most commonly, though not exclusively, arise from the traction on the neck during difficult childbirth....