The Shoulder

C-5 Nerve Root Lesion

Causes

Disco-radicular: posterolateral protrusion
A C5 nerve root palsy is usually not the result of a disc protrusion. In the rare event of a disc involvement, the compression is seldom severe enough to cause a root palsy.
More common is a progressive compression by a osteophyte in the fourth intervertebral foramen.

In elderly patients.
An osteophytic palsy of the C5 root results in a progressive development of gross weakness of the C5 muscles without pain nor paraesthesia. By the end of the evolution, which may take a few years, the palsy is complete.
Traction Palsy of C5 ( sometimes C6) , the "Burner syndrome"
This is a specific lesion in contact sports (judo, rugby) or after a fall on the shoulder (cyclist - motorcyclist).

The injury results from a sudden depression of the entire shoulder girdle, in combination with a simultaneous and forceful side flexion in the opposite direction of the neck.
The patient feels a sharp burning pain in the shoulder and the C-5 dermatome. The burning pain is accompanied by weakness of biceps and deltoid. The pain usually lasts for a couple of minutes but weakness may persist for a few days to a few weeks.

In most cases it is a rather benign lesion that has a spontaneous cure (neuropraxia or transitory physiologic block of the axons). Although permanent neurologic deficits are rare, they have been reported.

In permanent lesions there is complete weakness and atrophy of supraspinatus, infraspinatus, deltoid and biceps.

Pattern

Active elevation is impossible. No painful arc and a full and painless range of passive movement. Abduction (with atrophy of the deltoid) and the external rotation of the arm are extremely weak. Some weakness of the flexion of the elbow. The biceps jerk may be sluggish or absent; the brachioradialis jerk sluggish, absent or inverted.

Treatment
Dependent on the cause and the severity of the lesion