Patients suffering from brachialgia

Introduction
Brachialgia – radiating pain in the arm – is a symptom that can be caused by cervical nerve root compression, but can also be caused by damage (usually compression) along the pathway of peripheral nerves in the arm. Nerve root compression is, in most cases, caused by a herniated cervical disc but, similar to lumbar nerve root compression, can also be caused by spondylarthrosis, spinal canal stenosis, and tumours etc. More peripheral nerve damage can be caused by constriction of the thoracic outlet (thoracic outlet syndrome) due to narrowing of the space between the scalene muscles, a cervical rib, and too little space between the clavicle and the first rib [Figure 124]. Compression in the elbow (median nerve under the pronator teres muscle) or the wrist (carpal tunnel syndrome) is possible.
Conditions involving the shoulder or elbow in which nerves or plexus are not directly involved, can also cause shoulder and arm pain. With these conditions the nature of the pain is different, but since the nature of pain is often difficult for a patient to describe, joints and muscles will also have to be examined (refer to the publication entitled ‘The Examination of the Upper Extremities’ from this series).

Figure 124

Procedure

Inspection

• Ask the patient to undress the upper half of their body. 
• Assess the head position. 
• Assess whether there is any atrophy of the shoulder, arm and/or hand muscles.

Examination of neck movement

• Have the patient bend their neck to the left, right, forwards and backwards.
• Have the patient rotate their neck. 
• Keep asking whether it hurts, where it hurts, whether the pain radiates and if so, to where.

Palpation of the neck

• Palpate paravertebrally at the points where the C4-Th1 nerve roots exit.
• Ask whether this hurts, whether the pain radiates and if so, where to.

 

Examination of muscle strength
As described in the section ‘Motor function’, examine the strength of the following muscles: anterior serratus muscle, deltoid muscle, biceps muscle, triceps muscle of the arm, wrist extensor muscles, wrist flexor muscles, finger flexor muscles, finger extensor muscles, pollicis opponens muscle, interosseous muscles.

Examination of sensory function
As described in the section ‘Sensory function’, examine the spinothalamic and posterior column sensory functions in the C4-Th1 dermatomes.

Examination of the reflexes
As described in the section ‘The reflexes’, examine the biceps tendon reflex, the triceps tendon reflex and the radial reflex.

The nerve root irritation tests
By examining movement and palpating the cervical vertebral column, you should try to provoke the patient’s symptom. It is important to determine together with the patient whether the pain is typical radicular pain which radiates to a dermatome.

Other provocation tests

Military attitude test

• The patient should stand, or sit on a stool [Figure 125].
• Sit behind the patient and palpate the radial arteries on both sides.
• Have the patient pull their shoulders back as far as possible for about 1 minute.
• Ask the patient if this causes radiating pain.
• Assess whether the radial pulse disappears on the painful side.

Figure 125

Adson’s test

• The patient stands, or sits on a stool [Figures 126, 127].
• Stand or sit behind the patient and palpate the radial artery on the affected side.
• Ask the patient to bend the head backwards and to turn it away from the affected side, then to breathe in deeply and hold their breath for about 15 seconds.
• Ask the patient to repeat the same manoeuvre, but this time with the head turned to the affected side.
• Ask the patient whether this causes radiating pain.
• Assess whether the pulse disappears on the affected side (compare left and right).

Figure 126

Figure 127

Hyperabduction test

• The patient stands, or sits on a stool [Figure 128].
• Stand behind the patient and place the arm on the affected side in supination and slowly bring it into abduction.
• At the same time palpate the pulse on the affected side.
• Hold the arm in abduction for some time and keep palpating the pulse.
• Ask the patient whether this causes radiating pain.
• Assess whether the pulse disappears on the affected side (compare left and right).

Figure 128

The above-mentioned provocation tests may give false-positive or false-negative results and should therefore be interpreted carefully when establishing a diagnosis. The predictive value of the provocation tests used to confirm or rule out carpal tunnel syndrome has been tested and found to be very smaal. These tests are therefore not included in this program.

• Because brachialgia can also be caused by a Pancoast tumour where the sympathetic trunk is also often involved, you should look for signs of Horner’s syndrome.
• Because brachialgia can also be caused by a condition involving the spinal cord or surrounding region (tumour, syringomyelia), you should also examine long-tract function (dorsal columns, pyramidal pathways) (motor function, sensory function and reflexes of the legs).

Interpretation

Nature of the condition	Symptoms
Spinal cord condition	Long-tract signs
nerve root lesion caused by a herniated disc spondylarthrosis etc at C5	sensory deficit at C5 dermatome loss of strength in deltoid muscle
at C6	sensory deficit at C6 dermatome loss of strength in brachial biceps muscle, brachioradialis muscle, wrist extensor muscles impaired biceps tendon reflex
at C7	sensory deficit in C7 dermatome loss of strength in brachial triceps muscle, wrist flexor muscles, serratus anterior muscle impaired triceps tendon reflex
at C8	sensory deficit in C8 dermatome loss of strength in the interosseous muscles, flexor and extensor muscles of the fingers
Brachial plexus neuritis following immunisation or a viral infection	loss of strength in all muscles innervated by the plexus, in particular the serratus muscle and the rhomboid muscle sensory deficit rarely in 25% of the cases the condition is bilateral
Thoracic outlet syndrome	loss of strength in hand muscles radiating pain that can be provoked by the military attitude test, Adson’s test or hyperabduction test
Carpal tunnel syndrome	typical history: the patient wakes at night with painful tingling in one or both hands; after waking the patient shakes the hand(s) for some time after which the symptoms improve or disappear loss of strength in the muscles innervated by the median nerve, including the opponens pollicis muscle sensory deficit in the area innervated by the median nerve
Pancoast tumour	Horner’s syndrome pulmonary abnormalities lower plexus lesion (C8-Th1)

In the first place, try to distinguish between neurogenic, arthrogenic and myogenic or tendon-derived pain. If there is loss of muscle strength, neurogenic pain is more likely, but pain can also result in an arm or shoulder being used less and therefore becoming less strong. If there is loss of sensory function or clearly reproducible differences between reflexes, neurogenic pain becomes highly likely.
Should you believe neurogenic pain to be likely, try to determine the site of the lesion.
Finally plexus or nerve damage can also be caused by trauma, chronic external pressure (rucksack), surgery and irradiation (for example following breast cancer surgery).
It is often necessary to examine conduction times and carry out radiographic examination of the cervical spine and pulmonary apex to reach a diagnosis.