A prolapsed disc or injury to the nerve exit foramen in the neck can give very severe neck and arm pain known as cervical radiculopathy. The sixth cervical nerve is affected in 25% of cases and the seventh in 60% of cases. Of all arm pains of neck origin, about a quarter are due to an acute disc prolapse. With age disc bulges, ligament and joint enlargement and bony osteophytes encroach on the space the nerve has to travel through and this is a more common cause of cervical radiculopathy in older persons. Neck pain from cervical disc prolapse is routinely assessed and treated by physiotherapists.
Factors making nerve root pain more likely are routine lifting of weights above 25 pounds (12 kilograms), driving or operating vibrating machinery and smoking. Cervical radiculopathy is not common and occurs much less frequently than lumbar root lesions such as sciatica.
The vertebrae from the second to the seventh neck vertebra have discs between them which smooth out shocks applied to the spine and transmit the necessary loads. The bony, disc and joint structures make up the nerve exit channels on the side of the spine and the nerve roots take up to 33% of the available space. If the surrounding structures suffer from degenerative or arthritic changes they can narrow the exit foramen and cause nerve compression.
The physiotherapist will take a detailed history to establish the diagnosis is clearly that of cervical radiculopathy. The exact location and nature of the pain, numbness or weakness, aggravating or easing factors, mechanism of injury, previous occurrences, lower limb symptoms, bladder or bowel dysfunction and medical or other treatments are all noted.
People with root pain look tired due to poor sleep, don't find anything funny and guard their arm in a protective posture against the abdomen or hold it out to the side with their hand on the back of their neck or the other side of the head. This may reduce the forces through the inflamed nerve root and so reduce pain.
On physiotherapy examination patients look tired as they have not slept and they lose their sense of humour. They may hold their arm in a relieving posture cradled across the body or with the elbow out to the side and the hand behind the neck or over the head towards the opposite ear. This may reduce the tension through the irritated or compressed nerve root, reducing the pain.
Posture is usually abnormal with the head tilted away from the painful side and the neck held stiffly with reduced ranges of movement. The physio notes the muscle spasm and tests the muscle power to determine which nerve root is affected, looks for sensory and reflex loss and notes which combination of movements are provocative and if manual traction reduces symptoms.
In the sub-acute phase restoration of neck range of movements and strength is encouraged with isometric neck exercises with a progression to isotonic and multiple muscle groups. To prevent further problems, a long term exercise regime of aerobic fitness, stretching and strengthening may be helpful.