Severe neck pain with pain radiation into the arm and hand is usually the result of a herniated disc or a traumatic injury causing the nerve exit to be compromised, compressing the nerve. Most commonly affected are the C6 nerve in 25% of cases and the C7 nerve in 60%. About 25% of arm pains are from an acute prolapsed disc. In older people the cause is more likely to be narrowing of the exit channel from bony outgrowths, disc bulging, ligament infolding and arthritic enlargement of the facet joints. Physiotherapists routinely assess and treat this kind of neck pain.
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.
There can be many reasons for the onset of nerve root neck pain or it can come on slowly without clear reason. If the neck is moved backwards, tipped to one side and rotated to the same side this can sharply narrow the nerve exit space and injure the nerve, occurring in a traumatic accident or a sporting injury. The opposite can occur with a quick side bend, combined with flexion or extension, tractioning the nerve and causing injury. Sudden loading of the neck in any posture can cause disc prolapse. There may be degenerative changes in an older group and with repetitive or sustained neck postures an osteophyte can impinge the nerve and give a slower development of arm pain.
The onset of cervical radiculopathy can be insidious without obvious cause or after an incident. During sport or trauma like a fall the neck can be extended back, bent to one side and rotated, suddenly narrowing the exit for the nerve and compressing it, causing an injury. Or a sudden bend to the opposite side with either cervical flexion or extension can traction the nerve on the one side with consequent injury again. If there is a sudden load on the cervical spine, in any position, it’s possible for a disc prolapse to occur. If there are osteophytes present in an older person, sustaining or repeating extension with rotation may cause nerve irritation with a slower onset.
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.
A postural abnormality is often present with the neck held side flexed or rotated away from the painful side. Examination by the physiotherapist includes recording any muscle spasm, checking reflexes, sensibility and muscle power, any combined movements which might aggravate the pain and any easing factors such as manual traction. Acupuncture and cervical epidural injections of steroids may be useful if physiotherapy cannot reduce the pain sufficiently.
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.
Reducing the pain and inflammation is the first goal of treatment and the physiotherapist can employ analgesics such as NSAIDs, cryotherapy, mechanical or manual traction and avoidance of aggravating activities and postures. Limiting the forces transmitted through the nerve root is an overall goal of management, using a collar to reduce neck movement, a cervical pillow or collar at night and manual traction from the physio to distract the joints. After the acute phase has settled physiotherapy concentrates on regaining neck movement and muscle power, starting with isometric exercises and moving on to isotonic and exercises for multiple muscle groups. Long term adherence to a regime of aerobic exercise, muscle strengthening and stretching may be useful.