ABSTRACT
The usual symptoms of back disorders are pain, stiffness and deformity in the back, and pain, paraesthesia or weakness in the legs. The mode of onset is very important: did it start suddenly (perhaps after lifting) or gradually? Are the symptoms constant, or are there periods of remission? Are they related to any particular posture?
Bachache, either sharp and localized or chronic and diffuse, is the commonest presenting symptom. It is usually felt low down and on either side of the midline, but it may extend into the upper part of the buttock and even into the thighs. If there were no other symptoms it would be difficult to tell whether the pain originated in the intervertebral disc, the nerve root, the vertebral facet joints or the soft-tissue supports at that level of the lumbar spine.
Sciatica is the term originally used to describe intense pain radiating from the buttock into the thigh and calf — more or less following the distribution of the sciatic nerve and therefore suggestive of nerve root compression or irritation. However, Jonas Kellgren (more than 30 years ago) showed that almost any structure in a lumbar spinal segment can, if irritated sufficiently, give rise to referred pain radiating into the lower limbs. Unfortunately, with the passage of time, clinicians have taken to describing all types of pain extending from the lumbar region into the lower limb as ‘sciatica’. This is at best confusing and at worst a preparation for misdiagnosis! True sciatica, most commonly due to a prolapsed intervertebral disc pressing on a nerve root, is characteristically more intense than referred low back pain, is aggravated by coughing and straining and is often accompanied by symptoms of root pressure such as numbness and paraesthesiae.
Stiffness may be sudden and almost complete (after a disc prolapse) or continuous and predictably worse in the mornings (suggesting arthritis or ankylosing spondylitis).
Deformity is usually noticed by others, but the patient may become aware of shoulder asymmetry or of clothes not fitting well. In disc prolapse, arthritis and ankylosing spondylitis, deformity is usually secondary to, and overshadowed by, pain and stiffness. In structural disorders, such as scoliosis, it may be the only complaint.
Numbness or paraesthesia is felt anywhere in the lower limb, but can usually be mapped fairly accurately over one of the dermatomes. It 220is important to ask if it is aggravated by standing upright or walking and relieved by bending forward or sitting down – a classic feature of spinal stenosis.
Other symptoms important in back disorders are urethral discharge, diarrhoea and sore eyes; these are features of Reiter’s disease, one of the causes of ‘reactive’ spondylitis.
