Neurological examination of the patient with pain often allows some anatomic localisation of the cause, especially when there is involvement of the spinal cord or nerve roots. The distribution of the pain or sensory changes may correlate with dermatomes. Muscular weakness and loss of reflexes and the pattern of referred visceral pain may also be correlated with spinal segments.
Measurement of pain-As pain is a subjective phenomenon, objective measurement is not possible. A variety of instruments, of varying complexity, have been developed to measure pain. The more complex of these, which include assessment of the affective and behavioural associations of pain, can be very time consuming for both patients and staff and should be reserved for specific research projects. Simpler techniques, including visual analogue scales, numerical rating scales and verbal descriptor scales are more easily employed and may be seen by the patient as indicating concern about their pain rather than being a burden to complete . The Memorial Pain Assessment Card employs similar features. These simpler assessments are 6f particular use for patients whose pain is difficult to control, where repeated patient responses may show trends, or where the patient's responses can be compared with those given by the hospital or family caregivers.