Pain Assessment, Diagnosis, and Patient Evaluation
History and mechanism
Evaluation starts with a focused history: onset, quality, radiation, aggravating and relieving factors, temporal pattern, associated symptoms, prior treatments, and function. Classify pain as nociceptive, neuropathic, or nociplastic; these labels guide therapy but frequently coexist.
Measurement
Use validated instruments. The numeric rating scale is simple but nonlinear, and the visual analog scale is not interchangeable with it. For neuropathic pain, DN4, LANSS, and painDETECT are screening aids, not diagnostic tests. Assess function and psychosocial burden separately: ODI or PEG for function, PHQ-9 and GAD-7 for mood, PASS or ORT for opioid risk, and urine drug screening when opioids are considered.
Red flags
Urgent action precedes any elective procedure when saddle anesthesia, bladder or bowel dysfunction, bilateral leg weakness (cauda equina), progressive myelopathy, fever with spinal pain, nocturnal pain, unexplained weight loss, cancer history, or trauma is present. Imaging follows the history and examination; it does not replace them. Incidental degenerative findings are common and should not be over-read.
Examination includes inspection, palpation, range of motion, neurologic testing (strength, reflexes, sensation, straight leg raise, Spurling), and provocative maneuvers. Waddell signs may reflect distress rather than malingering.
Trap: a normal MRI does not exclude neuropathic pain, and abnormal imaging does not prove the pain source. Another trap: screening tools cannot establish a diagnosis alone.
Rule of thumb: red flags first, then mechanism, then measurement, then plan.