DIAGNOSTIC TESTS FOR THE EVALUATION OF BACK AND NECK PAIN

The past two decades have seen a proliferation of tests and treatment methods developed for the management of patients with back and neck pain. Many of the tests are for the evaluation of neurologic deficits or lesions that potentially could compress neural structures. Treatments such as surgery, steroid injections, and even certain exercises have been designed specifically to remove or ease neural compressive lesions. This has led to an increase in the referral of patients with back and neck pain to neurologists, sometimes only for electrodiagnostic testing but more often for a complete evaluation and opinion regarding diagnosis, treatment, prognosis, and disability or impairment. The neurologist often is being placed in the position of the primary treating physician or spine specialist for these patients and is responsible for the management of non-neurologic as well as neurologic causes of back and neck pain. Back and neck pain has become increasingly important as the costs for health care become the focus of attention in the 1990s. Grazier 23 estimated total direct costs for the treatment of patients with spinal disorders in 1981 to be nearly 13 billion dollars. Cats-Baril and Frymoyer 15 extrapolated these direct medical costs to be about 23.5 billion dollars by 1990. The figures for radiograms alone were estimated by Scavone et al 40 to be $600 million in 1981 which, when extrapolated to 1990, reaches a figure of $1.79 billion. 15 Furthermore, the figures in 1981 do not include tests such as magnetic resonance imaging (MRI), evoked potentials, high-technology thermography, computerized strength testing, and multiple other technological advances. Despite the advances in understanding and the proliferation of diagnostic tests and treatment methods, there is no evidence that there has been any decrease in the frequency or severity of back and neck pain. The yearly prevalence of this disorder remains at 15% to 20%, 4 and surveys of working-age people note that 50% admit to symptoms each year. 44 47 Back pain remains the most common cause of disability for persons under the age of 45 years, 17 and, at any given time, 2% of the population is on some form of chronic or temporary disability. 4 The increasing use and cost of diagnostic and treatment methods for back and neck pain without obvious change in morbidity has led to more intense investigation of all medical procedures used in this condition. It increasingly is becoming necessary to document the reliability of each procedure and each test is being examined for concepts such as the frequency of abnormalities in the asymptomatic population, sensitivity and specificity, and the effect on patient outcomes. A recent Clinical Practice Guideline on Acute Low Back Problems in Adults published by the Agency for Health Care Policy and Research (AHCPR) 10 illustrates how these tests are being evaluated. This issue can be addressed by a detailed analysis of the strengths and weaknesses of each testing method. This, however, would fill a textbook on the subject and often is confusing. A more practical approach is to define groups of patients according to their most common presentations and discuss current thoughts on the most appropriate manner in which to evaluate such patients.