Mohammed T. Abou-Saleh

NEURO-IMAGING 405neuro-imaging techniques are still needed 3 only adds to theproblem.The advent of treatments for dementia and the consequent needto identify early and potentially treatable cases has shifted theassessment of cost-effectiveness from investigation to treatment.The cost-benefit assessment of early treatment of dementia to ahealth economy has yet to be fully assessed but is likely to farexceed that of any neuro-imaging screening programme. A recentreview 4 neatly encapsulates what is now as much a socioeconomicas a medical dilemma in a single statement: ‘‘How much is societywilling to spend?’’.Given that these socioeconomic drivers are unlikely to change,clinicians are now seeking to devise assessment protocols fordementia that best address the conflict. Unfortunately, we are stillsome distance from achieving a consensus view. Some authors 4advocate routine neuro-imaging as part of a screening procedurein all patients in order to ‘‘include in’’ all treatable cases, perhapsavoiding litigation. Others, when attempting to define practiceparameters, have regarded neuro-imaging as optional in thedifferential diagnosis of dementia 5 . Subsequent analysis showedthat imaging studies did improve diagnostic accuracy but onlywith a significant increase in cost 6 .Considerations of cost and, in less well-developed countries, ofaccess continue to determine whether neuro-imaging in dementiais used as a universal screen or only when clinically indicated.Various protocols indicating that neuro-imaging is not required inall patients, but should be a first-line test, especially in youngerpatients and those cases where there is diagnostic doubt on clinicalgrounds, have been suggested 7–10 . It is likely that, as costs oftreatment increase relative to those of investigation, the use ofneuro-imaging as a screening tool rather than a diagnostic aid indementia will increase.REFERENCES1. van Crevel H, van Gool WA, Walstra GJM. Early diagnosis ofdementia: which tests are indicated? What are their costs? J Neurol1999; 246: 73–8.2. Chaves ML, Ilha D, Maia AL et al. Diagnosing dementia and normalageing: clinical relevance of brain ratios and cognitive performance ina Brazilian sample. Braz J Med Biol Res 1999; 32(9): 1133–43.3. Small GW, Leiter F. Neuroimaging for diagnosis of dementia. J ClinPsychiat 1998: 59(suppl 11): 4–7.4. Ajax E, de Leon MJ, Golomb J et al. Imaging the brain in dementia:expensive and futile? Am J Neuroradiol 1997; 18: 1847–50.5. Quality standards subcommittee of the American Academy ofNeurology Practice parameters for diagnosis: an evaluation ofdementia (summary statement). Neurology 1994; 44: 2203–6.6. Chiu H, Zhang Q. Evaluation of dementia: a systematic study of theAmerican Academy of Neurology’s practice parameters. Neurology1997; 49(4): 925–35.7. Hollister LE, Shah NN. Structural brain scanning in psychiatricpatients: a further look. J Clin Psychiat 1996; 57(6): 241–4.8. Stahelin HB, Monsch AU, Spiegel R. Early diagnosis of dementia viaa two-step screening and diagnostic procedure. Int Psychogeriat 1997;9(suppl 1): 123–30.9. Cammer Paris BE. The utility of CT scanning in diagnosing dementiaMt Sinai J Med 1997; 64(6): 372–5.10. Galton CJ, Hodges JR. The spectrum of dementia and its treatment. JR Coll Physicians Lond 1999; 33(3): 234–9.