Mohammed T. Abou-Saleh

REVERSIBLE DEMENTIAS 291INVESTIGATION PROTOCOLSA number of organizations have published guidelines for theinvestigation of dementia, largely with the aim of identifying thecommon reversible dementias 40–44 . Table 53.3 lists investigationssuggested in three sets of consensus statements 40,42,44 and showsthat there is broad agreement on the appropriate routine bloodinvestigations. Chui and Zhang 16 examined the added value of theinvestigations recommended by the American Academy ofNeurology 40 . After a complete clinical assessment, blood testsand neuroimaging results changed management in only 13% and15% of cases, respectively. van Crevel et al. 44 found that thenumber of patients requiring investigation to find one case ofreversible dementia was approximately 100, and that any financialsaving on care costs was insignificant. Lastly, Foster et al. 45 ,inadetailed examination of the cost-effectiveness of routine computedtomography (CT), concluded that patients aged over 65 yearsshould only be scanned if symptom duration was less than 1 year,if symptoms were rapidly progressive or if the presentation wasatypical of Alzheimer’s disease. Routine scanning was recommendedin all patients presenting under the age of 65.CONCLUSIONReversible dementias are rare but their identification is importantfrom the individual patient’s perspective. The literature encompassesa polarization of views. The evidence-based view wouldsuggest that extensive investigation is unnecessary and that, inany case, treatment of identified disorders is largely ineffective.The more traditional, patient-centred view, perhaps coloured bythe early literature and the fear of litigation, would demand thecontinued use of routine investigations in the hope of excludingtreatable aetiologies, however rare. 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