Diagnostic Accuracy in Presenile Dementia

Abstract

A follow-up study of patients diagnosed as suffering from presenile dementia has revealed a high incidence of erroneous diagnoses. Of 52 patients discharged from hospital with this diagnosis, information was obtained 5-15 years later on 51. Eighteen were alive and the diagnosis was rejected in 16 (31 per cent). Possible reasons for the mistaken diagnoses are discussed.

Depression and dementia: the multi-faceted relationship

“…Nott & Fleminger (1975) noted that only their true demented patients showed problems with naming, writing, calculation or motor praxis. Ron et al (1979) noted that, while overall intellectual impairment was present in 'pseudodements', they did not show a significant difference in verbal-performance IQ on the Wechsler Scale, whereas 'demented' patients showed a large discrepancy. Caine (1981), studying 17 patients with depressive cognitive disorders, found that specific functions such as repetition, reading and comprehension, naming, verbal delayed recall and recognition, mathematics, finger tapping and motor praxis were spared.…”

“…Nott & Fleminger (1975) noted that the gross widening of the ventricles occurred only in 'true' dementia, though nearly half of their 'pseudodements' were reported as having minimal sulcal or ventricular enlargement on the AEG. Ron et al (1979) also found the AEG of value, though they noted that 'the high incidence of abnormalities in the non-demented group should not be overlooked. Most occurred in patients with established or suspected brain disorder and had then lent spurious support to the clinical impression that a progressive dementing illness was afoot'.…”

“…Most occurred in patients with established or suspected brain disorder and had then lent spurious support to the clinical impression that a progressive dementing illness was afoot'. Unlike Nott & Fleminger (1975), Ron et al (1979) concluded that cortical atrophy on the AEG appeared to be a better predictor of dementia than ventricular enlargement in their patients.…”

“…When he reported his findings, a standard British psychiatric text (Mayer Gross et al 1960), in its second edition, described dementia as a progressive, irreversible and unbeatable condition. Subsequent clinical studies (Marsden & Harrison, 1972;Nott & Fleminger, 1975;Ron et al 1979;Wells, 1979;Smith & Kiloh, 1981;McAllister, 1983) continued to use this conceptualization o f pseudodementia'. These studies were reported in a critical spirit, the chief purpose usually being to draw attention to cases which, though demented at the time of presentation or examination, did not sustain their dementia, or even the cognitive disturbance in some cases, on follow-up.…”

Research into the dementias

“…Smith et al (1976) estimated the figure at 20%. Psychiatric conditions, especially depressive illness and severe neurotic disorders, can constitute a substantial source of error, as witnessed by follow-up studies of patients diagnosed as suffering from presenile dementia in psychiatric units (Nott & Fleminger, 1975;Ron et al 1978). The significance and the measurement of cerebral atrophy, in different age groups and in a variety of settings, needs thorough reappraisal, and computerized axial tomography is now at hand to allow this to be done.…”