Accidental MCI in healthy subjects: a prospective longitudinal study

Abstract

A study was realized on 130 healthy and autonomous volunteers (60-80 years old) who met specific medical and functional inclusion criteria. A comprehensive battery of neuropsychological tests was performed at baseline (M0), 6 and 12 months (M6, M12). At M0 the results indicated that 65% were cognitively normal on each of all the neuropsychological tests, whereas 35% presented a cognitive deficit on one or more tests. At M12, 52% of the subjects who had a cognitive deficit at M0 remained impaired, whereas 48% normalized their scores: they performed as well as the subjects classified normal at M0. The results also indicated that the subjects who remained impaired at M12, had at M0 low scores on three tests or more, whereas the ones who normalized their scores had one or two failed tests. This study focuses on the risk of false positive cases and shows that low scores can be accidental. The authors propose decision rules allowing to reduce the risk of false positive cases. The observation of accidental impairment invites to be cautious and makes this 1-year follow-up study particularly relevant, since a 1-year follow-up is generally needed to diagnose very mild dementia.

Short-term practice effects in amnestic mild cognitive impairment: implications for diagnosis and treatment

“…Nonetheless, future studies might examine the clinical utility of repeat testing for the diagnosis of amnestic MCI, as significant improvements in memory functioning (as evident with practice effects) might seriously question the validity of the original diagnosis. Furthermore, Darby et al (2002) have provided data to suggest that multiple assessments within the same day could be used to identify MCI, which might be better at identifying persistent vs. "accidental" MCI (de Rotrou et al, 2005).…”

Potential for misclassification of mild cognitive impairment: A study of memory scores on the Wechsler Memory Scale-III in healthy older adults

“…de Rotrou et al (2005) referred to this as "accidental MCI" to denote the likelihood that those people were misdiagnosed at the initial assessment. This kind of backcrossing from MCI to normal would not be consistent with a neurodegenerative disease and likely represents the inherent difficulty with accurately identifying those who will versus those who will not eventually progress to dementia.…”

“…For example, in Brooks et al (2007), 30.8% of healthy older adults would psychometrically meet the Petersen et al (1994Petersen et al ( , 1999Petersen et al ( , 2001) criterion for MCI. de Rotrou et al (2005) referred to those patients who were diagnosed with MCI at baseline, but who were later found to have returned to normal cognitive abilities, as having "accidental MCI." It is noteworthy that there are numerous studies with longitudinal data that often contain a subset of patients who no longer meet criteria for MCI at follow-up (see Table 1 for a review of the literature).…”

Minimizing Misdiagnosis: Psychometric Criteria for Possible or Probable Memory Impairment

“…Because healthy older adults may obtain some low memory scores [18] there is substantial concern regarding false-positive diagnosis of memory impairment [19][20][21][22][23] . If memory impairment is misdiagnosed [see ref.…”