Lost and found: bespoke memory testing for Alzheimer's disease and semantic dementia.

摘要: The neural network activated during Topographical Memory (TM) tasks in controls overlaps with the earliest affected regions Alzheimer's disease (AD) but not those of Semantic Dementia (SD). This suggests that clinical TM tests could be more bespoke to dysfunction early AD and therefore sensitive specific. We hypothesized impairment would characteristic SD making it useful both for diagnosis differential diagnosis. was assessed 69 patients (22 mild AD, 15 SD, 32 cognitive (MCI)) 35 controls, using three tasks: four mountains test two novel a virtual town (the Virtual Route Learning Test (VRLT) Heading Orientation Test). were impaired on all tasks. VRLT most discriminatory; had highest correlation caregiver reports navigation problems; correlated strongly memory, attention/executive function, lesser degree, visuospatial ability. In contrast, performed well battery only becoming abnormal very advanced dementia performance exclusively function. achieved 95% sensitivity 94% specificity discriminating from controls; at same cut-off, 70% MCI impaired. When combined either naming or global severity, there complete separation SD. is ecologically valid, highly non-Alzheimer dementia,