ABSTRACT
OBJECTIVE: To assess the role of impaired encoding in learning and in delayed recall disturbances, and to evaluate the rate of forgetting in AD. METHOD: Fifteen AD patients with mild or moderate dementia and 15 normal matched controls were assessed with the Buschke Selective Reminding Test. Delayed recall was evaluated after 30 minutes and after 24 hours. RESULTS: AD patients had a poorer performance across the six trials of the learning phase as well as in both delayed recall evaluations, with no difference between recall at 30 minutes and at 24 hours. CONCLUSION: Performance in the learning phase was as specific and almost as sensitive as the performance in delayed recall for AD diagnosis. Encoding impairment was responsible for poorer learning and rapid displacement of previous learned material in the AD group. Finally, we did not find a higher rate of forgetting in AD patients.
Subject(s)
Alzheimer Disease/complications , Memory Disorders/diagnosis , Aged , Alzheimer Disease/psychology , Case-Control Studies , Cues , Female , Humans , Learning , Male , Memory Disorders/etiology , Mental Recall , Neuropsychological Tests , Sensitivity and Specificity , Severity of Illness Index , Statistics, NonparametricABSTRACT
OBJECTIVE: To investigate why bilateral parietotemporal hypoperfusion, the typical SPECT pattern of Alzheimer's disease (AD), occurs in some but not in all patients with probable AD. METHODS: We reviewed the SPECT scans of 220 patients presenting with cognitive impairment. Among them, 104 patients fulfilled NINCDS-ADRDA criteria for probable AD, 48 (32 women) with early onset (before age of 65) and 56 (40 women) with late onset of the symptoms. Dementia severity was assessed by the Mini-Mental State Examination. The SPECT scans were classified by visual inspection blind to clinical diagnoses. RESULTS: Bilateral parietotemporal hypoperfusion was more frequent in patients with severe AD, in those with early onset of the symptoms, and in men. Duration of symptoms, type of gamma-camera or radiopharmaceutical agent used were not associated with this SPECT pattern. CONCLUSION: These findings may be useful in the clinical setting and point to heterogeneity of AD according to age at onset.
