Cognitive Decline and Amyloid Accumulation in Patients with Mild Cognitive Impairment

• Published in: Dementia and geriatric cognitive disorders 2012-01, Vol.34 (1), p.31-37
• Main Authors: Koivunen, Jaana, Karrasch, Mira, Scheinin, Noora M., Aalto, Sargo, Vahlberg, Tero, Någren, Kjell, Helin, Semi, Viitanen, Matti, Rinne, Juha O.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - metabolism; Alzheimer Disease - psychology; Amyloid - metabolism; Aniline Compounds; Biological and medical sciences; Caudate Nucleus - diagnostic imaging; Cognition - physiology; Cognition Disorders - diagnostic imaging; Cognition Disorders - metabolism; Cognition Disorders - psychology; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - metabolism; Cognitive Dysfunction - psychology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Disease Progression; Female; Follow-Up Studies; Humans; Longitudinal Studies; Male; Medical sciences; Neurology; Neuropharmacology; Neuropsychological Tests; Original Research Article; Pharmacology. Drug treatments; Positron-Emission Tomography; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer..., (alzheimer disease); Psychology. Psychoanalysis. Psychiatry; Psychometrics; Psychopharmacology; Radiopharmaceuticals; Temporal Lobe - diagnostic imaging; Thiazoles
• ISSN: 1420-8008; 1421-9824
• DOI: 10.1159/000341580

Background/Aims: The relationship between baseline 11 C-Pittsburgh compound B ( 11 C-PIB) uptake and cognitive decline during a 2-year follow-up was studied in 9 patients with mild cognitive impairment (MCI) who converted to Alzheimer’s disease (AD) and 7 who remained with MCI. Methods: 11 C-PIB PET scan was conducted at baseline and cognitive assessment both at baseline and at follow-up. To obtain quantitative regional values of 11 C-PIB uptake, automated region of interest analysis was done using spatially normalized parametric ratio (region-to-cerebellar cortex) images. Results: At baseline, there were statistically significant differences in 11 C-PIB uptake, but not in cognitive test performances between the converters and nonconverters. Memory and executive function declined only in the converters during follow-up. In the converters, lower baseline frontal 11 C-PIB uptake was associated with faster decline in verbal learning. Higher baseline uptake in the caudate nucleus was related to faster decline in memory consolidation, and higher temporal uptake was associated with decline in executive function. Conclusion: Higher 11 C-PIB uptake in the caudate nucleus and temporal lobe was related to decline in memory and executive functions, whereas lower frontal uptake was related to decline in verbal learning. The results indicate that in prodromal AD, frontal amyloid accumulation reaches its maximum in the MCI stage, characterized by memory problems without full-blown dementia.