Differential association of [11C]PIB and [18F]FDDNP binding with cognitive impairment.
OBJECTIVE
To evaluate associations of [(11)C]Pittsburgh compound B (PIB) and [(18)F]FDDNP with impairment in specific cognitive domains over the broader spectrum comprising cognitively normal elderly subjects, patients with mild cognitive impairment (MCI), and patients with Alzheimer disease (AD).


METHODS
Twelve patients with AD, 13 patients with MCI, and 15 cognitively normal elderly subjects were included. Paired [(11)C]PIB and [(18)F]FDDNP PET scans were performed in all subjects. Binding potential (BP(ND)) was calculated using parametric images of BP(ND) for global, frontal, parietal, and temporal cortex; medial temporal lobe; and posterior cingulate. Cognitive functions were assessed using a battery of neuropsychological tests. Linear regression analyses were used to assess associations of [(11)C]PIB and [(18)F]FDDNP binding with cognitive measures.


RESULTS
Adjusted for age, sex, and [(18)F]FDDNP binding, higher global [(11)C]PIB binding was associated with lower scores on the Mini-Mental State Examination, immediate and delayed recall of the Rey Auditory Verbal Learning Task (RAVLT), Visual Association Task, and Trail Making Test part B. Conversely, higher [(18)F]FDDNP binding was independently associated with lower scores on immediate recall of the RAVLT. After additional adjustment for diagnosis, higher [(11)C]PIB binding remained independently associated with delayed recall (standardized beta = -0.39, p = 0.01), whereas higher [(18)F]FDDNP binding remained independently associated with immediate recall (standardized beta = -0.32, p = 0.03). When regional binding was assessed using stepwise models, both increased frontal [(11)C]PIB and temporal [(18)F]FDDNP binding were associated with memory, whereas increased parietal [(11)C]PIB binding was associated with nonmemory functions.


CONCLUSIONS
Increased [(18)F]FDDNP binding is specifically associated with impairment of episodic memory, whereas increased [(11)C]Pittsburgh compound B binding is associated with impairment in a broader range of cognitive functions.
Tolboom
N
N
Department of Nuclear Medicine & PET Research, VU University Medical Centre, Amsterdam, the Netherlands. n.tolboom@vumc.nl
van der Flier
W M
WM
Yaqub
M
M
Koene
T
T
Boellaard
R
R
Windhorst
A D
AD
Scheltens
P
P
Lammertsma
A A
AA
van Berckel
B N M
BN
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism / Q000523:psychology*; D000814:Aniline Compounds / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002250:Carbon Radioisotopes; D003072:Cognition Disorders / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D009570:Nitriles / Q000378:metabolism; D049268:Positron-Emission Tomography; D012044:Regression Analysis; D013844:Thiazoles / Q000378:metabolism
C444520:2-(1-(6-((2-fluoroethyl)(methyl)amino)-2-naphthyl)ethylidene)malononitrile; C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000814:Aniline Compounds; D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D009570:Nitriles; D013844:Thiazoles