Working memory and FDG-PET dissociate early and late onset Alzheimer disease patients.
The aims of this study were to determine the influence of the onset of Alzheimer's disease (AD) on 1) memory and cerebral glucose metabolism, 2) the relationships between cognitive performance and cerebral glucose metabolism. Brain metabolism was measured by 18FDG-PET in 12 early onset AD patients (age < 65 years) and 26 late onset ones (> 65), with comparable mean MMSE scores. Working memory, semantic memory and episodic memory were assessed. Cognitivo-metabolic correlations (CMC) and complementary interregional correlations were performed in order to identify specific neurocognitive processes within each group. Both AD groups performed poorly on all tasks, except digit span in the late onset group. The early onset group performed more poorly than the late onset one on both the digit span and Brown-Peterson Paradigm (BPP) tasks. Temporo-parietal hypometabolism was found in both groups, the left hemisphere being more affected than the right, especially in the early onset patients, who also showed specific left frontal hypometabolism. For the BPP task, the CMC principally involved left frontal areas in the early onset group, and the cerebellum in the late onset one. For the digit span task, they involved cerebellar and occipital regions in the latter. Regarding the digit span, the occipital and cerebellar involvement may have reflected an effective compensatory mechanism in the late onset patients, while high left supramarginal gyrus hypometabolism in the early onset patients may have explained their failure in this task. In the BPP task, the lower performance of the early onset group may have been due to a frontal lobe dysfunction, as suggested by 1) the hypometabolism of this region, 2) the CMC results, 3) the interregional correlations, which indicated greater disruption of the antero- posterior loop.
Kalpouzos
Grégoria
G
Inserm-Université de Caen E0218, Laboratoire de Neuropsychologie, CHU Côte de Nacre, 14033 Caen Cedex, France.
Eustache
Francis
F
de la Sayette
Vincent
V
Viader
Fausto
F
Chételat
Gaël
G
Desgranges
Béatrice
B
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism* / Q000523:psychology; D000704:Analysis of Variance; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies
D019788:Fluorodeoxyglucose F18
Nucl Med Commun. 2003 Jul;24(7):785-90
12813197
Neuropsychologia. 1987;25(5):807-16
3501553
Alzheimer Dis Assoc Disord. 2002 Oct-Dec;16(4):228-38
12468897
Brain. 1998 Apr;121 ( Pt 4):611-31
9577389
J Exp Psychol. 1959 Sep;58:193-8
14432252
Neurosci Lett. 2002 Feb 15;319(2):91-4
11825678
Cortex. 1996 Sep;32(3):387-412
8886519
Proc Natl Acad Sci U S A. 2000 May 23;97(11):5696-8
10811924
Neuropsychologia. 1995 Mar;33(3):379-84
7792005
Brain. 2003 Sep;126(Pt 9):1955-67
12821520
Brain Lang. 1991 Nov;41(4):531-7
1777810
Neurology. 1994 Jul;44(7):1215-20
8035918
J Neurol Sci. 1994 May;123(1-2):11-7
8064302
Gerontologist. 1993 Oct;33(5):637-43
8225008
Nature. 1993 Apr 15;362(6421):583
8464509
Neurosci Biobehav Rev. 2002 Mar;26(2):105-25
11856556
J Psychiatr Res. 1999 Jan-Feb;33(1):7-16
10094234
Neuropsychologia. 1998 Sep;36(9):945-9
9740367
Neurology. 1985 Nov;35(11):1544-50
4058744
Arch Neurol. 1983 Mar;40(3):143-6
6830452
Hum Brain Mapp. 1997;5(2):110-8
10096415
Acta Neurol Scand. 1994 Feb;89(2):132-8
8191876
Neuropsychologia. 1985;23(3):351-7
4022302
Cortex. 1999 Feb;35(1):57-72
10213534
Dement Geriatr Cogn Disord. 1998 Mar-Apr;9(2):63-7
9524795
Neuropsychologia. 1996 Mar;34(3):195-207
8868277
Neuropsychol Rev. 2003 Jun;13(2):79-92
12887040
Proc Natl Acad Sci U S A. 1999 Oct 26;96(22):12959-64
10536030
J Clin Exp Neuropsychol. 1988 Mar;10(2):279-96
3280591
Brain. 1998 Nov;121 ( Pt 11):2175-87
9827776
Neuropsychologia. 2000;38(4):426-40
10683393
Arch Neurol. 1996 Oct;53(10):1056-61
8859068
Am J Psychiatry. 1985 May;142(5):638-40
3872604
J Neurol Neurosurg Psychiatry. 2003 Jun;74(6):715-9
12754337
Neuroimage. 2003 Feb;18(2):247-56
12595179
Psychiatr J Univ Ott. 1990 Nov;15(4):203-6
1980952
Neuroimage. 2002 Jan;15(1):273-89
11771995
Brain Lang. 2001 Dec;79(3):580-600
11781058
Union Med Can. 1993 Nov-Dec;122(6):420-6
8303783
Brain. 2002 May;125(Pt 5):1116-24
11960900
J Neurosci. 1998 Jul 1 ;18(13):5026-34
9634568
Neurology. 1996 Jan;46(1):136-41
8559362
Acta Neurol Belg. 1990;90(4):207-17
2124031
Hum Brain Mapp. 2000 May;10(1):39-48
10843517
Neurology. 1986 Nov;36(11):1497-9
3531918
J Neurol Sci. 2002 Aug 15;200(1-2):27-32
12127672
Neuropsychologia. 2002;40(7):846-52
11900735
Neuropsychologia. 1985;23(5):623-38
4058708
Neuropsychologia. 1999 Jul;37(8):905-18
10426516
Neurology. 1984 Jul;34(7):939-44
6610841
J Neurol Sci. 2003 May 15;209(1-2):25-30
12686398
Memory. 2001 Jul-Nov;9(4-6):223-31
11594348