Cortical responses to sustained and divided attention in Alzheimer's disease.

TY - JOUR

T1 - Cortical responses to sustained and divided attention in Alzheimer's disease.

AU - Johannsen, Peter

AU - Jakobsen, Johannes Klitgaard

AU - Bruhn, Peter

AU - Gjedde, A

N1 - Copyright 1999 Academic Press.

PY - 1999

Y1 - 1999

N2 - Neuropsychological data suggests that divided attention is more impaired than sustained attention during the early phases of Alzheimer's disease. The purpose of the present study was to compare cerebral activation patterns during sustained and divided attention between Alzheimer patients and healthy elderly. The O-15-water PET activation method was used to map sustained and divided attention in 16 patients with Alzheimer's disease (mean age +/- SD: 68 +/- 5 years; MMSE: 11-25, mean +/- SD = 19.5 +/- 4.9) and in 16 healthy age-matched control subjects. After stereotactical normalization, voxel-by-voxel t statistics was used to assess the significance of activated brain areas and to compare activations between patients and control subjects. In the healthy elderly, sustained and divided attention both elicited activation of the right inferior parietal lobule, and the right middle frontal gyrus, whereas the anterior cingulate gyrus was activated during sustained attention only. Only medial frontal structures (Brodmann Area (BA) 32/34) were activated in Alzheimer patients, and both frontal (BA-10), posterior cingulate (BA-23/31), and subcortical sites were deactivated. Compared to the healthy elderly, the activations in the patients of the right medial (BA-11) superior (BA-10) and inferior (BA-47) frontal gyri, the right middle temporal (BA-20), and the left lingual (BA-17) gyri were significantly reduced. More cortical sites differed statistically between Alzheimer patients and control subjects during divided than during sustained attention. The activation pattern elicited by attention supports the neuropsychological data that divided attention is more impaired than sustained attention in early Alzheimer's disease.

AB - Neuropsychological data suggests that divided attention is more impaired than sustained attention during the early phases of Alzheimer's disease. The purpose of the present study was to compare cerebral activation patterns during sustained and divided attention between Alzheimer patients and healthy elderly. The O-15-water PET activation method was used to map sustained and divided attention in 16 patients with Alzheimer's disease (mean age +/- SD: 68 +/- 5 years; MMSE: 11-25, mean +/- SD = 19.5 +/- 4.9) and in 16 healthy age-matched control subjects. After stereotactical normalization, voxel-by-voxel t statistics was used to assess the significance of activated brain areas and to compare activations between patients and control subjects. In the healthy elderly, sustained and divided attention both elicited activation of the right inferior parietal lobule, and the right middle frontal gyrus, whereas the anterior cingulate gyrus was activated during sustained attention only. Only medial frontal structures (Brodmann Area (BA) 32/34) were activated in Alzheimer patients, and both frontal (BA-10), posterior cingulate (BA-23/31), and subcortical sites were deactivated. Compared to the healthy elderly, the activations in the patients of the right medial (BA-11) superior (BA-10) and inferior (BA-47) frontal gyri, the right middle temporal (BA-20), and the left lingual (BA-17) gyri were significantly reduced. More cortical sites differed statistically between Alzheimer patients and control subjects during divided than during sustained attention. The activation pattern elicited by attention supports the neuropsychological data that divided attention is more impaired than sustained attention in early Alzheimer's disease.

U2 - 10.1006/nimg.1999.0475

DO - 10.1006/nimg.1999.0475

M3 - Journal article

C2 - 10458942

SN - 1053-8119

VL - 10

SP - 269

EP - 281

JO - NeuroImage

JF - NeuroImage

IS - 3 Pt 1

ER -