Original Research Article

Inferior Temporal Lobe Atrophy and APOE Genotypes in Alzheimer's Disease
x-Ray Computed Tomog raphy, Magnetic Resonance Imaging and Xe-133 SPECT Studies
Seigo Tanaka^a, Jun Kawamata^b, Shun Shimohama^b, Hiroshi Akaki^c, Ichiro Akiguchi^b, Jun Kimura^b, Kunihiro Ueda<sup>a

a</sup> Laboratory of Molecular Clinical Chemistry, Institute for Chemical Research, Kyoto University,
^b Department of Neurology, Kyoto University Graduate School of Medicine and
^c Narabigaoka Hospital, Kyoto, Japan

Address of Corresponding Author

Dement Geriatr Cogn Disord 1998;9:90-98 (DOI: 10.1159/000017029)

  Key Words

• Temporal lobe
• Hippocampus
• Amygdala
• Apolipoprotein E gene
• Alzheimer's disease
• x-Ray computed tomography
• Magnetic resonance imaging
• Xe-133 SPECT

  Abstract

The apolipoprotein E (APOE) gene 4 allele is known to be associated with late-onset familial and sporadic Alzheimer's disease (AD). We assessed the possible relationship between APOE genotypes and morphological or functional changes in AD brains by x-ray computed tomography (CT), magnetic resonance imaging (MRI) and Xe-133 single photon emission CT (SPECT). First, we estimated the change in size of the whole brain and total ventricular system by using two x-ray CT indices, the cerebral index (CI) and ventricular index (VI), respectively. Neither CI nor VI differed significantly among APOE genotypes. Then, we focused on the inferior temporal lobe regions by introducing new MRI indices, the inferior temporal index (ITI), temporal horn index (THI) and infero-medial temporal index (IMTI). We found a significant difference in each MRI index among APOE subgroups; ITI and IMTI were lower, while THI was higher in AD patients with at least one APOE 4 allele (4+ group) than in those without such an allele (4- group). Finally, we compared relative regional cerebral blood flow (rCBF) of Xe-133 SPECT among the AD subgroups. Relative rCBF in the cerebral cortex, particularly in the temporal lobe, was lower in the 4+ group than in the 4- group. These results indicate that possession, and thus expression, of the APOE 4 allele affects preferentially the inferior temporal lobe, encompassing the hippocampus and amygdala, in AD patients.

  Author Contacts

Kunihiro Ueda, MD, PhD
Laboratory of Molecular Clinical Chemistry
Institute for Chemical Research
Kyoto University, Uji, Kyoto 611 (Japan)
Tel. +81 774 38 3225, Fax +81 774 38 3226, E-Mail ueda@scl.kyoto-u.ac.jp

  Article Information

Received: Accepted: July 9, 1997
Number of Print Pages : 9
Number of Figures : 5, Number of Tables : 3, Number of References : 43