APOE and early-onset autosomal dominant Alzheimer disease: However, atrophy of the medial temporal lobe observed in the hearing-impaired individuals might be different from that seen in Alzheimer’s disease, because we found no relationship between hearing and the entorhinal cortex, which is known to be a region that shows prominently progressive atrophy in the early stages of Alzheimer’s disease (Gómez-Isla et al., 1996; Du et al., 2004).Third, information on the APOE genotype, of which APOE4 is known as a risk factor of Alzheimer’s disease, was not analyzed.