These studies presented opposing results whether the presence of Lewy bodies in AD patients has an effect on the age of onset of symptoms, death [51, 63–65], the likelihood of be an APOE ε4 carrier [51, 65, 66], parkinsonian symptoms [63, 64, 67, 68], cognitive impairment [63, 64], or visual hallucinations [64, 68–70]. This evidence concerns the gene APOE and Alzheimer disease.