Fig. 5.

Average SI in MCI subjects with regard to presence of APOE ε4 allele and levels of CSF Aβ. A) The SI increased faster in ε4⁺ subjects compared to ε4⁻ subjects (p = 0.006). B) The SI increased faster in Aβ⁺ subjects compared to Aβ⁻ subjects (p = 0.021). C) Within AD-like subjects, the ε4⁺ group had a greater increase of the SI compared to the ε4⁻ group (p = 0.003), but there is no significant difference within CN-like subjects. D) Within AD-like subjects, Aβ⁺ had a greater increase of the SI compared to the Aβ⁻ group (p = 0.004), but there was no significant difference within CN-like subjects.

CSF, cerebrospinal fluid; SI, disease severity index; AD, Alzheimer's disease; CN, cognitively normal subjects; MCI, mild cognitive impairment, Error bars show 95% confidence intervals.