Alzheimer disease neuropathologic change (ADNC) + Lewy body disease (LBD) (but not ADNC + vascular brain injury [VBI]) was associated with poorer executive function and attention compared to other pathology groupings, according to a recent study. However, the effect of co-occurring pathologies on cognitive trajectories may depend on the severity of ADNC. Data came from 1,603 autopsied participants evaluated at US Alzheimer's Disease Centers. Standardized z scores in memory, attention, language, and executive function were derived from neuropsychological test scores assessed at each annual visit. Researchers found:

• Compared to other participants, those with ADNC + LBD generally had worse cognitive trajectories, particularly lower initial executive function and faster attention decline.
• Participants with ADNC + VBI typically had less impairment and slower decline.
• Interactions were significant between LBD and ADNC for memory and between VBI and ADNC for language; decline was slower than expected if these neuropathologies acted additively on the rate of decline.
• In secondary models, these interactions were limited to those with high ADNC (but not intermediate ADNC).