Neuropsychological predictors of rapidly progressing patients with Alzheimer's disease

Alzheimer disease (AD) has heterogeneous clinical manifestations. Different neuropsychological profiles in AD patients might be indicative of the diffusion of the pathological process and might be associated with differences in rates of disease progression.

We studied 154 newly diagnosed AD patients (65.6% women; mean age: 73 years). Performance in memory, executive functions, praxis and language domains was categorized into mild, moderate and severe impairment. The time-dependent probability of losing 5 points on the Mini-Mental State Examination (MMSE) over 2 years was considered as disease progression and evaluated by survival analysis.

One fourth of the patients decreased by ≥ 5 MMSE points over the 2-year follow-up. Rapid disease progression was more frequent in more educated patients and in those with moderate severity of global cognitive impairment. In univariate analysis, more severe memory and executive functioning impairment were associated with higher probabilities of progression. The association with memory was explained by differences in executive function impairment that remained statistically significant in multivariate analyses.

Patients with more severe executive functioning impairment have a worse prognosis over 2 years. This might be due to involvement of the prefrontal cortex by the pathological process of AD in patients with severe executive deficits.