Correlation of cognitive decline and behavioral changes in patients with presenile and senile onset Alzheimer’s disease

Alzheimer’s disease (AD), the most prevalent dementia, is characterized not only by cognitive but also behavioral changes that pose the heaviest burden to caregivers. Differences in the clinical picture depending on the time of disease onset have been observed. We correlated cognitive and behavioral deficits in patients with presenile- and senile-onset AD to explore the differences. We tested 60 AD patients, 19 male and 41 female, mean age 65.2 years with the Dementia Behavior Disturbance Scale (DBD) and a standard neuropsychological battery. The patients were divided according to their DBD score into two groups: group I - score 0-2 (n=24; 40%), group II - score 3≥ (n=36; 60%), comparable in disease duration and neurological findings. The cognitive scores were significantly higher in the group with less behavioral changes than in the group with more behavioral changes: Mini Mental State Examination score (p=0.0015), serial subtraction (p=0.0009), block design (p=0.0049), copy of complex figure (p=0.0125), complex visual organization (p=0.0099), divided attention, visual memory and speech comprehension. A significantly higher frequency of behavioral disturbances was registered in patients with senile onset than in the presenile-onset group (p<0.005). There were no sex differences. Our data show a correlation between cognitive decline and behavioral changes in late onset AD patients, indicating that more behavioral disturbances were associated with a more severe degree of cognitive decline, especially in non-verbal functions and attention deficits, compared to early onset patients. [Projekat Ministarstva nauke Republike Srbije, br. 175033 i br. 175022