رفتار سوال تکراری در بیماری آلزایمر: ارتباط با جریان خون مغزی منطقه ای

Repetitive questioning is among the most common and burdensome of the behavioral and psychological symptoms of Alzheimer's disease (AD). Regardless of the clinical significance of the repetitive questioning, the neural substrates involved remain unclear. Fifty-eight consecutive patients with AD participated in this study. The score of repetitive questioning behavior was evaluated by multiplying the severity by the frequency of the behavior. They underwent brain SPECT with 99mTc-ethylcysteinate dimer. Scores of repetitive questioning behavior had a significant positive correlation with regional cerebral blood flow (rCBF) in the bilateral pericallosal regions. After removing the effect of memory test scores, we found a significant positive correlation of scores of repetitive questioning behavior to rCBF in the left pericallosal region. The pericallosal region includes the upper precuneus, cingulate, and posterior cingulate cortices on 3DSRT. Repetitive questioning behavior among AD patients might be a manifestation of mental state associated with a relative increase or preservation of rCBF in the left pericallosal region

Recently, researchers have focused on behavioral disturbances in dementia because they represent a major source of caregiver distress (Marini et al., 1997). Troublesome and disturbing behavior is a very frequent component of dementia (Baumgarten et al., 1990). Repetitive behaviors such as asking the same question many times or doing the same thing all day are observed quite frequently in demented patients (Baumgarten et al., 1990), and the behaviors exhaust and agitate caregivers (Miyamoto et al., 2002). Repetitive behaviors are among the most common and burdensome behavioral and psychological symptoms of Alzheimer's disease (AD), and repetitive questioning is the most frequent of the repetitive behaviors (Baumgarten et al., 1990, Marini et al., 1997, Miyamoto et al., 2002 and Cullen et al., 2005). In both mobile and non-mobile groups, ‘repeating the same questions’ was predictive of caregiver burden (Miyamoto et al., 2002). Repetitive questioning has been presumed to be a direct result of memory impairment (Ready et al., 2003). However, while memory impairment is present in all AD patients, repetitive questioning behavior is not. This could mean that the overall level of memory impairment is more severe in questioners or that other factors influence the occurrence of the symptom. Regardless of the clinical significance of repetitive questioning behavior in AD, the neural substrates involved remain unclear because neuroimaging studies investigating the brain regions related to the repetitive questioning behavior in patients with AD have not been performed (Hwang et al., 2000 and Cullen et al., 2005). In the present study, we investigated the relationship between repeated questioning behavior and regional cerebral blood flow (rCBF) in order to assess the neural substrates for the behavior.