Involvement of inflammation in the medial temporal region in the development of agitation in Alzheimer's disease: an in vivo positron emission tomography study

BACKGROUND

The evaluation of ¹¹ C-DPA-713 binding using positron emission tomography for quantifying the translocator protein can be a sensitive approach in determining the level of glial activation induced by neuroinflammation. Herein, we aimed to investigate the relationship between regional ¹¹ C-DPA713-binding potential (BP_ND ) and neuropsychiatric symptoms (NPS) in amyloid-positive Alzheimer's disease (AD) patients.

METHODS

Fifteen AD patients were enrolled in this study. Correlations were evaluated between the ¹¹ C-DPA713-BP_ND and Neuropsychiatric Inventory Questionnaire (NPI-Q) scores, including scores in its four domains: agitation, psychosis, affective, and apathy. ¹¹ C-DPA713-BP_ND values were compared between groups with and without the neuropsychiatric symptoms for which a relationship was observed in the abovementioned correlation analysis.

RESULTS

A positive correlation was found between the severity of agitation and ¹¹ C-DPA713-BP_ND in the Braak 1-3 area, including the amygdala, hippocampal and parahippocampal regions, and lingual and fusiform areas. An increase in the ¹¹ C-DPA713-BP_ND was observed in AD patients with agitation. We did not find any significant effects of possible confounding factors, such as age, duration of illness, education, gender, Mini-Mental State Examination score, cerebrospinal fluid amyloid β 42/40 ratio, and apolipoprotein E4 positivity, on either the ¹¹ C-DPA713-BP_ND or agitation score.

CONCLUSIONS

Neuroinflammation in the medial temporal region and its neighbouring area was shown to be associated with the development of agitation symptoms in AD patients. Our findings extend those of previous studies showing an association between some NPS and inflammation, suggesting that immunologically based interventions for agitation can serve as an alternative treatment for dementia.

Self-awareness for financial decision making abilities is linked to right temporal cortical thickness in older adults

Everyday financial decision making and the awareness of the integrity of one's financial decision making abilities (or financial awareness) are both critical to study in older adults as they can help identify those at risk for making suboptimal financial decisions and prevent financial loss. In the current study, we examined the cognitive and cortical thickness correlates of financial decision making and financial awareness in 59 community-dwelling participants co-enrolled in a larger study (mean age=68.35 years (SD=5.5), mean education=15.91 (SD=2.36), 61% = women, 67% = White, 30% = Black participants). Data from standardized measures of financial decision making and cognition was investigated along with FreeSurfer (v. 5.3) derived thickness regions. Based on metacognitive frameworks, financial awareness was measured along with a well-validated measure of memory awareness. Results revealed that numeracy, executive functioning and vocabulary were associated with financial decision making, whereas in analysis adjusted for financial decision making, memory awareness relative to cognition was most strongly linked to financial awareness. No significant associations between thickness and financial decision making were found. However, both financial and memory awareness were associated with the same right-hemisphere temporal thickness regions underscoring the idea of a common substrate of awareness. Interestingly, our findings converge with the emerging work on financial exploitation in which the right sided temporal regions have been found to play a prominent role. Incorporating the contributing role of self-awareness in various models of financial exploitation will be an important consideration for future studies.