Hippocampal calcifications: Risk factors and association with cognitive function

Abstract

Purpose: To identify risk factors for hippocampal calcifications and to investigate the association between hippocampal calcifications and cognitive function. Materials and Methods: For this retrospective study, consecutive patients visiting a memory clinic at a Dutch general hospital between April 2009 and April 2015 were identified. All individuals underwent a standard diagnostic work-up including cognitive tests and brain CT. The following vascular risk factors were assessed: hypertension, diabetes mellitus, hyperlipidemia, and smoking. Cognitive screening consisted of the Cambridge Cognitive Examination, which includes the Mini-Mental State Examination. CT scans were analyzed for the presence and severity (absent, mild, moderate, severe) of hippocampal calcifications. One measure per patient, only the most severe score, was used. Logistic regression was used to identify risk factors for hippocampal calcifications, and linear regression was used for the association between hippocampal calcifications (patient level) and cognitive function. Results: A total of 1991 patients (mean age, 78 years; range, 45-96 years) were included. The mean age of women was 79 years (range, 47-96 years), and the mean age of men was 77 years (range, 45-95 years). Of the 1991 patients, 380 (19.1%) had hippocampal calcifications. Older age (odds ratio [OR] per year, 1.05; 95% confidence interval [CI]: 1.03, 1.06), diabetes mellitus (OR, 1.50; 95% CI: 1.12, 2.00), and smoking (OR, 1.49; 95% CI: 1.05, 2.10) were associated with the presence of hippocampal calcifications. No associations were found between presence and severity of hippocampal calcifications and cognitive function. Conclusion: Older age, diabetes mellitus, and smoking were associated with an increased risk of hippocampal calcifications. A greater degree of hippocampal calcifications was not associated with lower cognitive function in patients with memory complaints.