Amyloid Deposits and Idiopathic Normal-Pressure Hydrocephalus: An ¹⁸F-Florbetaben Study

Background: The first aim of our study was to determine whether cortical ¹⁸F-florbetaben retention was different between healthy controls and idiopathic normal-pressure hydrocephalus (INPH) patients. Our second aim was to investigate whether there were any relationships between ¹⁸F-florbetaben retention and either hippocampal volume or clinical symptoms in INPH patients. Methods: Seventeen patients diagnosed with INPH and 8 healthy controls underwent studies with magnetic resonance imaging and ¹⁸F-florbetaben positron emission tomography imaging. Results: Automated region-of-interest analysis showed significant increases in ¹⁸F-florbetaben uptake in several brain regions in INPH patients compared to control subjects, with especially remarkable increases in the frontal (bilateral), parietal (bilateral), and occipital (bilateral) cortices. In the INPH group, right hippocampal volume was found to be negatively correlated with right frontal ¹⁸F-florbetaben retention. Korean-Mini Mental State Examination scores negatively correlated with right occipital ¹⁸F-florbetaben retention. Higher ¹⁸F-florbetaben retention correlated significantly with a higher Clinical Dementia Rating Scale score in the right occipital cortex. Conclusions: Our results indicate that INPH might be a disease exhibiting a characteristic pattern of cortical ¹⁸F-florbetaben retention. ¹⁸F-florbetaben retention in the frontal cortex may be related to hippocampal neuronal degeneration. Our findings may also help us understand the potential pathophysiology of cognitive impairments associated with INPH.