P66-F Resting-state source-space MEG detects hippocampal hyperactivity in amyloid-positive amnestic MCI

• Published in: Clinical neurophysiology 2019-07, Vol.130 (7), p.e86-e86
• Main Authors: de Haan, Willem, Hillebrand, Arjan, Gouw, Alida, Scheltens, Philip, Stam, Kees
• Format: Article
• Language: English
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2019.04.515

Early detection of pathological hippocampal hyperactivity in persons with Mild Cognitive Impairment (MCI) and positive AD biomarkers (CSF/PET) is desirable, but no method is available. Here, we test MEG-based detection of hippocampal activity in MCI patients with positive biomarkers for AD, hypothesizing that their levels will be higher than in controls and AD patients. We used resting-state MEG recordings from 18 AD patients (age 63.8 ± 6.5, 9 females, mean MMSE 17.9), 18 amyloid-positive amnestic MCI patients (age 64.1 ± 6.2, 10 females, mean MMSE 25.8) and 18 persons with subjective cognitive decline (SCD, age 64.2 ± 6.1, 10 females, mean MMSE 27.6). Group and regional differences in spectral power and peak frequency were identified. Patient data was compared with computational model simulations of hyperactivity. Peak frequency was similar in SCD and MCI groups, but lower in AD patients. MCI showed a strong increase in absolute and relative lower alpha (8–10 Hz) power, strongest in the (right) hippocampus. Gamma (30–45 Hz) relative power decreased in MCI. In all groups, absolute hippocampal power was larger than the mean, especially in the (right) hippocampus. Group classification was most accurate using hippocampal power in the gamma band. Hyperactivity simulations produced changes fitting the MCI data, supporting hyperactivity as interpretation. Our results support pathological neuronal activity increases in preclinical AD. Significant changes in the hippocampus and gamma band show the additional value of MEG. Besides diagnostic and trial patient selection relevance, this finding is valuable for activity-targeting therapy research in AD.