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MEG detects abnormal hippocampal activity in amyloid‐positive MCI
Author(s) -
Luppi Janne,
Schoonhoven Deborah N,
van Nifterick Anne M,
Arjan Hillebrand,
Gouw Alida A,
Scheltens Philip,
Stam Cornelis J,
de Haan Willem
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.040796
Subject(s) - hippocampal formation , hippocampus , medicine , pathological , alzheimer's disease , neuroscience , cognitive impairment , resting state fmri , psychology , cognition , disease
Abstract Background Early Alzheimer’s disease (AD) is characterized by pathological hippocampal hyperactivity 1,2 . Non‐invasive detection of hippocampal hyperactivity is relevant for diagnostic and therapeutic purposes, but no reliable method is available. We tested magneto‐encephalographical (MEG) detection of hippocampal activity, hypothesizing that in amyloid‐positive MCI patients resting‐state hippocampal activity would be higher than in both controls and AD patients. Method We used resting‐state MEG data from 18 mild/moderate AD patients, 18 amyloid‐positive (CSF) amnestic MCI patients, and 18 persons with subjective cognitive decline (SCD). MEG source space signals were reconstructed for 80 AAL regions using beamforming 3 . We obtained 20 non‐selected, eyes‐closed, 13‐second epochs per person. Global spectral power group differences were identified for common frequency bands using ANOVA and t‐tests. Classification was tested with ROC curves. Result Peak frequency was similar in SCD and MCI groups, but lower in AD patients (P<0.001). In MCI and AD, hippocampal total power increased, with a significant rise in the right hippocampus in MCI (p<0.01). In MCI, this was mainly driven by high relative lower alpha (8‐10 Hz) power, significant only in the right hippocampus (P<0.01). Relative gamma (30‐45 Hz) power was lowest in the MCI patient group, hippocampal as well as overall (p<0.01). Classification between MCI and SCD was most accurate using right hippocampal gamma power (Area under the curve = 0.821). Conclusion Resting‐state MEG detects abnormal hippocampal activity in preclinical AD patients. This may be a macroscale 'signature' of underlying neuronal hyperactivity 1,4 . Relevant findings in these subcortical regions and in the gamma frequency band show the added value of MEG compared to EEG and fMRI. The present approach may facilitate diagnostic and therapeutic strategies. References: (1) Canter ea. (2016). The road to restoring neural circuits for the treatment of Alzheimer's disease. Nature, 539(7628), 187; (2) Palop & Mucke (2016). Network abnormalities and interneuron dysfunction in Alzheimer disease. Nature Reviews Neuroscience, 17(12), 777; (3) López, ea. (2017). MEG beamformer‐based reconstructions of functional networks in mild cognitive impairment. Frontiers in aging neuroscience, 9, 107; (4) Busche & Konnerth (2016). Impairments of neural circuit function in Alzheimer's disease. Phil Trans Royal Soc B: Biological Sciences, 371(1700), 20150429.