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Decreased Frontal Gamma Activity in Alzheimer Disease Patients
Author(s) -
Casula Elias P.,
Pellicciari Maria C.,
Bonnì Sonia,
Borghi Ilaria,
Maiella Michele,
Assogna Martina,
Minei Marilena,
Motta Caterina,
D'Acunto Alessia,
Porrazzini Francesco,
Pezzopane Valentina,
Mencarelli Lucia,
Roncaioli Andrea,
Rocchi Lorenzo,
Spampinato Danny A.,
Caltagirone Carlo,
Santarnecchi Emiliano,
Martorana Alessandro,
Koch Giacomo
Publication year - 2022
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.26444
Subject(s) - transcranial magnetic stimulation , electroencephalography , frontal lobe , neuroscience , psychology , epilepsy , precuneus , neuroplasticity , temporal lobe , long term potentiation , alzheimer's disease , brain activity and meditation , audiology , cognition , disease , medicine , stimulation , receptor
Objective In Alzheimer disease (AD) animal models, synaptic dysfunction has recently been linked to a disorder of high‐frequency neuronal activity. In patients, a clear relation between AD and oscillatory activity remains elusive. Here, we attempt to shed light on this relation by using a novel approach combining transcranial magnetic stimulation and electroencephalography (TMS‐EEG) to probe oscillatory activity in specific hubs of the frontoparietal network in a sample of 60 mild‐to‐moderate AD patients. Methods Sixty mild‐to‐moderate AD patients and 21 age‐matched healthy volunteers (HVs) underwent 3 TMS‐EEG sessions to assess cortical oscillations over the left dorsolateral prefrontal cortex, the precuneus, and the left posterior parietal cortex. To investigate the relations between oscillatory activity, cortical plasticity, and cognitive decline, AD patients underwent a TMS‐based neurophysiological characterization and a cognitive evaluation at baseline. The latter was repeated after 24 weeks to monitor clinical evolution. Results AD patients showed a significant reduction of frontal gamma activity as compared to age‐matched HVs. In addition, AD patients with a more prominent decrease of frontal gamma activity showed a stronger impairment of long‐term potentiation–like plasticity and a more pronounced cognitive decline at subsequent follow‐up evaluation at 24 weeks. Interpretation Our data provide novel evidence that frontal lobe gamma activity is dampened in AD patients. The current results point to the TMS‐EEG approach as a promising technique to measure individual frontal gamma activity in patients with AD. This index could represent a useful biomarker to predict disease progression and to evaluate response to novel pharmacological therapies. ANN NEUROL 2022;92:464–475