{"doi":"10.1017/cjn.2025.79","title":"Assessing Motor Cortex Excitability and Its Relationship with Cortical Atrophy in Alzheimer’s Dementia","abstract":"ABSTRACT Background: Cortical excitability has been proposed as a novel neurophysiological marker of neurodegeneration in Alzheimer’s dementia (AD). However, the link between cortical excitability and structural changes in AD is not well understood. Objective: To assess the relationship between cortical excitability and motor cortex thickness in AD. Methods: In 62 participants with AD (38 females, mean ± SD age = 74.6 ± 8.0) and 47 healthy control (HC) individuals (26 females, mean ± SD age = 71.0 ± 7.9), transcranial magnetic stimulation resting motor threshold (rMT) was determined, and T1-weighted MRI scans were obtained. Skull-to-cortex distance was obtained manually for each participant using MNI coordinates of the motor cortex (x = −40, y = −20, z = 52). Results: The mean skull-to-cortex distances did not differ significantly between participants with AD (22.9 ± 4.3 mm) and HC (21.7 ± 4.3 mm). Participants with AD had lower motor cortex thickness than healthy individuals ( t (92) = −4.4, p = <0.001) and lower rMT (i.e., higher excitability) than HC ( t (107) = −2.0, p = 0.045). In the combined sample, rMT was correlated positively with motor cortex thickness ( r = 0.2, df = 92, p = 0.036); however, this association did not remain significant after controlling for age, sex and diagnosis. Conclusions: Patients with AD have decreased cortical thickness in the motor cortex and higher motor cortex excitability. This suggests that cortical excitability may be a marker of neurodegeneration in AD.","journal":"Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques","year":2025,"id":544678,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.8306,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":950206,"name":"Reza Zomorrodi","orcid":"0000-0002-1648-843X","position":1,"is_corresponding":false},{"id":106653,"name":"Michael Joseph","orcid":"0000-0002-0068-230X","position":2,"is_corresponding":false},{"id":1435598,"name":"Hiba Alhabbal","orcid":null,"position":3,"is_corresponding":false},{"id":1435599,"name":"Gifty Asare","orcid":null,"position":4,"is_corresponding":false},{"id":333475,"name":"Daniel M. Blumberger","orcid":"0000-0002-8422-5818","position":5,"is_corresponding":false},{"id":294684,"name":"Zafiris J. Daskalakis","orcid":"0000-0001-9502-0538","position":6,"is_corresponding":false},{"id":291331,"name":"Corinne E. Fischer","orcid":"0000-0002-1047-0167","position":7,"is_corresponding":false},{"id":226870,"name":"Benoit H. Mulsant","orcid":"0000-0002-0303-6450","position":8,"is_corresponding":false},{"id":226869,"name":"Bruce G. Pollock","orcid":"0000-0003-0802-3998","position":9,"is_corresponding":false},{"id":226868,"name":"Tarek K. Rajji","orcid":"0000-0002-8324-2560","position":10,"is_corresponding":false},{"id":230416,"name":"Aristotle N. Voineskos","orcid":"0000-0003-0156-0395","position":11,"is_corresponding":false},{"id":226867,"name":"Sanjeev Kumar","orcid":"0000-0002-8115-353X","position":12,"is_corresponding":false},{"id":1435205,"name":"Renee P Lawson","orcid":"0009-0008-2216-7326","position":0,"is_corresponding":true}],"reference_count":41,"raw_metadata":null,"created_at":"2026-07-19T02:53:17.418915Z","pmid":"40485143","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}