Diagnosis of Mild Cognitive Impairment Due to Alzheimer's Disease with Transcranial Magnetic Stimulation

• Published in: Journal of Alzheimer's disease Vol. 65; no. 1; p. 221
• Main Authors: Padovani, Alessandro, Benussi, Alberto, Cantoni, Valentina, Dell'Era, Valentina, Cotelli, Maria Sofia, Caratozzolo, Salvatore, Turrone, Rosanna, Rozzini, Luca, Alberici, Antonella, Altomare, Daniele, Depari, Alessandro, Flammini, Alessandra, Frisoni, Giovanni B, Borroni, Barbara
• Format: Journal Article
• Language: English
• Published: Netherlands 01.01.2018
• Subjects: short latency afferent inhibition; dementia; mild cognitive impairment; transcranial magnetic stimulation; Alzheimer’s disease; short interval intracortical inhibition
• ISSN: 1875-8908
• DOI: 10.3233/JAD-180293

Considering the increasing evidence that disease-modifying treatments for Alzheimer's disease (AD) must be administered early in the disease course, the development of diagnostic tools capable of accurately identifying AD at early disease stages has become a crucial target. In this view, transcranial magnetic stimulation (TMS) has become an effective tool to discriminate between different forms of neurodegenerative dementia. To determine whether a TMS multi-paradigm approach can be used to correctly identify mild cognitive impairment (MCI) due to AD (AD MCI). A sample of 69 subjects with MCI were included and classified as AD MCI or MCI unlikely due to AD (non-AD MCI) based on 1) extensive neurological and neuropsychological evaluation, 2) MRI imaging, and 3) cerebrospinal fluid analysis or/and amyloid PET imaging. A paired-pulse TMS multi-paradigm approach assessing short interval intracortical inhibition-facilitation (SICI-ICF), dependent on GABAergic and glutamatergic intracortical circuits, respectively, and short latency afferent inhibition (SAI), dependent on cholinergic circuits, was performed. We observed a significant impairment of SAI and unimpaired SICI and ICF in AD MCI as compared to non-AD MCI. According to ROC curve analysis, the SICI-ICF / SAI index differentiated AD MCI from non-AD MCI with a specificity of 87.9% and a sensitivity of 94.4%. The assessment of intracortical connectivity with TMS could aid in the characterization of MCI subtypes, correctly identifying AD pathophysiology. TMS can be proposed as an adjunctive, non-invasive, inexpensive, and time-saving screening tool in MCI differential diagnosis.