Coupling motor evoked potentials and brain [18F]FDG-PET in Amyotrophic Lateral Sclerosis: preliminary findings on disease severity

• DOI: 10.1016/j.nbd.2024.106579
• Publication Date: 2024-06-25T23:42:10Z
• Authors: Giacomo Tondo; Letizia Mazzini; Silvia Paola Cami...; Chiara Gallo; Roberta Matheoud; Cristoforo Comi; Gian Mauro Sacchetti; Daniela Perani; Fabiola De Marchi
• Keywords: Precentral gyrus; Hypermetabolism; Upper motor neuron; Supplementary motor area

The diagnosis of amyotrophic lateral sclerosis (ALS) is primarily clinical, supported by the electromyographic examination to reveal signs lower motor neuron damage. Identifying reliable markers upper (UMN) involvement challenging. On this regard, role transcranial magnetic stimulation-induced motor-evoked potentials (TMS-MEPs), and its relationship with UMN burden, still under investigation. To evaluate ability TMS-MEPs in delineating neurophysiological damage, determine between [18F]FDG-PET measures neural dysfunction. We retrospectively selected 13 ALS patients who underwent, during diagnostic process, scans. Demographic clinical data were collected. For MEP evaluation, we considered normal MEP, absent or significantly increased central-motor-conduction-time. [18F]FDG-PET, conducted voxel-wise analyses, both at single-subject group levels, exploring hypometabolism hypermetabolism patterns comparison a large dataset healthy controls (HC). Based on TMS-MEPs, identified 4/13 all limbs (GROUP-NO), while 9/13 had an abnormal least one limb (GROUP-AB). Despite analysis revealed heterogenous expression regional hypo- hyper-metabolism patients, group-level common hypometabolism, involving precentral gyrus supplementary area, paracentral lobule anterior cingulate cortex GROUP-AB. Moreover, exclusively for GROUP-AB compared HC, relative was observed right cerebellum, inferior middle temporal gyrus. GROUP-NO showed no specific cluster HC. This study altered brain metabolism only MEPs, suggesting association two biomarkers defining