OBJECTIVE: Recently, the utility of threshold tracking paired-pulse transcranial magnetic stimulation (TTTMS), to measure changes in cortical excitabilitability, has been established for diagnostic purposes across a range of neurological diseases. However, the impact of healthy aging on the GABA-ergic intracortical inhibitory system remains unclear. To improve the clinical applicability, TTTMS was performed across an age spectrum. METHODS: TTTMS, single-pulse TMS and nerve conduction studies (NCS) were performed in 113 healthy subjects aged between 20 and 83years (57 male and 56 female). RESULTS: Prolonged motor evoked potential (MEP) latency, increased central motor conduction time, decreased compound muscle action potential (CMAP) amplitude, prolonged F-wave latency and decreased neurophysiological index (NI), calculated from CMAP amplitude, latency and F-wave frequency, were observed as subjects aged. In contrast, short interval intracortical inhibition (SICI) and facilitation did not change. Compared to females, males exhibited a reduced SICI and NI along with longer MEP, CMAP with prolonged F-wave latencies. Multivariate analyses revealed similar results. CONCLUSION: Utilizing clinically applicable TTTMS protocols, findings suggest that GABA mediated intracortical inhibition may be greater in females but does not significantly change with age. SIGNIFICANCE: These findings may better inform the interpretation of diagnostic TTTMS studies in the clinical setting.
OBJECTIVE: Recently, the utility of threshold tracking paired-pulse transcranial magnetic stimulation (TTTMS), to measure changes in cortical excitabilitability, has been established for diagnostic purposes across a range of neurological diseases. However, the impact of healthy aging on the GABA-ergic intracortical inhibitory system remains unclear. To improve the clinical applicability, TTTMS was performed across an age spectrum. METHODS: TTTMS, single-pulse TMS and nerve conduction studies (NCS) were performed in 113 healthy subjects aged between 20 and 83years (57 male and 56 female). RESULTS: Prolonged motor evoked potential (MEP) latency, increased central motor conduction time, decreased compound muscle action potential (CMAP) amplitude, prolonged F-wave latency and decreased neurophysiological index (NI), calculated from CMAP amplitude, latency and F-wave frequency, were observed as subjects aged. In contrast, short interval intracortical inhibition (SICI) and facilitation did not change. Compared to females, males exhibited a reduced SICI and NI along with longer MEP, CMAP with prolonged F-wave latencies. Multivariate analyses revealed similar results. CONCLUSION: Utilizing clinically applicable TTTMS protocols, findings suggest that GABA mediated intracortical inhibition may be greater in females but does not significantly change with age. SIGNIFICANCE: These findings may better inform the interpretation of diagnostic TTTMS studies in the clinical setting.
Authors: Joyce Gomes-Osman; Aprinda Indahlastari; Peter J Fried; Danylo L F Cabral; Jordyn Rice; Nicole R Nissim; Serkan Aksu; Molly E McLaren; Adam J Woods Journal: Front Aging Neurosci Date: 2018-06-08 Impact factor: 5.750
Authors: Cynthia K Kahl; Rose Swansburg; Tasmia Hai; James G Wrightson; Tiffany Bell; Jean-François Lemay; Adam Kirton; Frank P MacMaster Journal: J Psychiatry Neurosci Date: 2022-07-06 Impact factor: 5.699
Authors: María Redondo-Camós; Gabriele Cattaneo; Vanessa Alviarez-Schulze; Selma Delgado-Gallén; Goretti España-Irla; Javier Solana-Sanchez; Ruben Perellón-Alfonso; Sergiu Albu; José M Tormos; Alvaro Pascual-Leone; David Bartres-Faz Journal: Front Psychol Date: 2022-09-28