A meta-analysis of the effects of aging on motor cortex neurophysiology assessed by transcranial magnetic stimulation

作者：Bhandari Apoorva; Radhu Natasha; Farzan Faranak; Mulsant Benoit H; Rajji Tarek K; Daskalakis Zafiris J; Blumberger Daniel M

来源：Clinical Neurophysiology, 2016, 127(8): 2834-2845.

DOI：10.1016/j.clinph.2016.05.363

• Aging
• Transcranial magnetic stimulation
• Motor cortex
• Cortical plasticity
• Cortical excitability
• Gamma-aminobutyric acid

Objective: Transcranial magnetic stimulation (TMS) is a non-invasive tool used for studying cortical excitability and plasticity in the human brain. This review aims to quantitatively synthesize the literature on age-related differences in cortical excitability and plasticity, examined by TMS.
Methods: A literature search was conducted using MEDLINE, Embase, and PsycINFO from 1980 to December 2015. We extracted studies with healthy old (50-89 years) versus young (16-49 years) individuals that utilized the following TMS measures: resting motor threshold (RMT), short-interval cortical inhibition (SICI), short-latency afferent inhibition (SAI), cortical silent period (CSP), intracortical facilitation (ICF), and paired associative stimulation (PAS).
Results: We found a significant increase in RMT (g = 0.414, 95% confidence interval (CI) [0.284, 0.544], p < 0.001), a significant decrease in SAI (g = 0.778, 95% CI [0.478, 1.078], p < 0.001), and a trending decrease in LTP-like plasticity (g = -0.528, 95% CI [-1.157, 0.100] p < 0.1) with age.
Conclusions: Our findings suggest an age-dependent reduction in cortical excitability and sensorimotor integration within the human motor cortex.
Significance: Alterations in the ability to regulate cortical excitability, sensorimotor integration and plasticity may underlie several age-related motor deficits.

• 出版日期2016-8