Time Dependent and Age Effects of Transcranial Direct Current Stimulation Combined with Neuromuscular Electrical Stimulation on Corticomotor Excitability in Healthy Adults

• Main Authors: Jhe-Yu Ye, 葉哲宇
• Other Authors: Jau-Hong Lin
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/78776769618810280799

碩士 === 高雄醫學大學 === 物理治療學系碩士班 === 105 === Background and purpose: Transcranial direct current stimulation (tDCS) is an innovative neurorehabilitation approach to facilitate sensorimotor recovery for patients after stroke. Research has proved that the feasibility and effectiveness of tDCS combined with neuromuscular electrical stimulation (NMES) on modulating the corticomotor excitability in healthy young adults. However, the stimulation timing of tDCS when combined with NMES and the age-related effects remain to be addressed. This study investigated the time dependent effects (concurrently vs. sequentially applied tDCS and NMES) and age effects (the elder vs. young adults) on corticomotor excitability in healthy adults. Methods: Fifteen young healthy subjects and fifteen the elder healthy subjects who were right-handed were recruited by convenience sampling. All participants received a 30-minute intervention of tDCS applied concurrently with NMES and a 30-minute tDCS followed by a 30-minute NMES intervention (60 minutes in total) on the next day. A constant direct current of 2 mA intensity was used for the tDCS, with the anodal and cathodal electrodes placed on the non-dominant (right brain) and dominant (left brain) primary motor cortex, respectively. A 50pps, 200μs pulse-width current with intensity of 10~20 mA was used for the NMES, with electrodes placed over the extensor carpi radialis and extensor digitorum communis of the non-dominant hands. Single pulse transcranial magnetic stimulation (TMS) was used to assess the changes on cortical excitability before and after these two intervention modes by measuring the motor threshold (MT), motor evoked potential (MEP) and size of cortical motor output map (map size) from both hemispheres. Results: All thirty subjects completed the study without adverse events or side effects. Decreased MT, increased MEP, and increased map size were found on the right and left hemispheres at both concurrent and sequential applications for both groups. However, the concurrent mode showed more map size changes (6.40±4.93 vs. 1.80±6.11 numbers) on the non-dominant hemispheres for the young group. The map size change on the non-dominant hemispheres for the young group was also bigger than that for the elder subjects (6.40±4.9 vs. 2.07±4.18 numbers). Conclusion: On the non-dominant hemisphere, concurrent application on the young group showed more map size change than sequential application on the young group and concurrent application on the elderly group. Clinical implication: The preliminary findings provide useful references to the usage of tDCS combined with NMES for upper limbs motor recovery of patients in physical therapy treatment program.