Abstract
BACKGROUND: Transcranial magnetic stimulation is frequently used to construct stimulus response (SR) curves in studies of motor learning and rehabilitation. A drawback of the established method is the time required for data acquisition, which is frequently greater than a participant's ability to maintain attention. The technique is therefore difficult to use in the clinical setting.
OBJECTIVE: To reduce the time of curve acquisition by determining the minimum acquisition time and number of stimuli required to acquire an SR curve.
METHODS: SR curves were acquired from first dorsal interosseous (FDI) and abductor digiti minimi (ADM) at 6 interstimulus intervals (ISI) between 1.4 and 4 s in 12 participants. To determine if low-frequency rTMS might affect the SR curve, MEP amplitudes were monitored before and after 3 min of 1 Hz rTMS delivered at 120% of resting motor threshold in 12 participants. Finally, SR curves were acquired from FDI, ADM and Biceps Brachii (BB) in 12 participants, and the minimum number of stimuli was calculated using a sequential MEP elimination process.
RESULTS: There were no significant differences between curves acquired with 1.4 s ISI and any other ISI. Low frequency rTMS did not significantly depress MEP amplitude (P = 0.87). On average, 61 ± 18 (FDI), 60 ± 16 (ADM) and 59 ± 16 (BB) MEPs were needed to construct a representative SR curve.
CONCLUSIONS: This study demonstrates that reliable SR curves may be acquired in less than 2 min. At this rate, SR curves become a clinically feasible method for assessing corticospinal excitability in research and rehabilitation settings.
Original language | English |
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Pages (from-to) | 59-65 |
Number of pages | 7 |
Journal | Brain Stimulation |
Volume | 7 |
Issue number | 1 |
Early online date | 3 Sept 2013 |
DOIs | |
Publication status | Published - Jan 2014 |
Keywords
- Corticospinal excitability
- rTMS
- Assessment
- Neuroplasticity
Profiles
-
Michael Grey
- School of Health Sciences - Honorary Fellow
- Rehabilitation - Member
Person: Honorary, Research Group Member