TY - JOUR
T1 - The effects of age and biological sex on the association between I-wave recruitment and the response to cTBS
T2 - An exploratory study
AU - Van Dam, Jago M.
AU - Graetz, Lynton
AU - Pitcher, Julia B.
AU - Goldsworthy, Mitchell R.
PY - 2023/7/1
Y1 - 2023/7/1
N2 - The neuroplastic response to continuous theta burst stimulation (cTBS) is inherently variable. The measurement of I-wave latencies has been shown to strongly predict the magnitude and direction of the response to cTBS, whereby longer latencies are associated with stronger long-term depression-like responses. However, potential differences in this association relating to age and sex have not been explored. We performed cTBS and measured I-wave recruitment (via MEP latencies) in 66 participants (31 female) ranging in age from 11 to 78 years. The influence of age and sex on the association between I-wave recruitment and the response to cTBS was tested using linear regression models. In contrast to previous studies, there was not a significant association between I-wave latencies and cTBS response at the group level (p = 0.142, R2 = 0.033). However, there were interactions between I-waves and both age and sex when predicting cTBS response. Subgroup analysis revealed that preferential late I-wave recruitment predicted cTBS response in adolescent females, but not in adolescent or adult males or adult females. These data suggest that the generalisability of I-wave measurement in predicting the response to cTBS may be lower than initially believed. Prediction models should include age and sex, rather than I-wave latencies alone, as our findings suggest that, while each factor alone is not a strong predictor, these factors interact to influence the response to cTBS.
AB - The neuroplastic response to continuous theta burst stimulation (cTBS) is inherently variable. The measurement of I-wave latencies has been shown to strongly predict the magnitude and direction of the response to cTBS, whereby longer latencies are associated with stronger long-term depression-like responses. However, potential differences in this association relating to age and sex have not been explored. We performed cTBS and measured I-wave recruitment (via MEP latencies) in 66 participants (31 female) ranging in age from 11 to 78 years. The influence of age and sex on the association between I-wave recruitment and the response to cTBS was tested using linear regression models. In contrast to previous studies, there was not a significant association between I-wave latencies and cTBS response at the group level (p = 0.142, R2 = 0.033). However, there were interactions between I-waves and both age and sex when predicting cTBS response. Subgroup analysis revealed that preferential late I-wave recruitment predicted cTBS response in adolescent females, but not in adolescent or adult males or adult females. These data suggest that the generalisability of I-wave measurement in predicting the response to cTBS may be lower than initially believed. Prediction models should include age and sex, rather than I-wave latencies alone, as our findings suggest that, while each factor alone is not a strong predictor, these factors interact to influence the response to cTBS.
KW - Continuous theta burst stimulation
KW - I-waves
KW - Neurodevelopment
KW - Neuroplasticity
KW - Sex
KW - Transcranial magnetic stimulation
UR - http://www.scopus.com/inward/record.url?scp=85153503533&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/NHMRC/1102272
UR - http://purl.org/au-research/grants/ARC/DE200100575
U2 - 10.1016/j.brainres.2023.148359
DO - 10.1016/j.brainres.2023.148359
M3 - Article
C2 - 37030620
AN - SCOPUS:85153503533
SN - 0006-8993
VL - 1810
JO - Brain Research
JF - Brain Research
M1 - 148359
ER -