Repetitive transcranial magnetic stimulation focusing on patients with neuropathic pain in the upper limb: a randomized sham-controlled parallel trial

Mori N., Hosomi K., Nishi A., et al. Repetitive transcranial magnetic stimulation focusing on patients with neuropathic pain in the upper limb: a randomized sham-controlled parallel trial. Scientific Reports 14, 11811 (2024); https://doi.org/10.1038/s41598-024-62018-x.This study aimed to evaluate the efficacy and safety of navigation-guided repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex in patients with neuropathic pain in the upper limb. This randomized, blinded, sham-controlled, parallel trial included a rTMS protocol (10-Hz, 2000 pulses/session) consisting of five daily sessions, followed by one session per week for the next seven weeks. Pain intensity, as well as pain-related disability, quality of life, and psychological status, were assessed. For the primary outcome, pain intensity was measured daily using a numerical rating scale as a pain diary. Thirty patients were randomly assigned to the active rTMS or sham-stimulation groups. In the primary outcome, the decrease (least square [LS] mean ± standard error) in the weekly average of a pain diary at week 9 compared to the baseline was 0.84 ± 0.31 in the active rTMS group and 0.58 ± 0.29 in the sham group (LS mean difference, 0.26; 95% confidence interval, − 0.60 to 1.13). There was no significant effect on the interaction between the treatment group and time point. Pain-related disability score improved, but other assessments showed no differences. No serious adverse events were observed. This study did not show significant pain relief; however, active rTMS tended to provide better results than sham. rTMS has the potential to improve pain-related disability in addition to pain relief

Common Motor Drive Triggers Response of Prime Movers When Two Fingers Simultaneously Respond to a Cue

This study investigated whether the motor execution process of one finger movement in response to a start cue is influenced by the participation of another finger movement and whether the process of the finger movement is dependent on the movement direction. The participants performed a simple reaction time (RT) task, the abduction or flexion of one (index or little finger) or two fingers (index and little fingers). The RT of the prime mover for the finger abduction was significantly longer than that for the flexion, indicating that the time taken for the motor execution of the finger response is dependent on the movement direction. The RT of the prime mover was prolonged when the abduction of another finger, whose RT was longer than the flexion, was added. This caused closer RTs between the prime movers for a two-finger response compared with the RTs for a one finger response. The absolute difference in the RT between the index and little finger responses became smaller when two fingers responded together compared with one finger response. Those results are well explained by a view that the common motor drive triggers the prime movers when two fingers move together in response to a start cue

Interhemispheric inhibition induced by transcranial magnetic stimulation over primary sensory cortex

The present study investigated whether the long-interval interhemispheric inhibition (LIHI) is induced by the transcranial magnetic stimulation over the primary sensory area (S1-TMS) without activation of the conditioning side of the primary motor area (M1) contributing to the contralateral motor evoked potential (MEP), whether the S1-TMS-induced LIHI is dependent on the status of the S1 modulated by the tactile input, and whether the pathways mediating the LIHI are different from those mediating the M1-TMS-induced LIHI. In order to give the TMS over the S1 without eliciting the MEP, the intensity of the S1-TMS was adjusted to be the sub-motor-threshold level and the trials with the MEP response elicited by the S1-TMS were discarded online. The LIHI was induced by the S1-TMS given 40 ms before the test TMS in the participants with the attenuation of the tactile perception of the digit stimulation (TPDS) induced by the S1-TMS, indicating that the LIHI is induced by the S1-TMS without activation of the conditioning side of the M1 contributing to the contralateral MEP in the participants in which the pathways mediating the TPDS is sensitive to the S1-TMS. The S1-TMS-induced LIHI was positively correlated with the attenuation of the TPDS induced by the S1-TMS, indicating that the S1-TMS-induced LIHI is dependent on the effect of the S1-TMS on the pathways mediating the TPDS at the S1. In another experiment, the effect of the digit stimulation given before the conditioning TMS on the S1- or M1-TMS-induced LIHI was examined. The digit stimulation produces tactile input to the S1 causing change in the status of the S1. The S1-TMS-induced LIHI was enhanced when the S1-TMS was given in the period in which the tactile afferent volley produced by the digit stimulation just arrived at the S1, while the LIHI induced by above-motor-threshold TMS over the contralateral M1 was not enhanced by the tactile input. Thus, the S1-TMS-induced LIHI is dependent on the status of the S1 modulated by the tactile input, and the pathways mediating the sub-motor-threshold S1-TMS-induced LIHI are not the same as the pathways mediating the above-motor-threshold M1-TMS-induced LIHI

The influence of muscular activities in a squat with hands on a table for "locomotion training"

[Purpose] We studied the muscular activities activated during standing-up exercises with subjects' hands on a table from a sitting position on a stool and compared them with muscle activities activated during normal squat exercises from the standing position. [Subjects] Healthy female subjects were selected for this study. [Methods] Muscular activities were measured by EMG during a normal squat exercise from the standing position and exercise from the sitting position using a table positioned slightly in front of a stool. The muscular activities during the latter exercise condition were evaluated by changing the height of the table in two different positions. [Results] Statistically signifi cant differences (p < 0.05) were found between the normal squat exercise and the low table exercise for the rectus femoris muscle, vastus medialis muscle, and semitendinosus muscle. The rectus femoris muscle also showed a signifi cant difference (p < 0.01) between the muscular activities obtained from the normal squat and high table exercises. [Conclusion] Our results failed to show a signifi cant difference in the muscular activities of the lower extremities between exercises in which tables with different heights were used. These results suggest that frail elderly people may strengthen their muscles reasonably and effectively by using heightadjusted tables.スクワットは運動療法として汎用性の高い運動である。本研究では健常女性を対象に，通常スクワット，および椅子と高さの異なる2つのテーブルを用いたスクワットの3条件で筋電図を測定し，各条件での筋活動量を比較した。この結果，測定したすべての筋で，通常スクワットの筋活動量が最も高く，他の2条件の筋活動量は通常スクワットの約3分の2の値となったが，高いテーブルでは四頭筋のみ有意差を確認できたが，低いテーブルでは大腿直筋，内側広筋，半腱様筋にて有意差を確認できた。これらの結果は，テーブルを用いることで下肢筋活動すべてが有意に減少するのではないことから，高齢者によっては効果的で安全なスクワットとして使用できる可能性を示唆できた。報