Interactions Between Cerebellum and the Intracortical Excitatory Circuits of Motor Cortex: a Mini-Review

Opie, George M.; Liao, Wei‐Yeh; Semmler, John G.

doi:10.1007/s12311-021-01278-z

Cited by 17 publications

(12 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The conventional interpretation of using different TMS coil orientations suggests preferential recruitment of early (I 1 ) waves with PA TMS and late (I 3 ) waves with AP TMS (Hamada et al., 2013 ), with either current direction able to recruit both early and late I‐waves as the stimulation intensity is increased (Di Lazzaro et al., 2003 , 2001 ). We therefore attempted to investigate the response of different I‐wave circuits to PMd iTBS by recording single‐pulse TMS at relatively lower stimulation intensities compared to MEP 1mV (PA 0.5mV and AP 0.5mV MEPs), where PA TMS is more selective to early circuits, whereas AP TMS is more selective to late circuits (Opie et al., 2022 ). Within the current study, the potentiation of both PA 0.5mV and AP 0.5mV MEPs (∼50–90% increase) in young adults following PMd iTBS therefore probably reflects the facilitation of early and late circuits respectively.…”

Section: Discussionmentioning

confidence: 99%

Modulation of dorsal premotor cortex differentially influences I‐wave excitability in primary motor cortex of young and older adults

Liao

Opie

Ziemann

et al. 2023

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

Previous research using transcranial magnetic stimulation (TMS) has demonstrated weakened connectivity between dorsal premotor cortex (PMd) and motor cortex (M1) with age. While this alteration is probably mediated by changes in the communication between the two regions, the effect of age on the influence of PMd on specific indirect (I) wave circuits within M1 remains unclear. The present study therefore investigated the influence of PMd on early and late I‐wave excitability in M1 of young and older adults. Twenty‐two young (mean ± SD, 22.9 ± 2.9 years) and 20 older (66.6 ± 4.2 years) adults participated in two experimental sessions involving either intermittent theta burst stimulation (iTBS) or sham stimulation over PMd. Changes within M1 following the intervention were assessed with motor‐evoked potentials (MEPs) recorded from the right first dorsal interosseous muscle. We applied posterior–anterior (PA) and anterior–posterior (AP) current single‐pulse TMS to assess corticospinal excitability (PA1mV; AP1mV; PA0.5mV, early; AP0.5mV, late), and paired‐pulse TMS short intracortical facilitation for I‐wave excitability (PA SICF, early; AP SICF, late). Although PMd iTBS potentiated PA1mV and AP1mV MEPs in both age groups (both P < 0.05), the time course of this effect was delayed for AP1mV in older adults (P = 0.001). Furthermore, while AP0.5mV, PA SICF and AP SICF were potentiated in both groups (all P < 0.05), potentiation of PA0.5mV was only apparent in young adults (P < 0.0001). While PMd influences early and late I‐wave excitability in young adults, direct PMd modulation of the early circuits is specifically reduced in older adults. Key points Interneuronal circuits responsible for late I‐waves within primary motor cortex (M1) mediate projections from dorsal premotor cortex (PMd), but this communication probably changes with advancing age. We investigated the effects of intermittent theta burst stimulation (iTBS) to PMd on transcranial magnetic stimulation (TMS) measures of M1 excitability in young and older adults. We found that PMd iTBS facilitated M1 excitability assessed with posterior–anterior (PA, early I‐waves) and anterior–posterior (AP, late I‐waves) current TMS in young adults, with a stronger effect for AP TMS. M1 excitability assessed with AP TMS also increased in older adults following PMd iTBS, but there was no facilitation for PA TMS responses. We conclude that changes in M1 excitability following PMd iTBS are specifically reduced for the early I‐waves in older adults, which could be a potential target for interventions that enhance cortical excitability in older adults.

show abstract

Section: Discussionmentioning

confidence: 99%

Modulation of dorsal premotor cortex differentially influences I‐wave excitability in primary motor cortex of young and older adults

Liao

Opie

Ziemann

et al. 2023

The Journal of Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the ROI seed analysis, we observed a significant increase in inhibition from the ROI to the bilateral DLPFC, language, motor, and sensory networks between pre- and post-CB-SMA iTBS protocols. The SMA and cerebellum communicate through the cortico-ponto-cerebellar tract and other possible CTC tracts ( 48 , 49 ). The inhibition effect ( 50 ), which originated from the SMA to the cortex including the anterior cingulate cortex, angular gyrus, and middle temporal, was observed through the fMRI after a 1-Hz repetitive TMS (rTMS) on SMA, interrupting the hyper-connections from the SMA to the cerebellum.…”

Section: Discussionmentioning

confidence: 99%

Cerebellum–Cerebrum paired target magnetic stimulation on balance function and brain network of patients with stroke: A functional near-infrared spectroscopy pilot study

Xia

Tang²,

Hu³

et al. 2022

Front. Neurol.

View full text Add to dashboard Cite

Transcranial magnetic stimulation (TMS) modulation over the cerebellum, primary motor cortex, and supplementary motor cortex individually can improve the balance function of patients with stroke. However, whether their combination could have a better balance modulation effect is uncertain. Therefore, we hypothesized that performing TMS over a combination of these targets can regulate the balance function of patients with stroke. We compared the effects of one-session TMS on eye-open and eye-closed balance conditions in patients with stroke, using different target pairs of unilateral cerebellar (CB-single), cerebellar–primary motor cortex (CB-M1), and cerebellar–supplementary motor area (CB-SMA) targets. A total of 31 patients with stroke were enrolled and randomly divided into three groups to receive single sessions of intermittent theta burst stimulation each. Functional near-infrared spectrum data on resting and standing task states (eye-open and eye-closed) and center of pressure parameters (eye-open and eye-closed) were collected before and after the intervention. Compared with the results in the CB-single group, five intergroup differences in the changes in the center of pressure parameters in the CB-M1 group and two significant differences in the CB-SMA group were observed after one session of intermittent theta burst stimulation. In the CB-SMA group, 12 out of the 14 parameters improved significantly in the EC condition after the intervention. Meanwhile, the functional near-infrared spectrum results showed that the CB-SMA group exhibited a significant inhibitory pattern in the resting-state functional connectivity, which was not observed in the other two groups. In conclusion, we believe that paired targeting of the CB-SMA can reshape the brain network and improve the balance function of patients with stroke.

show abstract

“…Although PD is primarily a basal ganglia disorder, cerebellar involvement in PD pathophysiology provides a basis for targeting it with tDCS [ 13 , 14 ]. While M1 plays the predominant role in skilled execution of hand and arm movements [ 16 ], the descending drive of M1 to the spinal motor neuron pools of upper limb muscles depends on input from many motor areas onto intracortical interneurons [ 17 ] including crucial cerebellum contributions [ 17 , 18 ]. Furthermore, previously unknown bi-directional pathways have recently been discovered between the cerebellum and basal ganglia [ 19 ].…”

Section: Introductionmentioning

confidence: 99%

A Single Application of Cerebellar Transcranial Direct Current Stimulation Fails to Enhance Motor Skill Acquisition in Parkinson’s Disease: A Pilot Study

et al. 2023

View full text Add to dashboard Cite

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that leads to numerous impairments in motor function that compromise the ability to perform activities of daily living. Practical and effective adjunct therapies are needed to complement current treatment approaches in PD. Transcranial direct current stimulation applied to the cerebellum (c-tDCS) can increase motor skill in young and older adults. Because the cerebellum is involved in PD pathology, c-tDCS application during motor practice could potentially enhance motor skill in PD. The primary purpose was to examine the influence of c-tDCS on motor skill acquisition in a complex, visuomotor isometric precision grip task (PGT) in PD in the OFF-medication state. The secondary purpose was to determine the influence of c-tDCS on transfer of motor skill in PD. The study utilized a double-blind, SHAM-controlled, within-subjects design. A total of 16 participants completed a c-tDCS condition and a SHAM condition in two experimental sessions separated by a 7-day washout period. Each session involved practice of the PGT concurrent with either c-tDCS or SHAM. Additionally, motor transfer tasks were quantified before and after the practice and stimulation period. The force error in the PGT was not significantly different between the c-tDCS and SHAM conditions. Similarly, transfer task performance was not significantly different between the c-tDCS and SHAM conditions. These findings indicate that a single session of c-tDCS does not elicit acute improvements in motor skill acquisition or transfer in hand and arm tasks in PD while participants are off medications.

show abstract

Interactions Between Cerebellum and the Intracortical Excitatory Circuits of Motor Cortex: a Mini-Review

Cited by 17 publications

References 67 publications

Modulation of dorsal premotor cortex differentially influences I‐wave excitability in primary motor cortex of young and older adults

Modulation of dorsal premotor cortex differentially influences I‐wave excitability in primary motor cortex of young and older adults

Cerebellum–Cerebrum paired target magnetic stimulation on balance function and brain network of patients with stroke: A functional near-infrared spectroscopy pilot study

A Single Application of Cerebellar Transcranial Direct Current Stimulation Fails to Enhance Motor Skill Acquisition in Parkinson’s Disease: A Pilot Study

Contact Info

Product

Resources

About