Ultrasound stimulation of the motor cortex during tonic muscle contraction

Abstract

Transcranial ultrasound stimulation (tUS) shows potential as a noninvasive brain stimulation (NIBS) technique, offering increased spatial precision compared to other NIBS techniques. However, its reported effects on primary motor cortex (M1) are limited. We aimed to better understand tUS effects in human M1 by performing tUS of the hand area of M1 (M1hand) during tonic muscle contraction of the index finger. Stimulation during muscle contraction was chosen because of the transcranial magnetic stimulation-induced phenomenon known as cortical silent period (cSP), in which transcranial magnetic stimulation (TMS) of M1hand involuntarily suppresses voluntary motor activity. Since cSP is widely considered an inhibitory phenomenon, it presents an ideal parallel for tUS, which has often been proposed to preferentially influence inhibitory interneurons. Recording electromyography (EMG) of the first dorsal interosseous (FDI) muscle, we investigated effects on muscle activity both during and after tUS. We found no change in FDI EMG activity concurrent with tUS stimulation. Using single-pulse TMS, we found no difference in M1 excitability before versus after sparsely repetitive tUS exposure. Using acoustic simulations in models made from structural MRI of the participants that matched the experimental setups, we estimated in-brain pressures and generated an estimate of cumulative tUS exposure experienced by M1hand for each subject. We were unable to find any correlation between cumulative M1hand exposure and M1 excitability change. We also present data that suggest a TMS-induced MEP always preceded a near-threshold cSP.

A review of functional neuromodulation in humans using low-intensity transcranial focused ultrasound

“…From the same group, Xia et al In some studies, multiple experimental blocks were performed within a single tFUS session, or multiple tFUS sessions on different days were conducted, but these are not summarized in this table. L, left; R, right; F, female; M, male; NR, not reported; N/A, not applicable; N, number of subjects who received active tFUS; y, years old, shown as mean with standard deviation, when available; 9-HPT, nine-hole peg test; ACC, anterior cingulate cortex; ADAS-cog, Alzheimer's disease assessment scale-cognitive subscale; ASL, arterial spin labeling; BAI, Beck anxiety scale; BDI-II, Beck's depression inventory; BDNF, brain-derived neurotrophic factor; BVMT-R, brief visuospatial memory test-revised; COWAT, controlled oral word association test; CRS-R, JFK coma recovery scale-revised; CWST, color word stroop test; DLPFC, dorsolateral prefrontal cortex; DOC, disorder of consciousness; DRE, drug-resistant epilepsy; FAQ, functional activities questionnaire; GAD, generalized anxiety disorder; GASE, generic assessment of side effects; HAM-A, Hamilton anxiety rating scale; HDRS-6 scores, 6-item version of Hamilton depression rating scale; IV, intravenous; BPI, brief pain inventory; MBI, modified bathel index; M1, primary motor cortex; MCS, minimally conscious state; MDS-UPDRS-III, the movement disorder society-the unified Parkinson's disease rating scale-III; MEPs, motor evoked potentials; MMSE, mini-mental state examination; MoCA, Montreal cognitive assessment; MRI, magnetic resonance imaging; mTLE, mesial temporal lobe epilepsy; NAc, nucleus accumbens; NPIQ, neuropsychiatric inventory-questionnaire; NRS, numerical rating scale (of pain); OASIS, overall anxiety severity and impairment scale; PANSS, positive and negative syndrome scale; PET, positron emission tomography; PGI-I, patient global impression of improvement; PSCI, post-stroke cognitive impairment; QDRS, quick dementia rating system; RAVLT, Rey auditory verbal learning test; RBANS, repeatable battery for the assessment of neuropsychological status; rCMRglu, regional cerebral metabolic rate for glucose; ROCFT, Rey-Osterrieth complex figure test; SANS, scale for the assessment of negative symptoms; SCC, subcallosal cingulate cortex; SEEG, stereo-EEG; SFG, superior frontal gyrus; SGC, subgenual cingulate cortex; ICF, intracortical facilitation; SICI, shortinterval intracortical inhibition; SOZs, seizure onset zones; SUD, substance use disorder; SVLT, Seoul verbal learning test; T25-FW, timed twenty-five-foot walk test; TCFT, total cognitive function test; TRD, treatment-resistant depression; VAMS; visual analog mood scales; VAS, visual analog scale; WMS-R, Wechsler memory scale-revised; ZBI, Zarit burden interview; µ-bubbles, microbubble ultrasound contrast agent [30] were unable to observe changes in either EMG of tonic muscle contraction or TMS-induced MEPs during/after tFUS.…”

“…Substance use disorder (SUD) patients N = 4 (F:1 / M:3) 34.0 ± 3.7y(30)(31)(32)(33)(34)(35)(36)(37)(38)(39) Bilateral nucleus accumbens (NAc) NCT04197921FF = 220 kHz PD = 100 ms PRF = (1) Hz DC = (10)% SD = 5 s, ISI = 10 s (20) trials of SD P r.0 = (1.276, 1.539) MPa I SPPA.0 = 55, 80 W/cm 2 I SPTA.0 = (5.5, 8.0) W/cm 2 MI. 0 = (2.72, 3.28) Offline: Self-report of cue-induced substance craving, daily craving ratings (without cues)patients N = 11 (F:5 / M:6) 60.6 ± 13.2y (19-75) Anterior cingulate cortex (ACC) KCT0007894 FF = 250 kHz PD = 5, 10 ms PRF = (100, 70) Hz DC = 50, 70% SD = NR, ISI = NR Trials of SD: NR P r.0 = (0.206, 0.174) MPa I SPPA.0 = (1.44, 1.03) W/cm 2 I SPTA.0 = 0.720 W/cm 2 MI.…”