scholarly journals Safety of transcranial focused ultrasound for human neuromodulation

2018 ◽  
Author(s):  
Wynn Legon ◽  
Priya Bansal ◽  
Leo Ai ◽  
Jerel K. Mueller ◽  
Gregg Meekins ◽  
...  
Keyword(s):  
Neck Pain ◽  
Focused Ultrasound ◽  
Neuronal Excitability ◽  
Acoustic Energy ◽  
Full Potential ◽  
University Of Minnesota ◽  
Serious Adverse Events ◽  
Low Intensity ◽  
Transcranial Focused Ultrasound

AbstractBackgroundLow intensity transcranial focused ultrasound (tFUS) is a new method of non-invasive neuromodulation that uses acoustic energy to affect neuronal excitability. tFUS offers high spatial resolution and adjustable focal lengths for precise neuromodulation of discrete regions in the human brain. Before the full potential of low intensity ultrasound for research and clinical application can be investigated, data on the safety of this technique is indicated.Objective/HypothesisTo provide an initial evaluation of the safety of tFUS for human neuromodulation through participant report and neurological assessment surrounding pilot investigation of tFUS for neuromodulation.MethodsParticipants (N = 120) that were enrolled in one of seven human ultrasound neuromodulation studies at the University of Minnesota (2015 – 2017) were queried to complete a follow-up Participant Report of Symptoms questionnaire assessing their self-reported experience and tolerance to participation in tFUS research and the perceived relation of symptoms to tFUS.ResultsA total of 64/120 participant (53%) responded to follow-up requests to complete the Participant Report of Symptoms questionnaire. During the conduct of the seven studies in this report, none of the participants experienced serious adverse effects. From the post-hoc assessment of safety using the questionnaire, 7/64 reported mild to moderate symptoms, that were perceived as ‘possibly’ or ‘probably’ related to participation in tFUS experiments. These reports included neck pain, problems with attention, muscle twitches and anxiety. The most common unrelated symptoms included sleepiness and neck pain. There were initial transient reports of mild neck pain, scalp tingling and headache that were extinguished upon follow-up. No new symptoms were reported upon follow up out to 1 month.Conclusions(s)To date, in the literature and including this report, no serious adverse events have been reported as a result of low intensity tFUS for human neuromodulation. Here, we report new data on minor transient events. As currently employed with the parameters used in the studies in this report, tFUS looks to be a safe form of transient neuromodulation in humans.

scholarly journals Noninvasive neuromodulation and thalamic mapping with low-intensity focused ultrasound

2018 ◽  
Vol 128 (3) ◽  
pp. 875-884 ◽  
Author(s):  
Robert F. Dallapiazza ◽  
Kelsie F. Timbie ◽  
Stephen Holmberg ◽  
Jeremy Gatesman ◽  
M. Beatriz Lopes ◽  
...  
Keyword(s):  
Focused Ultrasound ◽  
Thalamic Nucleus ◽  
Acoustic Energy ◽  
Similar Degree ◽  
Thalamic Nuclei ◽  
Low Intensity ◽  
Tissue Heating ◽  
The Central Nervous System ◽  
Selective Mapping ◽  
Noninvasive Neuromodulation

OBJECTIVEUltrasound can be precisely focused through the intact human skull to target deep regions of the brain for stereotactic ablations. Acoustic energy at much lower intensities is capable of both exciting and inhibiting neural tissues without causing tissue heating or damage. The objective of this study was to demonstrate the effects of low-intensity focused ultrasound (LIFU) for neuromodulation and selective mapping in the thalamus of a large-brain animal.METHODSTen Yorkshire swine (Sus scrofa domesticus) were used in this study. In the first neuromodulation experiment, the lemniscal sensory thalamus was stereotactically targeted with LIFU, and somatosensory evoked potentials (SSEPs) were monitored. In a second mapping experiment, the ventromedial and ventroposterolateral sensory thalamic nuclei were alternately targeted with LIFU, while both trigeminal and tibial evoked SSEPs were recorded. Temperature at the acoustic focus was assessed using MR thermography. At the end of the experiments, all tissues were assessed histologically for damage.RESULTSLIFU targeted to the ventroposterolateral thalamic nucleus suppressed SSEP amplitude to 71.6% ± 11.4% (mean ± SD) compared with baseline recordings. Second, we found a similar degree of inhibition with a high spatial resolution (∼ 2 mm) since adjacent thalamic nuclei could be selectively inhibited. The ventromedial thalamic nucleus could be inhibited without affecting the ventrolateral nucleus. During MR thermography imaging, there was no observed tissue heating during LIFU sonications and no histological evidence of tissue damage.CONCLUSIONSThese results suggest that LIFU can be safely used to modulate neuronal circuits in the central nervous system and that noninvasive brain mapping with focused ultrasound may be feasible in humans.

scholarly journals A pilot clinical study of low-intensity transcranial focused ultrasound in Alzheimer’s disease

2021 ◽  
Author(s):  
Hyeonseok Jeong ◽  
Jooyeon Jamie Im ◽  
Jong-Sik Park ◽  
Seung-Hee Na ◽  
Wonhye Lee ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Study ◽  
Focused Ultrasound ◽  
Low Intensity ◽  
Pilot Clinical Study ◽  
Transcranial Focused Ultrasound

Implication of Auditory Confounding in Interpreting Somatosensory and Motor Responses in Low-Intensity Transcranial Focused Ultrasound Stimulation

2021 ◽  
Author(s):  
Christine Park ◽  
Mengyue Chen ◽  
Taewon Kim
Keyword(s):  
Focused Ultrasound ◽  
Auditory Pathway ◽  
Localization Accuracy ◽  
Motor Responses ◽  
Non Invasive ◽  
Low Intensity ◽  
Ultrasound Stimulation ◽  
Transcranial Focused Ultrasound ◽  
Indirect Stimulation ◽  
Stimulation Of

Low-intensity transcranial focused ultrasound (LI-tFUS) stimulation is a non-invasive neuromodulation tool that demonstrates high target localization accuracy and depth penetration. It has been shown to modulate activities in the primary motor and somatosensory cortex. Previous studies in animals and humans acknowledged the possibility of indirect stimulation of the peripheral auditory pathway that could confound the somatosensory and motor responses observed with LI-tFUS stimulation. Here, we discuss the implications and interpretations of auditory confounding in the context of neuromodulation.

scholarly journals Effects of transcranial focused ultrasound on human primary motor cortex using 7T fMRI

2018 ◽  
Author(s):  
Leo Ai ◽  
Priya Bansal ◽  
Jerel K. Mueller ◽  
Wynn Legon
Keyword(s):  
Motor Cortex ◽  
Focused Ultrasound ◽  
Primary Motor Cortex ◽  
Neuronal Excitability ◽  
Activation Volume ◽  
Mechanical Energy ◽  
Premotor Cortex ◽  
Middle Finger ◽  
Single Element ◽  
Transcranial Focused Ultrasound

ABSTRACTBackgroundTranscranial focused ultrasound (tFUS) is a new non-invasive neuromodulation technique that uses mechanical energy to modulate neuronal excitability with high spatial precision. tFUS has been shown to be capable of modulating EEG brain activity in humans that is spatially restricted, and here, we use 7T MRI to extend these findings. We test the effect of tFUS on 7T BOLD fMRI signals from individual finger representations in the human primary motor cortex (M1) and connected cortical motor regions. Participants (N = 5) performed a cued finger tapping task in a 7T MRI scanner with their thumb, index, and middle fingers to produce a BOLD signal for individual M1 finger representations during either tFUS or sham neuromodulation to the thumb representation.ResultsResults demonstrated a statistically significant increase in activation volume of the M1 thumb representation for the tFUS condition as compared to sham. No differences in percent BOLD changes were found. This effect was spatially confined as the index and middle finger M1 finger representations did not show similar significant changes in either percent change or activation volume. No effects were seen during tFUS to M1 in the supplementary motor area (SMA) or the dorsal premotor cortex (PMd).ConclusionsSingle element tFUS can be paired with high field MRI that does not induce significant artifact. tFUS increases activation volumes of the targeted finger representation that is spatially restricted within M1 but does not extend to functionally connected motor regions.

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