Congrats on Yu (Andy) Huang and Lucas Parra’s paper on TES model validation accepted to be published on eLife. Also thank Anli Liu’s team from NYU School of Medicine for all the experimental recordings.
Feb 1, 2017 9:00 AM-12:00 PM: CE Workshop 2. Best-Practices of Transcranial Direct Current
Stimulation (tDCS) for Effective and Reliable Outcomes
Presenter: Marom Bikson
Location: Salon D (Mardi Gras Ballroom)
Download slides: INS_tDCS_2017_Bikson_Final.compressed
Feb 2, 2017. 9:00 AM-10:30 AM. Invited Symposium 1. Electrical Brain Stimulation and Cognitive Disorders
Chair: Marom Bikson
Presenters: Marom Bikson, Adam J. Woods, Leigh Charvet
Location: Carondelet (Grand Ballroom)
Download slides: INS_2017final2
Abstract: Measurements of perilymph hydrodynamics in the human cochlea are scarce, being mostly limited to the fluid pressure at the basal or apical turn of the scalae vestibuli and tympani. Indeed, measurements of fluid pressure or volumetric flow rate have only been reported in animal models. In this study we imaged the human ear at 6.7 and 3-mm resolution using mCT scanning to produce highly accurate 3D models of the entire ear and particularly the cochlea scalae. We used a contrast agent to better distinguish soft from hard tissues, including the auditory canal, tympanic membrane, malleus, incus, stapes, ligaments, oval and round window, scalae vestibule and tympani. Using a Computational Fluid Dynamics (CFD) approach and this anatomically correct 3D model of the human cochlea, we examined the pressure and perilymph flow velocity as a function of location, time and frequency within the auditory range. Perimeter, surface, hydraulic diameter, Womersley and Reynolds numbers were computed every 45° of rotation around the central axis of the cochlear spiral. CFD results showed both spatial and temporal pressure gradients along the cochlea. Small Reynolds number and large Womersley values indicate that the perilymph fluid flow at auditory frequencies is laminar and its velocity profile is plug-like. The pressure was found 102–106° out of phase with the fluid flow velocity at the scalae vestibule and tympani, respectively. The average flow velocity was found in the sub-mm/s to nm/s range at 20–100 Hz, and below the nm/s range at 1–20 kHz.
Minimal heating at the Skin surface during transcranial direct current stimulation (tDCS)
Khadka N.; Zannou A.L.; Zunura F.; Truong D.Q.; Dmochowski J.; Bikson M. 2017. Minimal Heating at the Skin Surface During Transcranial Direct Current Stimulation.
Neuromodulation 2017; E-pub ahead of print. DOI:10.1111/ner.12554
To assess if transcranial direct current stimulation (tDCS) produces a temperature change at the skin surface, if any change is stimulation polarity (anode or cathode) specific, and the contribution of passive heating (joule heat) or blood flow on such change.
Material and Methods:
Temperature differences (ΔTs) in an agar phantom study and an in vivo study (forearm stimulation) including 20 volunteers with both experimental measures and finite element method (FEM) multiphysics prediction (current flow and bioheat) models of skin comprising three tissue layers (epidermis, dermis, and subcutaneous layer with blood perfusion) or of the phantom for active stimulation and control cases were compared. Temperature was measured during pre, post, and stimulation phases for both phantom and subject’s forearms using thermocouples.
In the phantom, ΔT under both anode and cathode, compared to control, was not significantly different and less than 0.1°C. Stimulation of subjects resulted in a gradual increase in temperature under both anode and cathode electrodes, compared to control (at t = 20 min: ΔTanode = 0.9°C, ΔTcathode = 1.1°C, ΔTcontrol = 0.05°C). The FEM phantom model predicted comparable maximum ΔT of 0.27°C and 0.28°C (at t = 20 min) for the control and anode/cathode cases, respectively. The FEM skin model predicted a maximum ΔT at t = 20 min of 0.98°C for control and 1.36°C under anode/cathode electrodes.
Taken together, our results indicate a moderate and nonhazardous increase in temperature at the skin surface during 2 mA tDCS that is independent of polarity, and results from stimulation induced blood flow rather than joule heat.
Published in the same issue of Brain Stimulation.
—- Direct Current Stimulation Alters Neuronal Input/Output Function.
Lafon B, Rahman A, Bikson M, Parra LC. Brain Stimul. 2016 Sep 1. pii: S1935-861X(16)30248-0. doi: 10.1016/j.brs.2016.08.014.
— Direct Current Stimulation Modulates LTP and LTD: Activity Dependence and Dendritic Effects
Kronberg G, Bridi M, Abel T, Bikson M, Parra LC Brain Stimul. 2016 10 (2017) 51–58
NYC Neuromodulation 2017 will focus on technologies and mechanism for advanced brain stimulation in areas that include transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), transcranial magnetic stimulation (TMS), high-definition transcranial direct current stimulation (HD-tDCS), electroconvulsive therapy (ECT), deep brain stimulation (DBS), and other emerging areas. Applications span treatment of neuropsychiatric disorders, neurorehabilitation, and performance enhancement. Interactive lectures from key opinion leaders and emerging young scientists, poster sessions with abstracts published in Brain Stimulation and extensive opportunities to network with colleagues, along with an exhibit showcase featuring the latest neuromodulation technologies are all part of the main conference agenda.
This conference is among the most forward-looking neuromodulation meetings with the goal of advancing innovation from bench-top to bedside and home. Given the increased media, public, and commercial interest in personal non-invasive brain stimulation, the 2017 meeting will emphasize emerging “consumer” technologies, and their scientific and regulatory barriers. The off-label use of new clinical protocols will be addressed from scientific, medical, and regulatory perspectives. The conference will also focus on timely and novel targets of neuromodulation including glia, as well as new waveforms including high-rate (10 kHz) stimulation. Representatives from funding agencies and journal editors will be available to discuss priorities. NYC Neuromodulation is the largest meeting focused on non-invasive neuromodulation in North America, but this year it considers the role of invasive and non-invasive techniques in the continuum of care.
Chair: Marom Bikson
Cerebellar tDCS: A Novel Approach to Augment Language Treatment Post-stroke
People with post-stroke aphasia may have some degree of chronic deficit for which current rehabilitative treatments are variably effective. Accumulating evidence suggests that transcranial direct current stimulation (tDCS) may be useful for enhancing the effects of behavioral aphasia treatment. However, it remains unclear which brain regions should be stimulated to optimize effects on language recovery. Here, we report on the therapeutic potential of right cerebellar tDCS in augmenting language recovery in SMY, who sustained bilateral MCA infarct resulting in aphasia and anarthria. We investigated the effects of 15 sessions of anodal cerebellar tDCS coupled with spelling therapy using a randomized, double-blind, sham controlled within-subject crossover trial. We also investigated changes in functional connectivity using resting state functional magnetic resonance imaging before and 2 months post-treatment. Both anodal and sham treatments resulted in improved spelling to dictation for trained and untrained words immediately after and 2 months post-treatment. However, there was greater improvement with tDCS than with sham, especially for untrained words. Further, generalization to written picture naming was only noted during tDCS but not with sham. The resting state functional connectivity data indicate that improvement in spelling was accompanied by an increase in cerebro-cerebellar network connectivity. These results highlight the therapeutic potential of right cerebellar tDCS to augment spelling therapy in an individual with large bilateral chronic strokes.
Use of Computational Modeling to Inform tDCS Electrode Montages for the Promotion of Language Recovery in Post-stroke Aphasia.
Galletta EE, Cancelli A, Cottone C, Simonelli I, Tecchio F, Bikson M, Marangolo P.
Brain Stimul. 2015 Nov-Dec;8(6):1108-15. doi: 10.1016/j.brs.2015.06.018.
Download PDF: galletta2015