scholarly journals Effect of Percutaneous Electric Stimulation with High Frequency Alternating Currents on the Sensory-Motor System of Healthy Volunteers

2022 ◽  
Author(s):  
David Martín-Caro Álvarez ◽  
Diego Serrano-Muñoz ◽  
Juan José Fernández-Pérez ◽  
Julio Gómez-Soriano ◽  
Juan Avendaño-Coy
Keyword(s):  
Healthy Volunteers ◽  
Median Nerve ◽  
High Frequency ◽  
Sham Group ◽  
Muscle Tone ◽  
Ultrasound Guided ◽  
Post Intervention ◽  
Sham Stimulation ◽  
Intergroup Comparison ◽  
Over Time

Abstract BackgroundFormer studies investigated the application, both transcutaneous and with implanted electrodes, of high frequency alternating currents (HFAC) in humans for blocking the peripheral nervous system. The present trial aimed to assess the effect of HFAC on motor response, somatosensory thresholds, and peripheral nerve conduction, when applied percutaneously with ultrasound-guided needles at frequencies of 10 kHz and 20 kHz in healthy volunteers. MethodsA parallel, placebo-controlled, double-blind, randomized clinical trial was conducted. Ultrasound-guided HFAC at 10 kHz and 20 kHz and sham stimulation were delivered to the median nerve of 60 healthy volunteers (n=20 per group) for 20 minutes. The main assessed variables were maximum isometric flexion strength (MFFS) of the index finger, myotonometry, pressure pain threshold (PPT), mechanical detection threshold (MDT), and antidromic sensory nerve action potential (SNAP). Measurements were recorded pre-intervention, during the intervention 15 minutes after its commencement, immediately post-intervention, and at 15 minutes post-intervention.ResultsA decrease in the MFFS was observed immediately post-intervention compared to baseline, both in the 10 kHz group [-8.5 %; 95% confidence interval (CI) -14.9 to -2.1] and the 20 kHz group (-12.0%; 95%CI -18.3 to -5.6). At 15 minutes post-intervention, the decrease in the MFFS was -9.5% (95%CI -17.3 to -1.8) and -11.5% (95%CI -9.3 to -3.8) in the 10 kHz and 20 kHz groups, respectively. No changes over time were found in the sham group. The between-group comparison of changes in MFFS showed a greater reduction of -10.8% (95%CI -19.8 to -1.8) immediately post-intervention in the 20 kHz compared to the sham stimulation group. Muscle tone increased over time in both the 10 kHz and 20 kHz groups, but not in the sham group. The intergroup comparison of myotonometry showed a superior effect in the 20 kHz (6.7%, 95%CI 0.5 to 12.9) versus the sham group. No significant changes were observed in the rest of the assessed variables. ConclusionsThe ultrasound-guided percutaneous stimulation applying 10 kHz and 20 kHz HFAC to the median nerve produced reversible reductions in strength and increases in muscle tone with no adverse effects.

scholarly journals The Short-Run and Long-Run Effects of Behavioral Interventions: Experimental Evidence from Energy Conservation

2014 ◽  
Vol 104 (10) ◽  
pp. 3003-3037 ◽  
Author(s):  
Hunt Allcott ◽  
Todd Rogers
Keyword(s):  
Cost Effectiveness ◽  
Social Comparison ◽  
High Frequency ◽  
Behavioral Interventions ◽  
Repeated Treatment ◽  
Post Intervention ◽  
Empirical Estimates ◽  
Long Run ◽  
Short Run ◽  
Over Time

We document three remarkable features of the Opower program, in which social comparison-based home energy reports are repeatedly mailed to more than six million households nationwide. First, initial reports cause high-frequency “action and backsliding,” but these cycles attenuate over time. Second, if reports are discontinued after two years, effects are relatively persistent, decaying at 10–20 percent per year. Third, consumers are slow to habituate: they continue to respond to repeated treatment even after two years. We show that the previous conservative assumptions about post-intervention persistence had dramatically understated cost effectiveness and illustrate how empirical estimates can optimize program design.(JEL D12, D83, L94, Q41)

High-resolution ultrasonography of the cutaneous nerve branches in the hand and wrist

2009 ◽  
Vol 34 (6) ◽  
pp. 766-771 ◽  
Author(s):  
A. STOKVIS ◽  
J. W. VAN NECK ◽  
C. F. VAN DIJKE ◽  
A. VAN WAMEL ◽  
J. H. COERT
Keyword(s):  
High Resolution ◽  
Healthy Volunteers ◽  
Median Nerve ◽  
Nerve Injuries ◽  
Ultrasound Guided ◽  
Ultrasound Machine ◽  
Anatomical Dissection ◽  
High Resolution Ultrasonography ◽  
Ultrasound Probes

Ultrasonography can be used in the diagnosis of various neuropathies, including nerve injury. Nerves often involved in traumatic and iatrogenic injury are small cutaneous branches in the hand and wrist, which cannot be seen in detail using current ultrasound probes. This study explored the potential of high-resolution ultrasonography in seeing these nerve branches in the human. The VisualSonics Vevo 770 system with a 15–82.5 MHz probe was compared to a commonly used 5–12 MHz probe and ultrasound machine. The accuracy was validated by ultrasound guided dye injection into cadaver nerves, with subsequent anatomical dissection and verification. Results were confirmed in two healthy volunteers. The Vevo 770 system was able to accurately identify the small cutaneous nerves. It could also depict the median nerve and its fascicles in greater detail. This may be useful for clinical diagnosis, localisation and follow-up of neuropathies and nerve injuries.

Transcranial direct current stimulation: Adverse effects and the efficacy of a commonly utilised sham protocol

2017 ◽  
Vol 41 (S1) ◽  
pp. S374-S374 ◽  
Author(s):  
A. Kortteenniemi ◽  
T. Ali-Sisto ◽  
J. Wikgren ◽  
S. Lehto
Keyword(s):  
Adverse Effects ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Sham Group ◽  
Control Procedure ◽  
Current Standard ◽  
Sham Stimulation ◽  
Direct Current Stimulation ◽  
Cohen’S D ◽  
Cohen's D

IntroductionTranscranial direct current stimulation (tDCS) is a promising neuromodulation method that has, for example, been used to treat depression. Nevertheless, the adverse effects of tDCS and the validity of the current standard tDCS sham protocols have received limited attention.ObjectivesTo evaluate the extent and types of tDCS adverse effects and to assess the reliability of sham stimulation as a control procedure for tDCS in a double-blind setting.AimsTo compare adverse effects between tDCS and sham stimulation groups, and to determine how well the participants and the experimenter are able to distinguish tDCS from sham stimulation.MethodsA sample of healthy volunteers received a 20-minute session of either tDCS (n = 41; 2 mA) or sham stimulation (n = 41; ramp up 15 s, ramp down 15 s; no current in between). The anode was placed over F3 and cathode over F4. Both the participants and the experimenter reported immediate adverse effects and the perceived likelihood for the participant to receive tDCS. Analyses were conducted using the Mann–Whitney U-test.ResultsThe tDCS group reported more erythema compared with the sham group (P = 0.016, Cohen's D = 0.444). No other significant differences in adverse effects were observed. In the tDCS group, both the participants (P = 0.034, Cohen's D = 0.612) and the experimenter (P = 0.006, Cohen's D = 0.674) reported a higher perceived likelihood of the participant receiving tDCS than in the sham group.ConclusionstDCS has only modest adverse effects. Nevertheless, the current standard sham protocol appears insufficient.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Mood Effects of Prefrontal Repetitive High-Frequency TMS in Healthy Volunteers

CNS Spectrums ◽  
1997 ◽  
Vol 2 (1) ◽  
pp. 53-68 ◽  
Author(s):  
Juliet Dearing Martin ◽  
Mark S. George ◽  
Benjamin D. Greenberg ◽  
Eric M. Wassermann ◽  
Thomas E. Schlaepfer ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
High Frequency ◽  
Mood Effects

scholarly journals Different endurance exercises modulate NK cell cytotoxic and inhibiting receptors

2021 ◽  
Author(s):  
A. Pal ◽  
J. Schneider ◽  
K. Schlüter ◽  
K. Steindorf ◽  
J. Wiskemann ◽  
...  
Keyword(s):  
Target Genes ◽  
Acute Exercise ◽  
Cell Function ◽  
Nk Cell ◽  
Analysis Of Covariance ◽  
Autologous Serum ◽  
Post Intervention ◽  
Significant Group ◽  
Significant Difference ◽  
Over Time

Abstract Purpose Induction of IDO depends on the activation of AhR forming the AhR/IDO axis. Activated AhR can transcribe various target genes including cytotoxic and inhibiting receptors of NK cells. We investigated whether AhR and IDO levels as well as activating (NKG2D) and inhibiting (KIR2DL1) NK cell receptors are influenced by acute exercise and different chronic endurance exercise programs. Methods 21 adult breast and prostate cancer patients of the TOP study (NCT02883699) were randomized to intervention programs of 12 weeks of (1) endurance standard training or (2) endurance polarized training after a cardiopulmonary exercise test (CPET). Serum was collected pre-CPET, immediately post-CPET, 1 h post-CPET and after 12 weeks post-intervention. Flow cytometry analysis was performed on autologous serum incubated NK-92 cells for: AhR, IDO, KIR2DL1 and NKG2D. Differences were investigated using analysis-of-variance for acute and analysis-of-covariance for chronic effects. Results Acute exercise: IDO levels changed over time with a significant increase from post-CPET to 1 h post-CPET (p = 0.03). KIR2DL1 levels significantly decreased over time (p < 0.01). NKG2D levels remained constant (p = 0.31). Chronic exercise: for both IDO and NKG2D a significant group × time interaction, a significant time effect and a significant difference after 12 weeks of intervention were observed (IDO: all p < 0.01, NKG2D: all p > 0.05). Conclusion Both acute and chronic endurance training may regulate NK cell function via the AhR/IDO axis. This is clinically relevant, as exercise emerges to be a key player in immune regulation.

scholarly journals Differential impacts of repeated sampling on odor representations by genetically-defined mitral and tufted cell subpopulations in the mouse olfactory bulb

2020 ◽  
Author(s):  
Thomas P. Eiting ◽  
Matt Wachowiak
Keyword(s):  
Information Processing ◽  
Olfactory Bulb ◽  
High Frequency ◽  
Response Patterns ◽  
Repeated Sampling ◽  
Tufted Cell ◽  
Cell Subpopulations ◽  
Genetic Targeting ◽  
The Impact ◽  
Over Time

AbstractSniffing—the active control of breathing beyond passive respiration—is used by mammals to modulate olfactory sampling. Sniffing allows animals to make odor-guided decisions within ~200 ms, but animals routinely engage in bouts of high-frequency sniffing spanning several seconds; the impact of such repeated odorant sampling on odor representations remains unclear. We investigated this question in the mouse olfactory bulb, where mitral and tufted cells (MTCs) form parallel output streams of odor information processing. To test the impact of repeated odorant sampling on MTC responses, we used two-photon imaging in anesthetized male and female mice to record activation of MTCs while precisely varying inhalation frequency. A combination of genetic targeting and viral expression of GCaMP6 reporters allowed us to access mitral (MC) and superficial tufted cell (sTC) subpopulations separately. We found that repeated odorant sampling differentially affected responses in MCs and sTCs, with MCs showing more diversity than sTCs over the same time period. Impacts of repeated sampling among MCs included both increases and decreases in excitation, as well as changes in response polarity. Response patterns across ensembles of simultaneously-imaged MCs reformatted over time, with representations of different odorants becoming more distinct. MCs also responded differentially to changes in inhalation frequency, whereas sTC responses were more uniform over time and across frequency. Our results support the idea that MCs and TCs comprise functionally distinct pathways for odor information processing, and suggest that the reformatting of MC odor representations by high-frequency sniffing may serve to enhance the discrimination of similar odors.

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