Selective Laser Stimulation of Aδ- or C-Fibers Through Application of a Spatial Filter: A Study in Healthy Volunteers

Hoeben, Renske M.; Krabbenbos, Imre P.; Dongen, Eric P.A. van; Tromp, Selma C.; Boezeman, Eduard H.; Swol, Christiaan F. P. van

doi:10.14740/jnr361w

Cited by 3 publications

(2 citation statements)

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“…In contrast to earlier similar studies with standardized energy levels (2–4), we used individually titrated levels of laser energy to induce similar and more predictable pain responses and avoid epidermal damage. We consider this readily usable technique of selective C-fibre stimulation and evaluation to be clinically, but not necessarily scientifically, more applicable than spatial filter [20] or dissociating Aδ-fibre nerve block [21] techniques.…”

Section: Discussionmentioning

confidence: 99%

Single and double pain responses to individually titrated ultra-short laser stimulation in humans

2019

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Background This preclinical study in humans was designed to selectively induce delayed nociceptive pain responses to individually titrated laser stimulation, enabling separate bedside intensity scoring of both immediate and delayed pain. Methods Forty-four (fourteen female) healthy volunteers were subjected to repeated nociceptive dermal stimulation in the plantar arc, based on ultra-short carbon dioxide laser with individually titrated energy levels associated with mild pain. Results Data was analysed in 42 (12 female) subjects, and 29 of them (11 females) consistently reported immediate and delayed pain responses at second-long intervals to each nociceptive stimulus. All single pain responses were delayed and associated with lower levels ( p = 0.003) of laser energy density (median 61; IQR 54–71 mJ/mm 2 ), compared with double pain responses (88; 64–110 mJ/mm 2 ). Pain intensity levels associated with either kind of response were readily assessable at bedside. Conclusions This study is the first one to show in humans that individually titrated ultra-short pulses of laser stimulation, enabling separate pain intensity scoring of immediate and delayed responses at bedside, can be used to selectively induce and evaluate delayed nociceptive pain, most likely reflecting C-fibre-mediated transmission. These findings might facilitate future research on perception and management of C-fibre-mediated pain in humans.

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Section: Discussionmentioning

confidence: 99%

Single and double pain responses to individually titrated ultra-short laser stimulation in humans

2019

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“…Essas fibras nervosas não possuem bainha de mielina em seus axônios. Por isso, a velocidade de condução (< 2 m/s) é inferior às fibras mielinizadas (~ 10 m/s) 19 . Entretanto, a maioria das aferências vagais broncopulmonares é mediada pelas fibras-C. Os corpos celulares desses neurônios geralmente estão localizados no gânglio superior do nervo vago 20 .…”

Section: Fisiopatologiaunclassified

Aspectos fisiopatológicos do reflexo da tosse: uma revisão de literatura

Rodrigues

Galvão

2017

Rev. Med. (São Paulo)

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RESUMO:A tosse é um reflexo de defesa da via aérea em condições fisiológicas. Entretanto, ela compõe o quadro clínico de diversas doenças pulmonares, cardíacas e gastrintestinais. A persistência desse sintoma afeta a qualidade de vida do paciente e acomete 3 a 40% da população geral. Embora possua uma prevalência alta, a fisiopatologia desse sintoma ainda não é bem esclarecida. Nesse sentido, anualmente, são publicados novos achados sobre a fisiopatologia desse sintoma. Assim, o objetivo desse trabalho é realizar uma revisão de literatura sobre a fisiopatologia da tosse. Essa revisão utilizou quarenta publicações presentes nas seguintes bases de dados: Scholar Google, SciELO, Pubmed Central® (PMC), National Center for Biotechnology Information (NCBI) e Medline. A fisiopatologia da tosse está intimamente ligada à estimulação química das fibras-C e à ativação por estímulos mecânicos dos receptores de adaptação rápida (RARs) e dos receptores de estiramento de adaptação lenta (SARs). O conhecimento desses mecanismos fisiopatológicos é importante para o manejo clínico de pacientes com esse sintoma e contribui para o entendimento do mecanismo de ação de antitussígenos que agem sobre esses receptores.Descritores: Tosse/fisiopatologia; Tosse/diagnóstico; Reflexo; Antitussígenos. ABSTRACT:Cough is a reflex of airway defense under physiological conditions. However, it composes the clinical condition of several pulmonary, cardiac and gastrointestinal deseases. The persistence of the symptom affects the welfare of the patient and affects 3 to 40% of the general population. Although it has an important prevalence, the pathophysiology of the symptom is still not clear. In this sense, new symptom findings are published annually. Thus, the objective of the study is to perform a review of the pathophysiology of cough. This review used forty recent publications in the following databases: Scholar Google, SciELO, Pubmed Central® (PMC), National Center for Biotechnology Information (NCBI) and Medline. The pathophysiology of cough is closely linked to the chemical stimulation of C-fibers and to activation by mechanical stimuli of the rapid adaptation receptors (RARs) and the slow adaptating stretch receptors (SARs). The knowledge of these pathophysiological mechanisms is important for the clinical management of patients with this symptom and contributes to the understanding of the mechanism of action of antitussives that act on these receptors.

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A novel dual-wavelength laser stimulator to elicit transient and tonic nociceptive stimulation

et al. 2017

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This study aimed to develop a new laser stimulator to elicit both transient and sustained heat stimulation with a dual-wavelength laser system as a tool for the investigation of both transient and tonic experimental models of pain. The laser stimulator used a 980-nm pulsed laser to generate transient heat stimulation and a 1940-nm continuous-wave (CW) laser to provide sustained heat stimulation. The laser with 980-nm wavelength can elicit transient pain with less thermal injury, while the 1940-nm CW laser can effectively stimulate both superficial and deep nociceptors to elicit tonic pain. A proportional integral-derivative (PID) temperature feedback control system was implemented to ensure constancy of temperature during heat stimulation. The performance of this stimulator was evaluated by in vitro and in vivo animal experiments. In vitro experiments on totally 120 specimens fresh pig skin included transient heat stimulation by 980-nm laser (1.5 J, 10 ms), sustained heat stimulation by 1940-nm laser (50-55 °C temperature control mode or 1.5 W, 5 min continuous power supply), and the combination of transient/sustained heat stimulation by dual lasers (1.5 J, 10 ms, 980-nm pulse laser, and 1940-nm laser with 50-55 °C temperature control mode). Hemoglobin brushing and wind-cooling methods were tested to find better stimulation model. A classic tail-flick latency (TFL) experiment with 20 Wistar rats was used to evaluate the in vivo efficacy of transient and tonic pain stimulation with 15 J, 100 ms 980-nm single laser pulse, and 1.5 W constant 1940-nm laser power. Ideal stimulation parameters to generate transient pain were found to be a 26.6 °C peak temperature rise and 0.67 s pain duration. In our model of tonic pain, 5 min of tonic stimulation produced a temperature change of 53.7 ± 1.3 °C with 1.6 ± 0.2% variation. When the transient and tonic stimulation protocols were combined, no significant difference was observed depending on the order of stimuli. Obvious tail-flick movements were observed. The TFL value of transient pain was 3.0 ± 0.8 s, and it was 4.4 ± 1.8 s for tonic pain stimulation. This study shows that our novel design can provide effective stimulation of transient pain and stable tonic pain. Furthermore, it can also provide a reliable combination of transient and consistent stimulations for basic studies of pain perception.

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Selective Laser Stimulation of Aδ- or C-Fibers Through Application of a Spatial Filter: A Study in Healthy Volunteers

Cited by 3 publications

References 12 publications

Single and double pain responses to individually titrated ultra-short laser stimulation in humans

Single and double pain responses to individually titrated ultra-short laser stimulation in humans

Aspectos fisiopatológicos do reflexo da tosse: uma revisão de literatura

A novel dual-wavelength laser stimulator to elicit transient and tonic nociceptive stimulation

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