Background & Aims
The nociceptive blink reflex (nBR) is a neurophysiological test that measures brainstem reflexes and can be used to assess the excitability of trigeminal central pathways involved in trigeminal nociceptive processing in a valid and reliable manner. The use of nBR can be an adjunctive tool in mechanism-based treatment of orofacial musculoskeletal pain by determining reference values that aid in identifying neurophysiological alterations reflecting orofacial pain mechanisms. Thus, this ongoing investigation aims to determine reference values for the evaluation of the nBR from a sample of healthy adults.
Methods
One hundred and twenty healthy participants are being assessed. The acquisition of nBR is conducted with the participant in a dorsal decubitus position with a room temperature between 20 and 25ºC. Self-adhesive electrodes for recording are positioned over the lower part of the orbicularis oculi muscles. The electrical stimulator is positioned over the supraorbital (V1) and infraorbital (V2) entry zones of the trigeminal nerve (right and left sides) and the order of stimulation is randomized for each participant. Electrical stimuli of intensities 1.5, 2, and 3 times above the electrical pain threshold are randomly applied in a sequence of 10 stimuli for each intensity, with an interval of 10 to 15 seconds. The psychophysical parameters, amplitude, latency (ms), and habituation of R2, quantified as root mean square (RMS) (?V), responses of the nBR are being assessed. A descriptive analysis of the variables and Z-score transformation are applied.
Results
Eighteen healthy participants, comprising 13 females and 5 males, with a mean age of 26.28 (4.60) years, have successfully completed the study so far. The mean (SD) of electrical pain threshold, considering both sides, was 2.62 (1.04) for V1 and 1.99 (0.66) for V2. The mean (SD) of the RMS amplitude of R2 responses, considering both sides and all intensities of stimulation, for the V1 and V2, for the ipsilateral (i) and contralateral (c) stimulation side, was 38.75 (29.79) for V1i, 24.32 (32.64) for V1c, 56.70 (95.21) for V2i and 19.99 (17.98) for V2c. Likewise, the mean (SD) of the onset latencies of R2 responses was 38.03 (1.09) for V1i, 38.22 (1.11) for V1c, 38.16 (0.89) for V2i and 38.20 (0.94) for V2c. Finally, the mean (SD) of the R2 habituation responses for was 1.00 (1.22) for V1i, 1.87 (3.64) for V1c, 1.45 (3.05) for V2i and 3.24 (9.62) for V2c.
Conclusions
Establishing neurophysiological reference values for nBR from a sample of healthy participants represents a valuable tool for understanding trigeminal nociceptive mechanisms in pathological conditions. Furthermore, comprehending these neurophysiological patterns in healthy individuals serves as a crucial starting point for clinical research, opening avenues for precise treatment strategies in the effective management of orofacial pain-related conditions.
References
(1) Costa YM, Baad-Hansen L, Bonjardim LR, Conti PCR, Svensson P. Reliability of the nociceptive blink reflex evoked by electrical stimulation of the trigeminal nerve in humans. Clin Oral Investig. 2017;21(8):2453-63. (2) Kaube H, Katsarava Z, Kaufer T, Diener H, Ellrich J. A new method to increase nociception specificity of the human blink reflex. Clin Neurophysiol: official journal of the International Federation of Clinical Neurophysiology. 2000;111(3):413-6. (3) Katsarava Z, Ellrich J, Diener HC, Kaube H. Optimized stimulation and recording parameters of human ‘nociception specific’ blink reflex recordings. Clin Neurophysiol: official journal of the International Federation of Clinical Neurophysiology. 2002;113(12):1932-6. (4) Perrotta A, Anastasio MG, De Icco R, Coppola G, Ambrosini A, Serrao M, et al. Frequency-Dependent Habituation Deficit of the Nociceptive Blink Reflex in Aura With Migraine Headache. Can Migraine Aura Modulate Trigeminal Excitability? Headache. 2017;57(6):887-98. (5) Valls-Solé J. Aminoff’s Electrodiagnosis in Clinical Neurology. 2012.
Presenting Author
Rhayane da Conceição Monteiro
Poster Authors
Rhayane da Conceição Monteiro
Master's student
Piracicaba Dental School, University of Campinas
Lead Author
Ana Clara Hecker de Carvalho; Master's student
Piracicaba Dental School, University of Campinas
Lead Author
Soraya Salmanzadeh Ardestani; PhD student
Piracicaba Dental School, University of Campinas
Lead Author
Allen Matheus Nascimento
Department of Biosciences, Piracicaba Dental School, University of Campinas, Sao
Lead Author
Larissa Fuchs Barreto; Undergraduate student
Piracicaba Dental School, University of Campinas
Lead Author
Leonardo Rigoldi Bonjardim
Bauru School of Dentistry, University of São Paulo
Lead Author
Topics
- Assessment and Diagnosis