Respiratory evoked potentials and occlusion elicited sympathetic skin response.
BACKGROUND
Neurophysiological study of respiratory structures usually relies upon diaphragm electromyography and phrenic nerve conduction study, which do not assess the afferent sensory pathways.


OBJECTIVE
To assess the feasibility of respiratory evoked potentials (REPs) and sympathetic skin responses (SSRs) elicited by inspiratory occlusion.


METHODS
REPs and SSRs were studied in 12 healthy adults. REPs were elicited by inspiratory occlusions triggered by the physician within 1 s after the onset of a respiratory effort. They were recorded from C3, C4 and Cz needle electrodes (referenced to Fz). Each individual trial consisted of two superimposed 30-sweep averaged responses to inspiratory occlusions. SSRs were recorded from surface electrodes placed on the subject's hand and elicited by similar inspiratory occlusions.


RESULTS
Reproducible REPs and SSRs were obtained in all subjects. Mean latencies of initial P1 and N1 cortical responses were 41 and 72 ms, respectively. SSRs were similar to those usually elicited by peripheral nerve electrical stimulation.


CONCLUSIONS
Brief occlusion of inspiration induces cortical and sympathetic activation, both are easily recordable. Since REPs are considered to be the neurophysiological substrate of certain types of respiratory sensations and are altered in different chronic respiratory diseases, they, in addition to SSR, represent attractive new techniques that may provide better understanding of respiratory dysfunction.
Lanctin
Caroline
C
Laboratoire d'Explorations Fonctionnelles, Hôtel Dieu, Nantes, France.
Magot
Armelle
A
Chambellan
Arnaud
A
Tich
Sylvie Nguyen The
SN
Pereon
Yann
Y
D000328:Adult; D005071:Evoked Potentials / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012119:Respiration; D012867:Skin / Q000294:innervation; D012879:Skin Physiological Phenomena; D013564:Sympathetic Nervous System / Q000502:physiology*