The effect of topical anesthetics on skin sensation and soleus motoneuron reflex excitability. 1994

J Agostinucci
Physical Therapy Program, College of Human Sciences and Services, University of Rhode Island, Kingston 02881.

The effect that topical anesthetics has on cutaneous sensation and on soleus motoneuron reflex excitability was studied in a healthy population. Data were obtained from 16 volunteers (7 men and 9 women) between 20 and 47 years of age. The experiment consisted or recording H-reflexes and Achilles tendon reflexes (ATR) before and after administration of a 20% benzocaine spray or a placebo to the skin of the posterior calf. In addition, a sensory evaluation was conducted to determine objectively the actual quality of anesthesia obtained. Subjects served as their own controls, randomly receiving both the active medication and a placebo. The study was conducted in a single blind fashion with only the experimenter being aware of what medication (active/placebo) was being applied during a given experiment. H-reflex amplitudes increased significantly following the application of benzocaine and the placebo spray compared to control (p < .01). This increase was similar whether the active drug or placebo was administered. No significant difference was shown between active benzocaine and the placebo application. The ATR was not significantly affected by any of the treatment techniques used in this study, although some reduction in reflex amplitude was noted. No change in skin sensibility could be attributed to the topical anesthetic in any subject in this study. It was concluded that benzocaine spray did not have an effect on skin sensation and that the increased motoneuron reflex excitability was more likely in response to a stimulatory action upon cutaneous receptors from the spray technique. It is further suggested that topical anesthetics applied to intact skin may not permeate cutaneous tissue in large enough quantities to have a desensitizing effect.

UI MeSH Term Description Entries
D008297 Male Males
D008875 Middle Aged An adult aged 45 - 64 years. Middle Age
D009046 Motor Neurons Neurons which activate MUSCLE CELLS. Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D005260 Female Females
D006181 H-Reflex A monosynaptic reflex elicited by stimulating a nerve, particularly the tibial nerve, with an electric shock. H Reflex,H-Reflexes,H Reflexes,Reflex, H
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000125 Achilles Tendon Tendon that connects the muscles in the back of the calf to the HEEL BONE. Calcaneal Tendon,Tendo Calcaneus,Calcaneal Tendons,Tendon, Achilles,Tendon, Calcaneal,Tendons, Calcaneal
D000328 Adult A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available. Adults
D001566 Benzocaine A surface anesthetic that acts by preventing transmission of impulses along NERVE FIBERS and at NERVE ENDINGS. Ethyl Aminobenzoate,4-Aminobenzoic Acid Ethyl Ester,Americaine,Anaesthesin,Anesthesin,Bensokain,Benzocaine Acetate,Benzocaine Formate,Benzocaine Hydrobromide,Benzocaine Hydrochloride,Benzocaine Methanesulfonate,Ethoform,Acetate, Benzocaine,Formate, Benzocaine,Hydrobromide, Benzocaine,Hydrochloride, Benzocaine,Methanesulfonate, Benzocaine
D012677 Sensation The process in which specialized SENSORY RECEPTOR CELLS transduce peripheral stimuli (physical or chemical) into NERVE IMPULSES which are then transmitted to the various sensory centers in the CENTRAL NERVOUS SYSTEM. Sensory Function,Organoleptic,Function, Sensory,Functions, Sensory,Sensations,Sensory Functions

Related Publications

J Agostinucci
January 2001, Medicine and science in sports and exercise,
J Agostinucci
December 1994, Electromyography and clinical neurophysiology,
J Agostinucci
January 1995, Electromyography and clinical neurophysiology,
J Agostinucci
January 1987, Experimental neurology,
J Agostinucci
December 1982, Neuroscience letters,
J Agostinucci
January 2009, The International journal of neuroscience,
J Agostinucci
January 1989, Biomedica biochimica acta,
J Agostinucci
February 1993, Medicine and science in sports and exercise,
Copied contents to your clipboard!