Withdrawal response in healthy adults

Abstract

Abstract Background: Withdrawal response was used to explain extensor plantar response in population without pyramidal dysfunction but there is lack of data characterizing this response in normal population. Objective: To characterize withdrawal response from pain and tickle sensation in population without any neurological defi cit. Methods: The study was carried out using four different stimuli, namely heat-induced pain, cold-induced pain, electric-induced pain using electromyography stimulator and ticklish sensation using superworm (Zophobas morio), applied to normal subjects in University Malaya Medical Centre, Kuala Lumpur. Results: Heat-induced pain resulted in fl exion of the big toe (61.1%), other toes (62.3%), ankle dorsifl exion (82.6%), knee fl exion (83.9%) and hip fl exion (83.9%). Electric-induced pain showed fl exion of the big toe (27.7%), other toes (28.3%), ankle dorsifl exion (51.0%), knee fl exion (76.0%) and hip fl exion (76.0%). Ticklish sensation showed fl exion of the big toe (14.8%), other toes (14.8%), ankle dorsifl exion (22.7%), knee fl exion (21.9%), and hip fl exion (21.9%). There was signifi cant correlation between fear and ticklish sensation induced withdrawal responses and extension of big toe. Cold induced pain resulting in big toe fl exion (6.4%), other toes (6.9%), dorsifl exion of ankle (7.1%), fl exion of knee (6.9%), and hip fl exion (6.9%). Females were more responsive to heat, males to electrical stimulation. The prevalence of big toe extension ranged from 11.0% (electrical), 6.3% (ticklish), 4.8 (heat), to 0% (cold), a mean of 5.2% overall. Conclusion: Withdrawal response caused by nociceptive and ticklish sensation consists mostly of big toe fl exion and of other toes, ankle dorsifl exion and fl exion of the knee and hip. Extension of the big toe is seen in about 5% of all the stimulation