Presentation on theme: "Methods Fifteen healthy pain free volunteers (10 males, mean age = 22.26 years, range 19 to 26) completed two experimental sessions separated by a 24 hour."— Presentation transcript:
Methods Fifteen healthy pain free volunteers (10 males, mean age = 22.26 years, range 19 to 26) completed two experimental sessions separated by a 24 hour washout period. Participants, received an active Pain®Gone (MediDirect, UK) intervention during one experiment and placebo Pain®Gone intervention (identical device with no current output when button pressed) in the other. The order in which the two interventions were applied was randomised and participants were blind to the order in which the interventions were allocated. Participants were informed that they may or may not feel anything during the intervention. In each experimental session, volunteers were given 35 stimuli (1 stimulus being 1 depression of the devices button) to the LI4 (Hegu) acupuncture point located on the hand between the first and second metacarpal bones. Sensory detection and pain thresholds were measured using a Neurosensory Analyser TSA II (Medoc) which delivered hot and cold stimuli to the lateral aspect of the wrist crease on the C6 dermatome via a 30x30mm probe. Warm sensation (WS), heat pain (HP), cold sensation (CS) and cold pain (CP) thresholds (ºC) were recorded using a method of limits approach. Does Transcutaneous Piezoelectric Current affect Heat and Cold Pain Thresholds in Healthy Adults? Results: Sensory threshold Both interventions resulted in significant increases in sensory thresholds relative to baseline (Table 1). Anthony Blenkinship 1, Alex Benham 1,2, Osama Tashani 1,2 and Mark I Johnson 1,2 1: Faculty of Health, Leeds Metropolitan University, UK, 2: Leeds Pallium Research Group, UK Aim The aim of this study was to investigate wether a piezoelectric current changed the perception of pain and sensory thresholds in healthy human participants. Discussion Danziger et al (1998) reported that inhibitory after-effects on lower limb nociceptive flexion reflexes in human participants receiving Piezoelectric currents from a device similar to Pain®Gone. A case-series of 36 patients with chronic musculoskeletal pain found that Pain®Gone generated pain relief and was well tolerated (Ivanova-Stoilova and Howells, 2002). However, neither of these studies included a placebo control. The observed pre-post changes in threshold in the present study are likely to be due to placebo response or may be explained due to a pressure placed upon the skin during application of the intervention. Conclusion There was an increase in cold and warm sensory thresholds and Heat pain threshold after each intervention. However, this study found no differences between the effect active and placebo Pain®Gone on all responses. Introduction Piezoelectric current can be produced by exposing crystals to mechanical pressure. The resulting spark is characterized by high voltage and rectangular pulses of small duration. Pain®Gone pens (Fig 1) deliver piezoelectric current to areas of pain and are available without prescription as an analgesic treatment. References Danziger et al.. Arch Phys Med Rehabil 1998; 79: 191–200. Ivanova-Stoilova T and Howells D., British Pain Society ASM 2002. Pain Thresholds ( ºC ).Pre intervention Mean ± SD Post intervention Mean± SD Mean pre- post difference P value (paired t- test) Cold Pain Threshold (Active) 18.1±8.719.1±7.4-1.1.306 Cold Pain Threshold (Placebo) 16.5±8.319.4±6.9-2.9.079 Heat Pain Threshold (Active) 41.1±3.343.1±3.7-2.0.003 Heat Pain Threshold (Placebo) 42.1±3.843.9±3.4-1.8.000 Fig 1: Pain®Gone device Sensory Thresholds ºC Mean pre-post difference ±SD P value (paired t-test) Cold sensation Threshold (Active) -0.75 ± 0.85 p=0.004 Cold sensation Threshold (Placebo) -0.83 ± 1.2 p=0.02 Warm sensation Threshold (Active) 3.1 ± 2.9 p=0.001 Warm sensation Threshold (Placebo) 3.1 ± 2.4 p=0.001 Results: Pain threshold Results: Pain threshold Both interventions produced significant increases in heat pain threshold relative to baseline but there were no significant changes in cold pain thresholds (Table 2). There were no statistical significant differences in the change pre- post intervention between active and placebo Pain®Gone for any of the sensory or pain thresholds (Fig 2) (ºC) Fig 2. Means±SD of differences between active and placebo Pain®Gone pre-post thresholds changes in cold sensation (CS), warm sensation (WS), cold pain (CP) and heat pain (HP). No significant differences between the two interventions have been found: (CS) p=0.75, (WS) p=0.9, cold pain (CP) p=0.167 and (HP) p=0.81, paired t-tests.