Browsing by Person "Roche, Patricia"

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A model of ischemic pain in the calf and tens modification of lower limb pain: preliminary results.
(2007) Roche, Patricia; Santos, Derek
PURPOSE: To develop a model of laboratory induced ischemic calf pain; to test the analgesic efficacy of TENS for calf pain, and to describe induced calf pain, in healthy volunteers. RELEVANCE: We aimed to modify the sub maximum effort tourniquet technique (SMETT), a standardised method of inducing experimental ischemic pain into the upper limb of volunteers, to create a laboratory model of lower limb ischemia (LLI). With exercise, LLI could serve as a model of intermittent claudication (IC) - the exercise induced ischemic pain that is the main symptom of Peripheral Arterial Disease (PAD). Testing TENS for LLI pain could indicate its potential efficacy in IC related to PAD. PARTICIPANTS: 14 healthy males volunteered for Experiment 1 (E1) and 20 healthy females for Experiment 2 (E2). Subjects met inclusion and exclusion criteria for SMETT. METHODS: E1 was a within subject, crossover, single-blind study. A pilot study was undertaken with 4 independent subjects. The SMETT technique (with broad pressure cuff) was applied to the thigh. Subjects then performed 20 resisted plantar-flexion / dorsi-flexion exercises, using a pulley and weight apparatus developed for the study, in order to induce ischemia over a period of 5 minutes. Measurment of the Post Occlusive Reactive Hyperaemic response (PORHmax), demonstrated that ischemia had occurred in the calf of each subject, via the adapted SMETT technique. The main study in E1 applied (A) the standard SMETT in the upper limb and 20 minutes later (B) the modified SMETT (minus PORHmax) in the lower limb. Each application was for a maximum of 20 minutes. A linear pain scale rated subjective reports of pain intensity, at intervals between self-reported 'pain threshold' and 'pain tolerance'. The cuff was deflated at 'pain tolerance', or at 20 minutes, whichever came first. Subjects retrospectively described the ischemic pain in (i) the forearm and (ii) the calf, five minutes after cuff deflation. E2 utilised the E1 procedure for inducing lower limb ischemia and recording pain, to conduct an independent subject study of continuous TENS (100Hz, 200us) for induced LLI. Subjects were randomly allocated to a Control or TENS group. In the TENS group, electrodes were placed proximal and distal to the area of pain in the calf. ANALYSIS: Parametric or nonparametric tests examined differences between conditions; linear pain scales and weighted-rank MPQ - Pain Rating Index (PRI) scores For all statistical tests p-<-0.05. RESULTS: In E1, pain ratings at 300, 600, 900 12000 seconds showed similar incremental increases in pain intensity that are typical of SMETT induced ischemic pain, over time. In E2, TENS significantly raised the mean pain threshold and tolerance levels, and reduced MPQ-PRI scores, compared to controls (P-<-0.01 all comparisons). Qualitative MPQ descriptions reliably identified 4 sensory and 1 affective subclass of words to describe induced LLI pain. CONCLUSIONS: Lower limb ischemic pain induced with a modified SMETT can be modified by continuous TENS. IMPLICATIONS: A study into the efficacy of TENS during exercise in patients with PAD is indicated. Ref. 1. ROCHE PA et al.Physiotherapy Theory and Practice 2001, 18: 129-138 KEYWORDS: Pain; laboratory model, electrical stimulation. FUNDING ACKNOWLEDGEMENTS: None. CONTACT: proche@qmuc.ac.uk
Detection theory analysis of scaling and discrimination tasks: Responses to noxious thermal stimuli
(Psychonomic Society, 2007-08) Tan, Chee-Wee; Palmer, S.; Martin, D. J.; Roche, Patricia
This study's main purpose was to examine the sensitivity estimates obtained from scaling and discrimination approaches for nociception assessment in healthy individuals. This investigation may inform future applications in diagnostic procedures for painful conditions. Models of psychophysical judgment based on those of Durlach and Braida (1969), Laming (1984), and Irwin and Whitehead (1991) were used as the common analytical framework. Noxious thermal contact stimuli were used. The results show that the scaling approach produced lower detection theory sensitivity estimates than did the discrimination approach. The additional judgment variance in scaling tasks could explain this lowered sensitivity. The relative judgmental variance value of 2.18 obtained in this study is lower than variance values found in previous investigations. This discrepancy is probably due to the relatively smaller stimulus range employed in this study. The authors propose that the theoretical framework used in this study may be used in future studies to investigate the different dimensions of pain perception. Perception & Psychophysics,
Early development of a lower limb ischaemic pain test using the McGill Pain Questionnaire (MPQ) in healthy volunteers
(2008) Seenan, Christopher; Roche, Patricia; Santos, Derek
Modification of experimental lower limb ischaemic pain with transcutaneous electrical nerve stimulation.
(Lippincott Williams & Wilkins, 2012-10) Seenan, Christopher; Roche, Patricia; Tan, Chee-Wee; Mercer, Tom
Introduction: Transcutaneous electrical nerve stimulation (TENS)has been shown to be effective for the reduction of experimentally induced ischemic pain in the upper limb. No studies have been published on the effects of TENS for lower limb ischemic pain. Objectives: To investigate the pain-modifying effect of TENS on experimentally induced ischemic pain in the lower limb. Methods: A modified Submaximal Effort Tourniquet Test-induced ischemic pain in the nondominant lower limb of 27 healthy volunteers. Each of the participants completed a baseline modified Submaximal Effort Tourniquet Test (No TENS) and 1 of the experimental conditions: either high-frequency TENS (HF-TENS) or placebo TENS(P-TENS). The outcome measures were the time taken (in seconds) for the participants to report pain threshold and pain tolerance. Pain endurance was calculated as the difference between these points. Pain intensity during ischemia was assessed using a numerical rating scale. The McGill Pain Questionnaire recorded participants' retrospective description of 'intolerable' induced pain. The differences in scores between these measures at the baseline and TENS intervention was calculated and used for the analysis. Results: Paired Student t-tests found significant increases in time to pain tolerance and pain endurance in both the TENS groups(P<0.001 HF-TENS and P<0.05 for P-TENS, respectively). When compared with baseline, time to pain threshold increased significantly only with HF-TENS (P<0.01). The independent Student t-tests detected greater increases in pain threshold, tolerance, and endurance in the HF-TENS group compared with the PTENS group (P<0.05, 0.002, and 0.003, respectively). Compared with P-TENS, HF-TENS significantly reduced the pain intensity between the fifth and eigth minutes. Both HF-TENS and P-TENS significantly reduced the mean McGill Pain Questionnaire Pain Rating Index scores, but did not show a between-group difference. Conclusions: HF-TENS had stronger modifying effects on several aspects of laboratory-induced ischemic pain than did P-TENS. HFTENS delayed the onset of pain, reduced pain levels, and delayed the onset of extreme pain over a period of several mi
Noxious heat discrimination ability in persons with chronic pain: A psychophysical study.
(2007-06-02) Tan, Chee-Wee; Martin, D.; Roche, Patricia; Palmer, Shea
Preoperative predictors of knee range of motion during stair walking after total knee replacement
(2008-09) van der Linden, Marietta; Roche, Patricia; Rowe, P. J.; Nutton, R. W.
Summary: Hierarchical Multiple Regression was performed on the pre and postoperative measures of 56 patients with end-stage osteoarthritis. Post-operative range of knee motion during stair ascent and descent was predicted by pre-operative measures in different domain blocks. Conclusions: Pre-operative variables predicting post-operative stair walking differ between stair ascent and descent. This has consequences for the treatment of patients waiting for a total knee replacement.