Why does pain spread? Using touch to treat the spread of pain

Scan sessions (Electroencephalography, EEG, and Magnetic Resonance Imaging, MRI, and Magnetic Resonance Spectroscopy, MRS) will be conducted before and after the intervention in participants who are eligible and safe for neuroimaging. The scan sessions, where possible, will be conducted within a short time frame (or at least the second scanning session will, where possible, be conducted within approximately a week of training completion), in order to maximise chances of a positive training effect on pain (and detection of its effects with neuroimaging). The scan sessions will be used to explore brain activity (EEG and functional MRI) and neurochemistry (MRS) - and their relationship - before and after the intervention. EEG sessions will last a duration of approximately 45 minutes. The EEG sessions will occur at a University research laboratory at Curtin University, in a dedicated quiet room and will be conducted by a trained Research Assistant. MRI/S sessions will last a duration of approximately 1 hour and will be conducted at Perth Radiological Clinic, a private radiological clinic. The neuroimaging assessment provides an insight into the neural mechanisms that might be responsible for the hypothesised reduction in pain with our intervention - a tactile training program. The tactile training program is a two point discrimination (TPD) training program, consisting of stages, that has been designed specifically for this study. Participants will be randomly assigned to either the intervention group or the control group. In all instances the training will be completed by either the trial CI or the trained Research Assistant (both are registered physiotherapists). The location will be a quiet area - mutually convenient for the researcher and the participant. The training sessions will be of a duration of approximately one hour. Participants will attend up to 3 training sessions per week. They will attend a minimum of 2 sessions in a 'stage' (below). A maximum of 8 TPD training sessions will be conducted (10 total, when including the TPD training in the Scan Sessions). The intervention involves TPD training at locations remote from the participant's pain, or locations adjacent to their pain, or at the site of pain. TPD is defined as the shortest distance between two points on the skin that someone can recognise as two points, not one, touching the skin. That is, this is a measure of tactile acuity. This task relies heavily on inhibition in the nervous system. Precise callipers will be placed on the skin at the aforementioned sites, and the distance between the callipers will be increased and decreased repeatedly. The participant will state whether one or two points has touched the skin. They will be informed of correct and incorrect responses immediately (i.e. feedback is given). To make the training more motivating and engaging, training will delivered in stages: i.e. participants may also be asked to judge the relative differences between two-point distances as they are placed on the skin, or asked to visually identify and show the researcher the two-point distance they believed they received. All participant responses/judgements will be met with feedback from the researcher. Adherence to the intervention will be monitored by recording the participants’ attendance and intervention results on a data collection form. A pilot study of up to 10 participants will be conducted within three months of commencement of the main RCT. Participants in the pilot study will receive either the intervention or control training programs. The purpose of the pilot study is to familiarise the Research Assistant with procedures and fine-tune the protocols. The data from the pilot study will not be included for analysis. It is not anticipated any changes to the intervention described herein will be made prior to commencing the main RCT.