vi. Title: Novel non-pharmacological treatment of painful diabetic neuropathy
Supervisors: Professor Candy McCabe (University of the West of England) and Professor David Wynick
(UHBristol).
This project will be registered at the University of the West of England
Abstract
Painful diabetic neuropathy (PDN) affects over half a million people in the UK and responds poorly to
pharmacological treatments. A significant feature of PDN is intense pain to normally non-painful stimuli
(allodynia). Research in other neuropathic pain cohorts (Complex Regional Pain Syndrome (CRPS)) have
demonstrated a direct link between the degree of allodynia experienced and changes within cortical body
maps on fMRI scanning. These changes can be reversed via novel non-pharmacological techniques that
improve sensory processing and reduce pain. These techniques and imaging studies have not yet been
trialled in PDN.
This studentship will be jointly supervised by Professors Wynick and McCabe who run specialist regional
PDN and CRPS services. Their clinical research expertise and patient cohorts will provide the basis for an
innovative and exciting programme of research in an important but little researched area. Specifically the
studentship will include a systematic review of the literature, pilot studies to assess the efficacy of sensory
discrimination techniques in the treatment of PDN and an imaging (fMRI) cohort study to evaluate the
impact of PDN on cortical body maps pre- and post-treatment intervention. Training in all study techniques
will be provided by experts in the field and the successful applicant will be an integral member of a vibrant
clinical pain research community.
Project summary
Background: Painful diabetic neuropathy (PDN) affects 16-26% of all diabetic patients and approximately
416,000 - 676,000 people in the UK currently live with PDN, rising to over a million by 2025. Another form
of neuropathic pain (NP) is complex regional pain syndrome (CRPS) which occurs in approximately 10,000
patients/year in the UK, often following minor trauma or surgery, which becomes chronic in 10-15% of
patients. The annual total cost to the UK economy of PDN and CRPS is estimated to be over £1 billion.
Intense pain, exacerbated or generated by a normally innocuous stimulus, (allodynia) is a diagnostic feature
of PDN and CRPS. Current pharmacological treatments have shown only moderate evidence for their
effectiveness in treating PDN and CRPS, with less than half of patients having a >50% improvement in pain
scores. Thus there is still a huge unmet need for the treatment of NP and more effective long-term
therapies are urgently required.
Sensory Discrimination Training: fMRI imaging studies have shown that there is a smaller representation of
the affected allodynic limb in the contralateral somatosensory cortex (termed cortical remapping) in
patients with NP. There is a direct relationship between perceived pain and the extent of cortical
remapping with cortical maps reverting to premorbid patterns as pain diminishes. Active stimulation and
discrimination training using electrical tactile stimuli (a pair of electrodes on the skin are stimulated and the
challenge is progressively made harder by moving the electrodes closer together) over a two week period
to areas on, or adjacent to, the painful site, has been demonstrated to normalise cortical remapping and
reduce pain by up to 60% in patients with NP. We are currently developing a patient controlled electrical
stimulation device which is undergoing evaluation in a pilot study. To date sensory discrimination training
techniques have not been tested in PDN.
Proposal Summary: This studentship will be jointly supervised by Professors Wynick and McCabe who run
the specialist regional PDN and CRPS units at the Bristol Royal Infirmary and the Royal National Hospital for
Rheumatic Diseases, respectively. Their extensive clinical and research expertise will provide a stimulating
and rewarding research environment set within multi-disciplinary teams. Additional expertise and training
in multimodal sensory discrimination treatment approaches and imaging techniques will be provided by
our expert collaborators.
This studentship will include a: Systematic review of the literature on sensory discrimination techniques for neuropathic pain
 Pilot study to assess the efficacy of manual and electrical sensory discrimination techniques on
allodynic pain in PDN following tried and tested protocols from CRPS studies
 Small cohort study using fMRI undertaken at the Bristol Clinical Research Imaging Centre will
evaluate the cortical changes in PDN pre- and post-sensory discrimination therapy (the type of
intervention used and the timing of pre- and post-assessment will be determined by study 1)