The PENTAGONS Trial

We are conducting a randomised trial of a treatment for severe foot pain due to diabetes, using an implanted nerve stimulator system.

50% of people with diabetes have a type of nerve damage called diabetic peripheral neuropathy (DPN).  Often this causes pain, most commonly in the feet, which can be severe. The mainstays of treatment are painkilling medications, however in some cases such treatment is unsatisfactory, either because it fails to achieve adequate pain relief or because the required dose of medication is such that it produces severe side effects.

Some types of severe pain that cannot be adequately treated with drugs may respond to electrical stimulation of parts of the nervous system, a method of treatment known as neuromodulation.  In this trial we aim to determine whether a form of neuromodulation, called Dorsal Root Ganglion Stimulation (DRGS), can effectively treat pain due to DPN that cannot be controlled with medication alone. DRGS has proved to be a very successful treatment for another condition that causes severe pain in the feet, called complex regional pain syndrome (CRPS).  In a randomised trial of DRGS in CRPS, pain levels were reduced by at least half in over four out of every five patients treated. 

In DRGS, stimulator wires are inserted into the back, in a procedure that is similar to having an epidural anaesthetic. These are connected to a pacemaker-like device that is implanted under the skin and generates small electrical pulses which are transmitted by the wires to nerves coming from the feet that are entering the spine on their way to the spinal cord.  The dorsal root ganglion is a part of the nerve located just at the point where it enters the spine, and it is here that is stimulated by the wire tip.

The trial is running at 4 UK centres in Oxford, Middlesborough, Manchester, and London.

If you have severe foot pain due to your diabetes that has not responded well to painkillers, you may be eligible to take part.  If you would like to be considered please contact pentagons.recruitment@nds.ox.ac.uk.  We will go through some simple screening questions with you and can then arrange for you to be seen at your nearest trial centre.

UPDATE 12/03/2020: Although Covid-19 will cause delays to clinic appointments and treatment, we will always reply to email sent to pentagons.recruitment@nds.ox.ac.uk from potential participants.  We can send out information sheets through the post and go through screening questions on the telephone, so that if you are suitable for the trial we are ready to pick things up once the situation improves.