RS FIBRO v1.0
Research type
Research Study
Full title
Exploring the role of repetition suppression for symptoms in widespread and localised pain – an EEG study of patients with fibromyalgia or low back pain compared with healthy controls
IRAS ID
239133
Contact name
Michael Lee
Contact email
Sponsor organisation
Cambridge University Hospitals NHS Foundation Trust and The University of Cambridge
Duration of Study in the UK
2 years, 0 months, days
Research summary
Research Summary
We have all experience muscle and joint aches and pain. For most of us, it is short-lived and goes away. In others, pain becomes continual, lasting for months or even years, and this is common for back pain.
Less commonly, muscle and joint pain can be widespread without any obvious cause. There may also be sensations of heart palpitations, tiredness, difficulties with thinking and there can be sensitivity to noise or light. This condition is called fibromyalgia. For many patients, these symptoms reduce their quality of life and limit the capacity for work.
We think that fibromyalgia may be caused by differences in the way the brain senses signals coming up from the body. The aim of the study is to test how efficiently the brain processes touch and sound. We will use a variety of methods to measure ‘efficiency’. These methods include questionnaires, quantitative sensory tests and electroencephalography (EEG).
The plan is to compare results from three groups of people.
(1) Those who have diagnosis of fibromyalgia made by a specialist
(2) Those who have chronic back pain only
(3) Those who are generally healthy and do not have any history of chronic pain lasting more than 3 months in their lives.Summary of Results
Fibromyalgia might be known as a chronic widespread musculoskeletal pain syndrome but patients with fibromyalgia do not just suffer from muscle or joint pains. They report ‘tiredness’, ‘mind-fog’ and can be unusually sensitive to noise or light. Many patients complain of other types of bodily pain, for example, headaches and abdominal pains. There is good scientific evidence that fibromyalgia results from some form of dysfunction of the nervous system. A leading theory supports that the nervous system isn’t unable to adequate or normally suppress sensory signals, which are then experienced as unpleasant or painful. There are many ways through which the nervous system can control sensory signals. We focussed on a brain phenomenon called repetition suppression (RS).
RS happens when the brain is activated from a pair of identical stimuli, for example two loud bleeps about a second apart. The two bleeps sound the same but the brain response to the 2nd bleep is very much reduced compared to the 1st bleep. The reduced brain response to the 2nd stimulus is known as repetition suppression.
Repetition suppression occurs in the healthy brain for all sorts of stimuli, whether they are unpleasant or painful. Scientists believe that repetition suppression is one way the brain ‘saves energy’. The brain, within a split second, decides that the 2nd stimulus is the same as the 1st stimulus, and can represent it in our consciousness more efficiently. We believe that symptoms of fibromyalgia can be explained by some form of impairment of repetition suppression. The impairment might explain why patients with fibromyalgia are often hypersensitive to sounds or even light. Defects in repetition suppression would mean that the brain expends more energy and hence is less efficient at processing sensory signals, which may account for mental fatigue, or poor concentration in patients with fibromyalgia. Our primary analysis indicates the presence of RS in some (but not all) fibromyalgia patients. This likely reflects that fibromyalgia is not a uniform disorder for patients. Symptoms between patients can vary. Also, patients have better and worse days. Many take different medications that can affect how the brain works. Further work is being planned to explore if RS relates to these differences.REC name
London - Central Research Ethics Committee
REC reference
18/LO/0105
Date of REC Opinion
5 Jan 2018
REC opinion
Favourable Opinion