Dr Sanjay Kumar and Dr Farzaneh Yazdani
Oxford Brookes University, Oxford, UK
Background and aim
Our senses are constantly being bombarded with information from our surroundings – the sights, sounds, sensations and smells around us, as well as the tastes in our mouths.
The brain has to work hard to process all this information simultaneously, and filter out what’s irrelevant so we can concentrate on what’s important at any given moment. But this ability can be impaired in people with certain clinical conditions, leading to a disabling hypersensitivity to the stimuli around them.
The resulting physical and mental overload can lead to poor coordination, dizziness, clumsiness, numbness, tingling and nausea, and may affect individuals’ ability to take in information and make decisions.
Dr Sanjay Kumar, Dr Farzaneh Yazdani and colleagues at Oxford Brookes University have previously looked at this phenomenon in people with post-concussion syndrome following head injury. And we recently awarded funding to the team to investigate the problem in ME/CFS.
Although hypersensitivity is not considered a primary factor in the diagnosis of ME/CFS, it is a common finding in people with the condition. This was borne out when the team met with people from a local ME support group, many of whom identified with the issue and said that it interfered with their daily life.
This prompted a series of investigations to understand the nature and impact of the sensory problems experienced by people with ME/CFS, and to determine whether they are associated with any functional or electrical changes in the brain.
The team aims to recruit 40 patients with ME/CFS and 40 healthy control subjects, and will begin their investigations by using a self-report questionnaire to assess patterns of sensory processing and how they affect functional performance.
The participants will then complete a series of neuropsychological tests (see below) to investigate a range of cognitive processes, followed by some simple computer-based tasks, while the electrical activity of the brain is measured non-invasively using electroencephalography.
The investigators’ hope is that the results of this preliminary work will help in our understanding of the brain mechanisms that underlie the abnormal sensory experiences of people with ME/CFS, and also lead to the development of interventions to help manage these problems.
Motor Screening Task – Participants are introduced to the format of the tests and responding via a touchscreen, and are asked to select on-screen crosses as they appear. Measures speed of response and accuracy, and tests for sensorimotor deficits or lack of comprehension.
Rapid Visual Information Processing – Assesses how well someone can keep attention on a task, in this case pressing an on-screen button when they see a predefined sequence of numbers (e.g. 2-4-6) within a random stream of numbers. Measures speed of responses and number of false alarms.
Delayed Matching to Sample – Assesses visual recognition and short-term visual memory by asking participants to match a pattern to one of four options shown below it. Measures speed of responses and number of correct patterns selected.
Stop Signal Task – Assesses how well someone can control their impulses. Participants are presented with an arrow and asked to press an on-screen button corresponding to whether it points left or right, but they must not respond if they also hear a beep. Measures reaction time and number of errors.