Investigating brain-stem dysfunction in ME/CFS using 7-Tesla MRI

Principal investigator

Dr Leighton Barnden

Institution

Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia

Start date

April 2021

Funding

This project is funded by ME Research UK with the financial support of the Fred and Joan Davies Bequest.

Background and aim

Many of the symptoms experienced by people with ME/CFS – including problems with concentration, memory, vision and heart-rate control – suggest abnormalities in the brain and nervous system. Indeed, research has demonstrated changes to the brain structure of ME/CFS patients, as well as impairments in the connectivity between different regions of the brain, and disruption to the autonomic nervous system (which regulates many body functions).

Dr Leighton Barnden and his team at Griffith University in Queensland, Australia have been particularly active in this area, using magnetic resonance imaging (MRI) to demonstrate an upregulation in white-matter myelin that was associated with ME/CFS severity but independent of anxiety and depression.

Jiasheng Su, Leighton Barnden and Kiran Thapaliya

They also detected correlations between abnormal MRI findings and autonomic measures within the reticular activation system (RAS) of the brain stem. The RAS is a diffuse network of small interconnected nuclei with important regulatory functions, including controlling the sleep–wake cycle and brain arousal levels, which affect attention, sensory perception, cognitive performance and memory, all of which are deficient in ME/CFS.

In addition, functional MRI was used to confirm deficits in connectivity between RAS nuclei. These findings all suggest that nerve signalling in the brain stem is impaired in ME/CFS.

To date, Dr Barnden’s results have been limited by the strength of the magnetic used in his MRI scanner. While 3-Tesla MRI is commonly used and works well in clinical practice, a stronger magnet such as 7 Tesla allows much more detailed images to be obtained, which can be very valuable in research.

Dr Barnden therefore plans to repeat many of his previous brain-stem RAS measurements using a stronger 7-Tesla MRI scanner, which will provide increased sensitivity and resolution, and hopefully uncover more information about the RAS abnormalities in people with ME/CFS.

However, he will also add some more recently developed MRI measurement techniques to identify and characterise new aspects of RAS pathology. Although the studies will specifically target the brain-stem RAS, the team will also look for differences throughout the brain in ME/CFS.

To confirm and expand their understanding of RAS dysfunction in ME/CFS, they will also test associations between RAS connectivity and various clinical parameters, which could provide valuable biomarkers of ME/CFS.