Published: Monday 3 November 2014
One of our Postdoctoral Fellows, Dr Anna Kuppuswamy, has published a paper today in the journal Brain. Her research looks at what is happening in the brains of people who experience fatigue because of a stroke.
Fatigue is one of the most common effects of stroke. It can make people feel unwell and like they're not in control of their recovery. They may feel like they lack energy or strength and feel constantly weary or tired. Post-stroke fatigue does not always improve with rest and is not necessarily related to recent activity. So it is not like typical tiredness.
Post-stroke fatigue can range from relatively mild to severe and the intensity of the tiredness does not seem to be related to the severity or type of stroke experienced.
Although post-stroke fatigue is poorly understood, it is thought to be due to problems in the central nervous system (the brain and thes spinal cord) caused by stroke.
What did the researchers do and show?
Dr Kuppuswamy's study involved 71 people who reported non-exercise related fatigue and were in the chronic stages of stroke.
For these stroke survivors, Dr Kuppuswamy measured the responsiveness of the parts of the brain that control movement - what's known as 'corticomotor excitability'. To do this, she used a safe, non-invasive type of brain stimulation called TMS (transcranial magnetic stimulation), which involves placing a metal coil on the head, and delivering a targeted, magnetic pulse into the brain.
By delivering TMS to specific areas of each participant's brain, she created small muscle contractions in both their arm and hand, which she recorded with sensors placed on them. This allowed her to test how well the brain was communicating with the spinal cord and the nerves in the body responsible for movement.
Dr Kuppuswamy also recorded the reports of fatigue and perceived effort of movement from these stroke survivors with special questionnaires. She then compared the TMS recordings of how responsive the brain and spinal cord were, with the patients' reports of fatigue and perceived effort in moving. She found significant associations between the two, which together suggest that reduced responsiveness or 'excitability' of brain areas controlling movement are associated with high levels of fatigue post-stroke.
Although this research is at a very early stage, it lays important foundations which could help discover future treatments for stroke patients with fatigue.
Dr Kuppuswamy is a Post-Doctoral Research Associate at University College London. Visit her website for more information.