Up to 70% of stroke survivors complain of tiredness or fatigue, sometimes years after stroke.
Unlike normal tiredness, post stroke fatigue does not always respond to rest. The cause of extreme tiredness is not known and there are no definitive treatments available.
The researchers of the current study previously investigated how responsive or ‘excitable’ a key movement area of the brain called the ‘motor cortex’ is when someone is fatigued.
That study was conducted in 70 stroke patients, and suggested that in stroke patients with high levels of fatigue, the excitability of the motor cortex of the brain was low. Whilst a promising finding, the study was unable to establish whether a patient’s high levels of fatigue caused the low excitability of the brain’s motor cortex, or whether the opposite was the case.
Establishing causation is an important question, because if having low excitability of the motor cortex causes high levels of fatigue in a stroke patient, then it may be possible to intervene, stimulate and increase the excitability of the motor cortex, and consequently reduce the symptoms of fatigue experienced.
The current study will test 64 stroke patients with high levels of fatigue. Half of the participants will receive a safe, non-invasive type of brain stimulation called ‘tDCS’ to the motor cortex of their brain every day for five days. The rest will receive a dummy/sham treatment that will simulate the experience of receiving real brain stimulation
The excitability of the motor cortex of all participants will be measured before and after the real or ‘sham’ electrical stimulation intervention. Levels of fatigue and other physical and brain functions will also be measured to study the impact of tDCS. The prediction is that fatigue levels will decrease following real tDCS and not after sham tDCS.
The results of the study could provide a new direction to fatigue treatment after stroke. Fatigue is generally seen as a complaint associated with mood problems, but this research may establish that fatigue after stroke is related to low excitability levels of the brain, and that treatments should be targeted at increasing the excitability of those brain areas affected.