Do brain measures predict improvement of hand or arm function following brain stimulation in people with stroke?

None listed

Stroke is a leading cause of long term disability with around 60,000 people experiencing a stroke each year in Australia. In the acute post-stroke period over two thirds of patients experience some level of reduced upper limb function, while 15-30% of stroke survivors suffer permanent motor impairments despite extensive rehabilitation. Although extensive research has been devoted to establishing novel treatment modalities, few have made significant and reliable improvements to stroke rehabilitation and recovery. Brain based interventions which target affected brain networks are likely to be highly effective. Transcranial direct current stimulation (TDCS), a form of non-invasive brain stimulation, has demonstrated some promise for improving upper limb function post stroke. TDCS can facilitate motor learning by increasing network excitability. This raises the possibility that combining TDCS with therapy may lead to functional recovery beyond that normally achieved by therapy alone. However inconsistencies of both physiological and behavioural responses to TDCS suggests a ‘one-size-fits-all’ treatment might not be optimal. The neural sequelae arising from stroke are highly heterogeneous with the extent of subsequent impairment dependent upon lesion location and disruption of brain networks. Therefore individual differences in residual integrity of the lesioned motor network may contribute, at least in part, to variable TDCS responses. Motor network connectivity may be a valuable predictor of those who will benefit from TDCS application in general, or alternatively, benefit for different stimulation approaches (e.g. facilitatory vs inhibitory TDCS or ipsilesional vs contralesional stimulation). Biomarkers predictive of TDCS response would be beneficial to improve clinical translation of this ‘state-of-the-art’ intervention capable of substantially transforming stroke therapy and improving recovery. We hypothesise connectivity of the lesioned motor network will be greater in stroke patients who demonstrate a strong response to TDCS combined with upper limb exercise therapy.