New therapies have been developed to help the brain recover after stroke, yet we do not have biological markers of identifying individuals who may benefit from these therapies nor how to select the most optimal therapy. We propose a model of sensory recovery which identifies potential changes in brain regions and connections involved in somatosensory processing following lesions of somatosensory brain regions and pathways.
The CoNNECT study aims to investigate changes in brain activity that may be associated with the recovery of people’s ability to “feel things” following a stroke. This includes to:
- Identify and compare changes in functional connections in brain networks associated with sensory rehabilitation in stroke patients with somatosensory lesions in cortical or subcortical brain regions
- Predict ability to benefit from sensory rehabilitation based on structural connections of interhemispheric and thalamo-cortical tracts between key somatosensory regions
- Develop a data driven model of somatosensory recovery following cortical and subcortical lesions, based on evidence of functional and structural connections in the brain
Stroke patients (at least 3 months post-stroke) are randomized into one of three treatment packages. Patients are assessed at baseline, following 6 weeks of training or no training (post 1), then again following 6 weeks of training or no training (post 2), then finally at a 3 month follow-up session. Age-matched healthy controls are tested at 2-time points, 6 weeks apart, to provide a comparison. Assessments include demographic information, clinical assessments of recovery, sensation, motor, cognition, and mood, and advanced imaging allowing for analysis of functional resting-state connectivity, structural connectivity, task-related activation (involving a sensory paradigm) and anatomy. An example of changes in the brain is provided in the figure below.
Figure: Changes in brain activation and resting state connectivity may be observed following SENSe discrimination training, as shown in the figure below. Before training, brain activation was observed in the hemisphere opposite to that expected during touch stimulation to the affected hand. At this time the stroke survivor reported a 1/10 ability to feel the stimulus. After training, activation was observed in sensory regions within the lesioned hemisphere, as expected in healthy controls. This was associated with a reported ability to feel the stimulus of 9/10. A relative increase in resting state connectivity between primary somatosensory regions across hemispheres was also observed at the 6-month follow up. Most importantly these changes were associated with improvement in touch discrimination, limb position sense and tactile object recognition, as well as clinically significant improvement in performance and satisfaction ratings for occupational tasks identified by the client, such as using a fork.
Project Team include: Prof Leeanne Carey, Prof Alan Connelly, Prof Rudiger Seitz, Prof Chris Levi, Prof Thomas Matyas, Dr Mark Parsons, Dr Rishma Vidyasagar, Dr Jacques-Donald Tournier, Dr Peter Goodin, Gemma Lamp, Dr Megan Turville, Yvonne Mak-Yuen, Brendon Haslam, Caroline Bailey, Emily Ramage, Audrey Raffelt, and Christine Marsh.