None listed
Conditions
Brief summary
Stroke is the leading cause of adult disability worldwide. Inhibitory tone in the brain is altered by stroke and dictates how plasticity and recovery of function occur after stroke, but this varies from one individual to the next. Our objective is to identify factors that predict how best to apply noninvasive brain stimulation to modulate inhibitory tone and facilitate motor recovery in the initial days and weeks after stroke. To fuflill this objective advanced neuroimaging and neurophysiological assessments will be undertaken to establish links between inhibitory function, effects of brain stimulation on recovery, and patient outcomes. This project will increase the understanding of the molecular, cellular and neurophysiological mechanisms of recovery of motor function in human patients after stroke, and reduce inequalities in stroke outcomes for people who are more likely to suffer stroke earlier and live with disability longer.
Interventions
Participants will be recruited within 14 days of stroke. Assessments will be made at baseline, 6 weeks, 3 months, and 6 months after stroke. These assessments will measure motor function and intracortical GABA function within primary motor cortex, to observe the evolution of GABA function over the first 6 months after stroke. Motor function will be measured with clinical assessments of upper limb impairment (Fugl-Meyer scale) and function (Action Research Arm Test), at all 4 time points. Primary
Participants will be recruited within 14 days of stroke. Assessments will be made at baseline, 6 weeks, 3 months, and 6 months after stroke. These assessments will measure motor function and intracortical GABA function within primary motor cortex, to observe the evolution of GABA function over the first 6 months after stroke. Motor function will be measured with clinical assessments of upper limb impairment (Fugl-Meyer scale) and function (Action Research Arm Test), at all 4 time points. Primary motor cortex function will be assessed on both sides of the brain using single and paired pulse transcranial magnetic stimulation, to measure the excitability of the corticomotor pathway and intracortical GABAergic inhibitory networks. Transcranial direct current stimulation will be applied at baseline, 6 weeks and 3 months after stroke, to see whether the excitability of the corticomotor pathway and intracortical GABAergic inhibitory networks can be temporarily modulated at these time points. Patients will be randomised to receive either real or sham transcranial direct current stimulation, to control for potential non-specific effects. Each participant will receive the same TDCS protocol (either real or sham) at all three time points. Real transcranial direct current stimulation will be delivered for 20 minutes at an intensity of 1.5 milliamps. Sham stimulation will involve initially ramping up to 1.5 milliamps, then the stimulation will be switched off for the remainder of the 20 minutes. Both real and sham stimulation will be delivered via a pair of saline-soaked sponge electrodes, inside a 'MindCap' worn by the participant. The electrodes will be located over the primary motor cortices. This is not a clinical trial of transcranial direct current stimulation, as it is being used to probe motor cortical function at three time points, rather than to produce clinical benefits over multiple sessions. Motor cortex activation and GABA concentration will also be assessed using magnetic resonance imaging at baseline and 6 weeks after stroke. Participants will receive usual and standard rehabilitation care during the study, delivered by their clinical team. Therapy dose (therapist contact time) will be recorded for each participant.
Sponsors
The University of Auckland
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
First-ever mono-hemispheric ischaemic stroke within the previous 14 days. Upper limb symptoms requiring rehabilitation.
Exclusion criteria
Not requiring upper limb rehabilitation Contraindications to transcranial magnetic and direct current stimulation, including: epilepsy, history of seizures, cardiac pacemaker, metal implanted in the head or brain, pregnancy, medications that lower seizure threshold. Contraindications to magnetic resonance imaging, including: cardiac pacemaker, metallic fragments in the eyes, ferromagnetic metals in the head or body. Cognitive or communication impairment precluding informed consent or compliance with study assessments.
Outcome results
None listed