Postural feedback combined with Non-invasive transcranial direct current stimulation in patients with stroke, a randomized controlled clinical trial.

Postural instability, balance problems and subsequent falls are very common in
patients with a stroke and strongly associated with future functional recovery.
The early period after stroke is characterized by a critical time window of
neuroplasticity. Postural feedback training (PFT) is a common rehabilitative
therapy to improve standing balance control in patients with stroke, and is
equally effective to improve balance control as usual care. Studies suggest
that a positive, reproducible effect on motor learning may be achieved by
simultaneous non-invasive transcranial direct current stimulation (tDCS) and
motor training. A combination of early applied tDCS and PFT by modern virtual
reality techniques (VR-PFT) may therefore improve balance in patients with
stroke to a level unattained by VR-PFT alone. To date, non-invasive brain
stimulation has not been applied in combination with modern balance training
techniques in stroke.

POTENTIAL will be the first phase II RCT to assess the effects of combined
cerebellar tDCS and VR-PFT in terms of outcomes at the level of body functions,
activities and participation, as well as brain reorganization post stroke.
Ultimately, findings will be important for improving rehabilitation services
post stroke, allowing clinicians to apply new motor learning therapies more
effectively in the future.

double-blind controlled intervention study.

A three week VR-PFT intervention applied five days per week for one hour will
be started within five weeks post-stroke, in addition to usual care. This
intensive training will be given in order to test if VR-PFT in combination with
cerebellar tDCS is more effective in improving standing balance than VR-PFT
alone. Patients train in groups and go along workstations consisting of a
virtual reality setup in which instantaneous visual feedback is given regarding
centre of gravity or trunk movements during several balance tasks. These tasks
requiring active control of body posture and equilibrium in a virtual
environment. The training program is individually tailored and progressive with
systematic increments in task difficulty. tDCS will be simultaneously applied
with the training during the first 25 minutes of each session using a
pre-programmed stimulation paradigm. Sham-tDCS starts with a ramped stimulation
of 30s followed by 0 mA current without the subject knowing this.
Measurements: Clinical, posturographic and neurophysiological measurements will
take place at baseline and three, five and twelve weeks after the start of the
intervention. Measurements including preparation will take about 1,5 hour.

Patients will receive group therapy sessions of one hour, five times a week for
three weeks at the rehabilitation site where they reside or receive outpatient
therapy. Usual care will continue during the intervention. Measurements
including preparation will take approximately 1,5 hour and take place at the
same rehabilitation facility. The measurements will be carried out four times:
at baseline, three, five and twelve weeks after the start of the intervention.
Risks associated with the treatment are negligible or reduced with the
exclusion criteria. Improvement of functional balance performance is expected
for both groups but to a greater extent in the intervention group.