This study evaluates the neuromodulatory effect of combined tDCS and aphasia therapy in patients in the chronic phase after stroke. Half of the participants will receive aphasia therapy and tDCS, the other half will receive aphasia therapy and sham-tDCS.
Aphasia is present in about one third of all stroke patients in the chronic phase. The first few months after stroke, considerable spontaneous recovery is initiated, including neuronal plasticity and reorganization processes. Language recovery in aphasic stroke patients involves reorganization of brain functions. Longitudinal fMRI studies reveal that the right hemisphere shows increased activity at different times in the recovery process, but in the long-term is correlated with poorer performance. Left re-lateralization, if possible, seems to be the most effective in restoring language function. For a large subgroup of patients, aphasia therapy is not sufficient to resolve language deficits and not all patients are capable to endure intensive aphasia therapy. Therefore, non-invasive techniques (NIBS) such as transcranial direct current stimulation (tDCS) are currently explored as an add-on treatment to improve or accelerate therapy outcomes. tDCS is a painless and safe stimulation tool that modulates cortical excitability through weak polarizing currents (1 mA - 2 mA) between two electrodes. These weak currents are thought to induce a subthreshold shift of resting membrane potentials towards depolarization or hyperpolarization. The effects of stimulation depend on the polarity of the applied current relative to the axonal orientation. It has been found that tDCS not only triggers immediate aftereffects, but also long-lasting effects that persist beyond the stimulation time, even for up to 12 months. It was suggested that long-term potentiation (LTP) and long-term depression (LTD) might be responsible for these long-term effects, however the precise physiologic mechanisms of action are not yet fully understood.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
25
C-tDCS during the first 20 minutes of aphasia therapy, at an intensity of 1mA or sham-tDCS at an intensity of 0mA
Based on linguistic tests, individualized aphasia therapy will be provided
University Hospital Ghent
Ghent, East-Flanders, Belgium
Change in naming performance assessed with the Boston Naming Test
Naming performance will be assessed with the Boston Naming Test at baseline, immediately following therapy, and after 3 +/- 1 month following treatment
Time frame: baseline, 3 weeks, 3 +/-1 month
Change in tolerability assessed with a Visual analogue scale
A Visual analogue scale will asses tolerability before and immediately after each session
Time frame: baseline, 2 hour (each session)
Change in spontaneous speech assessed with a Semi-standardized interview of the AAT
A Semi-standardized interview of the AAT will assess functional communication at baseline, immediately after therapy, and at 3 +/- 1 month follow-up
Time frame: baseline, 3 weeks, 3 +/- 1 month
Change in ERPs
Evoked potentials will be measured at baseline, immediately after treatment and after 3 +/- 1 month
Time frame: baseline, 3 weeks, 3 +/- 1 month
Change in quality of life assessed with the SAQOL-39-NL
The SAQOL-39-NL will assess the quality of life at baseline, immediately after treatment and at 3 +/-1 month follow-up
Time frame: baseline, 3 weeks, 3+/- 1 month
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.