P 66 Transcranial DC stimulation enhances recovery of swallowing function after stroke – a randomized clinical and MEG trial

Abstract

Introduction Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation tool that has shown some potential to aid motor rehabilitation following stroke. In the present clinical and neuroimaging study we evaluated whether tDCS is able to speed up the recovery of swallowing function in acute dysphagic stroke patients. Besides relating clinical effects with neuroplastic changes in cortical swallowing processing we aimed to identify factors influencing treatment success. Material and methods In this single-center, double-blind, randomized study (NCT01970384), 60 acute dysphagic stroke patients received anodal tDCS (20 min, 1 mA) or sham stimulation over the contralesional swallowing motor cortex on four consecutive days. If the patient’s condition allowed it, swallowing exercises were performed during stimulation. Swallowing function was thoroughly assessed before and after the study intervention using the Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS), the dysphagia limit swallow test and two clinical scores, the Dysphagia Severity Rating Scale (DSR) and the Functional Oral Intake Scale (FOIS). In 15 patients, cortical swallowing-associated activation could be recorded during a volitional swallowing task applying 270-channel whole-head MEG before and after the treatment intervention. Results 59 patients completed the study. One patient suffered from recurrent stroke during the study period and was therefore excluded. Study groups did not differ according to demographic data or stroke characteristics. Time from admission to study intervention was 116 h in mean in both groups. Baseline FEDSS, FOIS, DSR and dysphagia limit were comparable. Following stimulation, patients from the treatment group showed significantly greater improvement in FEDSS (1.3 vs 0.4 points, p When looking for indicators of treatment success in the stimulation group only, there was a trend towards a greater improvement of all assessed swallowing scores with early treatment initiation (p Discussion According to our clinical and neurophysiological data, application of tDCS over the contralesional swallowing motor cortex supports cortical swallowing network reorganization, thereby leading to faster rehabilitation of acute post stroke dysphagia. The positive effect was independent of patient age and stroke characteristics, suggesting tDCS as a suitable treatment option for a broad patient population. Early treatment initiation within the suspected time window of maximum neuroplasticity after stroke seems to be beneficial.