Title: Evaluating brain stimulation for dysphagia after stroke
Funder: Department of Health (England)

Abstract: At present, due to the lack of evidence-based practice for dysphagia rehabilitation [11], swallowing difficulty is not managed appropriately and dysphagic patients rely on alternative forms of feeding and stay in hospitals longer compared to non-dysphagic patients, with consequent increase in NHS costs. Recently, a number of rehabilitation-based therapeutic interventions have been proposed that target the brain and restore swallowing function after stroke [2]. Our group has pioneered research of the central nervous system (CNS) mechanisms for swallowing and dysphagia rehabilitation and one of the techniques developed and studied thoroughly, Pharyngeal Electrical Stimulation (PES), has provided a framework for conducting studies in order to deliver evidence [3]. However, PES is an exciting and potentially promising approach to treating dysphagia, there are some patients that cannot be easily treated with this neurostimulation technique (around 30%), since they may not tolerate the invasive tube insertion every day for three days or have damaged sensory brain function. On these grounds, our group has been actively conducting studies to provide the preliminary evidence for the use of another rehabilitation technique, called Transcranial Direct Current Stimulation (tDCS). TDCS uses a weak constant current on the scalp to induce sustained changes in the brain [12, 13] and has been utilised for intervention to various conditions, including stroke, with encouraging results [14]. Likewise, as with all neurostimulation techniques, repetition and timing of delivering of this stimulation is critical [15]. Preliminary work on the parameters for the application of this technique has been conducted by our group in healthy volunteers [4] and in our stroke ‘virtual’ lesion model [5]. In addition, tDCS has been applied to a number of dysphagic stroke patients in North America [9] and Korea [10], in protocols with many methodologies insufficiencies. The evidence from US study suffered from a) the small group of patients studied, b) the fact that previous knowledge on the parameters was not used and c) the outcome measures used do not provide the information for the quick adaptation of the technique in the rehabilitation of dysphagic stroke patients. Here we propose a phase II randomised trial (n=69), based on our pilot work and knowledge of the precise parameters necessary for therapeutic effect in swallowing rehabilitation of dysphagic stroke patients in the acute and subacute stages of recovery. Patients will be recruited from 2 main University Hospitals and interventions will be performed at bedside or in the laboratories at Salford Royal Hospital (for discharged patients). A series of screening and swallowing assessments (including real time barium X-ray, videofluoroscopy) will be performed before and after the randomisation of patients to one of the three arms: real tDCS followed by sham (pretend) or real tDCS followed by real tDCS, or sham tDCS followed by sham tDCS. All treatments will be delivered every day for 5 days with a 4 hour gap within the treatments. Changes in patients’ swallowing safety and swallowing physiology will be followed-up 1, 2 weeks and 3 months post intervention, to assess medium term outcome. The proposal and outcome measurements for this application were decided after 2 separate PPI meetings with patients with swallowing problems and former participants in rehabilitation studies by our group. It was agreed that the PPI members will form an external advisory panel for the research study for independent advice throughout the course of the study. We anticipate our proposed protocol will provide the evidence for utilising this new approach for dysphagia rehabilitation. The expectation is that this portable user-friendly non-invasive stimulation will be rapidly rolled out into larger clinical trials and will lead into changes in practice at a national level in the NHS.


Research activity codes: 6.4 SURGERY
Health categories: STROKE