Mark R. Etherton, MD, PhD
Occurring in up to 50% of patients, post stroke dysphagia represents a common byproduct of stroke. The long term clinical and rehabilitation consequences of post stroke dysphagia are widespread as dysphagia increases the risk of aspiration and subsequent pneumonia, and malnutrition. At present, there is no definitive treatment for dysphagia aside from behavioral techniques like modified diet consistencies or surgical intervention with gastrotomy tubes.
Pharyngeal electrical stimulation (PES), is a developing technique that has shown promise in small phase II trials for the treatment of post stroke dysphagia. A meta-analysis of three trials showed that PES reduced aspiration and dysphagia while also being safe. Based on these findings, the authors in this study performed a large, randomized-controlled phase III trial of PES in patients with subacute poststroke dysphagia.
One hundred sixty-two patients with recent ischemic or hemorrhagic stroke and evidence of dysphagia, as defined by a penetration aspiration score (PAS) of 3 or greater on video fluoroscopy, were randomized to PES versus sham treatment daily for 3 days. Primary outcome measure was radiological aspiration as measured by PAS at 2 weeks. Secondary outcomes included PAS at 12 weeks, functional outcomes (mRS, BI, and NIHSS at 12 weeks) and clinical dysphagia scores.
With PES treatment, there was no difference in the PAS at 2 weeks (sham 3.6 +/- 1.9; PES 3.7 +/- 2.1; p=0.6) or 12 weeks (sham 3.0 +/- 2.1; PES 3.3 +/- 2.2; p=0.41). The authors also found no effect with PES on the secondary outcomes involving clinical dysphagia and functional outcomes. PES was well tolerated, as there was no difference in adverse or device-related events.
In summary, while PES was safe, it did not improve dysphagia in this randomized controlled trial of patients with post stroke dysphagia. Important consideration for this study and its interpretations, however, include high intraindividual variability in PAS and the authors’ note that up to 58% of patients may have received subtherapeutic stimulation. Based on these findings in conjunction with the positive prior meta-analysis, it would seem that further studies with different outcome measures are warranted.