Neural Mechanisms of Swallowing Dysfunction and Apraxia of Speech in Acute Stroke.

This was a pilot secondary analysis of 68 patients, so the sample is too small to support firm clinical conclusions. Patients had to be able to follow directions and complete apraxia testing within 48 hours, so people with larger or more severe strokes were not included. Only left hemisphere strokes were studied, although swallowing can be affected by left, right, or bilateral stroke. Aspiration risk was based on a bedside pass/fail screen, not videofluoroscopy or endoscopy, and the screen has reported sensitivity 96.4% and specificity 46.4%, so false positives are possible. There were only 7 patients with anterior insula lesions and 18 with posterior insula lesions, which may explain the lack of association with insular damage. The analysis used broad brain regions, and the paper notes that different subregions or white matter connections may matter. The paper reports associations, not treatment effects, so it does not show that treating one deficit improves the other.

The authors declared no conflict of interest. The paper is listed as supported by NIH extramural research.

Do not conclude that a Broca area lesion causes both apraxia of speech and swallowing dysfunction, or that treating one deficit will improve the other. The study found associations, not treatment effects, and in patients with Broca area lesions the two deficits rarely occurred together. The swallowing outcome was also a screening result, not an instrumental confirmation.