Lateral Medullary Stroke (LMS)

James Coyle writes:

a lateral medullary stroke (LMS). These strokes damage the important brainstem nuclei that mediate sensory and motor functions in the pharynx as the interconnections between them and other centers. Immediately prior to pharyngeal stage onset the UES resting pressure is seen to drop a little, due to inhibition of the vagal motor outflow to the sphincter. This tight, resting pressure keeps the UES tightly closed all of the time except when we swallow. In LMS the patient may have no inhibition of UES resting pressure, hence the h yolaryngeal musculature cannot overcome the intertia of the tight UES.


One clue is the side to which bolus flow is preferential. You said right. If this is true then the right pyriform sinus is more compliant than the left. Provided that you have trained him in airway protection maneuvers, head rotation might be worth assessing. I would expect that rotation away from the compliant side would facilitate flow to the more compliant side, but you cannot always predict this outcome based on lesion site knowledge because if an upper motor neuron lesion has produced denervation of the hypopharynx you will have a spastic paresis and less compliance, while a flaccid paralysis caused by a lower motor neuron (nucleus or nerve root) lesion will make the sinus more compliant. You will need to evaluate it provided it is safe to do so based on airway protection ability.

...Nearly 90-95% of the dysphagia seen in most patients with LMS resolves to a functional swallow or one that can be compensated with intervention.



James L. Coyle

University of Pittsburgh