Abstract
A lateral medullary infarction is the most common type of a brainstem stroke, and it presents completely differently than typical cortical cerebral vascular accidents. There is a need to raise public awareness of this type of stroke, as the cluster of symptoms in lateral medullary syndrome includes nausea and vomiting, which the person may mistake for a gastrointestinal infection or flu. The effects of this infarction need not be devastating. With early identification and treatment, including early swallowing evaluations, the medical team can prevent aspiration pneumonia, intubation, and death from pneumonia.
The goals of the paper are to: (a) provide a review of the literature of LMS, (b) discuss the symptoms and challenges of differential diagnosis, (c) analyze the dysphagia research in LMS, especially how it relates to the central pattern generators (CPG) for swallowing, (d) discuss the pharyngeal, laryngeal, and esophageal aspects of the dysphagia in LMS; and (e) review recovery, prognosis, and treatment options. Finally, the author presents two cases that illustrate key points, such as the younger age of onset of LMS in comparison with most stroke populations, symptomatology, early identification, the need for instrumental evaluations of swallowing, therapy techniques, and outcomes. LMS patients tend to show rapid and steady recovery of their swallowing function. The subjects of the two case studies at the end of this paper made significant progress in swallowing (even based on a comparison between the evaluations at two days after the stroke and at just six days later).
Introduction
Lateral medullary syndrome is caused by a stroke in the lateral medulla and is also known as Wallenberg syndrome. This is the most common and classic brain stem vascular syndrome, involving the territory of the vertebral arteries (VA) and/or the posterior inferior cerebellar artery (PICA), usually affecting the dominant branch (Groher, 1992; Sacco et al., 1993). Wallenberg syndrome was initially reported by Gaspard Vieusseux, MD of Geneva in 1810 at the Medical and Chirurgical Society of London. He described his own affliction as “vertigo, unilateral facial numbness, loss of pain and temperature appreciation in the opposite limbs, dysphagia and hoarseness, minor tongue involvement, hiccups (cured by the taking of the habit of a morning cigarette) and a dropped eyelid” (Pearce, 2000, p. 570). Marcet (1811) published ahighly detailed case study of Gaspard Vieusseux, in which he speculated that the peculiar sensations in Vieusseux’s head and the derangement of equilibrium arose from a nervous state, rather than an “organic affection of the brain” (p. 233). However, Alex Marcet, MD perfectly related the sudden onset of LMS with vomiting, followed by a complete loss of voice (without affecting articulation), considerable difficulty in swallowing liquids, weakness of his left side, insensible right side to being scratched or pricked, and finally hiccups by the third day. Vieusseux also noted that an “etherized julep” (a cold cocktail) felt lukewarm when taken in the right hand but cold when held in the left hand (p. 221). Other than cures by cigarettes or sensory testing with cold cocktails, Vieusseux and Marcet hit upon the main cluster of symptoms that are consistent with the research of today. However, it was not until Adolf Wallenberg from 1895 through 1922 provided case reports and anatomical evidence of lesions in the lateral medulla that this syndrome got its name (Pearce, 2000).
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