Autonomic dysfunction in Wallenberg’s syndrome: pathophysiology and clinical significance

Abstract

Wallenberg’s syndrome (lateral medullary syndrome) is caused by infarction of the lateral medulla and is characterized by a constellation of distinctive neurological signs, including dissociated sensory loss, ataxia, vertigo, hoarseness, and Horner’s syndrome, which appear in various combinations. In contrast, the occurrence of diverse autonomic symptoms resulting from damage to the numerous autonomic regulatory centers within the medulla has not been fully recognized. These autonomic disturbances may affect cardiovascular, respiratory, thermoregulatory, gastrointestinal, and urinary functions. Bradycardia, cardiac arrest, and respiratory dysregulation are directly related to prognosis, whereas gastrointestinal and urinary dysfunction substantially impair quality of life. Asymmetry of body surface temperature is relatively easy to assess and can provide valuable clues for diagnosis and pathophysiological understanding. In this review, based on accumulated evidence as well as the authors’ clinical and research experience, we focus on central autonomic dysfunction in Wallenberg syndrome, organize its pathophysiology and clinical features, and discuss its significance for diagnosis and clinical management.