Lateral medullary syndrome (also called Wallenberg's syndrome) is a disease in which the patient has difficulty with swallowing or speaking or both owing to one or more patches of dead tissue (known as an infarct) caused by interrupted blood supply to parts of the brain.
It is the clinical manifestation resulting from occlusion of the posterior inferior cerebellar artery or one of its branches or of the vertebral artery, in which the lateral part of the medulla oblongata infarcts, resulting in a typical pattern.
This syndrome is characterized by sensory deficits affecting the trunk and extremities on the opposite side of the infarct and sensory and motor deficits affecting the face and cranial nerves on the same side with the infarct. Other clinical symptoms and findings are ataxia, facial pain, vertigo, nystagmus, Horner's syndrome, diplopia and dysphagia. The cause of this syndrome is usually the occlusion of the posterior inferior cerebellar artery (PICA) at its origin.
The affected persons have difficulty in swallowing (dysphagia) resulting from involvement of the nucleus ambiguus, and slurred speech (dysphonia, dysarthria). Damage to the spinal trigeminal nucleus causes absence of pain on the ipsilateral side of the face, as well as an absent corneal reflex.
The spinothalamic tract is damaged, resulting in loss of pain and temperature sensation to the opposite side of the body. The damage to the cerebellum or the inferior cerebellar peduncle can cause ataxia.
Nystagmus and vertigo, which may result in falling, caused from involvement of the region of Deiter's nucleus and others vestibular nuclei.
Onset is usually acute with severe vertigo.
This syndrome was first described in 1808 by the Geneva physician Gaspard Viesseux, who rendered an exact description of his own disease at a meeting of the Société médicochirurgicale de Genève. First descriptions by Wallenberg were in 1895 (clinical) and 1901 (autopsy findings).
- National Institute of Neurological Disorders and Stroke (http://www.ninds.nih.gov/health_and_medical/disorders/wallenbergs.htm) page
- Department of Biomedical Engineering (http://www.bme.jhu.edu/labs/chb/disorders/wallenbe.html) at Johns Hopkins University
- An advertiser-supported online factsheet (http://www.wrongdiagnosis.com/w/wallenbergs_syndrome/basics.htm)