Walsh & Hoyt: Wallenberg's Syndrome (Lateral Medullary Infarction)

Lesions of the vestibular nuclei commonly affect neighboring structures, in particular the cerebellar peduncles and perihypoglossal nuclei. The best-recognized syndrome involving the vestibular nuclei is caused by a lateral medullary infarction (Wallenbergs syndrome). The typical findings of Wallenbergs syndrome are impairment of sensation of pain and temperature over the ipsilateral face, ipsilateral Horners syndrome and limb ataxia, and dysarthria and dysphagia. Sensation of pain and temperature are impaired over the contralateral trunk and limbs. The ipsilateral facial nerve may also be affected if the infarct extends more rostrally. Wallenbergs syndrome is most commonly caused by occlusion of the ipsilateral vertebral artery; occasionally, the posterior inferior cerebellar artery is selectively involved. Dissection of the vertebral artery (either spontaneous or traumatic, such as following chiropractic manipulation) may cause Wallenbergs syndrome. Rarely, demyelinating disease is the cause.