Wallenberg syndrome

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Wallenberg syndrome (synonyms: lateral medullary syndrome, dorsolateral medullary syndrome, posteroinferior cerebellar artery syndrome) is a symptom complex that includes alternating sensitivity disorders, dysphagia, dysarthria, ataxia, vertigo and Horner syndrome, and is usually attributed to cerebellar artery occlusion, however, recent data suggest occlusion of the vertebral artery as the leading cause of Wallenberg syndrome. The anatomical region responsible for producing Wallenberg syndrome is the portion of the spinal bulb located posterior to the lower olive nucleus.

Wallenberg syndrome was first described clinically and morphopathologically in 1895 by Adolf Wallenberg, a German neurologist. However, the components of this syndrome were described as early as 1808 by Gaspard Vieusseux. The complete description of the syndrome was made by Fisher and colleagues in 1961.

Signs and symptoms

Complete Wallenberg syndrome, as described by Fisher, includes:

  • damage to the vestibular nuclei - vertigo, nystagmus, oscillopsia, vomiting;
  • spinothalamic tracts - disorder of pain and thermal sensitivity in the contralateral or, less frequently, ipsilateral hemibody;
  • descending sympathetic tracts - ipsilateral Horner syndrome;
  • emerging fibers of cranial nerves IX and X (glossopharyngeal and vague) - dysphonia, dysphagia, ipsilateral paresis of the soft palate and vocal cords, diminished pharyngeal reflex;
  • otolytic nucleus - vertical diplopia and the illusion of tilting images;
  • olivocerebellar and / or spinocerebellar fibers, restiform body and lower cerebellum - ipsilateral ataxia of the limbs, fall or deviation towards the ipsilateral part or lateropulsion;
  • descending tracts and cranial nerve nucleus V (trigeminal) - pain, burning sensation and sensitivity disorder on the ipsilateral hemifata;
  • nucleus and solitary tract - loss of taste sensitivity;
  • and rarely the nucleus cuneate and gracil - paresthesias in the ipsilateral limbs;

Most often, however, there are incomplete, fragmentary syndromes, which can associate vertigo and ptosis, lateropulsion and vertical diplopia, dysphonia and balance disorders, etc.

The most common symptoms of onset in Wallenberg syndrome are diplopia, dizziness, facial pain and gait disorders.

Causes

Complete Wallenberg syndrome, one of the most prominent syndromes in neurology, is practically in most cases due to an ischemic stroke, with only a few cases being the result of hemorrhage or tumor. Although Wallenberg syndrome has traditionally been attributed to occlusion of the inferior posterior cerebellar artery, careful studies have shown that in 8 out of 10 cases the vertebral artery is the one that is occluded; in all other cases, either the inferior posterior cerebellar artery or one of the lateral medullary arteries is affected. Embolism is a much rarer cause.

Treatment

Treatment for Wallenberg syndrome is generally symptomatic. Facial pain will sometimes respond to entiepileptics such as gabapentin. Swallowing disorders if pronounced will require the installation of a nasogastric tube. Patients with Wallenberg syndrome need intensive speech therapy to maintain and recover vocal and swallowing function. An extremely important problem in these patients may be hiccups, which can sometimes be so pronounced that the patient has difficulty feeding, sleeping or communicating. Unfortunately, there are few remedies that would be helpful in relieving hiccups in these cases.

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