• Clinical science

Wallenberg syndrome


Wallenberg syndrome is a neurological condition caused by a lateral medullary infarction, which results from occlusion of either the posterior inferior cerebellar artery (PICA) or the vertebral artery. For this reason, it is also referred to as lateral medulla syndrome or PICA syndrome. Symptoms include ipsilateral Horner syndrome, palate weakness, hemiataxia, and contralateral sensory disturbances. Management is supportive, and may include swallowing and speech therapy, as well as a feeding tube in some cases.


Clinical features

Clinical features Structure affected
  • Dysphagia
  • ↓ Gag reflex
  • Hoarseness, dysphonia
Nucleus ambiguus (motor neuron)
Inferior cerebellar peduncle

Sympathetic fibers

  • Vertigo (with falling towards the same side of the lesion) → vomiting
  • Nystagmus that changes direction with gaze change diplopia

Vestibular nuclei

  • Loss of pain and temperature in the face
Trigeminal nucleus and tract (sensory)
  • Loss of pain and temperature in the trunk and limbs
Lateral spinothalamic tract (sensory)