Wallenberg syndrome is a condition that affects the nervous system. Signs and symptoms may include swallowing difficulties, dizziness, hoarseness, nausea and vomiting, nystagmus, and problems with balance. Some people have uncontrollable hiccups, loss of pain and temperature sensation on one side of the face, and/or weakness or numbness on one side of the body. Wallenberg syndrome is often caused by a stroke in the brain stem. Treatment addresses each symptom and may include a feeding tube for swallowing problems, speech and/or swallowing therapy, and medication for pain. While some people's symptoms may improve within weeks or months, others may have long-term neurological problems.

• pain and temperature sensory loss on one side of the face as well as on the opposite side of the body
• rapid involuntary movements of the eyes (nystagmus)
• problems with balance and gait (walking) coordination
• vomiting
• vertigo
• nystagmus
• dysphagia
• hoarseness
• uncontrollable hiccups
• Horner syndrome (decreased pupil size, a drooping eyelid and decreased sweating on the affected side of the face) with visual deficits

The most common underlying cause of Wallenberg syndrome is a brain stem stroke in the vertebral or posterior inferior cerebellar arteries of the brain stem. However, several other disorders or conditions reportedly have been associated with Wallenberg syndrome, including:

• mechanical trauma to the vertebral artery in the neck
• vertebral arteritis (inflammation of the wall of the artery)
• metastatic cancer
• hematoma
• aneurysm of the vertebral artery
• herpetic brainstem encephalitis (relating to herpes)
• head injury
• arteriovenous malformations (AVMs)
• multiple sclerosis
• varicella infection
• brainstem tuberculoma (a rare form of tuberculosis)