Wallenberg syndrome

Acute infarct is seen involving the right lateral medulla.

The main supply to the lateral medullary area is from direct penetrating arteries of the distal VA, hence the VA system is the most common location of vascular lesion in patients with LMI. When the PICA or AICA is involved, patients usually have cerebellar symptoms due to cerebellar infarct.

Symptoms of lateral medullary syndrome consist of vertigo, headache, facial pain, dysequilibrium, nausea and vomiting, ataxia, hiccups, and contralateral burning pain.

Ataxia is the rule, not the exception. All patients with LMI have abnormal gait. Ataxia of gait is the most frequent symptom at onset, and it can be severe enough to prevent sitting or standing.