Delayed central respiratory dysfunction after Wallenberg's syndrome--case report.

A 68-year-old man presented with Wallenberg's syndrome consisting of ataxia, dysphagia, hypesthesia on the left side of the body, and Horner's syndrome on the right. Magnetic resonance (MR) imaging revealed a right lateral medullary infarction and small multiple lacunae scattered in the upper medulla. Neurological symptoms improved in a week and the patient was discharged with mild residual hypesthesia on the left side. However, 31 days later, he was emergently admitted after suddenly becoming apneic and losing consciousness. MR imaging detected no new lesion. The patient was placed under ventilation support for 48 hours before regaining normal respiratory function. Medullary infarction sometimes causes catastrophic respiratory failure, but Wallenberg's syndrome caused by lateral medullary infarction is rarely associated with central respiratory dysfunction, and delayed onset of central respiratory dysfunction is extremely unusual. Delayed onset of central respiratory failure is a life-threatening complication of the medullary infarction causing Wallenberg's syndrome, which in general is not recognized.