Loss of ability to sneeze in lateral medullary syndrome.

Four consecutive patients with lateral medullary syndrome reported reversible inability to complete a reflex sneeze, despite retaining the urge to do so and the ability to mimic the motor act. This previously undescribed feature of a relatively common syndrome is in keeping with the known location of a "sneeze center" in the lateral medulla of cat. In man, unilateral brainstem lesion is sufficient to abolish the sneeze reflex temporarily.