Sleep-related periodic breathing in acquired sleep apnea
The present case has been published in the journal Neurology.

A 68-year-old man complained of the subtle onset of postural instability. A detailed investigation revealed the presence of ataxia with pulling to the right, right face and contralateral (left) trunk and limb hypoesthesia, slight dysphagia, right eyelid ptosis, and enophthalmos (figure, A) caused by medullary infarct (figure, B) (Wallenberg syndrome).

Due to snoring, the patient underwent polysomnography, which showed central sleep apnea with Biot breathing ataxia (figure, C). Biot periodic breathing is an irregular, gasping respiration caused by respiratory pacemaker lesions, observed in comatose patients with bulbar damage.

Here, Biot breathing presented in the context of central sleep apnea. Medullary breathing control circuit lesions impair autonomic respiration, which is critical for nighttime respiration.