Ataxic respiration is an abnormal pattern of breathing characterized by complete irregularity of breathing, with irregular pauses and increasing periods of apnea

Apnea

Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...

. As the breathing pattern deteriorates, it merges with agonal respirations.

It is caused by damage to the medulla oblongata

Medulla oblongata

The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...

 due to strokes or trauma. It generally indicates a poor prognosis, and usually progresses to complete apnea

Apnea

Apnea, apnoea, or apnœa is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged...

.

The term is sometimes used interchangeably with Biot's Respirations, but technically, Biot's respirations refers to groups of similar-sized breaths alternating with regular periods of apnea.