Originally described in patients with meningitis by Biot (in 1876) as an irregular respiration with pauses.
Nowadays, it is used to describe successive uniform periods of hyperpnea/hyperventilation and apneas -- i.e. uniformly deep gasps, apnea, then more deep gasps.
It is said to be different from Cheyne-Stokes respiration in that it lacks the regularity and pattern of increasing and decreasing rate of respiration.
Biot's breathing is caused by brain damage, increased intracranial pressure and drug-induced respiratory depression.