Sporadic apnea: paradoxical transformation to eupnea by perturbations that inhibit inspiration.

We speculate that sporadic apneas may be initiated and terminated by stochastic neural perturbations arising within or impinging upon the respiratory oscillator. A curious situation can then arise in which tiny perturbations that inhibit inspiration, paradoxically stimulate breathing. The plausibility of the hypothesis is supported by numerical analysis of a noisy attractor-cycle oscillator, and in studies of a preterm sleeping infant with sporadic apnea; low-level vibratory stimulation transformed the irregular apneic rhythm to eupnea.