These recurrent conditions, which have a sudden onset and no epileptiform focus, resolve spontaneously. The two types of BHS are cyanotic and pallid. The cyanotic type is more common. Affected children experience several spells per week. Cyanotic episodes are most often provoked by an upsetting event, anger, frustration, or scolding rather than by injury or fear.
Children usually cry or scream loudly.
The cries become noiseless as children open their mouths and hold their breath in expiration. After approximately 30 seconds of apnea, a color change is apparent as children become cyanotic. The spell may terminate at this point, or children may proceed to lose consciousness and become limp. Some physicians refer to attacks that terminate prior to the loss of consciousness as simple BHS, whereas others do not classify such episodes as BHS at all. Rarely, loss of consciousness may be followed by a few seconds of rhythmic clonic jerking of the extremities, mimicking seizure-like activity, or rigid opisthotonic posturing of the body.