The clinical characteristics, types, diagnosis, and management of breath-holding spells are reviewed from The Department of Pediatrics (Neurology), Park Nicollet Medical Center, Minneapolis, MN. There are two forms, pallid and cyanotic. Pallid breath-holding spells (BHS) result from vagal hyperresponsiveness, following a sudden, unexpected, unpleasant stimulus, usually a mild head injury. Cardiac monitoring reveals prolonged asystoles, which can also be induced by ocular compression, and is accompanied by syncope or an anoxic seizure. Vagal cardiac inhibition with cerebral anoxia is the pathophysiology of pallid BHS. Cyanotic breath-holding spells result from a complex interplay of hyperventilation followed by apnea in expiration, and increased intrathoracic pressure. Whereas pallid BHS occur after injury, cyanotic BHS are precipitated by anger. Diagnosis may be confirmed by EEG with ocular compression and cardiac monitoring. A pallid spell is associated with cardiac asystole and EEG hypersynchronous slowing. Cyanotic spells have similar EEG changes without bradycardia or asystole. Prolonged QT syndrome is a rare but serious cause of anoxic seizure, induced by exercise, injury, or fright. Cerebral hypoxia may result from ventricular tachycardia. More protracted loss of consciousness with hypotension may indicate a cardiac pathology. A more protracted seizure following a BHS may represent an anoxic-epilepsy, requiring anticonvulsant therapy. Spontaneous remission of BHSs is to be expected, but parents require frequent reassurance about the benign nature of the spells. 
COMMENT. Although anticonvulsant therapy is sometimes advisable when the convulsive episode is prolonged and represents an anoxic-epilepsy, traditional therapy will not generally prevent the breath-holding spell. Perhaps some of the newer antiepileptic medications should be tried in children with numerous attacks. The therapeutic nihilistic approach to BHS practiced by many physicians is often difficult for a parent to accept. An iron deficiency anemia may be an underlying causative factor in about 20% of cases of breath-holding . Neurologic deficits with iron deficiency anemia are discussed in Progress in Pediatric Neurology 1991, PNB Publ, pp397-8.
Apnea and bradycardia during epileptic seizures were studied at the Telemetry Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London . Apnea occurred in 20 of 47 clinical seizures and 10 of 17 patients. It was generally central, but obstructive apnea occurred in 3. Oxyhemoglobin saturation dropped to <85%, and tachycardia was common. Bradycardia/sinus arrest was documented with a change in respiration in 4. Similar mechanisms involving cardiorespiratory reflexes are suggested in relation to cases of sudden death in epilepsy.