Central hypoventilation syndrome (CHS) is a disorder characterized by little or no ventilatory or arousal sensitivity to hypercapnia and variable reactivity to hypoxemia, with little or no hypoxic arousal responsiveness. CHS may be congenital or acquired and can be idiopathic or secondary to a known central nervous system abnormality. Infants often present with life-threatening apnea during quiet sleep and develop severe respiratory acidosis because of the inadequate response to hypercapnia and hypoxia. Long-term treatment usually involves use of mechanical ventilation during sleep.

Cardiac size is only one parameter in the evaluation of the cardiovascular system on the neonatal chest x-ray examination. More specific information will be given in future columns when specific cardiac defects are discussed. It was our intention to present a few basic principles of x-ray interpretation before proceeding to the radiologic evaluation of specific disease states. In the next few columns we will discuss x-ray findings in infants with respiratory diseases. Hyaline membrane disease will be discussed in the next issue.

Seizures in the newborn are different from those occurring in older children and adults. Health care professionals may find it difficult to recognize neonatal seizures because of their sometimes subtle manifestations. Convulsive behavior has many etiologies; some are associated with a favorable and some with a poor prognosis. Treatment protocol is controversial because both the seizures themselves and the drugs used to treat them may damage the immature brain. The high mortality and morbidity rates of infants who experience seizures make it imperative that the neonatal seizure be recognized, its etiology diagnosed, and treatment begun promptly.