BRAINSTEM

Brainstem lesions produce apnea by disrupting multiple respiratory structures localized to the pons and medulla (Figure 25.1). Brainstem involvement occurs with posterior fossa tumors, developmental abnormalities, and microscopic or functional abnormalities. Brainstem lesions in neonates can produce any type of apnea (obstructive, central, or mixed) during any behavioral state except in idiopathic hypoventilation syndrome. Neonates with idiopathic hypoventilation syndrome have central apnea usually during quiet sleep. Neonates with apnea due to brainstem abnormalities often have cranial nerve dysfunction. The diagnosis of brainstem pathology in a neonate with apnea is based on clinical impression, polysomnogram interpretation, MRI and CT findings, and brainstem auditory and somatosensory evoked responses.

Figure 25.1— Possible respiratory structures involved in brainstem lesions between black lines. Pontine respiratory centers are not represented.