Reversible Central Sleep Apnea in Acute Necrotizing Encephalopathy of Childhood: A Case Report.

Acute necrotizing encephalopathy of childhood (ANEC) is a rare, rapidly progressive neuroinflammatory disorder typically triggered by viral infections and characterized by bilateral thalamic and brainstem involvement. While its neurological manifestations are well described, its impact on sleep-related respiratory control remains underrecognized. Brainstem dysfunction in ANEC may impair central ventilatory drive, resulting in central sleep apnea. We report a previously healthy five-year-old boy who presented with fever, headache, and prolonged generalized seizure, followed by decreased consciousness. Neuroimaging revealed extensive bilateral involvement of the thalami, brainstem, and cerebellum, consistent with ANEC. During recovery, he developed severe central sleep apnea, with polysomnography demonstrating an apnea-hypopnea index (AHI) of 102 events per hour, entirely central in nature. Non-invasive ventilation using bi-level positive airway pressure (BiPAP) led to complete resolution of respiratory events. Despite persistent neurological impairment, follow-up polysomnography after one year showed marked improvement, with only mild residual central events (central apnea index (CAI) 3.4 events/hour) and no clinically significant hypoventilation, allowing discontinuation of ventilatory support. This case highlights central sleep apnea as a potentially severe but reversible complication of ANEC, likely related to transient brainstem dysfunction. Early recognition and evaluation with polysomnography are essential, particularly in patients with brainstem involvement. Timely initiation of non-invasive ventilation may stabilize respiratory function and allow eventual weaning as central control improves. This report expands the clinical spectrum of ANEC and underscores the importance of respiratory monitoring in affected children.