Arnold Chiari type 1 malformation presenting with sleep disordered breathing in well children.

Healthy children, aged 3, 9, and 13 years referred with sleep disordered breathing had marked central apnoea and bradypnoea on polysomnography, necessitating the use of non-invasive bilevel ventilation in two cases. Each had normal neurological examinations and an Arnold Chiari type 1 malformation was confirmed on magnetic resonance imaging. All underwent urgent posterior fossa decompression which normalised their sleep breathing.