MRI of pneumorachis in a newborn infant with open myelomeningocele.

Pneumorachis, or air within the spinal canal, is a very rare radiographic finding, frequently of traumatic origin. A newborn infant with an open lumbosacral myelomeningocele presented with severe paraparesis and an unexpected dysfunction of the brainstem with somnolence, irregular respiration, and motor deficits of the upper extremities. Magnetic resonance imaging revealed hypoplasia of the brainstem and cerebellum and low-signal lesions on T(2)-weighted images at the cervicocranial junction, in the lateral ventricles, and in the spinal canal. Computed tomography confirmed the presence of intracranial and intraspinal air. The air disappeared 2 weeks later according to magnetic resonance imaging, but no clinical improvement occurred, even after 6 months. Pneumorachis and pneumocephalus can occur in newborn infants as an unexpected complication of an open myelomenigocele, with or without signs. The radiographic appearance of intraspinal air on magnetic resonance imaging was not described previously.