Syringomyelia in the pediatric age

Abstract

Syringomyelia is the cystic cavitation of the spinal cord extending more than two spinal segments. Syringomyelia has a prevalence of 8.4 cases per 100,000 population, less frequent in children in comparison with adults. It can be associated with several pathologies, including Chiari I malformation (the commonest), tethered spinal cord due to spinal lipoma, diastematomyelia, thickened filum terminale or previous myelomeningocele repair, scoliosis, spinal cord tumors, syndromic craniosynostosis, posterior fossa cysts, spinal arachnoid cysts, post-infectious meningitis (tuberculous meningitis, infected dermoid cyst), rare malformations affecting the foramen magnum region (achondroplasia, osteogenesis imperfecta, mucopolysaccharidosis, platybasia), and spinal trauma. The latest theories on the formation and propagation of syringomyelia include the creation of increased subarachnoid pressure waves due to the pistonlike action of the prolapsed cerebellar tonsils and the theory of "altered timing of CSF pulse wave." Syringomyelia affects commonly the cervical and upper thoracic spinal cord but can occupy the entire spinal cord, holocord syringomyelia, or the medulla, syringobulbia. Symptoms and signs originate from cerebellum, lower cranial nerves, and/or long tracts dysfunction. Symptomatic Chiari I-related syringomyelia merits surgical treatment. Asymptomatic patients with Chiari I malformation should not be offered surgery. A tense cervical syringomyelia, even if asymptomatic, merits surgical treatment. The presence of scoliosis with a Cobb angle of 30 or more requires surgical treatment to stabilize the progress of scoliosis. Cranio-vertebral decompression for Chiari I malformation includes occipital craniectomy and removal of C1 arch. Controversy exists on whether to perform bony decompression only, split the dura, or open the dura and the arachnoid matter. Another controversy, if the dura is opened, is cisterna magna enlargement with graft duraplasty versus closure without duraplasty (pseudomeningocele). Recent variations include cranial augmentation of the posterior fossa and use of the endoscope to perform the craniectomy. Up to 80% of patients experience clinical and radiological improvement after cranio-vertebral decompression. The latest tendency in children with syringomyelia is toward less aggressive surgery, with increasing tendency toward extradural decompression. Careful clinical and radiological follow-up is needed.