title: Idiopathic syrinx in the pediatric population: a combined center experience.
abstract: OBJECTIVE
  Discovery of a syrinx in a child, without a readily identifiable proximate cause such as a Chiari malformation, tumor, or site of tethering, is often a cause of concern for families and a source of consternation for clinicians. There is a paucity of data describing the natural history of an idiopathic syrinx in the pediatric population. The authors present the combined data of 2 major pediatric neurosurgical centers to describe their experience with this condition.
  
  
  METHODS
  Data were collected at Children's Hospital Boston and St. Louis Children's Hospital according to institutional review board-approved protocols and captured visits over a 2.5-year interval (October 2006-March 2009), with records reviewed if the patient had a preexisting diagnosis of syrinx. Patients were identified by ICD-9 codes derived from departmental databases. All pediatric patients (age < 19 years) in whom idiopathic syrinx had been diagnosed, as defined by MR imaging findings (dilated central canal in the spinal cord of ≥ 1 mm in axial dimension and extending over at least 2 vertebral levels), were included.
  
  
  RESULTS
  Forty-eight patients met the criteria for idiopathic syrinx during this period, and in 32 of them detailed follow-up imaging was available. Discovery of a syrinx was incidental in 6 patients, whereas the others were referred for imaging because of the presence of pain, neurological symptoms, scoliosis, or skin markings. The average age at the first MR imaging session was 9.7 years, with a mean syrinx size of 4 mm (range 1.2-9.4 mm). The majority (52%) of patients had a thoracic syrinx, with the average lesion spanning 7.1 vertebral levels. The average follow-up was 23.8 months (range 2-64 months), and subgroups of patients with < 3 years and ≥ 3 years of follow-up were independently reviewed. Overall, symptoms improved in 34% and worsened in 9%; 57% of the patients remained asymptomatic or stable. Radiographically (in the subgroup of 32 patients with detailed follow-up imaging), syrinx size decreased in 25% of patients, increased in 12.5%, and remained unchanged in 62.5%, with no apparent correlation between change in syrinx size and clinical symptoms.
  
  
  CONCLUSIONS
  Clinically, children with an idiopathic syrinx remained asymptomatic, stable, or improved in 91% of cases. The majority of syringes (87.5%) remained stable or shrank over time, with no apparent correlation between changes in size and changes in symptoms. Although longer follow-up is needed, these data suggest that the natural history of an idiopathic syrinx in children is benign, and that repeated imaging may not be necessary.
authors.affiliation: Department of Neurosurgery, Children's Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Suresh N
authors.initials: SN
authors.lastname: Magge
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Smyth
authors.forename: Lance S
authors.initials: LS
authors.lastname: Governale
authors.forename: Liliana
authors.initials: L
authors.lastname: Goumnerova
authors.forename: Joseph
authors.initials: J
authors.lastname: Madsen
authors.forename: Becca
authors.initials: B
authors.lastname: Munro
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Nalbach
authors.forename: Mark R
authors.initials: MR
authors.lastname: Proctor
authors.forename: R Michael
authors.initials: RM
authors.lastname: Scott
authors.forename: Edward R
authors.initials: ER
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D010348:Patient Care Team; D012189:Retrospective Studies; D012600:Scoliosis / Q000209:etiology; D013120:Spinal Cord Neoplasms / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D013595:Syringomyelia / Q000150:complications / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult