title: Development of a Scoring System to Evaluate the Severity of Craniocervical Spinal Cord Compression in Patients with Mucopolysaccharidosis IVA (Morquio A Syndrome).
abstract: BACKGROUND
  As spinal cord compression at the craniocervical junction (CCJ) is a life-threatening manifestation in patients with mucopolysaccharidosis (MPS) IVA, surgical decompression should be performed before damage becomes irreversible. We evaluated the diagnostic value of several examinations for determining the need for decompression surgery.
  
  
  METHODS
  We retrospectively analysed results of clinical neurological examination, somatosensory evoked potential (SEP) and magnetic resonance imaging (MRI) in 28 MPS IVA patients. A scoring system - based on the severity of findings - was used to compare results of patients with and without indication for decompression surgery. Individual test scores and two composite scores were evaluated for their potential to assess severity of CCJ impairment.
  
  
  RESULTS
  Sixteen patients had an indication for surgery; 12 of them had undergone surgery. Twelve patients had no indication for surgery; none had received surgery. Neurological (P = 0.004), MRI (P < 0.001) and atlantoaxial subluxation (P = 0.006) scores, but not SEP and odontoid hypoplasia scores, differed significantly between patients with and without surgical indication. Both the abbreviated CCJ score, i.e. sum of neurological and MRI scores, and the extended CCJ score, i.e. sum of abbreviated CCJ and atlantoaxial subluxation score, discriminated between patients with and without surgical indication (abbreviated: 0-2 points vs 2-5 points, P < 0.001; extended: 0-3 points vs 3-7 points; P < 0.001). Although CCJ instability plays a major role in cervical cord pathology, decompression surgery without occipito-cervical stabilisation may yield good postoperative results.
  
  
  CONCLUSIONS
  The abbreviated and extended CCJ scores are objective, transparent and reproducible tools for assessing the CCJ pathology and the need for surgery.
authors.affiliation: Department of Paediatric and Adolescent Medicine, Villa Metabolica, University Medical Centre of the Johannes Gutenberg-University Mainz, Langenbeckstr. 2, 55131, Mainz, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Möllmann
authors.forename: Christian G
authors.initials: CG
authors.lastname: Lampe
authors.forename: Wibke
authors.initials: W
authors.lastname: Müller-Forell
authors.forename: Maurizio
authors.initials: M
authors.lastname: Scarpa
authors.forename: Paul
authors.initials: P
authors.lastname: Harmatz
authors.forename: Manfred
authors.initials: M
authors.lastname: Schwarz
authors.forename: Michael
authors.initials: M
authors.lastname: Beck
authors.forename: Christina
authors.initials: C
authors.lastname: Lampe