title: A radiological study on intra- and extra-cranial calcifications in adults with X-linked hypophosphatemia and associations with other mineralizing enthesopathies and childhood medical treatment.
abstract: OBJECTIVE
  1) The objective of this study was to explore radiological signs of intracranial and nuchal ligament calcifications in adult patients with X-linked hypophosphatemia (XLH) compared with controls and 2) to correlate signs of cranial calcifications in XLH patients with the presence of other extra-cranial enthesopathies, with the severity of skeletal XLH impact and with medical treatment during childhood.
  
  
  METHODS
  Lateral and postero-anterior cephalograms from 36 adult XLH patients and 49 adult controls and X-rays from spine, pelvis, knees and ankles from 31 of the 36 XLH patients.
  
  
  METHODS
  Radiological signs of intracranial and nuchal ligament calcifications in XLH patients were compared with controls by Fischer's exact test. In XLH patients, the presence of cranial calcifications was correlated with the presence of other enthesopathies, with the severity of skeletal XLH impact and with medical treatment by Fischer's exact or chi-squared test.
  
  
  RESULTS
  Six (17%) XLH patients revealed major signs of intracranial calcifications. Nuchal ligament calcifications were common in XLH patients compared with controls (p = 0.018). Enthesopathy was present at 0-24 sites per XLH patient (median 2). Intracranial calcifications trended to correlate positively with vertebral enthesopathies (p = 0.059). Nuchal calcifications correlated positively with the severity of skeletal XLH impact (p = 0.040). Vertebral enthesopathies correlated negatively with medical treatment (p = 0.008).
  
  
  CONCLUSIONS
  More XLH patients than controls showed nuchal ligament calcifications, and some XLH patients showed intracranial calcifications. Severely affected XLH patients often had nuchal ligament calcifications. Medically treated XLH patients had few vertebral enthesopathies.
authors.affiliation: Section of Oral Health in Rare Diseases, Department of Maxillofacial Surgery, Aarhus University Hospital, Aarhus, Denmark.|Section for Paediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Gjørup
authors.affiliation: Department of Orthodontics, Institute of Odontology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: I
authors.initials: I
authors.lastname: Kjaer
authors.affiliation: H.C. Andersen Children's Hospital, Odense University Hospital, Odense, Denmark.|Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors.forename: S S
authors.initials: SS
authors.lastname: Beck-Nielsen
authors.affiliation: Department of Diagnostic Radiology, Odense University Hospital, Odense, Denmark.
authors.forename: M R
authors.initials: MR
authors.lastname: Poulsen
authors.affiliation: Section for Paediatric Dentistry, Department of Dentistry, Health, Aarhus University, Aarhus, Denmark.
authors.forename: D
authors.initials: D
authors.lastname: Haubek
mesh_terms: D000328:Adult; D000070676:Enthesopathy; D053098:Familial Hypophosphatemic Rickets; D006801:Humans; D011859:Radiography; D000072177:Radiologists
keywords: X-linked hypophosphatemia; enthesopathy; extra-skeletal calcifications; radiography; skull