High Incidence of Cranial Synostosis and Chiari I Malformation in Children With X-Linked Hypophosphatemic Rickets (XLHR) - PubMed (original) (raw)

. 2019 Mar;34(3):490-496.

doi: 10.1002/jbmr.3614. Epub 2018 Nov 20.

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High Incidence of Cranial Synostosis and Chiari I Malformation in Children With X-Linked Hypophosphatemic Rickets (XLHR)

Anya Rothenbuhler et al. J Bone Miner Res. 2019 Mar.

Abstract

X-linked hypophosphatemic rickets (XLHR) represents the most common form of genetic hypophosphatemia and causes rickets and osteomalacia in children because of increased FGF23 secretion and renal phosphate wasting. Even though cranial vault and craniovertebral anomalies of potential neurosurgical interest, namely early closure of the cranial sutures and Chiari type I malformation, have been observed in children with XLHR, their actual incidence and characteristics are not established. The aims of this study were to analyze the incidence of cranial and cervico-occipital junction (COJ) anomalies in children with XLHR and describe its features. This is a retrospective study of CT scans of the head and skull in 44 XLHR children followed at the French Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism. Forty-four children with XLHR, 15 boys and 29 girls, aged 8.7 ± 3.9 years at time of CT scan, were studied. We found that 59% of XLHR children had a complete or partial fusion of the sagittal suture and 25% of XLHR children showed protrusion of the cerebellar tonsils. A history of dental abscesses was associated with craniosynostosis, and craniosynostosis was associated with abnormal descent of cerebellar tonsils. Only 2 patients showed neurologic symptoms. Four of 44 patients (9%) required neurosurgery. This study highlights that sagittal suture fusion and Chiari type I malformation are frequent complications of XLHR. The incidence of sagittal synostosis in XLHR is actually extremely high and was probably underestimated so far. Chiari type I malformation is also frequent. Because diagnosis of craniovertebral anomalies can be underestimated on a purely clinical basis, radiological studies should be considered in XLHR children if a proper diagnosis is warranted. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Keywords: CHIARI TYPE I MALFORMATION; CRANIOSYNOSTOSIS; SCAPHOCEPHALY; X-LINKED HYPOPHOSPHATEMIC RICKETS (XLHR).

© 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

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Figures

Figure 1

Figure 1

Study population flow chart. CI = cranial index.

Figure 2

Figure 2

(A) An 8‐year‐old XLHR patient. Three‐dimensional CT skull bone window reconstruction. Complete closure of the sagittal and the right coronal sutures. The left coronal suture is patent but narrow. The patient also shows a congenital parietal foramina. (B) A 6‐year‐old XLHR patient. Three‐dimensional CT skull bone window reconstruction. Complete closure of the sagittal suture and both lambdoid sutures. (C) A 12‐year‐old XLHR patient. Three‐dimensional CT skull bone window reconstruction. Patent sagittal and coronal sutures. All very narrow. (D) An 8‐year‐old XLHR patient. Head CT sagittal slice parenchyma window showing a 6.8‐mm descent of the cerebellar tonsils. Continuous black arrows indicate sagittal suture. Discontinuous black arrows indicate coronal sutures. Continuous white arrow indicates lambdoid suture. Asterisks indicate closed sutures.

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