Skull base and temporal lobe abnormalities in FGFR3- related skeletal dysplasias: A pictorial essay

Congress:

ECR 2020

Poster Number:

C-12591

Type:

Educational Exhibit

Keywords:

Not applicable, Congenital, Education, MR, CT, Paediatric, Neuroradiology brain, Head and neck, Neuro

Authors:

A. D. F. Ferreira¹, T. A. L. Freddi², F. D. G. Dantas¹, N. Ferreira¹, H. B. Zuppani¹, K. SAYEGH¹, D. Costa¹, A. Wolosker¹, M. Borri¹; ¹Sao Paulo/BR, ²Sao Paulo, SP/BR

DOI:

10.26044/ecr2020/C-12591

DOI-Link:

https://dx.doi.org/10.26044/ecr2020/C-12591

Fig. 1: Coverpage

Fig. 2: Learning objectives

Fig. 3: FGFR3 mutation overview.

Fig. 4: Findings on FGFR3- related skeletal dysplasias.

Learning objectives

To recognize the findings related to the skull base and temporal lobe malformations in FGFR3-related skeletal dysplasias patients.

Background

Thanatophoric dysplasia, achondroplasia, and hypochondroplasia belong to the fibroblast growth factor receptor 3 (FGFR3) group of genetic skeletal disorders and mutations on this gene are associated to MAPK signaling changes. Different allelic mutations result in the variable severity of expression. Fig. 3 There is a growing body of literature elucidating the role of FGFR3 mutations in neural and skeletal development. In embryonic tissues in mice, FGFR3 expression is limited principally to neural tube derivatives (developing brain and spinal cord), cartilage rudiments of developing bone, the...

Findings and procedure details

A wide spectrum of imaging findings can be observed such as stenosis of the foramen magnum, narrowing of the jugular foramen, dysplasia of the temporal bone with towering of the petrous ridges and rotation of temporal bone structures. This abnormalities are directly associated with high mortality due to craniocervical junction stenosis and cord compression besides hearing loss. In addition to the bone changes new studies demonstrated temporal lobe abnormalities, already described in other pathologies associated with FGFR3 gene mutation, but only recently depicted in achondroplasia,...

Conclusion

Understanding the morphologic changes of the skull base and malformations of the temporal lobe associated to FGFR3-related skeletal dysplasias may help in diagnostic workup and comprehend possible neurological complications.

Personal information and conflict of interest

A. D. F. Ferreira; Sao Paulo/BR - nothing to disclose T. A. L. Freddi; Sao Paulo, SP/BR - nothing to disclose F. D. G. Dantas; Sao Paulo/BR - nothing to disclose N. Ferreira; Sao Paulo/BR - nothing to disclose H. B. Zuppani; São Paulo/BR - nothing to disclose K. Sayegh; São Paulo/BR - nothing to disclose D. Costa; São Paulo/BR - nothing to disclose A. Wolosker; Sao Paulo/BR - nothing to disclose M. Borri; Sao Paulo/BR - nothing to disclose

References

Cobb SR, Shohat M, Mehringer CM, et al. CT of the temporal bone in achondroplasia. AJNR. 1988:9:1195-9. Horton WA, Hall JG, Hecht JT. Achondroplasia. Lancet. 2007; 370:162-72 Manikkam SA, Chetcuti K, Howell KB, et al. Temporal lobe malformations in achondroplasia: Expanding the brain imaging phenotype associated with FGFR3-related skeletal dyspasias. AJNR 2018; 39:380-84 Matsushita T, Wilcox WR, Chan YY, et al. FGFR3 promotes synchondrosis closure and fusion of ossification centers through the MAPK pathway. Hum Mol Genet. 2009:18:227-40. Pascoe HM, Yang JYM, Chen J, et...