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
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, that might be associated with seizures. These abnormalities are represented by temporal lobe dysgenesis and abnormal hippocampal configuration.
Ultimately, macrocerebellum, an abnormally enlarged cerebellum, despite being associated with many other syndromic conditions and also be an isolated finding was described with its typical appearance in children with achondroplasia, and hypothesized that macrocerebellum may be due to the direct effects of the FGFR3 mutation.
Findings ( Fig. 4 )
1. Temporal lobe malformations
- Sagittal clefting in the medial temporal lobe (Fig. 5)
- Deep transverse temporal sulcus (Fig. 6 and Fig. 7)
- Incomplete hippocampal inversion (Fig. 8)
- Oversulcation of the mesial temporal lobe (Fig. 9 )
- Extension of oversulcation to the calcar avis (Fig. 10)
2. Macrocerebellum (Fig. 11 and Fig. 12)
3. Morphologic changes of the skull base
- Foramen magnun stenosis (Fig. 13)
- Short clivus (Fig. 13)
- Tail-like notch foramen magnun (Fig. 13)
- Narrowing of the jugular foramen (Fig. 14)
- Enlargement of collateral veins (Fig. 15)
- Foreshortening of the carotid canals (Fig. 16)
- Towering petrous ridge (Fig. 17)
- Rotation of the temporal bone structures (Fig. 18)
- Poor development of the mastoid air cell (Fig. 19)