Thangamadhan Bosemani1, Gunes Orman, Benedikt Hergan, Kathryn A Carson, Thierry A G M Huisman, Andrea Poretti. 1. Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Charlotte R. Bloomberg Children's Center, Sheikh Zayed Tower, Room 4174, 1800 Orleans Street, Baltimore, MD, 21287-0842, USA.
Abstract
PURPOSE: Achondroplasia is a skeletal dysplasia with diminished growth of the skull base secondary to defective enchondral bone formation. This leads to narrowing of the foramen magnum and jugular foramina, which further leads to ventricular dilatation and prominence of the emissary veins. The primary goal of our study was to determine a correlation between the degree of ventricular dilatation, jugular foramina and foramen magnum narrowing, as well as emissary vein enlargement. METHODS: Conventional T2-weighted MR images were evaluated for surface area of the foramen magnum and jugular foramina, ventricular dilatation, and emissary veins enlargement in 16 achondroplasia patients and 16 age-matched controls. Ratios were calculated for the individual parameters using median values from age-matched control groups to avoid age as a confounder. RESULTS: Compared to age-matched controls, in children with achondroplasia, the surface area of the foramen magnum (median 0.50 cm(2), range 0.23-1.37 cm(2) vs. 3.14 cm(2), 1.83-6.68 cm(2), p < 0.001) and jugular foramina (median 0.02 cm(2), range 0-0.10 cm(2) vs. 0.21 cm(2), 0.03-0.61 cm(2), p < 0.001) were smaller, whereas ventricular dilatation (0.28, 0.24-0.4 vs. 0.26, 0.21-0.28, p < 0.001) and enlargement of emissary veins (6, 0-11 vs. 0, p < 0.001) were higher. Amongst the patients, Spearman correlation and multiple regression analysis did not reveal correlation for severity between the individual parameters. CONCLUSIONS: Our study suggests that in children with achondroplasia, (1) the variation in ventricular dilatation may be related to an unquantifiable interdependent relationship of emissary vein enlargement, venous channel narrowing, and foramen magnum compression and (2) stable ventricular size facilitated by interdependent factors likely obviates the need for ventricular shunt placement.
PURPOSE:Achondroplasia is a skeletal dysplasia with diminished growth of the skull base secondary to defective enchondral bone formation. This leads to narrowing of the foramen magnum and jugular foramina, which further leads to ventricular dilatation and prominence of the emissary veins. The primary goal of our study was to determine a correlation between the degree of ventricular dilatation, jugular foramina and foramen magnum narrowing, as well as emissary vein enlargement. METHODS: Conventional T2-weighted MR images were evaluated for surface area of the foramen magnum and jugular foramina, ventricular dilatation, and emissary veins enlargement in 16 achondroplasiapatients and 16 age-matched controls. Ratios were calculated for the individual parameters using median values from age-matched control groups to avoid age as a confounder. RESULTS: Compared to age-matched controls, in children with achondroplasia, the surface area of the foramen magnum (median 0.50 cm(2), range 0.23-1.37 cm(2) vs. 3.14 cm(2), 1.83-6.68 cm(2), p < 0.001) and jugular foramina (median 0.02 cm(2), range 0-0.10 cm(2) vs. 0.21 cm(2), 0.03-0.61 cm(2), p < 0.001) were smaller, whereas ventricular dilatation (0.28, 0.24-0.4 vs. 0.26, 0.21-0.28, p < 0.001) and enlargement of emissary veins (6, 0-11 vs. 0, p < 0.001) were higher. Amongst the patients, Spearman correlation and multiple regression analysis did not reveal correlation for severity between the individual parameters. CONCLUSIONS: Our study suggests that in children with achondroplasia, (1) the variation in ventricular dilatation may be related to an unquantifiable interdependent relationship of emissary vein enlargement, venous channel narrowing, and foramen magnum compression and (2) stable ventricular size facilitated by interdependent factors likely obviates the need for ventricular shunt placement.
Authors: Ravi Savarirayan; Penny Ireland; Melita Irving; Dominic Thompson; Inês Alves; Wagner A R Baratela; James Betts; Michael B Bober; Silvio Boero; Jenna Briddell; Jeffrey Campbell; Philippe M Campeau; Patricia Carl-Innig; Moira S Cheung; Martyn Cobourne; Valérie Cormier-Daire; Muriel Deladure-Molla; Mariana Del Pino; Heather Elphick; Virginia Fano; Brigitte Fauroux; Jonathan Gibbins; Mari L Groves; Lars Hagenäs; Therese Hannon; Julie Hoover-Fong; Morrys Kaisermann; Antonio Leiva-Gea; Juan Llerena; William Mackenzie; Kenneth Martin; Fabio Mazzoleni; Sharon McDonnell; Maria Costanza Meazzini; Josef Milerad; Klaus Mohnike; Geert R Mortier; Amaka Offiah; Keiichi Ozono; John A Phillips; Steven Powell; Yosha Prasad; Cathleen Raggio; Pablo Rosselli; Judith Rossiter; Angelo Selicorni; Marco Sessa; Mary Theroux; Matthew Thomas; Laura Trespedi; David Tunkel; Colin Wallis; Michael Wright; Natsuo Yasui; Svein Otto Fredwall Journal: Nat Rev Endocrinol Date: 2021-11-26 Impact factor: 47.564
Authors: Ravi Savarirayan; David E Tunkel; Laura M Sterni; Michael B Bober; Tae-Joon Cho; Michael J Goldberg; Julie Hoover-Fong; Melita Irving; Shawn E Kamps; William G Mackenzie; Cathleen Raggio; Samantha A Spencer; Viviana Bompadre; Klane K White Journal: Orphanet J Rare Dis Date: 2021-01-14 Impact factor: 4.123