Concomitant achondroplasia and Chiari II malformation: A double-hit at the cervicomedullary junction

Figure 1 Pre-operative magnetic resonance imaging imaging of the patient to evaluate and screen for anatomical abnormalities. A: Axial T2 MRI of the head at birth demonstrating no signs of hydrocephalus; B: Sagittal T1 MRI of the head and neck at birth with evidence of a tight cervicomedullary junction, a small posterior fossa, and hypoplastic corpus callosum and cerebellar vermis; C: Sagittal T2 MRI of the spine at birth demonstrating a large 7 cm × 7 cm sacral myelomeningocele with evidence of tethering. MRI: Magnetic resonance imaging.

Figure 2 T-2 weighted magnetic resonance imaging demonstrating shunt failure and progression of hydrocephalous over the course of 4 mo of treatment. A: Pre-shunting axial T-2 weighted MRI ordered after patient had increased head circumference and suture splaying demonstrating ventriculomegaly; B, C: Subtle increase in ventricular size at 2 wk (B) and 6 wk post-shunting (C); D: At 4 mo post-operative shunting with significant increase in ventriculomegaly and extra axial fluid spacing. MRI: Magnetic resonance imaging.