Presentation
Routine first trimester scan at 12-13 weeks .
Patient Data
Variable degree of absence of cranial vault / cervicothoracic vertebrae associated with large occipital encephalocele.
Fixed hyper-extended head (stargaze appearance).
Normal yolk sac seen.
Case Discussion
Iniencephaly is a rare neural tube defect with characteristic retro-flexion of the fetal head and variable defect in the occipital bone. Pathogenesis is unknown. Crown-rump length is always small and discordant as compared to gestational age. Absence of cervicothoracic vertebrae. Associated occipital encephalocele can be seen. Associated spinal rachischisis can be seen. Prognosis is lethal.
Ultrasound findings includes :
- "stargaze " appearance is the key to diagnosis
- hyperextension of the head