Posterior vault encephaloceles: from antenatal management to post-surgical follow-up-a cooperative study.

Purpose: Encephalocele is a herniation of intracranial structures associated with a skull anomaly. In Western countries, posterior encephaloceles are more common than anterior encephaloceles and may occur in the parietal (parietal encephalocele, PE) or occipital (occipital encephalocele, OE) region. Although those entities are relatively common in pediatric neurosurgery, large clinical series are scarce, and their clinical outcomes are poorly documented in the literature.

Methods: We retrospectively analyzed the clinical and radiological findings, post-operative long-term outcomes of consecutive patients diagnosed with posterior encephaloceles from 2010 to 2021 in 3 centers: Hôpital Femme Mère Enfant (Lyon, France); Hôpital Roger Salengro (Lille, France); and Charité Universitätsmedizin (Berlin, Germany).

Results: We collected 79 observations, 46 PEs and 33 OEs. Cerebral anomalies were more common in OEs than PEs (15/33, 45% vs 7/46, 15%, p = 0.001). Vascular anomalies were more common in PEs than OEs (41/46, 88% vs 5/33, 15%). All children underwent a surgical correction of the malformation. CSF disorders requiring surgical management were present in 4/33 OEs and 4/46 PEs. During the mean follow-up of 33 months (12-160 months), 3 OEs patients died, and various degrees of psychomotor impairment were found in both entities: 18/33 (54%) OEs and 8/46 (17%) PEs (p = 0.005); however, in most cases of PE, developmental delay was mild.

Conclusions: The clinical evolution in OEs is significantly more unfavorable than in PEs. However, even in case of PEs, psychomotor impairments are not uncommon. The presence of herniated cerebral tissue, hydrocephalus, and syndromic context increase the risk of developmental delay.