Parietal encephalocele is a rare congenital condition involving herniation of brain matter through skull openings. Although isolated cases are reported, concurrent parietal encephalocele with porencephalic cyst is exceptionally rare. A 45-day-old infant presented with parietal scalp swelling since birth. Imaging revealed parietal encephalocele with porencephalic cyst. The encephalocele was surgically repaired with a favorable outcome, while the associated porencephalic cyst was managed conservatively. Preoperative neuroimaging is essential to evaluate the lesion and identify any associated brain abnormalities.

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. 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). 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. 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.

Aventriculy is a very rare observation and is generally associated with holoprosencephaly. We report here a case of polymalformation affecting the brain, hands, and feet observed in a highly consanguineous family in Niger. A boy was born from a highly consanguineous family presenting multiple malformations (aventriculy, extreme microcephaly, polydactyly, polymicrogyria, callosal agenesis, and parietal encephalocele). To the best of our knowledge, such association has never been reported so far. We propose to name this association PAPEC (for polymicrogyria, aventriculy, polydactyly, encephalocele, and callosal agenesis). The occurrence of this disease in a highly consanguineous family suggests a genetic origin. Furthermore, we propose hypotheses that could explain pathophysiology of this defect.

Encephaloceles are the type of dysraphism in which a skull defect allows for herniation of meninges, with or without the inclusion of neural tissue, and are commonly associated with agenesis of the corpus callosum. Encephaloceles are classified as frontal, occipital, or parietal, with parietal cephaloceles, or vertex cephaloceles (VC), being the least common. Despite this, VCs present as the most common cause of a midline scalp mass, displaying complex venous and neural malformations commonly referred to as the "tip of the iceberg." Atretic parietal encephaloceles (APC), a type of VC, are benign lesions arising from meningeal and vestigial tissue which have undergone fibrotic degeneration. As a result, prognosis will generally be better than other encephaloceles due to vestigial tissue involvement. Here, we report a neonate presenting with APC, corpus callosum agenesis, and a cingulate gyrus lesion, along with a sinus pericranii companion case for comparison.

We present a case of a newborn with a fenestrated superior sagittal sinus and persistent falcine sinus with a parietal encephalocele. The patient was born full-term without any associated pregnancy complications other than meconium-stained amniotic fluid at delivery. Following delivery, MRI brain demonstrated midline parietal encephalocele, persistent falcine sinus, fenestration of the superior sagittal sinus at the level of the encephalocele, subependymal heterotopia, and thick tectum. The patient underwent resection and repair on day 2 of life. MRI performed at 15 weeks of life showed a mild increase in the size of lateral ventricles. The patient did not require a ventriculoperitoneal shunt. This is a novel case that provides a valuable contribution to the existing body of literature about congenital encephalocele associated with persistent falcine sinus, fenestrated superior sagittal sinus, subependymal heterotopia, and thick tectum.