Meningocele

BackgroundPseudomeningoceles are a rare complication after spinal surgery, and studies on these complex formations are few.MethodsBetween October 2000 and March 2008, 11 patients who developed symptomatic pseudomeningoceles after spinal surgery were recruited. In this retrospective study, we reported our experiences in the management of these complex, symptomatic pseudomeningoceles after spinal surgery. A giant pseudomeningocele was defined as a pseudomeningocele >8 cm in length. We also evaluated the risk factors for the formation of giant pseudomeningoceles.ResultsAll patients were treated successfully with a combined treatment protocol of open revision surgery for extirpation of the pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage. Surgery-related complications were not observed. Recurrence of pseudomeningocele was not observed for any patient at a mean follow-up of 16.5 months. This result was confirmed by magnetic resonance imaging.ConclusionsWe conclude that a combined treatment protocol involving open revision surgery for extirpation of pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage is safe and effective to treat giant pseudomeningoceles.

BackgroundTangential migration presents the primary mode of migration of cortical interneurons translocating into the cerebral cortex from subpallial domains. This migration takes place in multiple streams with the most superficial one located in the cortical marginal zone. While a number of forebrain-expressed molecules regulating this process have emerged, it remains unclear to what extent structures outside the brain, like the forebrain meninges, are involved.ResultsWe studied a unique Foxc1 hypomorph mouse model (Foxc1hith/hith) with meningeal defects and impaired tangential migration of cortical interneurons. We identified a territorial correlation between meningeal defects and disruption of interneuron migration along the adjacent marginal zone in these animals, suggesting that impaired meningeal integrity might be the primary cause for the observed migration defects. Moreover, we postulate that the meningeal factor regulating tangential migration that is affected in homozygote mutants is the chemokine Cxcl12. In addition, by using chromatin immunoprecipitation analysis, we provide evidence that the Cxcl12 gene is a direct transcriptional target of Foxc1 in the meninges. Further, we observe migration defects of a lesser degree in Cajal-Retzius cells migrating within the cortical marginal zone, indicating a less important role for Cxcl12 in their migration. Finally, the developmental migration defects observed in Foxc1hith/hith mutants do not lead to obvious differences in interneuron distribution in the adult if compared to control animals.ConclusionsOur results suggest a critical role for the forebrain meninges to promote during development the tangential migration of cortical interneurons along the cortical marginal zone and Cxcl12 as the factor responsible for this property.

BackgroundCaudal regression syndrome (CRS) or sacral agenesis is a rare congenital disorder characterized by a constellation of congenital caudal anomalies affecting the caudal spine and spinal cord, the hindgut, the urogenital system, and the lower limbs. CRS is a complex condition, attributed to an abnormal development of the caudal mesoderm, likely caused by the effect of interacting genetic and environmental factors. A well-known risk factor is maternal type 1 diabetes.MethodWhole exome sequencing and copy number variation (CNV) analyses were conducted on 4 Caucasian trios to identify de novo and inherited rare mutations.ResultsIn this pilot study, exome sequencing and copy number variation (CNV) analyses implicate a number of candidate genes, including SPTBN5, MORN1, ZNF330, CLTCL1 and PDZD2. De novo mutations were found in SPTBN5, MORN1 and ZNF330 and inherited predicted damaging mutations in PDZD2 (homozygous) and CLTCL1 (compound heterozygous). Importantly, predicted damaging mutations in PTEN (heterozygous), in its direct regulator GLTSCR2 (compound heterozygous) and in VANGL1 (heterozygous) were identified. These genes had previously been linked with the CRS phenotype. Two CNV deletions, one de novo (chr3q13.13) and one homozygous (chr8p23.2), were detected in one of our CRS patients. These deletions overlapped with CNVs previously reported in patients with similar phenotype.ConclusionDespite the genetic diversity and the complexity of the phenotype, this pilot study identified genetic features common across CRS patients.

Skull base meningoceles are extremely rare, most commonly resulting from congenital defects in sphenoid bone fusion. Inadequate embryonic fusion between the posterior sphenoid and the occipital bones may result in a transclival meningocele. Given the absence of a formal classification system for clival meningoceles and clear guidelines for the most appropriate endoscopic skull base surgical approach, we combined an anatomical study and a systematic review to characterize anatomical patterns, propose a preliminary classification, and discuss transoral and endonasal surgical corridors according to each clival subtype. In addition, we report the first known case of a primary clival meningocele successfully treated via a transoral endoscopic approach. The study was registered with PROSPERO (CRD42024575282) and received approval from the Ethics Committee (82878724.1.0000.5259). The systematic review followed PRISMA guidelines. PubMed/MEDLINE, Embase, and Cochrane were rigorously searched. Anatomical dissection of midsagittal skull base specimens was performed to assess surgical access to clival regions. Seventeen studies comprising 18 patients (mean age 30.7 years; 72.2% female) were included. Clival defects were classified as posterior transsphenoidal (n = 11), spheno-occipital (n = 1), and basioccipital (n = 6). The endoscopic endonasal approach appeared more appropriate for posterior transsphenoidal cases and the transoral route for basioccipital defects. Anatomical dissection studies confirmed that the endonasal corridor is more suitable for the upper third of the clivus and the transoral route for the lower third.