The deletion 9p syndrome is caused by a constitutional monosomy of part of the short arm of chromosome 9. It is clinically characterized by dysmorphic facial features (trigonocephaly, midface hypoplasia, and long philtrum), hypotonia and mental retardation. Deletion 9p is known to be heterogeneous and exhibits variable deletion sizes. The critical region for a consensus phenotype has been reported to be located within a approximately 4-6 Mb interval on 9p22. In the present study, deletion breakpoints were determined in 13 Dutch patients by applying fluorescence in situ hybridization (FISH) and in some specific cases by array-based comparative genomic hybridization (array CGH). No clear genotype-phenotype correlation could be established for various developmental features. However, we were able to narrow down the critical region for deletion 9p syndrome to approximately 300 kb. A functional candidate gene for trigonocephaly, the CER1 gene, appeared to be located just outside this region. Sequence analysis of this gene in nine additional patients with isolated trigonocephaly did not reveal any pathogenic mutations.

A specific group of intrinsic dorsal midbrain tumors was identified in six children by computerized tomography (CT) and magnetic resonance (MR) imaging. Each patient presented with raised intracranial pressure as a result of hydrocephalus due to obstruction of the sylvian aqueduct. No patient had brain-stem signs referable to the tectal tumor initially or subsequently. All six children underwent cerebrospinal fluid (CSF) diversionary procedures. The radiological features were consistent and specific, with all patients showing tectal calcification or primary increased attenuation of the tectal plate on CT scans. In addition, lack of contrast enhancement was noted initially in four patients and eventually in all six patients. In all patients MR imaging showed a focal tectal tumor distorting the collicular plate with no cystic component and increased signal intensity on T2-weighted images. There has been no evidence of progression in these six patients in the follow-up period ranging from 8 months to 17 years (8 months and 2 1/2, 4 1/2, 8, and 17 years). Diversion of CSF has been the only surgical treatment and no patient underwent deep x-ray therapy. Five patients have had normal intellectual development. In contrast to the majority of previously described periaqueductal and tectal tumors, this group of lesions appeared to be truly benign. The authors suggest that patients presenting with these clinical and radiological features may be managed by CSF diversion, serial examination, and MR imaging.

Objectives: To evaluate the role of endoscopic third ventriculostomy (ETV) as a primary treatment for hydrocephalus in children less than 1 year old and to determine its impact as a whole on the reduction of shunts necessary in a new population of hydrocephalic infants. Methods: Data were collected prospectively on 47 infants with newly diagnosed hydrocephalus of all aetiologies who were referred between 1st April 1998 and 30th September 2000. Twenty-one patients (median age 6 weeks, range 34 weeks of gestation to 10 months) underwent ETV, while the remaining 26 patients had insertion of a ventriculoperitoneal shunt. Anatomical criteria and demonstration of third ventricle outflow obstruction on preoperative magnetic resonance imaging were used to select patients for ETV. Results: There was no mortality or major morbidity following ETV. The median follow-up period was 18 (range 8–36) months. During the follow-up period, the ETV remained patent in 7 (33%) of the 21 patients. Of the 14 patients with failed ETV, 11 had insertion of a ventriculoperitoneal shunt, while 3 have undergone successful redo ETV. Therefore, in total 10 patients (48%) of the ETV group remain shunt independent. The best results were obtained in patients with congenital aqueduct stenosis with 71% (5 of 7 patients) success rate, while patients with posthaemorrhagic hydrocephalus did particularly badly with only 1 of 10 patients having a successful ETV. Overall, 10 of 47 (21%) infants with newly diagnosed hydrocephalus have avoided a shunt. Conclusions: Our results suggest that the selective use of ETV as the primary treatment in infants with hydrocephalus is safe and can lead to a reduction in the shunted population of all newly diagnosed hydrocephalic infants by up to 21%. Success of ETV is aetiology, not age dependent.

Metopic synostosis is thought to have an incidence of about 1 in 15,000 births. Traditionally, this makes it the third most frequent single-suture craniosynostosis, after scaphocephaly (1 in 4200-8500) and plagiocephaly (1 in 11,000). Our units have, independently from each other, noted a marked increase in the number of metopic synostosis over the recent years. This is a pan-European, retrospective epidemiological study on the number of cases with metopic synostosis born between January 1, 1997, and January 1, 2006. This number was compared to the prevalence of scaphocephaly, the most frequently seen craniosynostosis. In the 7 units, a total of 3240 craniosynostosis were seen from 1997 until 2006. Forty-one percent (n = 1344) of those were sagittal synostosis, and 23% (n = 756) were metopic synostosis. There was a significant increase of the absolute number as well as of the percentage of metopic synostosis over these years (regression analysis, P = 0.017, R2 = 0.578) as opposed to a nonsignificant increase in the percentage of sagittal synostosis (P > 0.05, R2 = 0.368). The most remarkable increase occurred around 2000-2001, with the average of metopics being 20.1% from 1997 to 2000 and 25.5% from 2001 to 2005 (independent t-test, P = 0.002). The sagittal synostosis showed a smaller and nonsignificant increase in the same years: from 39.9% in 1997-2000 leading up to 42.5% in 2001-2005 (independent t-test, P > 0.05). The number of metopic synostosis has significantly increased over the reviewed period in all of our units, both in absolute numbers as in comparison to the total number of craniosynostosis.

Third ventricle-related arachnoid cysts can be satisfactorily and safely treated by endoscopy. This approach leaves the patient shunt independent.