Foramen magnum decompression for Chiari I malformation: a procedure not to be underestimated.

OBJECTIVE: Chiari I malformation may be treated with foramen magnum decompression (FMD). We aim to describe the symptoms with which patients initially present, and to determine the number and type of complications occurring after FMD for Chiari I malformation. METHODS: Retrospective review of medical records for patients who had FMD performed for Chiari I malformation between January 2009 and December 2011. Post-operative outcomes were recorded and analysed. Patient demographic details and other relevant medical conditions were also noted. RESULTS: Between January 2009 and December 2011, 54 FMDs were performed for Chiari I malformation. Among them, 40(74%) patients were female and 14 patients (26%) were male. The majority of patients (42.6%) were aged 16-39 years and 24.07% of patients were children aged < 16 years. A total of 30(55.6%) patients had documented evidence of a syrinx pre-operatively. 18(33.3%) patients developed complications. Nine of these developed multiple complications while nine had a single problem. One mortality was reported. Ten (18.5%) patients developed hydrocephalus requiring shunting. Two patients developed subdural collections requiring evacuation associated with hydrocephalus. Six (11.1%) patients developed post-operative infections: two CNS infections; one wound infection; and three other infections. CONCLUSIONS: FMD for Chiari I malformation is a procedure which carries risk. In particular, the risk of developing post-operative hydrocephalus requiring permanent shunting is relatively high. ICP monitoring prior to FMD may be required to definitively rule out raised intracranial pressure.

Behavioral, developmental, and educational problems in children with nonsyndromic trigonocephaly.

OBJECT: The neurobehavioral morbidity of nonsyndromic trigonocephaly is incompletely understood. The purpose of this study was twofold: first, to assess the degree of developmental, educational, and behavioral problems in patients with nonsyndromic trigonocephaly and second, to establish whether patients with mild degrees of trigonocephaly had a lower frequency of such problems. METHODS: The authors performed an observational study of the frequency of developmental, educational, and behavioral problems in 63 children with trigonocephaly at the National Craniofacial Centre in the Republic of Ireland between 1989 and 2004. The parents of the children completed a follow-up questionnaire. Thirty percent of patients had a mild form of trigonocephaly and were treated conservatively. The remainder underwent surgical correction. Speech and/or language delay was reported in 34% of the children. Thirty-three percent of the children needed to be assessed by a school psychologist, and 47% were receiving remedial or resource hours within the school system. Twenty percent of children required a special needs classroom assistant because of behavioral issues, and 37% of parents expressed concerns about their child's behavior. There were no statistically significant differences between children treated with surgery and those who had a mild deformity and were treated conservatively. CONCLUSIONS: Nonsyndromic trigonocephaly is associated with a high frequency of developmental, educational, and behavioral problems. The frequency of these problems is not related to the severity of the trigonocephaly.

Spinal level of myelomeningocele lesion as a contributing factor in posterior fossa volume, intracranial cerebellar volume, and cerebellar ectopia.

OBJECT: McLone and Knepper's unified theory of Chiari malformation Type II (CM-II) describes how the loss of CSF via the open posterior neuropore fails to create adequate distending pressure for the developing rhomboencephalic vesicle. The authors of the present article describe the relationship between the posterior fossa volume and intracranial cerebellar volume as being related to the distance from the obex of the fourth ventricle to the myelomeningocele lesion using a common mathematical model, the Hagen-Poiseuille law. METHODS: All newborns who required closure of a myelomeningocele at the authors' institution between 2008 and 2011 and who were between 4 weeks premature and 2 months, corrected gestational age, at the time of MRI were included in this study. Volumes and measurements were obtained from axial and sagittal T2-weighted MR images of the brain and spine. RESULTS: A total of 56 newborn infants met the inclusion criteria. There was a direct linear relationship between both posterior fossa volume and cerebellar volume and the spinal level of the myelomeningocele lesion (p = 0.0012 and p = 0.0041, respectively). There was a negative linear relationship between the cerebellar descent, the spinal level of the lesion, and posterior fossa volume and cerebellar volume. These relationships strengthen in patients with no syringomyelia and are not significant in those groups with syringomyelia. The results of a 1-way ANOVA for the 3 groups did not reach significance. CONCLUSIONS: Using a linear equation derived from the Hagen-Poiseuille law that describes pressure in the fourth ventricle as being directly related to the length of the central canal from the obex to the myelomeningocele lesion, the authors were able to explain the directly observed linear relation between posterior fossa volume, intracranial cerebellar volume, and cerebellar descent to the level of the spinal lesion. As this model assumes a uniform radius of the central canal they were able to validate this model when they observed a strengthening in relationships in the no syringomyelia group and statistically insignificant correlations in the groups with syringomyelia. They therefore propose that the spinal level of the lesion is one of the major determinants of posterior fossa volume, intracranial cerebellar volume, and cerebellar ectopia.

Sagittal synostosis: a review of 53 cases of sagittal suturectomy in one unit.

The role of sagittal suturectomy in the treatment of scaphocephaly remains controversial. The purpose of this study was to report the experience of the National Craniofacial Unit in Dublin. This unit is the referral centre for the Republic of Ireland and serves a population of approximately 3.5 million. Quantitative assessments were made using radiographs and the pre- and postoperative cephalic index (CI) was calculated. Patients were asked to score their head shapes in a questionnaire. The mean age at surgery for the 53 children was 4.9 months with a mean follow up of 8 years. Pre- and postoperative radiographs were available for analysis in 24 patients. The mean preoperative CI was 65.3. There was a statistically significant increase in the CI postoperatively to 73.7. Seventy five per cent of children achieved a 'normal' CI and 86% scored their head shapes as good to excellent. There was no correlation between the age at surgery and the CI achieved. Although only one child was not happy with the shape of the head, the impression was that the CI correlated poorly with the clinical assessment of the head shape. There were no significant complications. We therefore conclude that the sagittal suturectomy is a safe procedure that has a limited but definite potential to improve the CI. This procedure still has a place in the surgical repertoire of the craniofacial surgeon dealing with scaphocephaly.

Non-syndromic trigonocephaly: surgical decision making and long-term cosmetic results.

BACKGROUND: Surgical correction is often required for cosmetic correction of trigonocephaly. The purpose of this paper was to report the long-term aesthetic outcome as appreciated by the parents/patients themselves. The self-evaluation of cosmetic outcome after trigonocephaly correction has not previously been reported. The management and different surgical techniques utilized over a 16-year period are discussed. MATERIALS AND METHODS: An observational study was undertaken of the clinical outcome, operative data, complications and cosmetic satisfaction of these trigonocephaly patients. The parents/child were asked to rate their satisfaction with the cosmetic outcome both in terms of head shape and scar appearance, on a five-point scale (excellent-5, very good-4, good-3, fair-2 and poor-1). RESULTS: Sixty-three patients presented with non-syndromic trigonocephaly over the 16 years. Nineteen of 63 had a mild form of trigonocephaly and were managed conservatively. The remainder underwent surgical correction. Forty-two of 44 (95%) underwent fronto-orbital advancement with either barrel staving (26/44) or frontal bone rotation/re-modelling (16/44), with 2 of 44 having burring of the metopic ridge. Head shape rating was regarded as excellent in 25 of 63 (40%), very good in 18 of 63 (28%), good in 18 of 63 (28%) and fair in 2 of 63 (4%). Of those that underwent surgery, the scar was zigzag in 32 of 44 and straight in 12 of 44. Scar was rated as being excellent in 21 of 44 (48%), very good in 12 of 44 (28%) good in 11 of 44 (24%). CONCLUSIONS: Metopic synostosis can result in varying degrees of severity. Milder forms can be treated conservatively, with more severe forms requiring both frontal bone re-modelling and fronto-orbital advancement. Surgical correction results in a high level of patient/parent satisfaction.

Choroid plexus adenoma: case report and review of the literature.

CASE REPORT: An 8-month-old infant with macrocephaly was found to have hydrocephalus and a cystic third ventricular tumour; biopsy of the tumour showed a choroid plexus adenoma. The tumour was attached to the ependymal lining and was strongly adherent to the walls and floor of the anterior third ventricle. TREATMENT: After biopsy, it was felt that a radical resection would carry a high risk of injury to the floor of the third ventricle and cause new neurological deficits. Therefore, an external ventricular drain was inserted and bilateral ventriculo-peritoneal shunts were inserted 1 week post-operatively. In view of the benign nature of the tumour, no adjuvant radiotherapy or chemotherapy was given. OUTCOME: There was no further tumour growth or clinical deterioration over a 6-year follow-up period.