The Relationship of High Septal Deviation, the Depth of Olfactory Fossa, and Gera Angle: Is High Septal Deviation Associated With Any Anatomic Abnormalities in the Anterior Skull Base?

OBJECTIVE: To investigate the association of high septal deviation with the olfactory fossa depth and Gera angle. METHODS: Fifty-four computed tomography scans of patients with high septal deviation were evaluated. The olfactory fossa depth and Gera angle were measured. The values of the deviated and nondeviated sides were compared. RESULTS: No association between high septal deviation and the olfactory fossa depth and Gera angle was found. CONCLUSION: High septal deviation does not affect the olfactory fossa depth and Gera angle. In other words, the olfactory fossa depth and Gera angle have no association with the high septal deviation.

Asymmetric Meckel Cave Enlargement: A Potential Marker of PHACES Syndrome.

BACKGROUND AND PURPOSE: PHACES syndrome is a complex of morphologic abnormalities of unknown cause and includes posterior fossa abnormalities; head and neck infantile hemangiomas; arterial, cardiac, and eye anomalies; and sternal or abdominal wall defects. Accurate identification of the syndrome is important for optimal treatment. The purpose of this study was to investigate the incidence of asymmetric Meckel cave enlargement, a potential novel imaging marker, in a population of patients referred for evaluation of possible PHACES syndrome. MATERIALS AND METHODS: Eighty-five patients referred for neuroimaging evaluation of possible PHACES syndrome were identified and stratified on the basis of their ultimate clinical PHACES diagnosis categorization into PHACES, possible PHACES, or not PHACES. MR imaging studies were subsequently reviewed for the presence or absence of unilateral Meckel cave enlargement, with the reviewer blinded to the ultimate PHACES syndrome categorization. RESULTS: Twenty-five of 85 patients (29%) were ultimately categorized as having PHACES or possible PHACES according to consensus guidelines. Asymmetric Meckel cave enlargement was present in 76% (19/25) of these patients and in 82% (19/23) of only those patients with definite PHACES. This finding was present in none of the 60 patients determined not to have PHACES syndrome. In 7/19 patients (37%) with this finding, subtle MR imaging abnormalities consistent with PHACES were missed on the initial MR imaging interpretation. CONCLUSIONS: Asymmetric Meckel cave enlargement was a common feature of patients with PHACES in our cohort and may serve as a novel imaging marker. Increased awareness of this imaging feature has the potential to increase the diagnostic accuracy of PHACES.

Rhombencephalosynapsis: embryopathology and management strategies of associated neurosurgical conditions with a review of the literature.

OBJECT: Rhombencephalosynapsis (RS) is a rare congenital posterior fossa malformation characterized by dorsal fusion of the cerebellar hemispheres, hypogenesis or agenesis of the vermis, and fusion of the dentate nuclei and superior cerebellar peduncles. The objective of this institutional study is to review the clinical conditions associated with RS and analyze the varied biological profile of this unique condition. METHODS: The study data were collected retrospectively from the medical records of patients at Rainbow Babies and Children's Hospital. After required institutional review board approval, the authors obtained information regarding the cases of RS reviewed by the Departments of Radiology, Genetics, and/or Pediatric Neurology. Medical charts were systematically reviewed, and 9 patients were analyzed in detail. RESULTS: The authors describe 6 cases of RS and 3 cases of partial RS. This case series demonstrates an association between RS and symptomatic hydrocephalus (7 of 9 patients) and RS and Chiari malformation (5 of 9 patients). Patients with symptomatic hydrocephalus underwent endoscopic third ventriculostomy or ventriculoperitoneal shunt insertion. One of the patients with an associated Chiari malformation underwent foramen magnum decompression. CONCLUSIONS: The authors present a large case series of RS. Patients with RS often had hydrocephalus and/or a Chiari Type I or II hindbrain malformation. Neuroimaging findings of RS are presented along with hypotheses to explain the embryopathology of this unusual condition.

Treatment of anterior skull base defects by a transnasal endoscopic approach in children.

OBJECT: The object of this study was to assess the efficacy and complications of endoscopic management of anterior skull base defects. METHOD: The authors reviewed the medical records of 28 children (20 boys and 8 girls) undergoing endoscopic repair of anterior skull base defects in their tertiary referral center between 2001 and 2008; 18 cases were congenital and 10 cases posttraumatic. During the endoscopic procedure, rigid telescopes--2.7 or 4 mm in diameter, with 0° or 30° lenses--were used. In 23 patients the anterior skull base defect was sealed with fragments of middle turbinate (bone and mucosa). In the remaining 5 patients it was sealed with cartilage harvested from the nasal septum (3 cases) or from the auricle (2 cases), fibrin glue, and oxidized cellulose. A combined external and endoscopic approach was required in 3 cases because of the size and extensions of the encephalocele. Outcome was primarily assessed by means of clinical examination, nasal fibroscopy, and imaging. RESULTS: The mean duration of follow-up was 26.7 months (range 9-57 months). One patient treated by a combined approach died of meningitis 2 years after surgery. In the remaining 27 patients, there was no recurrence of CSF leak, meningitis, or encephalocele. An iatrogenic frontal or ethmoidal mucocele was observed in 4 cases. CONCLUSIONS: The endoscopic approach is a minimally invasive, safe, and efficient technique for removing nasal encephaloceles in children.

Nasal dermoid sinus cyst.

Midline congenital abnormalities of the skin may be related to subjacent visceral developmental defects. We report on three unrelated children presenting a small midline pit on the bridge of the nose from which a small tuft of hair was emerging. This presentation is the hallmark of a nasal dermoid sinus cyst. In one of the patients the sinus tract was connected to the anterior cerebral fossa and required neurosurgical management. Although midline cutaneous abnormalities may look trivial, dermatologists should keep a high index of suspicion for possible association with more severe underlying defect. The diagnosis of nasal dermoid sinus cyst requires appropriate imaging studies to determine the extension of the sinus tract thus allowing proper management.

Trigonocephaly: surgical considerations and long term evaluation.

Trigonocephaly accounts for approximately 10% of all craniosynostosis. Severe trigonocephaly results in a triangular-shaped forehead, superior-lateral orbital depression, hypotelorism, and compensatory occipital-parietal calvarial changes. Radiographic findings include ovoid orbits with parallel medial borders, thickened keel-shaped frontal bone, small ethmoid sinuses, and a short anterior cranial fossa with pitched sphenoid wings. Our experience with 50 infantile cases of severe nonsyndromic trigonocephaly patients treated from 1987 to 2005 is clinically reviewed to assess long-term growth based on a standardized operative technique. The average age of the patients at surgery was 6 months and the mean follow-up was 12 years. Our complication rate was 2%; the reoperative rate was 12%. The use of resorbable rigid plate fixation combined with alloplastic augmentation has improved the cosmetic outcome in patients treated since 1996 and reduced the reoperative rate.

Pseudoclosure of anterior fontanelle by wormian bone in isolated sagittal craniosynostosis.

AIMS AND OBJECTIVES: Although syndromic craniosynostosis is one of the causes for early closure of the anterior fontanelle, there is no literature on the incidence and causes of fontanelle closure in isolated single-suture craniosynostosis. The objective of this study was to review the incidence of fontanelle closure by a wormian bone in isolated, nonsyndromic sagittal craniosynostosis. MATERIALS AND METHODS: Intraoperative records of 100 consecutive children under 1 year of age, operated for isolated sagittal synostosis over a 14-year period (1987- 2000), were reviewed to identify the presence of a wormian bone closing the anterior fontanelle. RESULTS: The median age at surgery was 4.2 months with a range of 1.9-11.7 months. Intraoperatively, a wormian bone was seen replacing the anterior fontanelle in 4 cases giving an incidence of 4%. CONCLUSIONS: A wormian bone can occupy the anterior fontanelle in children with isolated sagittal craniosynostosis giving the appearance of a 'closed fontanelle'.

Study on skull asymmetry.

The aim of this study is to determine the type of skull as well as to examine its internal appearance and configuration of skull base. Special attention is given to the direction and position of the pyramid of the temporal bone, the volume and appearance of all the three cranial fossas, and the direction and appearance of crista alaris--all of those compared to the skull type. Considering the obtained results (specially for crista alaris and middle fossa) we can ascertain outstanding independence of sphenoid bone and its parts in the formation of cranial base. Located in the middle of the skull, in front of strong pyramids transversal axis and two vertical axis, frontal crest and internal occipital crest, it by itself with her lesser wing presents an important transversal axis of cranial base. Cases in which crista alaris with its position does not follow the type of skull (in 20 % cases crista alaris does not follow skull protuberances), may probably be explained by strong and independent development of this bone, which is placed among other bones of cranial base like a peg. It also, by itself dictates form and configuration of the middle part of skull. That is also confirmed by middle fossa which, according to its position in the middle of cranial base and relation with sphenoid bone, shows significant deviation with respect to posterior fossa (follows the type of skull in 47 % cases).

Neural-dural transition at the medial anterior cranial base: an anatomical and histological study with clinical applications.

OBJECT: Few anatomical studies have been focused on the morphological features and microscopic anatomy of the transition from the intracranial space to the medial anterior cranial base. The authors of the current study performed histological analyses to define the structure of the transition from neural foramina to the cranial base (neural-dural transition) at the cribriform plate, particularly as related to cerebrospinal fluid (CSF) fistula formation and surgical intervention in the region. METHODS: The medial anterior cranial base was resected in six cadaveric specimens. Histological methods were used to study the anatomy of the region on the microscopic level. Results of these examinations revealed a multilayered neural-dural transition at the cribriform plate, which consisted of an arachnoid membrane and a potential subarachnoid space as well as dura mater, periosteum, ethmoid bone, and associated layers of submucosa and mucosa of the paranasal air spaces. A subarachnoid space was identified around the olfactory nerves as they exited the neural foramina of the cribriform plates. The dura mater eventually thinned out and became continuous with the periosteum in the ethmoid bone. The dura, arachnoid membrane, and associated potential subarachnoid space were obliterated at a place 1 to 2 mm into the olfactory foramen. The authors present a case of recurrent CSF rhinorrhea successfully treated using a technique of multilayered reconstruction with pericranium, fat, and bone. CONCLUSIONS: The findings provide an anatomical basis for CSF fistula formation in the region of the cribriform plate and help to explain the unusual presentations in patients who have CSF rhinorrhea and meningitis. These results may facilitate the treatment of CSF fistulas, repair of defects in the medial anterior cranial base, and approaches to tumors and other pathological entities in the region.

Intracranial anatomic asymmetry in situs inversus totalis.

Situs inversus is a rare condition in which the position of the thoracic and the abdominal viscera are exchanged from the left to the right sides. A possible inversion of normal dominant intracranial anatomy, has however, rarely been discussed. We examine here the gross anatomy of an elderly cadaveric female for a possible "situs inversus" of the intracranial contents. This study has found that many structures commonly dominant on one side in the intracranial compartment were reversed in this specimen. These findings support the concept that a reversal of more commonly found intracranial anatomy may occur in situs inversus totalis, and this should alert the clinician performing invasive procedures in this population. These data will also hopefully provide further insight into possible mechanisms that contribute to situs inversus totalis.