Surgery of Anterior Skull Base Lesions in Children.

INTRODUCTION: Lesions affecting the anterior skull base represent a rare group of craniofacial pathologies. A tumor of the facial midline, meningitis, or rhinoliquorrhea may be indicative of malformations like dermoid cysts, gliomas, encephaloceles, or nasal fistulas. METHODS: We present a case series of 13 children (4 months to 12 years; 8 males, 5 females) with lesions involving the anterior skull base, which were treated surgically in an interdisciplinary setting. This case series includes cases of nasal fistulae (n = 5), nasal cysts (n = 5), aneurysmal bone cyst, nasal glioma, and meningoencephalocele (n = 1). RESULTS: All lesions were resected with a transnasal, transcutaneous, and/or transcranial approach with reconstruction of the anterior skull base if intracranial/intradural extension was detected. In 5 cases, a dura leakage was visible, which was sealed via Onlay-technique in 3 cases, whereas in 2 cases involving a greater dural defect, the GAP-CAS technique was performed. No complications occurred, and no recurrence was visible in a long-term follow-up. An algorithm for a systematic approach to these various pathologies is provided. CONCLUSION: Congenital pathologies of the anterior skull base are rare, challenging to diagnose, and present as clinical emergencies. An interdisciplinary surgical approach is needed for best functional and aesthetic results.

Predictors for the benefit of selective dorsal rhizotomy.

Selective dorsal rhizotomy (SDR) is a spasticity reducing treatment option for children with spastic cerebral palsy. Selection criteria for this procedure are inconclusive to date. Clinical relevance of the achieved functional improvements and side effects like the negative impact on muscle strength are discussed controversially. In this prospective cohort study one and two year results of 54 children with a mean age of 6.9 (±2.9) years at the time of SDR are analyzed with regard to gross motor function and factors affecting the functional benefit. Only ambulatory children who were able to perform a gross motor function measure test (GMFM-88) were included in this study. Additionally, the modified Ashworth scale (MAS), a manual muscle strength test (MFT), and the body mass index (BMI) were evaluated as possible outcome predictors. MAS of hip adductors and hamstrings decreased significantly (p<0.001) and stayed reduced after two years, while GMFM improved significantly from 79% to 84% 12 months after SDR (p<0.001) and another 2% between 12 and 24 months (p=0.002). Muscle strength did improve significantly concerning knee extension (p=0.008) and ankle dorsiflexion (p=0.006). The improvement of function correlated moderately with age at surgery and preoperative GMFM and weakly with the standard deviation score of the BMI, the dorsiflexor and plantarflexor strength preoperatively as well as with the reduction of spasticity of the hamstrings and the preoperative spasticity of the adductors and hamstrings. Correctly indicated SDR reduces spasticity and increases motor skills sustainably in children with spastic cerebral palsy corresponding to clinically relevant changes of GMFM without compromising muscular strength. Outcome correlates to GMFM and age rather than to MAS and maximal strength testing. The data of this evaluation suggest that children who benefit the most from SDR are between 4 and 7 years old and have a preoperative GMFM between 65% and 85%.

Changes in hip geometry after selective dorsal rhizotomy in children with cerebral palsy.

PURPOSE: Hip development in children with spastic cerebral palsy (CP) may be different in comparison to that of typical developing children due to impaired motor function and altered lever arms. Selective dorsal rhizotomy (SDR) is known to reduce spasticity. It is postulated that it also improves mobility. Its influence on hip development is unclear. The aim of this study is to evaluate changes in hip geometry before and after selective dorsal rhizotomy. METHODS: Conventional radiographs (Rippstein I and II) of 33 ambulatory children aged 2.67 to 11.75 years who underwent SDR were analysed pre- and postoperatively at a mean of 18 months (range 12-29 months). Migration percentage, acetabular index, and anteversion were evaluated. The reduction of spasticity was measured with the modified Ashworth scale. A priori power analysis was performed. As data was normally distributed statistical analysis was performed applying the t-test for paired variables. RESULTS: Radiographic parameters concerning hip geometry improved significantly after SDR. The spasticity of adductors and hamstrings was significantly reduced through SDR from on average 1.7 to 0.8 on the modified Ashworth scale (p<0.001). The acetabular index decreased from 19° to 17° (p = 0.001), the migration percentage improved from 24% to 21% (p<0.001). Anteversion was also significantly reduced from 41° to 38° (p<0.001). Function improved significantly from 80% to 85% when measured with the GMFM-88 (p<0.001). CONCLUSIONS: The results confirm that SDR improves hip geometry as well as function in ambulatory CP children. Long-term studies need to show whether this radiographic improvement has clinical relevance with regard to pain and function.

Virtual planning for craniomaxillofacial surgery--7 years of experience.

Contemporary computer-assisted surgery systems more and more allow for virtual simulation of even complex surgical procedures with increasingly realistic predictions. Preoperative workflows are established and different commercially software solutions are available. Potential and feasibility of virtual craniomaxillofacial surgery as an additional planning tool was assessed retrospectively by comparing predictions and surgical results. Since 2006 virtual simulation has been performed in selected patient cases affected by complex craniomaxillofacial disorders (n = 8) in addition to standard surgical planning based on patient specific 3d-models. Virtual planning could be performed for all levels of the craniomaxillofacial framework within a reasonable preoperative workflow. Simulation of even complex skeletal displacements corresponded well with the real surgical result and soft tissue simulation proved to be helpful. In combination with classic 3d-models showing the underlying skeletal pathology virtual simulation improved planning and transfer of craniomaxillofacial corrections. Additional work and expenses may be justified by increased possibilities of visualisation, information, instruction and documentation in selected craniomaxillofacial procedures.

Temporal but not spatial variability during gait is reduced after selective dorsal rhizotomy in children with cerebral palsy.

INTRODUCTION: Variability in task output is a ubiquitous characteristic that results from non-continuous motor neuron firing during muscular force generation. However, variability can also be attributed to errors in control and coordination of the motor neurons themselves in diseases such as cerebral palsy (CP). Selective dorsal rhizotomy (SDR), a neurosurgical approach to sever sensory nerve roots, is thought to decrease redundant or excessive afferent signalling to intramedullary neurons. In addition to its demonstrated ability to reduce muscular spasticity, we hypothesised that SDR is able to decrease variability during gait, the most frequent functional motor activity of daily living. METHODS: Twelve CP children (aged 6.1 ± 1.3 yrs), who underwent SDR and performed gait analysis pre- and 12 months postoperatively, were compared to a control group of eleven typically developing (TD) children. Coefficients of variability as well as mean values were analysed for: temporal variables of gait, spatial parameters and velocity. RESULTS: Gait parameters of cadence (p = 0.006) and foot progression angle at mid-stance (p = 0.041) changed significantly from pre- to post-SDR. The variability of every temporal parameter was significantly reduced after SDR (p = 0.003-0.049), while it remained generally unchanged for the spatial parameters. Only a small change in gait velocity was observed, but variability in cadence was significantly reduced after SDR (p = 0.015). Almost all parameters changed with a tendency towards normal, but differences between TD and CP children remained in all parameters. DISCUSSION: The results confirm that SDR improves functional gait performance in children with CP. However, almost exclusively, parameters of temporal variability were significantly improved, leading to the conjecture that temporal variability and spatial variability may be governed independently by the motor cortex. As a result, temporal parameters of task performance may be more vulnerable to disruption, but also more responsive to treatment success of interventions such as SDR.

The oculo-auriculo-fronto-nasal syndrome (OAFNS) - description of a rare and complex craniofacial deformity and its interdisciplinary management before school age.

Craniofacial clefts are certainly among the most challenging congenital malformations with respect to functional, aesthetic and psychosocial consequences. The aetiology is still under discussion, recent molecular genetic findings suggest defects in the ciliary function of neural crest cells during facial development. The severity of craniofacial clefting is known to be extremely variable. Different classifications have been proposed however nomenclature is not uniform. If vertical, median craniofacial clefting of fronto-naso-maxillary structures is accompanied by auriculo-mandibular malformations the term oculo-auriculo-fronto-nasal syndrome (OAFNS) has been proposed. Extreme craniofacial abnormalities have to be expected in this rare disorder. Adequate correction is a surgical challenge and interventions have to be adapted individually to patient's needs with respect to general condition, age and growth. This case report describes both the underlying pathology as well as the interdisciplinary management of a female patient from birth to 6 years of age affected by this rare combination of vertical craniofacial clefting and bilateral auriculo-mandibular dysplasia.

Necrotizing soft tissue infection of the scalp after fronto-facial advancement by internal distraction in a 7-year old girl with Gorlin-Chaudhry-Moss syndrome--a case report.

In 1960, Gorlin, Chaudhry and Moss described a syndrome consisting of craniofacial dysostosis in association with hypertrichosis, cardiac, genital, dental and ocular anomalies. Diagnosis is based on typical clinical findings and cannot be performed by molecular genetic analysis until now. There is little in the clinical literature concerning this rare craniofacial syndrome. For functional and psychosocial reasons, surgical correction of the complex craniofacial malformation in a 7-year old Hungarian girl with Gorlin-Chaudhry-Moss syndrome was performed by fronto-facial advancement using internal distraction devices. Postoperatively necrotizing soft tissue infection of the scalp developed leading to termination of the distraction process ahead of schedule and requiring aggressive surgical management. Typical physiological and clinical characteristics were observed both during the initial craniofacial correction as well as during the management of the infectious complication suggesting that the linking of different conditions (surgical trauma plus the selection of toxic microorganisms) has caused tissue destruction rather than the syndromal disorder or the surgical technique of distraction osteogenesis. Although skeletal improvement was achieved residual damage from the infectious complication must be considered as severe.

Antley-Bixler-syndrome--staged management of craniofacial malformations from birth to adolescence--a case report.

In 1975 Antley and Bixler described an unusual syndromal disorder consisting of complex craniosynostosis with midfacial hypoplasia, dysplasia of ears and nose, radiohumeral synostosis, congenital fractures of the femur and upper airway impairment in a newborn. Additional urogenital and cardiac malformations can be associated however diagnosis is based on a characteristic craniofacial deformity in association with humeroradial synostosis. Complex disturbance of craniofacial growth due to premature synostoses of the cranial base and vault results in a characteristic phenotype. Steroidogenesis due to intrinsic or extrinsic disturbance by maternal fluconazole ingestion during early pregnancy may be impaired. The mode of inheritance is supposed to be autosomal recessive. Mutations in the fibroblast growth factor receptor 2 (FGFR2) as well as mutations in the cytochrome P450 oxidoreductase (OR) gene have been verified. Like in other craniofacial dysostosis syndromes malformation of neuro- and viscerocranium is complex and requires a staged age- and growth-related interdisciplinary management with respect to the individual situation. This case report of a female patient born in 1994 suffering from that rare syndrome describes the interdisciplinary long-term management in one craniofacial centre over 16 years from birth to adolescence.

Spinal cord tethering following myelomeningocele repair.

OBJECT: Symptom response to spinal cord untethering, and the impact of duraplasty and scoliosis on retethering, are poorly understood in tethering after myelomeningocele (MMC) repair. In this retrospective study, the authors examined the outcomes of children who developed first-time spinal cord tethering following MMC repair. The response of symptoms to untethering and the role of duraplasty and scoliosis in retethering are explored. METHODS: The authors performed a review of 54 children with first-time symptomatic spinal cord tethering following MMC repair to determine the impact of untethering on symptoms, the impact of dural repair type on retethering, and the role of scoliosis on the prevalence and time to retethering. RESULTS: The average patient age was 10.3 ± 4.9 years, and 44% were males. The most common presenting symptoms of tethered cord syndrome were urinary (87%), motor (80%), gait (78%), and sensory (61%) dysfunction. The average postoperative time to symptom improvement was 2.02 months for sensory symptoms, 3.21 months for pain, 3.50 months for urinary symptoms, and 4.48 months for motor symptoms, with sensory improvement occurring significantly earlier than motor improvement (p = 0.02). At last follow-up (an average of 47 months), motor symptoms were improved in 26%, maintained in 62%, and worsened in 11%; for sensory symptoms, these rates were 26%, 71%, and 3%, respectively; for pain, 28%, 65%, and 7%, respectively; and for urinary symptoms, 17%, 76%, and 7%, respectively. There was no difference in symptom response with type of dural repair (primary closure vs duraplasty). Symptomatic retethering occurred in 17 (31%) of 54 patients, but duration of symptoms, age at surgery, and type of dural repair were not associated with retethering. Scoliosis was not associated with an increased prevalence of retethering, but was associated with significantly earlier retethering (32.5 vs 61.1 months; p = 0.042) in patients who underwent additional untethering operations. CONCLUSIONS: Symptomatic retethering is a common event after MMC repair. In the authors' experience, sensory improvements occur sooner than motor improvements following initial untethering. Symptom response rates were not altered by type of dural closure. Scoliosis was associated with significantly earlier retethering and should be kept in mind when caring for individuals who have had previous MMC repair.

Perforation holes in ventricular catheters--is less more?

OBJECTIVE: Obstruction is a common cause of cerebrospinal fluid (CSF) shunt failure. Risk factors for proximal obstructive malfunction are suboptimal ventricular catheter positioning and slit-like ventricles. A new ventricular catheter design to decrease risk of obstruction was evaluated. METHODS: A review of histopathological tissue investigation from occluded ventricular catheters (n = 70) was performed. A new ventricular catheter design was realized with six perforation holes. These catheters were compared to regular catheters (16 holes, Miethke, Aesculap) for flow characteristics using ink studies and flow velocity at hydrostatic pressure levels from 14 to 2 cmH(2)O in an experimental setup. The six-hole catheters were implanted in hydrocephalic patients with slit-like ventricles (n = 55). A follow-up was performed to evaluate the need of catheter revisions. RESULTS: Histological evaluation showed that obstructive tissue involved 43-60% extraventricular tissue, including gliosis, connective and inflammatory cells. In flow characteristic studies, the 16-hole catheters showed that only proximal perforations are of functional relevance. For six-hole catheters, all perforations were shown to be relevant with remaining reserve capacity. Flow velocity however showed no significant differences between six and 16 perforations. The six-hole catheter was implanted in 55 patients with a mean follow-up period of 15 +/- 9 months. A total of 12 catheters were explanted, revealing an overall survival proportion of 77.4%. CONCLUSION: In narrow ventricles, we assume that catheter perforations that are located also in the tissue might be a risk for CSF shunt obstruction. Fewer amounts of perforations in the catheters with equal flow features might decrease this risk when catheters can be implanted with adequate precision.

Experiences with a gravity-assisted valve in hydrocephalic children. Clinical article.

OBJECT: Over the past decade, a gravity-assisted valve (GAV) has become a standard device in many European pediatric hydrocephalus centers. Because past comparative clinical outcome studies on valve design have not included any GAV, the authors in this trial evaluated the early results of GAV applications in a pediatric population. METHODS: For a minimum of 2 years the authors monitored 169 of 182 hydrocephalic children who received a pediatric GAV at their first CSF shunt insertion (61.5%) or as a substitute for any differential pressure valve (38.5%) at 1 of 7 European pediatric hydrocephalus centers. Outcomes were categorized as valve survival (primary outcome) or shunt survival (secondary outcome). The end point was defined as valve explantation. RESULTS: Within a follow-up period of 2 years, the valve remained functional in 130 (76.9%) of 169 patients. One hundred eight of these patients (63.9%) had an uncomplicated clinical course without any subsequent surgery, and 22 (13%) were submitted to a valve-preserving catheter revision without any further complications during the follow-up period. Thirty-nine patients (23.1%) reached an end point of valve explantation: 13 valve failures from infection (7.7%), 8 (4.7%) from overdrainage, and 18 (10.6%) from underdrainage. CONCLUSIONS: Compared with nongravitational shunt designs, a GAV does not substantially affect the early complication rate. Valve-preserving shunt revisions do not increase the risk of subsequent valve failure and therefore should not be defined as an end point in studies on valve design. A significant impact of any well-established valve design on the early complication rate in shunt surgery is not supported by any current data; therefore, this correlation should be dismissed. As overdrainage-related complications have been shown to occur late, the presumed advantages of a pediatric GAV remain to be shown in a long-term study.

Intratentorial osteochondrolipoma in a 9-year-old boy.

Intracranial osteolipomas and chondromas are rare benign tumors. Forty-five chondromas, mostly supratentorial, have been reported in the literature since 1981, with origins most commonly in the sellar regions. Twenty-one osteolipomas have been described to date, usually located near the tuber cinereum or the corpus callosum. The authors present a case of an osteochondrolipoma arising from the tentorium diagnosed in a pediatric patient at the age of 9 years. The case and treatment are discussed, and a review of the literature is provided.

First experiences with an adjustable gravitational valve in childhood hydrocephalus.

OBJECT: The goal of this report was to describe the authors' initial experiences with an adjustable gravity-assisted valve (GAV) called the ProGAV in treating childhood hydrocephalus. METHODS: The ProGAV was implanted in 53 children (29 boys and 24 girls, median age 7.3 years) with hydrocephalus of various origins. The ProGAV consists of a differential-pressure unit with adjustable opening pressures and a gravitational unit with a fixed opening pressure. RESULTS: The mean follow-up period was 15.2 months (range 6-44 months). The authors did not observe any valve-related complications. Four infections (7.5%) occurred, warranting the removal of the shunt. In 19 children, the opening pressure was changed at least once during the follow-up period, for underdrainage in 10, overdrainage in 8, and shunt weaning in 1, with substantial clinical improvement in 18 children. Overall, good clinical results were obtained in 47 (88.7%) of the 53 valve placements. CONCLUSIONS: With an overall success rate of 88.7%, the first experiences with the ProGAV in childhood hydrocephalus are promising and justify its further use in the pediatric population.