Chiari malformation Type I in children younger than age 6 years: presentation and surgical outcome

Fourth ventricular roof angle does not predict surgical outcome in paediatric patients with Chiari I malformation

PURPOSE

Pre-operative fourth ventricle roof angle (FVRA) has recently been highlighted as a novel radiographic predictor of clinical severity in Chiari type-I malformation (CM-I) as reported by Seaman et al. (J Neurosurg Pediatr 25:1-8, 2021). This has led to suggestions that FVRA could be included in algorithms to determine indications for surgery. We aimed to test the accuracy of FVRA as a predictor of clinical severity and its effect on post-operative outcome in a large retrospective cohort of paediatric patients who underwent decompression for CM-I.

METHODOLOGY

Patients undergoing craniocervical decompression for CM-I at the Queensland Children's Hospital and Mater Hospital, Brisbane, between 2006 and 2018 were included. Data was collected from 66 patients aged 0-18 years. Post-operative outcome was assessed by calculating Chicago Chiari Outcomes Score (CCOS) at follow-up. The FVRA was taken from a mid-sagittal T1-weighted MRI as previously described (Seaman et al. in J Neurosurg Pediatr 25:1-8, 2021). The angle is subtended between superior and inferior medullary velum.

RESULTS

Whilst results from Seaman et al. demonstrated a strong correlation between a FVRA > 65° and symptomatic CM-I, this did not translate to our dataset (p = 0.61). Additionally, pre-operative FVRA is not useful as a predictive tool for post-surgical outcome as assessed by CCOS (p = 0.50), and post-operative reduction in FVRA did not correlate with improved outcomes (p = 0.81). We did note significantly worse outcomes in patients presenting with pre-operative brainstem dysfunction (p = 0.03).

CONCLUSION

Paediatric CM-I is a challenging cohort to manage, often due to young age and a lack of language skills. There is a heavy reliance on radiological findings. Whilst FVRA has previously been reported to be of value as a determinant of clinical severity in adult and paediatric patients, we find that this measurement is of dubious value in our retrospective cohort.

A Unique Clinical Presentation of Congenital Thumb Aplasia, Radioulnar Synostosis, and Chiari Malformation: A Potential Pediatric Syndromic Association

The medical literature does not currently report a case of co-occurring congenital thumb aplasia, radioulnar synostosis (RUS), and Chiari malformation with scoliosis. Furthermore, there is an overlap of clinical features with other documented syndromes and associations that have potential cardiac, gastrointestinal, hematologic, and nephrological implications, thus contributing to increased morbidity and mortality if left undetected. We describe an interesting case of congenital thumb aplasia, RUS, and Chiari malformation with scoliosis in the absence of non-musculoskeletal abnormalities. These findings prompted further investigation to determine whether this is a unique presentation of a previously described syndrome, due to teratogenic exposure in utero, or a syndromic association yet to be adequately identified by the scientific community. We also identified several candidate genes that may guide genetic testing in the future.

Neurologic Dysphagia

Dysphagia is commonly associated with neurologic/neuromuscular disorders including prematurity, cerebral palsy, traumatic brain injury, brain tumors, genetic disorders, and neuromuscular diseases. This article aims to review the major categories of neurologic dysphagia, to outline specific findings and special considerations for each population, and to acknowledge the importance of integrating each patient's medical prognosis, goals of care, and developmental stage into a multidisciplinary treatment plan.

Brain imaging abnormalities in children with dysphagia with aspiration: A retrospective study

OBJECTIVE

Head imaging is often performed in children with persistent dysphagia with aspiration to evaluate for Chiari malformations that may be associated with dysphagia. Unfortunately, the frequency of Chiari malformations or other head imaging abnormalities in children who aspirate is unknown. The goal of this study is to determine the frequency of head imaging abnormalities in children with evidence of aspiration or penetration on video fluoroscopic swallow study (VFSS).

SETTING

Tertiary Children's Hospital.

METHODS

We performed retrospective analysis of children with a diagnosis of aspiration evaluated at our center from January 2010 through April 2021. In this study, we included children with VFSS confirmed aspiration or penetration, brain magnetic resonance imaging (MRI) performed at our center, and without known genetic, congenital craniofacial, or neurologic abnormalities.

RESULTS

Of the 977 patients evaluated in our system during that time with a diagnosis of aspiration, 185 children met the inclusion criteria. Eight children were diagnosed with Chiari malformations (4.3%) and 94 head MRIs were abnormal (51.4%). There was no difference in VFSS findings (frequency of aspiration, penetration, penetration-aspiration score, or recommended thickness of liquid) in children with a Chiari malformation versus other abnormalities or normal brain imaging. The majority of other non-Chiari brain imaging abnormalities were nonspecific. There was no difference in VFSS findings in children with abnormal MRI findings versus normal MRI.

CONCLUSIONS

Brain imaging abnormalities are common in children who aspirate. Intervenable lesions are rare. Further studies are required to determine patients that will most likely benefit from brain imaging.

A systematic review of the power of standardization in pediatric neurosurgery

In the current neurosurgical field, there is a constant emphasis on providing the best care with the most value. Such work requires the constant optimization of not only surgical but also perioperative services. Recent work has demonstrated the power of standardized techniques in limiting complication while promoting optimal outcomes. In this review article, protocols addressing operative and perioperative care for common pediatric neurosurgical procedures are discussed. These articles address how various institutions have optimized procedures through standardization. Our objective is to improve patient outcomes through the optimization of protocols.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Symptoms

BACKGROUND

Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or obstruction of the flow of cerebrospinal fluid. Diagnosis and treatment of CIM is varied, and guidelines produced through systematic review may be helpful for clinicians.

OBJECTIVE

To perform a systematic review of the medical literature to answer specific questions on the diagnosis and treatment of CIM.

METHODS

PubMed and Embase were queried between 1946 and January 23, 2021, using the search strategies provided in Appendix I of the full guidelines.

RESULTS

The literature search yielded 430 abstracts, of which 79 were selected for full-text review, 44 were then rejected for not meeting the inclusion criteria or for being off-topic, and 35 were included in this systematic review.

CONCLUSION

Four Grade C recommendations were made based on Class III evidence, and 1 question had insufficient evidence. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/2-symptoms .

The prevalence of Chiari malformation among children with persistent dysphagia

BACKGROUND

Brain imaging has been utilized as a diagnostic tool in the workup of persistent pediatric dysphagia, yet the indications for imaging and the prevalence of Chiari malformation (CM) have not been established.

OBJECTIVE

to evaluate the prevalence of CM anomalies in children who underwent brain magnetic resonance imaging (MRI) for pharyngeal dysphagia and to review the clinical findings in the CM group compared to the non-CM group.

METHODS

A retrospective cohort study of children who underwent MRI as part of the workup for the diagnosis of dysphagia in a tertiary care children's hospital between 2010 and 2021.

RESULTS

150 patients were included. The mean age at diagnosis of dysphagia was 1 ± 3.4 years, and the mean age at MRI was 3.5 ± 4.2 years. Common comorbidities in our cohort included prematurity (n = 70, 46.7 %), gastroesophageal reflux (n = 65, 43.3 %), neuromuscular/seizure disorder (n = 53,35.3 %), and underlying syndrome (n = 16, 10.7 %). Abnormal brain findings were seen in 32 (21.3 %) patients, of whom 5 (3.3 %) were diagnosed with CM-I and 4 (2.7 %) patients with tonsillar ectopia. Clinical characteristics and dysphagia severity were similar between patients with CM-I/tonsillar ectopia and patients without tonsillar herniation.

CONCLUSIONS

Brain MRI should be pursued as part of the work-up for persistent dysphagia in pediatric patients given the relatively higher prevalence of CM-I. Multi-institutional studies are required to establish the criteria and timing of brain imaging in patients with dysphagia.

Knowledge mapping of syringomyelia from 2003 to 2022: A bibliometric analysis

BACKGROUND

Syringomyelia is a chronic, progressive disease of the spinal cord. Syringomyelia is an etiologically diverse affliction caused by disturbance of normal cerebrospinal fluid flow dynamics. Lesions are characterized by the formation of tubular cavities in the gray matter of the spinal cord and gliosis; however, the etiology is unknown and treatment methods differ. Many existing studies have focused on the relationship between other diseases and syringomyelia. There is a lack of comprehensive and objective reports on the research status of syringomyelia. Therefore, this study aimed to conduct a bibliometric analysis to quantify studies on Syringomyelia and trending issues in the last 20 years.

METHODS

Articles were acquired from the Web of Science Core Collection database. We used the Library Metrology online analysis platform, BICOMB, gCLUTO, CiteSpace bibliometrics tools for analysis, VOSviewer 1.6.16 (Nees Jan van Eck and Ludo Waltman, 2010), and Microsoft Excel 2019 to perform bibliometric analysis and visualization. Individual impact and collaborative information were quantified by analyzing annual publications, journals, co-cited journals, countries/regions, institutions, authors, and co-cited authors. We then identified the trending research areas of syringomyelia by analyzing the co-occurrence of keywords and co-cited references.

RESULTS

From January 2003 to August 2022, 9,556 authors from 66 countries published a total of 1,902 research articles on syringomyelia in 518 academic journals. Most publications come from the United States, China, the United Kingdom, and Japan, with the United States dominating. Nanjing University and the University of Washington are the most active institutions, Dr. Claire Rusbridge has published the most papers, and Miholat has the most co-citations. The Journal of Neurosurgery has the highest number of co-cited articles, which are mainly in the fields of neurology, surgery, and biology. High-frequency keywords included syringomyelia, Chiari-I malformation, children, surgical treatment, and spinal cord.

CONCLUSIONS

The number of articles on syringomyelia has increased steadily over the past two decades. At present, research on syringomyelia is mainly focused on the age of onset, potential therapeutic interventions, surgical treatment, avoidance of recurrence, and delay of pain. The use of surgical treatment of the disease and the mechanism of further treatment are the current hot research topics. The correlation between trauma and congenital factors, translational application, the effect of surgical treatment, postoperative recurrence, and complications are further hot research areas. These may provide ideas for further research into a radical cure for syringomyelia.

Identifying Posterior Fossa Abnormality in Pediatric Aerodigestive Patients, a Case Series

OBJECTIVES

Multidisciplinary clinics like Aerodigestive programs focus on issues associated with airway, pulmonary, and gastrointestinal issues. Rarely, significant neurological issues like posterior fossa abnormality are identified as the primary etiology. We describe 3 such patients and compare their clinical presentation to the other patients seen in Aerodigestive clinic.

METHODS

A retrospective chart review was conducted to review the 3 posterior fossa patients and the remainder of children that were referred to the Aerodigestive Clinic at Children's Hospital Los Angeles from June 2016 to August 2018. Clinical characteristics including triple endoscopies and sleep studies were recorded.

RESULTS

Of the 110 patients included for review, 3 patients (3%) had an underlying posterior fossa abnormality; all of whom had symptoms of sleep disordered breathing along with dysphagia compared with 30% incidence of this symptom profile in the remaining Aerodigestive population.

CONCLUSION

Presence of sleep disordered breathing and dysphagia, with underlying vomiting history, warrants considering evaluation for posterior fossa abnormalities in addition to traditional workup for aerodigestive disorders. Due to the rarity of this presentation and small sample size, future studies with multicenter collaboration may help better describe identifiers to delineate this population with similar aerodigestive symptoms and clarify diagnostic algorithms.

Above-The-Hairline Suboccipital Transverse Approach for the Treatment of Chiari I Malformation

BACKGROUND

Chiari I malformation is a common pediatric neurosurgical disorder with an established treatment paradigm. Posterior fossa decompression and duraplasty (PFDD) is associated with symptom improvement but it carries postoperative risk, particularly cerebrospinal fluid (CSF) leak and wound complications. In addition, the cosmetic outcomes of PFDD have been overlooked in the literature.

OBJECTIVE

To describe a novel approach for PFDD in which the transverse surgical incision is completely hidden above the hairline and to report early outcomes in a prospective patient cohort.

METHODS

Clinical and cosmetic outcomes were recorded for 15 consecutive pediatric patients who underwent PFDD for Chiari I malformation via the above-the-hairline transverse suboccipital approach.

RESULTS

The median clinical follow-up time was 6 months (range 1-12 months), and the majority of patients experienced significant improvement of their preoperative symptoms. Three patients (20%) experienced complications associated with surgery, which included injury to the greater occipital nerve, CSF hypotension and subfascial pseudomeningocele, and superficial wound dehiscence that resolved spontaneously with oral antibiotics. Zero patients (0%) returned to the operating room for persistent CSF leak, deep wound infection, or revision decompression. An excellent cosmetic outcome was achieved in 12 patients (80%). No patient had a poor cosmetic outcome.

CONCLUSION

The above-the-hairline transverse suboccipital approach for PFDD in patients with Chiari I malformation offers favorable cosmetic outcomes and fascial closure while permitting adequate decompression.

Progressive Flaccid Paraplegia in a Toddler due to Chiari Type I Malformation Complicated with Hydrocephalus and Syringomyelia. A Case Report

Chiari malformation is a clinico-radiological entity defined by herniation of rhombencephalic structures through the foramen magnum. The most common type, Chiari I, involves herniation of the cerebellar tonsils specifically. We present the case of a 2-year-old with three weeks of progressive bilateral leg weakness, absent reflexes, and the inability to walk. The patient was found to have Chiari I with hydrocephalus and syringomyelia. This is the youngest patient reported in the literature presenting with a clinical picture of spinal shock. Early recognition of this entity allows for proper treatment and improved outcomes.

CSF-space volumetric change following posterior fossa decompression in paediatric Chiari type-I malformation: a correlation with outcome

OBJECTIVE

We have previously reported inferior post-operative clinical outcomes in younger children with Chiari type-I malformation (CIM). We sought to quantify the CSF volumetric changes pre- and post-decompression, in a paediatric cohort, to determine whether cisternal volume change is associated with clinical outcomes.

METHODS

In this retrospective clinical study, the CSF spaces of the posterior fossa (supracerebellar/quadrigeminal, prepontine, fourth ventricle, cisterna magna) were measured on magnetic resonance images pre- and post-operatively using a semi-automated method. Additionally, we describe a novel CSF space of the upper cervical canal incorporating the subarachnoid space from the foramen magnum to the inferior cortex of the C2 body, FM-C2 cistern. Morphometric measurements included the pB-C2 distance, clivoaxial angle, clival length, clival angle and Boogard's angle. Volumetric and morphometric data were correlated with clinical outcomes at 4-12 months post-operatively as measured by the Chicago Chiari Outcome Scale (CCOS).

RESULTS

Of 59 adequate clinical cases, 57 and 36 patients had acceptable imaging for morphometric and volumetric analysis respectively. All CSF spaces measured had a significant increase in volume post-operatively (p < 0.05). There was no correlation between the change in volume or post-operative CSF volumes and CCOS. The pre-operative volume of the FM-C2 was positively correlated with total CCOS (Wald [Formula: see text], [Formula: see text]) and was significantly smaller in the 0-6-year age group (2.38 ± 1.27 ml vs. 3.67 ± 1.56 ml, p = 0.014). No morphometric measurement changed significantly after surgery or demonstrated a relationship with CCOS.

CONCLUSIONS

Volumetric changes in the CSF cisterns of the posterior cranial fossa and upper cervical canal do not correlate with the age-related differences in clinical outcomes in paediatric CIM. The pre-operative volume of the FM-C2 cistern may have a role in predicting the likelihood of a beneficial post-operative outcome in paediatric CIM.

Clinicoradiographic data and management of children with Chiari malformation type 1 and 1.5: an Italian case series

INTRODUCTION

The widespread use of imaging has increased Chiari malformation (CM) diagnosis. CM shows clinical heterogeneity that makes management controversial. We aimed to evaluate the occurrence and clinical and radiographic presentation of children with CM-1 and CM-1.5, reporting possible differences according to age and management.

METHODS

We retrospectively reviewed 46 children diagnosed with CM-1 or CM-1.5, between 2006 and 2019 at our institute. We evaluated for each subject: reason for hospital admission, clinical presentation, age at diagnosis, extent of cerebellar tonsillar herniation (CTH) and type of treatment when carried out. Affected children were assigned to three age groups. In some patients, a clinical follow-up was carried out.

RESULTS

Mean age at diagnosis was 7.61 years. Mean CTH was 8.72 mm. Syringomyelia was found in 10.9%. Twenty-six individuals (56.5%) were symptomatic. The most frequent symptom was headache (34.8%). There were no statistically significant differences between the age groups with regard to the amount of CTH (p = 0.81). Thirteen children (28.3%) underwent surgical treatment. CTH was significantly higher in the surgical group (p < 0.01). Twenty-three patients (50%) performed a 3-year mean follow-up, 17 of whom had no surgery treatment. CTH was stable in 58.8%, reduced in three and increased in three, without any change in symptoms. Only one child showed a worsening in herniation and symptoms, then requiring surgery.

CONCLUSION

Frequency and type of symptoms were consistent with those reported in the literature. Conservative approach is a viable option for minimally symptomatic patients, most of whom did not show clinical worsening at follow-up.

Standardizing postoperative care for pediatric intradural Chiari decompressions to decrease length of stay

OBJECTIVE

Amid national and local budget crises, cutting costs while maintaining quality care is a top priority. Chiari malformation is a relatively common pediatric neurosurgical pathology, and postoperative care varies widely. The postoperative course can be complicated by pain and nausea, which can extend the hospital stay. In this study, the authors aimed to examine whether instituting a standardized postoperative care protocol would decrease overall patient hospital length of stay (LOS) as well as cost to families and the hospital system.

METHODS

A retrospective study of pediatric patients who underwent an intradural Chiari decompression with expansile duraplasty at a single institution from January 2016 to September 2019 was performed. A standardized postoperative care protocol was instituted on May 17, 2018. Pre- and postprotocol groups were primarily analyzed for demographics, LOS, and the estimated financial expense of the hospital stay. Secondary analysis included readmissions, opioid consumption, and follow-up.

RESULTS

The analysis included 132 pediatric patients who underwent an intradural Chiari decompression with expansile duraplasty. The preprotocol group included 97 patients and the postprotocol group included 35 patients. Patient age ranged from 0.5 to 26 years (mean 9.5 years). The mean LOS preprotocol was 55.48 hours (range 25.90-127.77 hours), and the mean postprotocol LOS was 46.39 hours (range 27.58-77.38 hours). The comparison between means showed a statistically significant decrease following protocol initiation (95% CI 1.87-16.31 hours, p = 0.014). In the preprotocol group, 21 of 97 patients (22%) were discharged the first day after surgery compared with 14 of 35 patients (40%) in the postprotocol group (p = 0.045). The estimated cost of one night on the pediatric neurosurgical intermediate ward was approximately $4500, which gives overall cost estimates for 100 theoretical cases of $927,800 for the preprotocol group and $732,900 for the postprotocol group.

CONCLUSIONS

By instituting a Chiari protocol, postoperative LOS was significantly decreased, which resulted in decreased healthcare costs while maintaining high-quality and safe care.

Extradural decompression versus duraplasty in Chiari malformation type I with syrinx: outcomes on scoliosis from the Park-Reeves Syringomyelia Research Consortium

OBJECTIVE

Scoliosis is common in patients with Chiari malformation type I (CM-I)-associated syringomyelia. While it is known that treatment with posterior fossa decompression (PFD) may reduce the progression of scoliosis, it is unknown if decompression with duraplasty is superior to extradural decompression.

METHODS

A large multicenter retrospective and prospective registry of 1257 pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for patients with scoliosis who underwent PFD with or without duraplasty.

RESULTS

In total, 422 patients who underwent PFD had a clinical diagnosis of scoliosis. Of these patients, 346 underwent duraplasty, 51 received extradural decompression alone, and 25 were excluded because no data were available on the type of PFD. The mean clinical follow-up was 2.6 years. Overall, there was no difference in subsequent occurrence of fusion or proportion of patients with curve progression between those with and those without a duraplasty. However, after controlling for age, sex, preoperative curve magnitude, syrinx length, syrinx width, and holocord syrinx, extradural decompression was associated with curve progression > 10°, but not increased occurrence of fusion. Older age at PFD and larger preoperative curve magnitude were independently associated with subsequent occurrence of fusion. Greater syrinx reduction after PFD of either type was associated with decreased occurrence of fusion.

CONCLUSIONS

In patients with CM-I, syrinx, and scoliosis undergoing PFD, there was no difference in subsequent occurrence of surgical correction of scoliosis between those receiving a duraplasty and those with an extradural decompression. However, after controlling for preoperative factors including age, syrinx characteristics, and curve magnitude, patients treated with duraplasty were less likely to have curve progression than patients treated with extradural decompression. Further study is needed to evaluate the role of duraplasty in curve stabilization after PFD.

Chiari Malformation in Children

Chiari malformation type 1 (CM1) is often found incidentally. However, patients with symptoms or signs referable to CM1 or an associated syrinx will likely benefit from surgical intervention. Patients who are not symptomatic from CM1 at presentation are unlikely to become symptomatic at follow-up.

Interlayer dural split technique for Chiari I malformation treatment in adult-Technical note

OBJECTIVE

To present an alternative surgical technique in treating cases of Chiari I Malformation with mild-to-moderate syringomyelia after decompressive suboccipital craniectomy: incising only the outer layer of the dura mater, then dissecting it from the inner layer without opening the latter.

PATIENTS AND METHODS

We utilized this technique in a short series of three cases who were admitted to our department for mild symptoms such as intermittent headache and dissociated sensory loss in the upper limbs, caused by a Chiari Malformation Type I. The patients were placed in the sitting position. We performed a reduced median suboccipital craniectomy and resection of the posterior arch of C1 adapted to the level of tonsil descent, from a limited superior half to complete resection. Afterward, we incised the outer dural layer, while sparing the inner one. Using a fine dissector, we then split apart the outer and inner layers to the margin of the craniectomy. Through the transparency of the inner layer and the arachnoid, the cerebellum and the medulla were visible and pulsating. An autologous fascia duraplasty was then performed.

RESULTS

The postoperative course was favorable in all cases, the patients being discharged without any deficits and with complete symptom resolution. Follow-up at 3, 6, and 12 months after surgery revealed a significant reduction in brainstem compression and syringomyelia.

CONCLUSIONS

Interlayer dural split technique can be used effectively in treating symptomatic cases of type I Chiari malformation in adults, with mild-to-moderate syringomyelia. It is less invasive than opening the dura and possibly more effective than decompressive craniectomy and C1 laminectomy alone. This technique must be validated in a larger case-control series.

Natural history of Chiari I malformation in children: a retrospective analysis

PURPOSE

While there are increasing numbers of studies published regarding Chiari I malformation (CM1) in children, most of these focus on surgical indications, technique, and outcomes. Few studies examine the natural history of CM1 once the decision is made to treat a patient conservatively. In this study, we seek to determine the percentage of pediatric patients who undergo surgery for CM1, both after initial consultation and in a delayed fashion, the natural history of CM1 after a decision to pursue non-operative management, and attempt to identify patient factors that may predict development of new or worsening CM1 symptoms.

METHODS

From our database of 465 pediatric patients with CM1, we identified those who were seen for initial consultation from July 1, 2011, to June 30, 2016. We examined rates of surgical intervention, types of surgical intervention, age, gender, and presence or absence of headache and syrinx, and looked carefully at the patients who had new or worsening symptoms prompting delayed surgical intervention.

RESULTS

We identified 226 patients meeting inclusion criteria. Overall, 15% of patients had surgery, the majority being Chiari decompression. Just over half of these patients had surgery within 6 months of initial consultation. Of those with delayed surgery, only 4 patients had new symptoms/syrinx and 1 patient had symptom progression. The other patients had various reasons for surgical delay not related to symptom development or progression. There were no obvious commonalities among these 5 patients that could predict progression prospectively. All patients who had surgery did so within 2 years of initial consultation.

CONCLUSION

Overall, the natural history of asymptomatic CM1 is benign. Patients treated non-operatively are unlikely to progress. If they do progress, this is likely to occur within 2 years of initial consultation. There were no factors identified in this study that predicted new or worsening symptoms over time.

Revision Chiari Surgery in Young Children: Predictors and Outcomes

INTRODUCTION

Children aged 0-6 years with Chiari malformation (CM) often present with atypical symptoms and require revision surgery more often than older children. We studied characteristics and outcomes of CM patients in this age-group who underwent one or more revision surgeries to assess how often revision surgery is necessary and successful in this age-group.

METHODS

We retrospectively reviewed patients who were diagnosed with CM 1 or CM 1.5 and surgically treated with posterior fossa decompression (PFD) with or without duraplasty before their 7th birthday. Basic demographics, preoperative presentation, operative details, and postoperative outcomes were analyzed.

RESULTS

Forty patients (mean age 3.2 ± 1.7 years, 35% female) were reviewed. The most common presenting symptoms were headache, dysphagia, and respiratory problems. Eight patients required one or more revision surgeries 11.6 ± 7.6 months on average after their initial surgery. Comparing the revision and no revision groups, dysautonomia was significantly more common prior to initial surgery in the children requiring revision (37.5 vs. 3.1%, p = 0.02). The revision group also trended toward more dysphagia (75.0 vs. 46.9%, p = 0.24) and respiratory problems (75.0 vs. 40.6%, p = 0.12). The most frequent reasons for reoperation were symptom recurrence (6/8), residual posterior fossa compression (3/8), significant scar tissue formation (2/8), ventral brainstem compression (1/8), and suspected craniocervical instability (1/8). Of the 8 children undergoing reoperation, surgery achieved symptom resolution or improvement in 5, while 3 had unchanged symptoms. Two patients underwent a third surgery, after which 1 showed improvement and the other did not. This last patient showed short-term improvement after a fourth surgery but had symptom recurrence 12 months later.

DISCUSSION/CONCLUSION

Oropharyngeal and respiratory problems are particularly common in children aged 0-6 years with CM. Presentation with dysautonomia or other signs of brainstem compression will often predict an additional surgery will be needed after an initial PFD. Symptom recurrence is the most frequent reason for reoperation, and revision surgeries lead to improved clinical outcomes in the majority but not all of these young patients. Surgery in very young children is successful, but reoperation should be integrated into an up-front discussion algorithm particularly in children with severe symptoms.

Chiari 1 malformation: age-based outcomes in a paediatric surgical cohort

PURPOSE

Substantial evidence exists describing differences between paediatric and adult Chiari 1 malformation (CM1) patients. Differences in clinical presentation between very young (0-6 years old) and older (7-18 years old) paediatric patients is similarly well-established. However, progression on these findings with regard to surgical outcomes is limited. We aimed to establish whether inter-paediatric age group modifies surgical outcome for CM1 decompression.

METHODS

Retrospective chart review was conducted for 65 patients receiving posterior fossa decompression between 2006 and 2018. Presenting features, surgical management, and outcome were evaluated and stratified into very young patients (0-6 years) or older patients (7-18 years). Outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS), a validated 16-point framework for comparison.

RESULTS

Very young patients (21 patients) scored significantly lower in surgical outcome overall compared with older patients (44 patients) (12.1 ± 3.2/16 vs 14.2 ± 1.6/16, p = 0.011), and across 3/4 CCOS subscores: non-pain symptoms, functionality, and complications. Very young patients also returned to theatre more commonly (47.6% vs 13.6%, p = 0.003), primarily for re-do decompression (7/10 patients, 70%). Finally, the presentation of very young patients differed to older patients with significantly more oropharyngeal (38.1% vs 9.0%, p = 0.014) and motor symptoms (47.6% vs 22.7%, p = 0.042).

DISCUSSION

Very young patients (0-6 years) do not appear to respond as well to standard posterior fossa decompression, as their older (7-18 years) paediatric counterparts, in the absence of several baseline cohort characteristic differences. We hypothesise underlying anatomical differences may contribute to this finding.

Radiological and clinical associations with scoliosis outcomes after posterior fossa decompression in patients with Chiari malformation and syrinx from the Park-Reeves Syringomyelia Research Consortium

OBJECTIVE

In patients with Chiari malformation type I (CM-I) and a syrinx who also have scoliosis, clinical and radiological predictors of curve regression after posterior fossa decompression are not well known. Prior reports indicate that age younger than 10 years and a curve magnitude < 35° are favorable predictors of curve regression following surgery. The aim of this study was to determine baseline radiological factors, including craniocervical junction alignment, that might predict curve stability or improvement after posterior fossa decompression.

METHODS

A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and a syrinx (≥ 3 mm in width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°) in patients who underwent posterior fossa decompression and who also had follow-up imaging.

RESULTS

Of 825 patients with CM-I and a syrinx, 251 (30.4%) were noted to have scoliosis present at the time of diagnosis. Forty-one (16.3%) of these patients underwent posterior fossa decompression and had follow-up imaging to assess for scoliosis. Twenty-three patients (56%) were female, the mean age at time of CM-I decompression was 10.0 years, and the mean follow-up duration was 1.3 years. Nine patients (22%) had stable curves, 16 (39%) showed improvement (> 5°), and 16 (39%) displayed curve progression (> 5°) during the follow-up period. Younger age at the time of decompression was associated with improvement in curve magnitude; for those with curves of ≤ 35°, 17% of patients younger than 10 years of age had curve progression compared with 64% of those 10 years of age or older (p = 0.008). There was no difference by age for those with curves > 35°. Tonsil position, baseline syrinx dimensions, and change in syrinx size were not associated with the change in curve magnitude. There was no difference in progression after surgery in patients who were also treated with a brace compared to those who were not treated with a brace for scoliosis.

CONCLUSIONS

In this cohort of patients with CM-I, a syrinx, and scoliosis, younger age at the time of decompression was associated with improvement in curve magnitude following surgery, especially in patients younger than 10 years of age with curves of ≤ 35°. Baseline tonsil position, syrinx dimensions, frontooccipital horn ratio, and craniocervical junction morphology were not associated with changes in curve magnitude after surgery.

Acute presentation of Chiari 1 malformation in children

PURPOSE

To review the literature about the acute presentation of Chiari 1 malformation in children, with a focus on acute cervical cord syndromes with impairment of the cortico-spinal tract. To analyze the possible precipitating factors and the pathophysiology of the acute onset.

METHOD

Illustrative case presentation with literature review.

RESULTS

The literature includes just a few dozens of children with acute presentation of Chiari 1 malformation. The more frequent presentations consist of oropharyngeal dysfunction, cranial nerve impairment, high intracranial pressure, peripheral motor deficit. Acute impairment of cervical long tracts is very rare and we could find only 16 previously reported cases of cervical cord impairment with quadriparesis or hemiparesis.

CONCLUSIONS

Nowadays, a lot of asymptomatic Chiari 1 malformations are frequently observed owing to the wide diffusion of magnetic resonance imaging. This raised the question about the management of these patients. Despite severe and even lethal manifestations being reported in previously asymptomatic patients, the absolute rarity of acute deterioration does not justify prophylactic surgery. The diagnosis of Chiari malformation may be initially difficult in patients with isolated, acute, and unusual presentations but physicians should bear in mind its possibility, because prompt cranio-cervical decompression may be decisive.

Ventrolateral Tonsillar Position Defines Novel Chiari 0.5 Classification

BACKGROUND

Cervicomedullary compression in young children has been described in the context of Chiari type 1 malformation, with symptoms associated with the extent of tonsillar herniation below McRae line. Historically, Chiari type 1 malformation has been defined by tonsillar herniation of at least 5 mm. However, in certain populations, including very young children, Chiari symptoms may be present without this finding. A new Chiari classification is thus necessary.

METHODS

Cases involving patients up to 5 years of age evaluated for possible posterior fossa decompression were retrospectively reviewed. Preoperative symptoms, magnetic resonance imaging findings, surgical management, and short- and long-term outcome and follow-up were recorded. Tonsillar descent and presence of ventral herniation (VH) were recorded. We define VH as the tonsils crossing a line that bisects the caudal medulla at the level of the foramen magnum, thus creating a novel entity, Chiari type 0.5 malformation. Patients with ventrally herniated tonsils were compared with patients exhibiting more typical Chiari morphology.

RESULTS

Of 41 cases retrospectively reviewed, 20 met criteria for VH. These differed from cases without VH because of the predominance of medullary symptoms. In the VH cohort, 11 patients underwent surgical decompression with symptom resolution; 9 were initially managed conservatively, but 3 subsequently required surgery.

CONCLUSIONS

We define a novel Chiari entity, Chiari type 0.5 malformation, characterized by ventral tonsillar wrapping around the medulla in young children in the absence of classic Chiari type 1 malformation imaging findings. These patients are more likely to present with medullary symptoms than patients without VH. They are also more likely to require surgical decompression and respond favorably to intervention.

Management of Chiari malformations: opinions from different centers-a review

PURPOSE

Surgical decision-making in Chiari malformation type I (CM-I) patients tends to depend on the presence of neurological signs and symptoms, syringomyelia, and/or scoliosis, but significant variability exists from center to center. Here, we review the symptoms of CM-I in children and provide an overview of the differences in opinion regarding surgical indications, preferred surgical techniques, and measures of outcome.

METHODS

A review of the literature was performed to identify publications relevant to the surgical management of pediatric CM-I patients.

RESULTS

Most surgeons agree that asymptomatic patients without syringomyelia should not undergo prophylactic surgery, while symptoms of brainstem compression and/or lower cranial nerve dysfunction warrant surgery. Patients between these extremes, however, remain controversial, as does selection of the most appropriate surgical technique.

CONCLUSIONS

The optimal surgical procedure for children with CM-I remains a point of contention, and widespread variability exists between and within centers.

Opinion for different centers: surgical experience with Chiari malformation type I in children at Xuanwu Hospital, China

PURPOSE

To evaluate the presenting symptoms, surgical strategy, and outcome in children with Chiari malformation type I (CM-I).

METHODS

The medical records of children who were diagnosed with CM-I under 14 years old and subsequently underwent surgery for CM-I between 2014 and 2018 were reviewed. The medical records for presentation, radiological image, surgical intervention, and outcome were evaluated.

RESULTS

Twelve children with CM-I and syringomyelia were included. All of the children were symptomatic. The most common presenting symptom was weakness, followed by scoliosis. All of them underwent posterior fossa decompression with/without duraplasty. Relief of preoperative pathologies and syringomyelia was experienced by all of them.

CONCLUSIONS

The presenting symptoms of CM-I in children may be neurological deficits and scoliosis, which have a relationship with syringomyelia. Early recognition and a tailored operative procedure of CM-I in children could lead to good outcomes. Additional therapies for syringomyelia and scoliosis could be avoided.

Clinical diagnosis-part II: what is attributed to Chiari I

PURPOSE

Chiari malformation type I is identified as radiological appearance of cerebellar tonsil herniation below the foramen magnum. The wide spectrum of clinical manifestations variably associated sometimes encompasses signs and symptoms whose correlation with the malformation remains debatable. However, a correct clinical framework is relevant in tailoring the strategy of management, and in particular, establishing the appropriate surgical intervention.

METHODS

An analysis of relevant articles on this issue was performed, involving both single case reports and case series. The papers were obtained from electronic databases including PubMed/MEDLINE and Google Scholar, as well as direct contact with some authors.

RESULTS

This review focuses on those unusual clinical pictures attributed to Chiari malformation type I (CMI), investigating their actual relationship with the morphological condition. Supposed physiopathogenetic mechanisms and clinical relevance are discussed along with an analysis on the surgical indications and results.

CONCLUSION

There is no clear explanation on why some patients may exhibit uncommon symptoms, often in association with the most frequent ones, but even reported as single initial clinical occurrence. Their actual incidence may have been roughly underestimated in the literature so far, because of wide heterogeneity of selection and analysis among different studies. Most of the authors appear sharing the impression that CMI surgical decompression plays a significant role in controlling the majority of these unusual symptoms, stressing their actual occurrence in relation with the malformation. A routinely multidisciplinary clinical approach has become advisable to encompass the diversity of conditions potentially associated with CMI and improve the care of CMI patients.

Complex Chiari malformation: using craniovertebral junction metrics to guide treatment

The complex Chiari, characterized by abnormal craniocervical bony anatomy in addition to Chiari tonsillar herniation, is a relatively recent addition to the concepts surrounding the Chiari literature. The primary findings of complex Chiari include craniocervical kyphosis and retroflexed odontoid, both of which can be described with radiographic measurements. This manuscript will outline the background literature regarding Chiari craniocervical morphometrics and supply an algorithm for the general management of complex Chiari patients.

Management of Chiari I malformations: a paradigm in evolution

PURPOSE

Despite decades of experience and research, the etiology and management of Chiari I malformations (CM-I) continue to raise more questions than answers. Controversy abounds in every aspect of management, including the indications, timing, and type of surgery, as well as clinical and radiographic outcomes. This review aims to outline past experiences, consolidate current evidence, and recommend directions for the future management of the Chiari I malformation.

METHODS

A review of recent literature on the management of CM-I in pediatric patients is presented, along with our experience in managing 1073 patients who were diagnosed with CM-I over the past two decades (1998-2018) at Children's National Medical Center (CNMC) in Washington DC.

RESULTS

The general trend reveals an increase in the diagnosis of CM-I at younger ages with a significant proportion of these being incidental findings (0.5-3.6%) in asymptomatic patients as well as a rise in the number of patients undergoing Chiari posterior fossa decompression surgery (PFD). The type of surgical intervention varies widely. At our institution, 104 (37%) Chiari surgeries were bone-only PFD with/without outer leaf durectomy, whereas 177 (63%) were PFD with duraplasty. We did not find a significant difference in outcomes between the PFD and PFDD groups (p = 0.59). An analysis of failures revealed a significant difference between patients who underwent tonsillar coagulation versus those whose tonsils were not manipulated (p = 0.02).

CONCLUSION

While the optimal surgical intervention continues to remain elusive, there is a shift away from intradural techniques in favor of a simple, extradural approach (including dural delamination) in pediatric patients due to high rates of clinical and radiographic success, along with a lower complication rate. The efficacy, safety, and necessity of tonsillar manipulation continue to be heavily contested, as evidence increasingly supports the efficacy and safety of less tonsillar manipulation, including our own experience.

Scoliosis in patients with Chiari malformation type I

The literature about the association between Chiari malformations (CMs) and scoliosis has been growing over the last three decades; yet, no consensus on the optimal management approach in this patient population has been reached. Spinal anomalies such as isolated syrinxes, isolated CM, and CM with a syrinx are relatively common among patients with presumed idiopathic scoliosis (IS), a rule that also applies to scoliosis among CM patients as well. In CM patients, scoliosis presents with atypical features such as early onset, left apical or kyphotic curvature, and neurological deficits. While spinal X-rays are essential to confirm the diagnosis of scoliosis among CM patients, a magnetic resonance imaging (MRI) is also recommended in IS patients with atypical presentations. Hypotheses attempting to explain the occurrence of scoliosis in CM patients include cerebellar tonsillar compression of the cervicomedullary junction and uneven expansion of a syrinx in the horizontal plane of the spinal cord. Early detection of scoliosis on routine spinal examination and close follow-up on curve stability and progression are essential initial steps in the management of scoliosis, especially in patients with CM, who may require full spine MRI to screen for associated neuro-axial anomalies; bracing and spinal fusion may be subsequently pursued in high-risk patients.

Surgical Experience in Pediatric Patients with Chiari-I Malformations Aged ≤18 Years

Objective:

The objective of this study was to retrospectively study Chiari I malformation patients (<18 years) treated surgically.

Materials and Methods:

Chiari I malformation patients (<18 years) treated surgically at our institute were retrospectively studied.

Results:

During the study period between January 1999 and June 2011, fifty patients, aged ≤18 years with Chiari malformation, were treated surgically and formed the basis for this series. There were 21 female children (42%) and 29 male children (58%), with a female-to-male ratio of 1:1. At the last follow-up, oropharyngeal symptoms were improved in 33% (n = 3/9). Headache/neck/back pain improved in 69.56% of children (n = 16/23). Upper-extremity pain/weakness/numbness improved in 73.91% of children (n = 17/23). Ataxia improved in 66.66% of children (n = 4/6). Lower-limb weakness/hyperreflexia improved in 83.33% of children (n = 5/6). At follow-up, magnetic resonance imaging for patients with syrinx was available for 75% of patients (n = 30/50) and not available for 25% of patients (n = 10/40). Syrinx was diminished in size or resolved in 66.33% of patients (n = 19/30) and the remaining was same for 36.66% of patients (n = 11/30).

Conclusions:

The main goal of surgery is to arrest the progression of neurological deficits. Foramen magnum decompression with a lax duroplasty is the surgical procedure of choice.

Analysis of Clinical and Radiographic Outcomes of the Angle between Clivus and Supraocciput in Patients with Chiari's Malformation Type I Following Surgical Decompression

Background  The objective of this study was to investigate whether different angles between the clivus and supraocciput (C-SO angle) in patients with Chiari's malformation type I (CMI) after posterior fossa decompression lead to different clinical and radiographic outcomes. Methods  A total of 73 patients who underwent surgical decompression at our institution between 2010 and 2016 were retrospectively divided into two groups: group A, with an angle less than 96 degrees, and group B, with an angle ≥ 96 degrees. Patient clinical outcomes were determined using the Chicago Chiari Outcome Scale (CCOS), and radiographic outcomes were determined by changes in the syrinx size before and after surgery. Direct comparisons were made between the two groups. Results  There were no statistically significant differences between the two groups regarding demographics, preoperative symptoms or radiographic characteristics ( p  > 0.05), except for the cerebellar tonsillar descent ( p ≤ 0.001). The mean overall CCOS score was 13.11 ± 1.99. The total CCOS score was significantly different between the two patient groups ( p  < 0.05). Moreover, group A demonstrated significantly better postoperative improvements than group B in clinical outcome measures based on the CCOS system ( p  = 0.035). For radiographic outcomes, the change in the syrinx between the two groups was also significantly different, with a value p =  0.024. Conclusions  A direct comparison between the two groups revealed that a smaller C-OS angle (< 96 degrees) was related to unsatisfactory clinical and radiographic outcomes. Thus, the C-OS angle may emerge as a predictor of clinical or radiographic outcomes following surgical decompression in patients with CMI.

Bony Decompression for Chiari Malformation Type I: Long-Term Follow-Up

BACKGROUND

Several surgical techniques are used for the management of Chiari malformation type I (CM-I). Bony posterior fossa decompression is considered a good option in children, though with a higher risk of requiring reoperation. However, there is not enough evidence from the series in the literature, which are often limited by inadequate follow-up. The goal of this study was to assess the effectiveness of suboccipital craniectomy alone in children after long-term follow-up.

METHODS

Forty-two children (25 female and 17 male; mean age 6.7 years), operated on with bony decompression alone, were retrospectively reviewed. All patients underwent suboccipital craniectomy. Thirty-eight children required C1 laminectomy, and 21 also underwent dural delamination on the basis of intraoperative ultrasound investigations. The outcome was assessed using the traditional measurement and the Chicago Chiari Outcome Scale (CCOS). The mean follow-up period was 11.3 years (range 5-15 years).

RESULTS

Headache was the most frequent preoperative symptom (81%), followed by neck pain (40%), vertigo (40%), ataxia (26%), and upper and lower extremity paraesthesia (26%). Syringomyelia was present in 19 patients (45%). Resolution and significant improvement of preoperative clinical symptoms were observed in 36.5% and 21.5% of cases, respectively. Three children required adjunctive surgery for symptom recurrence (7%). The tonsil position and syringomyelia were normalized or improved in 50% and 79% of cases, respectively. No complications occurred. According to the CCOS scores, 69.5% of children had an excellent outcome, 28.5% had a functional outcome and 2% had an impaired outcome.

CONCLUSION

Bony decompression alone is an effective, safe and long-lasting treatment for children with CM-I. A certain risk of symptom recurrence requiring new surgery exists, but it is widely counterbalanced by the low risk of complications. Careful patient selection is crucial for a good outcome. Prospective and randomized studies are needed for further validation.

Headaches in Loyes-Dietz Syndrome

Loeys-Dietz syndrome is a rare connective tissue disorder characterized by cardiovascular, craniofacial, skeletal, and neurocognitive abnormalities. Recurrent headaches may constitute the neurological presentation of Loyes-Dietz syndrome in the absence of an intracranial aneurysm, subarachnoid hemorrhage, or dissection. The etiology of headaches occurring in Loeys-Dietz syndrome can be diverse but underrecognized and underreported. We described 3 children with Loeys-Dietz syndrome and significant headaches who did not develop neurovascular aneurysms or dissections at presentation and during the short follow-up period. One patient had a confirmed Loeys-Dietz syndrome diagnosis previously and presented with an acute headache due to spontaneous intracranial hypotension and other 2 children had intermittent headaches due to migraine and Chiari I malformation, respectively, and subsequent diagnosis of Loeys-Dietz syndrome was made due to characteristic phenotypic and neuroradiologic abnormalities. Migraine, Chiari I malformation, and spontaneous intracranial hypotension are known features of Loeys-Dietz syndrome and these 3 children will require serial angiographic monitoring for development of intra- and extracranial dissections and aneurysms and appropriate interventions to forestall neurologic complications. It is important to raise awareness of headaches in this population so that appropriate counseling can be given to the child and parents at diagnosis. The neurology community must familiarize itself with the phenotype of the disease for earlier recognition and meticulous surveillance for optimum care for these patients.

Chiari I malformation with significant motor and autonomic dysfunction in an infant

Quadriparesis and cardiovascular instability are not symptoms commonly associated with Chiari I malformation diagnoses, less so in a 3-month-old toddler. Chiari I malformations have a wide array of symptoms, varying with regard to both the nature of onset and the age of the patient presenting. This variation is illustrated in this report, presenting a novel description of a set of symptoms in a particularly young patient, a case lacking the common insidious nature of Chiari I malformation symptoms. Acute onset of cardiovascular instability, global hypertonia, hyperreflexia, and proximal upper limb weakness in a 3-month-old toddler are discussed. Parallels between the presented case and previous case reports are few, however some key features are distinguishable among similar cases. A successful posterior fossa craniectomy allowed the acutely unwell toddler to become a healthy, fully functional child. We believe this case contributes to elucidating the rare presentations of a curious pathology.

Evaluation of Soft Tissue Hypertrophy at the Retro-Odontoid Space in Patients with Chiari Malformation Type I on Magnetic Resonance Imaging

INTRODUCTION

Chiari malformation type I (CM-I) is a well-known hindbrain disorder in which the cerebellar tonsils protrude through the foramen magnum. The soft tissues, including the transverse ligament and the tectorial membrane at the retro-odontoid space, can compress the cervicomedullary junction if they become hypertrophic.

METHODS

Twenty-two symptomatic patients with CM-I (aged 5-19 years) were treated between 2007 and 2017 at our institute. The retro-odontoid soft tissue was evaluated using T2-weighted magnetic resonance imaging. Anteroposterior (AP) distances and craniocaudal distances of the soft tissue were measured in patients with CM-I and 48 normal control children. Modified clivoaxial angles were also evaluated as the index of ventral compression of the cervicomedullary junction.

RESULTS

Of the 18 patients treated with foramen magnum decompression, 16 patients improved postoperatively, whereas the condition of 2 remained unchanged. The AP distances in the CM-I group (6.0 mm) were significantly larger than those in the control group (3.5 mm), whereas there were no apparent differences in the craniocaudal distances. Modified clivoaxial angles were obviously smaller in the CM-I group (131.5°) than in the control group (146.9°). Moreover, the AP distances were significantly reduced postoperatively (5.5 mm), although the other parameters did not change significantly.

CONCLUSIONS

The retro-odontoid soft tissue in symptomatic patients with CM-I can be hypertrophic enough to compress the cervicomedullary junction ventrally even if there are no combined osseous anomalies. Foramen magnum decompression works to reduce the hypertrophic changes significantly, suggesting that downward tonsil movement might participate in hypertrophic soft tissue formation at the retro-odontoid space.

Should all paediatric patients with presumed idiopathic scoliosis undergo MRI screening for neuro-axial disease?

BACKGROUND

Idiopathic scoliosis is a relatively common childhood condition affecting 0.47-5.2% of the population. Traditional interventions focus on orthopaedic correction of the curve angle. There is a spectrum of patients with scoliosis who are found to have neuro-axial abnormality on full MRI of the spine, but not all surgeons request imaging in the absence of neurological symptoms. There is evidence to suggest that treatment of neuro-axial disease may improve scoliosis curve outcome. We therefore sought to estimate what proportion of patients with normal neurology and scoliosis are found to have neuro-axial abnormality on full MRI imaging of the spine, in particular Chiari malformation and syringomyelia.

RESULTS

Out of 11 identified studies consisting of 3372 paediatric patients (age < 18 years), mean weighted proportion demonstrates that 14.7% of patients with scoliosis (Cobb angle > 20°) and normal neurological examination will demonstrate a neuro-axial abnormality on full MRI imaging of the spine. Of patients, 8.3 and 8.4% were found to have Chiari malformation and syringomyelia, respectively.

CONCLUSIONS

Up to one in seven paediatric patients with scoliosis and normal neurological examination will demonstrate neuro-axial disease on MRI imaging of the spine. Given that younger age and earlier age of decompression is associated with improvement in curve angle, it seems important that MRI screening be considered in all patients regardless of neurological examination findings. There is a potentially long-term benefit in these patients. Multi-cross institutional prospective studies are encouraged to further investigate effect on curve angle.

Chiari type I malformation of infants and toddlers

OBJECTIVES

Chiari I malformation has been a well-recognized clinical entity; however, its occurrence among infants and toddlers is unusual. Their clinical presentations may be different from other age groups due to their lack of effective verbal communication. The authors analyze their personal series of patients focusing on symptomatology and MRI characteristics. Treatment methods, results, and outcome are analyzed in order to identify appropriate surgical management among infants and toddlers with Chiari I malformation.

METHODS

The authors retrospectively reviewed 16 patients who were diagnosed and surgically treated between 2007 and 2014 during the first 3 years of life with minimum follow-up of 3 years. We focused on the presenting symptoms, magnetic resonance imaging findings, and surgical techniques used for posterior fossa decompression (PFD) and their postoperative outcome.

RESULTS

Twelve patients (75%) presented with signs of headaches such as irritability, inconsolable crying, head grabbing, and/or arching back. Ten patients (62.5%) presented with oropharyngeal and/or respiratory symptoms such as emesis, choking, gagging, snoring, sleep apnea, breathing pause, and/or vocal cord palsy. Only one patient had segmental cervical hydromyelia. At the first surgery, ten patients had PFD with dural scoring (Type 1 procedure), while six others had PFD with duraplasty (Type 2 procedure) with thermal reduction of the cerebellar tonsils in four. Following the first operation, all initially had varying degrees of symptomatic improvement; however, seven patients subsequently had symptomatic recurrence. Persistent crowding at the PFD site on the postoperative imaging indicated greater risk of recurrences in both Type 1 procedure and Type 2 procedure groups. Of seven patients who needed a second operation, fivewere after Type 1 procedure and the two were after Type 2 procedure. The difference of recurrence rates between these two groups is not significant. CSF-related complications occurred in 4 out of 11 patients who had Type 2 procedure (one after primary decompression and three after the second decompression for recurrence).

CONCLUSION

Young patients lacking effective verbal communication often present their Chiari I malformation differently from olderage groups. Behavioral changes indicative of headaches/irritability and oropharyngeal/respiratory symptoms are the primary presenting symptoms. The recurrence rate tends to be higher among the patients after Type 1 procedure (particularly those younger than 18 months) than after Type 2 procedure. We observed that duraplasty at primary or at redo PFD provides for better decompression and long-term outcome. However, one should keep it in mind that there is risk of CSF-related complications following duraplasty, particularly higher tendency after redo PFD.

The addition of duraplasty to posterior fossa decompression in the surgical treatment of pediatric Chiari malformation Type I: a systematic review and meta-analysis of surgical and performance outcomes

OBJECTIVE Surgery is the definitive treatment of Chiari malformation Type I (CM-I). It involves posterior fossa decompression, which can be performed along with C-1 laminectomy, reconstructive duraplasty, or tonsil shrinkage. The aim of this study was to provide an updated systematic review and meta-analysis of the latest available evidence regarding posterior fossa decompression only (PFDO) versus posterior fossa decompression with duraplasty (PFDD) in the treatment of CM-I in children. METHODS A literature search was performed in compliance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for article identification, screening, eligibility, and inclusion. Relevant articles were identified from 6 electronic databases from their inception to April 2016. These articles were screened against established criteria for inclusion into this study. RESULTS From 12 relevant studies identified, 1492 pediatric patients treated via PFDD were compared with 1963 pediatric patients treated by PFDO for CM-I. PFDD was associated with greater overall clinical improvement (p = 0.009), along with longer length of stay (p < 0.0001) and more postoperative complications (p = 0.0001) compared with PFDO. No difference was observed between PFDD and PFDO in terms of revision surgery incidence (p = 0.13), estimated blood loss (p = 0.14), syrinx improvement (p = 0.09), or scoliosis improvement (p = 0.95). CONCLUSIONS It appears that the addition of duraplasty to posterior decompression in the definitive treatment of CM-I in children may alter surgical and performance outcomes. In particular, parameters of overall clinical improvement, length of stay, and postoperative complication may differ between children undergoing PFDD and those undergoing PFDO. Current evidence in the literature is of low to very low quality that, as of yet, has not been able to completely control for inherent selection bias both in study design and surgeon preference. Future, large prospective registries and randomized controlled trials are warranted to validate the findings of this study.

Pediatric Chiari malformation type I: long-term outcomes following small-bone-window posterior fossa decompression with autologous-fascia duraplasty

Chiari malformation type I (CM-I) is a common hindbrain disorder that is associated with deformity and elongation of the cerebellar tonsils. Although CM-I occurs in both pediatric and adult patients, its prevalence, clinical features and management in the pediatric population are not well defined. The current study evaluated a consecutive case series of 92 children (38 females and 54 males) who were diagnosed with congenital CM-I. All patients underwent small-bone-window posterior fossa decompression with autologous-fascia duraplasty. Clinical and radiological features were analyzed and long-term follow-up data were recorded. Risk factors associated with clinical outcomes were investigated using comprehensive statistical methods. Out of the 92 children, 11 (12.0%) were asymptomatic. Associated ventricular dilation was observed in 24 children (26.1%) and concomitant syringomyelia was observed in 72 children (78.3%). A total of 44 children (47.8%) showed scoliosis on plain films. Follow-up data (mean duration, 88.6 months) were available for all patients. Syringomyelia was absent or markedly reduced in 56 patients (77.8%). Symptoms were alleviated in 66 patients, remained unchanged in 12 patients and progressed in 3 patients. Statistical analysis indicated that the cerebellar tonsillar descent (CTD) grade, basilar invagination and platybasia influenced the clinical outcome (P<0.05). In conclusion, early recognition and surgical treatment of CM-I in pediatric patients can lead to good outcomes. The current results suggested that small-bone-window posterior fossa decompression with autologous-fascia duraplasty was an effective safe treatment option with a low complication rate. High CTD grade, basilar invagination and platybasia were indicated to be predictors of poor clinical prognosis.

Chiari-related hydrocephalus: assessment of clinical risk factors in a cohort of 297 consecutive patients

OBJECTIVE Patients treated for Chiari I malformation (CM-I) with posterior fossa decompression (PFD) may occasionally and unpredictably develop postoperative hydrocephalus. The clinical risk factors predictive of this type of Chiari-related hydrocephalus (CRH) are unknown. The authors' objective was to evaluate their experience to identify risk factors that may predict which of these patients undergoing PFD will develop CRH after surgery. METHODS The authors performed a retrospective clinical chart review of all patients who underwent PFD surgery and duraplasty for CM-I at the Primary Children's Hospital in Utah from June 1, 2005, through May 31, 2015. Patients were dichotomized based on the need for long-term CSF diversion after PFD. Analysis included both univariate and multivariable logistic regression analyses. RESULTS The authors identified 297 decompressive surgeries over the period of the study, 22 of which required long-term postoperative CSF diversion. On multivariable analysis, age < 6 years old (OR 3.342, 95% CI 1.282-8.713), higher intraoperative blood loss (OR 1.003, 95% CI 1.001-1.006), and the presence of a fourth ventricular web (OR 3.752, 95% CI 1.306-10.783) were significantly associated with the need for long-term CSF diversion after decompressive surgery. CONCLUSIONS Younger patients, those with extensive intraoperative blood loss, and those found during surgery to have a fourth ventricular web were at higher risk for the development of CRH. Clinicians should be alert to evidence of CRH in this patient population after PFD surgery.

Craniocervical spinal instability after type 1 Arnold Chiari decompression: a case report

To present and describe an unusual case of spinal instability after craniocervical spinal decompression for a type-1 Chiari malformation. Type-1 Chiari malformation is a craniocervical disorder characterized by tonsillar displacement greater than 5 mm into the vertebral canal; posterior fossa decompression is the most common surgical treatment for this condition. Postoperative complications have been described: cerebrospinal fluid leak, pseudomeningocele, aseptic meningitis, wound infection, and neurological deficit. However, instability after decompression is unusual. A 9-year-old female presented with symptomatic torticollis after cervical decompression for a type-1 Chiari malformation. Spinal instability was diagnosed; craniocervical stabilization was performed. After a 12-month follow-up, spinal stability was achieved, with a satisfactory clinical neck alignment. We present a craniocervical instability secondary to surgical decompression; clinical and radiological symptoms, and definitive treatment were described.

Factors associated with spinal fusion after posterior fossa decompression in pediatric patients with Chiari I malformation and scoliosis

OBJECTIVE The authors performed a study to identify clinical characteristics of pediatric patients diagnosed with Chiari I malformation and scoliosis associated with a need for spinal fusion after posterior fossa decompression when managing the scoliotic curve. METHODS The authors conducted a multicenter retrospective review of 44 patients, aged 18 years or younger, diagnosed with Chiari I malformation and scoliosis who underwent posterior fossa decompression from 2000 to 2010. The outcome of interest was the need for spinal fusion after decompression. RESULTS Overall, 18 patients (40%) underwent posterior fossa decompression alone, and 26 patients (60%) required a spinal fusion after the decompression. The mean Cobb angle at presentation and the proportion of patients with curves > 35° differed between the decompression-only and fusion cohorts (30.7° ± 11.8° vs 52.1° ± 26.3°, p = 0.002; 5 of 18 vs 17 of 26, p = 0.031). An odds ratio of 1.0625 favoring a need for fusion was established for each 1° of increase in Cobb angle (p = 0.012, OR 1.0625, 95% CI 1.0135-1.1138). Among the 14 patients older than 10 years of age with a primary Cobb angle exceeding 35°, 13 (93%) ultimately required fusion. Patients with at least 1 year of follow-up whose curves progressed more 10° after decompression were younger than those without curve progression (6.1 ± 3.0 years vs 13.7 ± 3.2 years, p = 0.001, Mann-Whitney U-test). Left apical thoracic curves constituted a higher proportion of curves in the decompression-only group (8 of 16 vs 1 of 21, p = 0.002). CONCLUSIONS The need for fusion after posterior fossa decompression reflected the curve severity at clinical presentation. Patients presenting with curves measuring > 35°, as well as those greater than 10 years of age, may be at greater risk for requiring fusion after posterior fossa decompression, while patients less than 10 years of age may require routine monitoring for curve progression. Left apical thoracic curves may have a better response to Chiari malformation decompression.

Chiari malformations: An important cause of pediatric aspiration

Chronic aspiration poses a major health risk to the pediatric population. We describe four cases in which work up for chronic aspiration with a brain MRI revealed a Chiari I malformation, a poorly described etiology of pediatric aspiration. All patients had at least one non-specific neurologic symptom but had swallow studies more characteristic of an anatomic than a neurologic etiology. Patients were referred to neurosurgery and underwent posterior fossa decompression with symptom improvement. A high index of suspicion for Chiari malformation should be maintained when the standard work up for aspiration is non-diagnostic, particularly when non-specific neurologic symptoms are present.

Chiari malformation Type I surgery in pediatric patients. Part 2: complications and the influence of comorbid disease in California, Florida, and New York

OBJECTIVE Chiari malformation Type I (CM-I) is a common and often debilitating pediatric neurological disease. However, efforts to guide preoperative counseling and improve outcomes research are impeded by reliance on small, single-center studies. Consequently, the objective of this study was to investigate CM-I surgical outcomes using population-level administrative billing data. METHODS The authors used Healthcare Cost and Utilization Project State Inpatient Databases (SID) to study pediatric patients undergoing surgical decompression for CM-I from 2004 to 2010 in California, Florida, and New York. They assessed the prevalence and influence of preoperative complex chronic conditions (CCC) among included patients. Outcomes included medical and surgical complications within 90 days of treatment. Multivariate logistic regression was used to identify risk factors for surgical complications. RESULTS A total of 936 pediatric CM-I surgeries were identified for the study period. Overall, 29.2% of patients were diagnosed with syringomyelia and 13.7% were diagnosed with scoliosis. Aside from syringomyelia and scoliosis, 30.3% of patients had at least 1 CCC, most commonly neuromuscular (15.2%) or congenital or genetic (8.4%) disease. Medical complications were uncommon, occurring in 2.6% of patients. By comparison, surgical complications were diagnosed in 12.7% of patients and typically included shunt-related complications (4.0%), meningitis (3.7%), and other neurosurgery-specific complications (7.4%). Major complications (e.g., stroke or myocardial infarction) occurred in 1.4% of patients. Among children with CCCs, only comorbid hydrocephalus was associated with a significantly increased risk of surgical complications (OR 4.5, 95% CI 2.5-8.1). CONCLUSIONS Approximately 1 in 8 pediatric CM-I patients experienced a surgical complication, whereas medical complications were rare. Although CCCs were common in pediatric CM-I patients, only hydrocephalus was independently associated with increased risk of surgical events. These results may inform patient counseling and guide future research efforts.