Chiari type I malformation in children

Minimum 5-year follow-up outcomes for one-stage posterior instrumentation without neurosurgery intervention for correction of scoliosis associated with Chiari I malformation and syringomyelia

INTRODUCTION

Traditionally, the common belief has been that, all patients with Chiari I malformation (CM-1) and syringomyelia (SM) undergoing a neurosurgical procedure even if they are neurologically asymptomatic. As the pathology of CM-1 and SM has become better understood, the traditional concepts have been challenged. The objective of this study was to investigate the minimum 5-year follow-up clinical outcomes of surgical treatment of patients with scoliosis associated with CM-1 and SM and to evaluate the necessity of neurosurgical intervention before corrective surgery.

METHODS

This retrospective study was performed from May 2009 to September 2014. We enrolled 35 patients with scoliosis associated with CM-1 and SM who were undergoing spinal correction surgery without neurosurgical intervention. During the surgery, spinal cord monitor and wake-up test were used. Preoperative, postoperative, and final follow-up major curve coronary Cobb angle, correction rate, apical vertebral rotation (AVR), apical vertebral translation (AVT), thoracic kyphosis angle (T5-T12), lumbar lordosis angle (L1-S1) were analyzed on radiographs.

RESULTS

The mean follow-up period was 82.5 months. The preoperative and postoperative mean curve coronary Cobb angle was from 55.7 ± 7.5° to 20.1 ± 5.8°, correction rate was 63.9%, AVR from 2.8 ± 0.6° to 1.3 ± 0.5°, AVT from 5.1 ± 1.4 to 1.7 ± 0.7 cm, thoracic kyphosis angle from 18.7 ± 4.0° to 32.2 ± 2.7°, lumbar lordosis angle from 36.3 ± 4.1° to 43.8 ± 3.2°. No neurological deficits occurred during the operation and follow-up.

CONCLUSIONS

Our minimum 5-year follow-up outcomes showed that in a distinct patient population of neurologically asymptomatic individuals with CM-1, SM and progressive scoliosis, posterior instrumented spinal deformity surgery can be safely done without neurosurgical interverventions with the help of preoperative flexibility evaluation and intraoperative neuromonitoring.

Chiari 1: Is decompression always necessary previous to scoliosis surgery?

The association between Chiari 1 malformation and scoliosis is well known in the literature. Prevalence has increased after the advent of magnetic resonance imaging. In children with this association, prophylactic suboccipital decompression prior to scoliosis correction is a common surgical procedure although the rationale for this surgical management and whether not performing it may lead to spinal cord injury has not been clearly elucidated. We conducted a systematic review of the literature with the aim to obtain strong data to support the hypothesis that it is safe to proceed with scoliosis correction without prior prophylactic suboccipital decompression for Chiari 1 in an asymptomatic population. Using the Prisma methodology, we analyzed 3250 studies published between 1972 and 2018. Only four studies met the inclusion criteria. None of the studies had a level of evidence high enough to recommend prophylactic decompression previous to correction of the spinal deformity.

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.

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.

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.

Radiological and clinical predictors of scoliosis in patients with Chiari malformation type I and spinal cord syrinx from the Park-Reeves Syringomyelia Research Consortium

OBJECTIVE

Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors' goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis.

METHODS

A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°).

RESULTS

Based on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB-C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude.

CONCLUSIONS

Syrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.

Posterior fossa decompression for Chiari malformation type I: clinical and radiological presentation, outcome and complications in a retrospective series of 105 procedures

OBJECTIVE

Determining clinical and radiological characteristics, complication rates and outcome for patients undergoing posterior fossa decompression (PFD) and duraplasty for Chiari malformation type I (CM-I).

METHODS AND MATERIALS

Retrospective, single-university hospital study of all PFDs for CM-I between January 1995 and December 2016.

RESULTS

PFD was performed in 105 patients with CM-I (n = 105), of whom 62 suffered from associated syringomyelia and 37 were pediatric cases. There was a female preponderance in the syringomyelia, non-syringomyelia, pediatric and adult groups (62.9%, 65.1%, 54.1% and 69.1%, respectively). Mean age at diagnosis was higher in the syringomyelia group (32.3 versus 26.9 years, p = 0.06) and in both groups delay for diagnosis was long (33.4 and 47.1 months, p = 0.50). Headache during Valsalva maneuver and on exertion was significantly more present in the non-syringomyelia group (27.9% versus 16.1%, p < 0.0001 and 39.5% versus 11.3%, p = 0.0009); cranial nerve dysfunction and cerebellar signs did not differ significantly (p = 0.07 and p = 0.53). Spinal cord syndrome was significantly more present in the syringomyelia group (72.6% versus 25.6%, p < 0.0001). Scoliosis was present in five patients, of whom four had syringomyelia. Duraplasty was performed in 101 surgeries. For 100 patients, PFD was the primary treatment of CM-I; 2 patients had previously undergone syrinx drainage and 3 ventriculoperitoneal shunting for hydrocephalus. Only one patient presented with hydrocephalus. Duraplasty (n = 101) was complicated by CSF leak in 4.0% (n = 4), symptomatic pseudomeningocele in 4.0% (n = 4), aseptic meningitis in 2.0% (n = 2) and hydrocephalus in 1.0% (n = 1). Osseous decompression without duraplasty was performed in only four highly selected patients, not allowing a comparative analysis with duraplasty. Post-operative symptom improvement is reported for 67.3% of all patients and stabilization of symptoms in 23.9%. Symptom improvement was significantly more frequent in the non-syringomyelia group (p = 0.03). Outcome seemed similarly good in the pediatric and the adult groups.

CONCLUSION

PFD performed with duraplasty is a safe procedure. The majority of patients do report symptom stabilization or improvement. Non-syringomyelia patients reported significantly more frequent improvement of clinical symptoms.

Outcomes and resource utilization in surgery for Chiari I malformation in a national network of children's hospitals

INTRODUCTION

Chiari malformation type 1 (CM-1) is a common congenital or acquired malformation of the posterior fossa. We aimed to characterize preoperative risk factors, perioperative complications, and postoperative outcomes related to CM-1 surgery in pediatric populations across a nationwide network of pediatric hospitals in the United States (US).

METHODS

The Children's Hospital Association's Pediatric Health Information System (PHIS) database was used to examine patients < 21 years old in the US-based nationwide database who underwent inpatient surgery for CM-1 from 2007 to 2015. Data analyzed included patient characteristics, preoperative comorbidities, perioperative outcomes, short-term postoperative surgical and medical complications, and healthcare resource utilization.

RESULTS

Among the 5976 patients identified, those age 0-4 years had higher medical and surgical complication rates compared to older patients. Those with pre-existing comorbidity of hydrocephalus had higher odds of 30- and 90-day medical and surgical complications. Those with any complications at 90 days had an increased length of stay and higher healthcare costs compared to those without complications. 6.88% of complications were surgical and 1.67% medical. Patients with medical complications had the longer mean stay and associated costs compared to those with surgical complications (13 vs. 6.9 at 95% CI, and $71,300-94,500 vs. $110,400-195,000 at 95% CI).

CONCLUSIONS

Use of a US-based national children's hospital database presents outcomes and resource utilization from a multi-institutional, real-world experience in pediatric hospitals. There was a higher risk of perioperative complications in younger patients and those with pre-existing comorbidities, namely hydrocephalus. Understanding preoperative risk factors, perioperative complications, and postoperative outcomes, as well as healthcare utilization and costs, can help target areas for improvement and guide preoperative counseling and risk stratification.

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.

Clinical and surgical management of a congenital Type II split cord malformation presenting with progressive cranial neuropathies: case report

Split cord malformation (SCM) is a rare abnormality of notochord development. The majority of cases occur in the thoracolumbar region, with more than 30 cases of cervical SCM reported. The clinical impact of SCMs involving the cervical cord is therefore largely unknown. In addition, the concomitant finding of brainstem involvement is presumably incompatible with life in the majority of patients, resulting in a paucity of data regarding this clinical scenario. In this paper the authors present the first case, to their knowledge, of an incomplete cervical SCM involving the brainstem and discuss its clinical impact, diagnosis, and management.

The prevalence of intraspinal anomalies in infantile and juvenile patients with "presumed idiopathic" scoliosis: a MRI-based analysis of 504 patients

Background

Though several studies have reported the incidence of intraspinal neural axis abnormalities in infantile and juvenile “presumed idiopathic” scoliosis, there has been a varying prevalence ranging from 11.1 to 26.0 % based on a limited sample size. Therefore, such inconclusive findings have resulted in some questions on the MRI-associated role in the management of these patients. We aimed to investigate the prevalence and distribution of intraspinal anomalies in the infantile and juvenile patients with “presumed idiopathic” scoliosis and to explore the radiographic and clinical indicators with large sample size.

Methods

A total of 504 infantile and juvenile patients diagnosed with “presumed idiopathic” scoliosis were examined for potentially-existing neural axis abnormalities by MRI. Patients were grouped into two cohorts according to the presence of neural axis abnormalities. Radiographic parameters including curve magnitude, curve pattern, location of apex, degree of thoracic kyphosis, and span of curve were recorded and compared between the two groups. The prevalence of the neural abnormalities between the infantile-age group and juvenile-age group was also compared. The student t test was used to evaluate the differences of continuous variables and the chi-square test was used to evaluate the difference of categorical variables. Fisher exact test was applied to detect the difference of the rate of intraspinal anomalies between the “infantile idiopathic scoliosis” and “juvenile idiopathic scoliosis” group.

Results

Involving the spinal cord, 94 patients (18.7 %) were found to have a neural abnormality: Arnold-Chiari malformation alone in 43 patients, Arnold-Chiari malformation combined with syringomyelia in 18 patients, isolated syringomyelia in 13 patients, diastematomyelia in six patients, tethered cord combined with diastematomyelia in six patients, tethered cord alone in four patients, and other uncommon intraspinal abnormalities in the remaining four patients. Totally Arnold-Chiari malformation with or without syringomyelia accounted for 64.8 % (61/94) among all these abnormalities. Male gender, left thoracic curve and right lumbar curve were found to be significantly associated with the presence of neural axis abnormalities on MRI.

Conclusions

The incidence of neural axis abnormalities in the presumed IIS and JIS was 18.7 %. Thus a routine MRI evaluation appears warranted for those “presumed idiopathic” scoliosis patients if aged less than 10 years, being male or having left thoracic or right lumbar curve.

Pediatric and adult Chiari malformation Type I surgical series 1965-2013: a review of demographics, operative treatment, and outcomes

OBJECT

Chiari malformation Type I (CM-I) is a hindbrain disorder associated with elongation of the cerebellar tonsils, which descend below the foramen magnum into the spinal canal. It occurs in children and adults. Clinical symptoms mainly develop from alterations in CSF flow at the foramen magnum and the common subsequent development of syringomyelia.

METHODS

The authors reviewed English-language reports of pediatric, adult, and combined (adult and pediatric) surgical series of patients with CM-I published from 1965 through August 31, 2013, to investigate the following: 1) geographical distribution of reports; 2) demographics of patients; 3) follow-up lengths; 4) study durations; 5) spectrum and frequency of surgical techniques; 6) outcomes for neurological status, syrinx, and headache; 7) frequency and scope of complications; 8) mortality rates; and 9) differences between pediatric and adult populations. Research and inclusion criteria were defined, and all series that contained at least 4 cases and all publications with sufficient data for analysis were included.

RESULTS

The authors identified 145 operative series of patients with CM-I, primarily from the United States and Europe, and divided patient ages into 1 of 3 categories: adult (>18 years of age; 27% of the cases), pediatric (≤18 years of age; 30%), or unknown (43%). Most series (76%) were published in the previous 21 years. The median number of patients in the series was 31. The mean duration of the studies was 10 years, and the mean follow-up time was 43 months. The peak ages of presentation in the pediatric studies were 8 years, followed by 9 years, and in the adult series, 41 years, followed by 46 years. The incidence of syringomyelia was 65%. Most of the studies (99%) reported the use of posterior fossa/foramen magnum decompression. In 92%, the dura was opened, and in 65% of these cases, the arachnoid was opened and dissected; tonsillar resection was performed in 27% of these patients. Postoperatively, syringomyelia improved or resolved in 78% of the patients. Most series (80%) reported postoperative neurological outcomes as follows: 75% improved, 17% showed no change, and 9% experienced worsening. Postoperative headaches improved or resolved in 81% of the patients, with a statistical difference in favor of the pediatric series. Postoperative complications were reported for 41% of the series, most commonly with CSF leak, pseudomeningocele, aseptic meningitis, wound infection, meningitis, and neurological deficit, with a mean complication rate of 4.5%. Complications were reported for 37% of pediatric, 20% of adult, and 43% of combined series. Mortality was reported for 11% of the series. No difference in mortality rates was seen between the pediatric and adult series.

CONCLUSIONS

Before undergoing surgical treatment for CM-I, symptomatic patients and their families should be given clear information about the success of treatment and potential complications. Furthermore, surgeons may benefit from comparing published data with their own. In the future, operative CM-I reports should provide all details of each case for the purpose of comparison.

Chiropractic care for headaches and dizziness of a 34-year-old woman previously diagnosed with Arnold-Chiari malformation type 1

OBJECTIVE

The purpose of this case study is to describe the chiropractic care of a patient with headaches and dizziness.

CLINICAL FEATURES

A 34-year-old woman with a history of headaches, dizziness, photophobia, and temporary loss of vision aggravated by postural positions while bending forward sought conservative care for her symptoms. She reported a prior diagnosis of Arnold-Chiari malformation (ACM) type 1 by magnetic resonance imaging in 2005 that revealed descending cerebellar tonsils measured at 5 mm with an impression of ACM type 1. A new magnetic resonance image taken in 2013 indicated the cerebellar tonsils measured at 3 mm and did not project through the plane of the foramen magnum. The diagnosis of ACM type 1 was no longer applicable; however, the signs and symptoms of ACM type 1 persisted.

INTERVENTION AND OUTCOME

She was treated using cervical chiropractic manipulation using diversified technique. The dizziness and headache were resolved after 3 visits. At her 3-month follow-up, she continued to be symptom-free.

CONCLUSION

A patient with headaches and dizziness and a previous diagnosis of ACM type 1 responded positively to chiropractic care.

Indication for preoperative MRI of neural axis abnormalities in patients with presumed thoracolumbar/lumbar idiopathic scoliosis

PURPOSE

The purpose of this study was to investigate the incidence of neural axis abnormalities in patients with presumed "idiopathic" thoracolumbar or lumbar scoliosis by magnetic resonance imaging (MRI) and try to determine which clinical and radiographic characteristics correlate with neural axis abnormalities on MRI in these patients.

METHODS

The database of a single spinal deformity center was retrospectively reviewed to identify all patients with a primary diagnosis of idiopathic scoliosis (IS) between January 2003 and August 2011. A total of 446 patients with main thoracolumbar or lumbar curves were identified. Radiographic parameters including main curve Cobb angles, location of curve apex, span of main curve, thoracic kyphosis (T5-T12), thoracolumbar junction kyphosis (T10-L2), lumbar lordosis (L1-S1), and sagittal and coronal balance were measured.

RESULTS

Neural axis abnormalities were detected in 35 (7.8 %) patients. For patients with neural axis abnormalities, a higher proportion of male gender and long thoracolumbar curves were presented. In these patients, the mean age was smaller and the mean Cobb angle of main curve was larger. Greater thoracic kyphosis (≥ 30°) was more frequently found in those with neural axis abnormalities. The incidences of thoracolumbar junction hyperkyphosis were similar between two groups (P > 0.05). There was no difference between two groups as to lumbar lordosis and coronal and sagittal balance.

CONCLUSION

We recommend the routine use of MRI in the patients with one or more of the following characteristics: right curves, long curve span, apex at thoracolumbar spine and hyperthoracic kyphosis.

Unusual presentation of Chiari I in toddlers: case reports and review of the literature

Toddlers with Chiari malformations can present with common symptoms, such as cough or drooling, which are associated with respiratory illnesses, delaying a correct diagnosis. Presentation does vary with age, and therefore can be different in older children when compared to infants. We present two cases of unusual presentations in toddlers and review the literature with an emphasis on acute presentation of Chiari in different age groups in children.

Outcomes of Chiari I-associated scoliosis after intervention: a meta-analysis of the pediatric literature

PURPOSE

Various series have reported successful management of scoliosis after surgical treatment of the associated Chiari malformation, syrinx, or bracing. Multiple factors have been associated with curve progression, but interpretation of outcomes is confounded by the wide range of reported results and size of individual series. We attempted to evaluate the outcomes of Chiari I-associated scoliosis by performing a meta-analysis of currently published data.

METHODS

We conducted a systematic review of published articles using Medline, PubMed (from 1950 to January 2010), and reference lists of identified articles for Chiari malformation and scoliosis.

RESULTS

One hundred and twenty patients were identified in 12 studies, of them, 37 % were male. The mean age at the time of surgery was 9.7 ± 4.1 years. The mean curve magnitude at presentation was 34.4 ± 13.0° and progressed to a mean value of 38.9 ± 20.2°, with an average follow-up of 48.3 ± 48.2 months. After surgical intervention, curve magnitude improved in 37 % of patients (n = 42); there was no change in 18 % (n = 20), and curves progressed in 45 % (n = 51). Age (p = 0.0097) and presence of surgical intervention (foramen magnum decompression [p = 0.0099] and syrinx shunting/drainage [p = 0.0039]) were statistically associated with improvement of the scoliotic curve. Surgical decompression of the foramen magnum had the greatest impact on the scoliotic curves.

CONCLUSIONS

Data accrued from our analysis suggest that curve magnitude will improve after surgical treatment of the Chiari malformation in one third of patients, and curve progression will stabilize or improve in one half.

Rare association between cystic fibrosis, Chiari I malformation, and hydrocephalus in a baby: a case report and review of the literature

Introduction

Cystic fibrosis, an epithelial cell transport disorder caused by mutations of the cystic fibrosis transmembrane conductance regulator gene, is not generally associated with malformations of the central nervous system. We review eight previously published reports detailing an infrequent association between cystic fibrosis and Chiari I malformation.

Case presentation

To the best of our knowledge, our report describes only the ninth case of a baby presenting with a new diagnosis of cystic fibrosis and Chiari I malformation, in this case in a 10-month-old, full-term Caucasian baby boy from the United States of America. Neurosurgical consultation was obtained for associated developmental delay, macrocephaly, bulging anterior fontanel, and papilledema. An MRI scan demonstrated an extensive Chiari I malformation with effacement of the fourth ventricle, obliteration of the outlets of the fourth ventricle and triventricular hydrocephalus without aqueductal stenosis. Our patient was taken to the operating room for ventriculoperitoneal shunt placement.

Conclusions

It is possible that the cystic fibrosis transmembrane conductance regulator gene may play a previously unrecognized role in central nervous system development; alternatively, this central nervous system abnormality may have been acquired due to constant valsalva from recurrent coughing or wheezing or metabolic and electrolyte imbalances that occur characteristically in cystic fibrosis.

Magnetic resonance imaging evaluation of patients with idiopathic scoliosis: a prospective study of four hundred seventy-two outpatients

STUDY DESIGN

A prospective study of magnetic resonance imaging findings in outpatients with idiopathic scoliosis.

OBJECTIVE

The purpose of this study was to determine the prevalence of neural axis abnormalities in outpatients with scoliosis and to analyze the characteristics of patients who had such abnormalities.

SUMMARY OF BACKGROUND DATA

In previous studies, neural axis abnormalities were found in 2.9% to 37% of patients with idiopathic scoliosis. The current guidelines for MRI screening in scoliosis are valuable, and the proposed indications for performing MRI in the literature include early onset, atypical curvature, double thoracic curve (King type-5), rapid progression, male gender, and abnormal neurologic findings.

METHODS

A total of 472 outpatients with a primary diagnosis of idiopathic scoliosis were examined for neural axis abnormalities by magnetic resonance imaging. Logistic regression was used to determine significant predictors of neural axis abnormalities on MRI.

RESULTS

The incidence of neural axis abnormalities on MRI was 3.8% (18 of 472 patients). Among the 18 patients, 6 had a Chiari I malformation alone, 10 had a Chiari I malformation combined with syringomyelia, and 2 had a syringomyelia without Chiari I malformation. Male gender, patients younger than 11 years old, and abnormal superficial abdominal reflexes were significantly associated with the detection of neural axis abnormalities on MRI.

CONCLUSION

We recommend routine use of MRI in male patients, younger than 11 years old, and abnormal superficial abdominal reflexes. Even if a patient has no specific indications for MRI, we recommend its routine use in preoperative planning.

Institutional experience with 500 cases of surgically treated pediatric Chiari malformation Type I

OBJECT

The diagnosis and treatment of Chiari malformation Type I (CM-I) has evolved over the last few decades. The authors present their surgical experience of over 2 decades of treating children with this form of hindbrain herniation.

METHODS

The authors conducted a retrospective review of their institutional experience with the surgical treatment of the pediatric CM-I from 1989 to 2010.

RESULTS

The 2 most common presentations were headache/neck pain (40%) and scoliosis (18%). Common associated diagnoses included neurofibromatosis Type 1 (5%) and idiopathic growth hormone deficiency (4.2%). Spine anomalies included scoliosis (18%), retroversion of the odontoid process (24%), Klippel-Feil anomaly (3%), and atlantooccipital fusion (8%). Approximately 3% of patients had a known family member with CM-I. Hydrocephalus was present in 48 patients (9.6%). Syringomyelia was present in 285 patients (57%), and at operation, 12% of patients with syringomyelia were found to have an arachnoid veil occluding the fourth ventricular outlet. Fifteen patients (3%) have undergone reoperation for continued symptoms or persistent large syringomyelia. The most likely symptoms and signs to resolve following surgery were Valsalva-induced headache and syringomyelia. The average hospital stay and "return to school" time were 3 and 12 days, respectively. The follow-up for this group ranged from 2 months to 15 years (mean 5 years). Complications occurred in 2.4% of cases; there was no mortality. No patient required acute return to the operating room, and no blood transfusions were performed.

CONCLUSIONS

The authors believe this to be the largest reported series of surgically treated pediatric CM-I patients and hope that their experience will be of use to others who treat this surgical entity.

Chiari 1 malformation and holocord syringomyelia presenting as abrupt onset foot drop

We present two patients with a Chiari 1 malformation and holocord syringomyelia who presented with abrupt onset unilateral foot drop. Neurophysiologic testing was consistent with a proximal nerve root lesion. This assisted with localization and directed magnetic resonance (MR) imaging to lumbosacral spine and nerve roots. Each child underwent a suboccipital craniectomy and laminectomy with duroplasty to decompress the foramen magnum. Each child also showed rapid and complete clinical recovery despite the significant electromyographic and MRI abnormalities on initial study.

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

OBJECT

The authors conducted a study to evaluate the unique presenting signs and symptoms of Chiari malformation Type I (CM-I) in children younger than 6 years of age and highlight the benefits of early surgical treatment in this patient population.

METHODS

The authors reviewed the medical records of patients who presented to the neurosurgery department before their 6th birthday and subsequently underwent surgery for CM-I. They identified 39 patients who had been evaluated between 1984 and 2007 and examined the medical records for presentation, surgical intervention, and outcome.

RESULTS

Children aged 0-2 years commonly presented with oropharyngeal dysfunction (77.8%). Children aged 3-5 years more frequently presented with syringomyelia (85.7%), scoliosis (38.1%), and/or headache (57.1%). All patients underwent posterior fossa craniectomy. Additionally, in many patients cervical laminectomy and/or duraplasty was performed. A few patients required transoral decompression and occipitocervical fusion. In most cases, surgery led to resolution or dramatic improvement of initial symptoms.

CONCLUSIONS

Early recognition and surgical treatment of CM-I in young children leads to good outcomes in the majority of patients. Additional therapies for oropharyngeal dysfunction, syringomyelia, and scoliosis can frequently be avoided.

Chiari type I malformation causing central apnoeas in a 4-month-old boy

Apnoea is a rare but well-known clinical presentation of the Chiari type I malformation. It may be either obstructive or central in nature, and has been described in children, adolescents and adults. Here, we report a 4-month-old infant who presented with frequent central sleep apnoeas leading to the diagnosis of a Chiari type I malformation. Surgical repair resulted in complete resolution of the symptoms, normal respiratory parameters during sleep and normal psychomotor development. This case illustrates a very early presentation of the Chiari type I malformation with central apnoeas and suggests that this aetiology should be considered in the differential diagnosis of central apnoeas in infants, especially when they are associated with other neurological sign or symptom.

Delamination technique together with longitudinal incisions for treatment of Chiari I/syringomyelia complex: a prospective clinical study

Background

Treatment modalities in Chiari malformation type 1(CMI) accompanied by syringomyelia have not yet been standardized. Pathologies such as a small posterior fossa and thickened dura mater have been discussed previously. Various techniques have been explored to enlarge the foramen magnum and to expand the dura. The aim of this clinical study was to explore a new technique of excision of the external dura accompanied by widening the cisterna magna and making longitudinal incisions in the internal dura, without disturbing the arachnoid.

Methods

Ten patients with CMI and syringomyelia, operated between 2004 and 2006, formed this prospective series. All cases underwent foramen magnum decompression of 3 × 3 cm area with C1–C2 (partial) laminectomy, resection of foramen magnum fibrous band, excision of external dura, delamination and widening of internal dura with longitudinal incisions.

Results

Patients were aged between 25 and 58 years and occipital headache was the most common complaint. The mean duration of preoperative symptoms was 4 years and the follow-up time was 25 months. Clinical progression was halted for all patients; eight patients completely recovered and two reported no change. In one patient, there was a transient cerebrospinal fluid (CSF) fistula that was treated with tissue adhesive. While syringomyelia persisted radiologically with radiological stability in five patients; for three patients the syringomyelic cavity decreased in size, and for the remaining two it regressed completely.

Conclusion

Removal of the fibrous band and the outer dural layer, at level of foramen magnum, together with the incision of inner dural layer appears to be good technique in adult CMI patients. The advantages are short operation time, no need for duraplasty, sufficient posterior fossa decompression, absence of CSF fistulas as a result of extra arachnoidal surgery, and short duration of hospitalization. Hence this surgical technique has advantages compared to other techniques.

Chiari type I malformation in a pediatric population

The natural history of Chiari I malformation in children remains unclear. A population-based retrospective cohort study was therefore conducted. Radiology reports from all head and spine magnetic resonance imaging scans (n = 5248) performed among 741,815 children under age 20 within Kaiser Northern California, 1997-1998, were searched for Chiari I. Medical records and imaging studies were reviewed to determine clinical and radiographic predictors of significant neurologic symptoms, defined as moderate to severe headache, neck pain, vertigo, or ataxia. The 51 patients identified with Chiari I represented 1% of the children who had head or spine magnetic resonance imaging scans performed during the study period. Headache (55%) and neck pain (12%) were the most common symptoms. Syringomyelia was present in 6 patients (12%) at initial diagnosis; no new syrinxes developed during follow-up. Older age at time of diagnosis was associated with increased risk of headache (odds ratio OR = 1.3, 95% confidence interval CI = 1.1-1.5) and significant neurologic symptoms (OR = 1.2, 95% CI = 1.04-1.4). Chiari I, an underrecognized cause of headaches in children, is also frequently discovered incidentally in children without symptoms. Larger and longer-term studies are needed to determine the prognosis and optimal treatment of pediatric Chiari I.

Bilateral abducens palsies and facial weakness as initial manifestations of a Chiari 1 malformation

PURPOSE

Chiari I malformations are rare, congenital anomalies involving the caudal herniation of the cerebellar tonsils into the upper cervical spinal canal. Osseous abnormalities of the skull permit the extension of the hindbrain below the foramen magnum and engender syringohydromyelia formation. Neuroophthalmic manifestations are not uncommon; nevertheless, this is the first report of concomitant bilateral abducens palsies and facial nerve impairment as presenting manifestations of a Chiari I malformation.

CASE REPORT

A 30-year-old black female presented with a recent history of blurred vision and binocular diplopia in both left and right gazes. Headaches, dizziness, and orofacial sensorimotor impairments were noted in conjunction with the onset of her diplopia. No history of surgery, trauma, or systemic illness was elicited. Extraocular motility testing confirmed a complete bilateral abduction deficit. Additional cranial nerve testing revealed bilateral facial nerve weakness and tactile hypesthesia in the perioral region. No taste disturbances were reported. Nuclear magnetic resonance imaging studies revealed a Chiari I malformation with a syringohydromyelia formation in the vicinity of the patient's sixth cervical vertebrae. Foramen magnum decompression surgery was performed. Two months after surgery, abduction capacity was restored along with resolution of symptoms of perioral numbness and signs of facial weakness.

CONCLUSION

Bilateral sixth nerve palsies are rare clinical commodities especially when they do not occur in isolation. Intracranial neoplams, trauma, subarachnoid hemorrhaging, demyelinating disease, and meningeal infarcts have all been shown to induce mixed cranial neuropathies. The concomitant bilateral abducens palsy and concomitant facial nerve weakness reported in this case represents an atypical and previously unreported presentation of a Chiari I malformation.

Chiari I malformation and intra-cranial hypertension:a case-based review

OBJECTIVE

To present clinical and morphological findings before and after surgery in a child with Chairi I malformation (CMI) and intra-cranial hypertension (IH). The literature is reviewed and pathophysiologic factors are discussed.

CLINICAL PRESENTATION

A 13-year-old obese boy with a 3-week history of headaches, neck pain, torticollis and progressive visual deterioration was admitted. Bi-lateral chronic papilloedema and decrease in visual acuity were found in the presence of a previously diagnosed CMI. INTERVENTION AND FOLLOW-UP: Intra-cranial pressure monitoring demonstrating increased pressure levels was followed by a sub-occipital decompression, C1 laminectomy and duroplasty. Post-operatively, the boy improved markedly, the 6 months follow-up opthalmological examination demonstrated resolution of papilloedema, but consecutive bi-lateral optic nerve atrophy.

CONCLUSION

IH with progressive visual deterioration represents one of the varying clinical presentations of CMI and may be classified as a secondary form of idiopathic IH. Neuro-ophthalmological examination in all patients with CMI is recommended to identify the real incidence of this presentation. Altered CSF dynamics, venous hypertension and obesity as co-factors may be causative pathophysiologic factors.

Chiari-like tonsillar herniation associated with intracranial hypotension in Marfan syndrome

The authors describe the case of a 12-year-old girl with Marfan syndrome, sacral dural ectasia, and tonsillar herniation, who presented with headache. Initially, it was hypothesized that the headaches were secondary to the tonsillar herniation, and the patient consequently underwent surgical decompression of the foramen magnum. Postoperatively, the patient's condition did not improve, and additional magnetic resonance (MR) imaging demonstrated evidence of a cerebrospinal fluid (CSF) leak at the level of the dural ectasia. It was surmised that the girl's symptoms were due to spontaneous intracranial hypotension (SIH) and that the tonsillar herniation was caused by the leakage. The patient responded well to application of a blood patch at the level of the demonstrated leak, and her headache resolved. This appears to be the first reported case of a patient with Marfan syndrome presenting with a symptomatic spontaneous CSF leak complicated by tonsillar herniation. In this rare association of SIH and connective tissue disorders, recognition of the clinical signs and typical MR imaging features of SIH may lead to more appropriate and less invasive treatment, potentially avoiding surgery.

Surgical management of Chiari malformation: analysis of 128 cases

OBJECTIVE

A variety of surgical interventions have been recommended for patients with Chiari malformations (CMs). In this study, we have evaluated the intraoperative findings and clinical outcome in different-aged patients with CMs undergoing posterior fossa decompression.

METHODS

Sixteen pediatric and 112 adult cases with CMs underwent suboccipital craniectomy and wide duraplasty as well as autogenous bone grafting in selected cases. The clinical outcome was assessed by evaluation of postoperative signs and symptoms and magnetic resonance imaging of the craniocervical junction.

RESULTS

The most striking intraoperative finding was the presence of a very thin membrane over the opening of the central canal; the occurrence of this membrane in pediatric patients was significantly higher than that in adults (94 and 43%, respectively; p < 0.05, Fisher's exact probability test). During the immediate postoperative period, 81% of pediatric CMs and 90% of adult CMs showed improved symptomatology and magnetic resonance imaging revealed favorable findings comprising syrinx collapse or reduction of the syrinx diameter in 14 (88%) pediatric and 92 (82%) adult CMs. During discharge from hospital, 103 (90%) patients with CMs type I and 11 (85%) with CMs type II achieved good results. However, there was a statistically significant difference in the occurrence of poor results between patients treated with bony fusion and those without fusion (24 vs. 6%;p < 0.05, Fisher's exact probability test). The incidence of vertebral instability was markedly augmented in pediatric CMs in comparison to adult CMs (19 vs. 2%; p < 0.01, Fisher's exact probability test).

CONCLUSIONS

Suboccipital decompression and duraplasty with autogenous bone grafts in selected cases are effective treatments for most patients with CMs. A higher incidence of a special membrane over the obex and atlantoaxial instability were closely associated with childhood CMs.

Scoliosis in a child with Chiari I malformation and the absence of syringomyelia: case report and a review of the literature

BACKGROUND

Scoliosis is a common finding in children with Chiari I malformation and syringomyelia. The development of scoliosis associated with a Chiari malformation typically has been ascribed to the presence of syringomyelia. Decompression of the hindbrain hernia will often alleviate the syringomyelia and, in many cases, stabilize or reverse the scoliosis.

CASE REPORT

We report a child with Chiari I malformation and scoliosis who presented with Valsalva-induced headache/neck pain. MRI revealed no syringomyelia or hydrocephalus. Radiographs revealed that her scoliotic curvature was approximately 13 degrees and was a single levoscoliotic curve. This patient underwent a posterior fossa decompression with duraplasty for her Valsalva-induced pain. Postoperatively, she had resolution of her pain and there has been no progression of her scoliosis at 3 years follow-up.

PROGNOSIS

Intriguingly, and scattered throughout the medical literature, many have noted cases of scoliosis in patients with only a Chiari I malformation and no syringomyelia. Moreover, experimental studies have induced scoliosis in animals after compression of the dorsal columns. After a review of the medical literature regarding a potential cause and effect of herniated hindbrain-induced scoliosis in the absence of syringomyelia, this association although rare, does seem plausible.

"Benign" imaging abnormalities in children and adolescents with headache

OBJECTIVE

To study the frequency of "benign" abnormalities on brain imaging in children with headache, compare it with the frequency of imaging findings that dictate a change in patient management, and determine the association of benign findings with headache.

METHODS

A database of 681 headache patients from the pediatric outpatient neurology department over 2 years was reviewed. Patients with benign imaging abnormalities were compared to those with nonbenign findings. Benign abnormalities were defined as those that did not result in a change in patient management. Using literature review, we discuss the benign findings and their possible association with headache.

RESULTS

Two-hundred and forty-one patients (35.4%) had imaging at our facility. Two-hundred and eighteen had brain magnetic resonance imaging and 23 had brain computed tomography (CT) only. Twenty-two patients had CT of the sinuses in addition to brain imaging. Forty-six (19.1%) were found to have 50 benign abnormalities including 13 sinus disease, 11 Chiari I malformations, 7 nonspecific white matter abnormalities, 5 venous angiomas, 5 arachnoid cysts, 4 enlarged Virchow-Robin spaces, 2 pineal cysts, 1 mega cisterna magna, 1 fenestration of the proximal basilar artery, and 1 periventricular leukomalacia. Twenty-three patients (9.5%) had findings requiring a change in management. These included 5 sinus disease, 4 tumors, 4 old infarcts, 3 Chiari I, 2 moyamoya, 1 intracranial vascular stenosis, 1 internal jugular vein occlusion, 1 arteriovenous malformation, 1 demyelinating disease, and 1 intracerebral hemorrhage. When excluding sinusitis, which was evident clinically prior to imaging, 3 patients had absence of abnormal neurologic symptoms and signs and imaging findings that resulted in a change in management.

CONCLUSIONS

Approximately 20% of pediatric headache patients with brain imaging have benign abnormalities that do not result in a change in headache management. Imaging findings that require a change in management are rare in patients with an absence of abnormal neurologic symptoms and signs, occurring in 1.2% of patients imaged in this study.

Correlation of cerebrospinal fluid flow dynamics and headache in Chiari I malformation

OBJECTIVE

The management of patients with a Chiari I malformation who present with headaches alone remains unclear. We studied the cerebrospinal fluid (CSF) flow dynamics of Chiari I malformation patients presenting with headaches alone so as to identify headache types that are associated with CSF flow obstruction versus those that may be unrelated to Chiari I malformations.

METHODS

Preoperative cine phase-contrast magnetic resonance imaging of the craniocervical junction was prospectively performed in 33 patients presenting with headaches alone and a Chiari I malformation (tonsillar ectopia >5 mm below the foramen magnum). Headaches were classified as frontal, occipital, or generalized. CSF flow dynamics were then prospectively compared with presenting symptomatology. A subgroup of 17 patients underwent surgical decompression of the Chiari I malformations.

RESULTS

Patients with frontal or generalized headaches were 10-fold less likely to demonstrate obstructed CSF flow (odds ratio, 0.10; 95% confidence interval, 0.02-0.52) and 8-fold less likely to have tonsillar descent greater than 7 mm (odds ratio, 0.12; 95% confidence interval, 0.03-0.62) compared with patients with occipital headaches. Adjusting for degree of tonsillar herniation in multivariate analysis, frontal and generalized headaches remained independently associated with nonobstructed CSF flow pathological findings, whereas occipital headaches remained associated with obstructed CSF flow independent of tonsil location (odds ratio, 5.84; 95% confidence interval, 1.01-34.28). In the surgical group, all patients with obstructed CSF flow did well compared with the group with normal flow, regardless of headache location.

CONCLUSION

Regardless of the degree of tonsillar ectopia, occipital headaches were strongly associated with hindbrain CSF flow abnormalities, whereas frontal and generalized headaches were not. Normal magnetic resonance imaging-cine CSF flow in the setting of a Chiari I malformation and frontal headaches alone suggests that frontal headaches are not pathologically or causatively associated with the Chiari I malformation in the vast majority of patients. Frontal headaches with obstructed flow may respond to surgery.

Preoperative MRI analysis of patients with idiopathic scoliosis: a prospective study

STUDY DESIGN

A prospective trial of preoperative MRI study in patients with "idiopathic" scoliosis.

OBJECTIVES

To investigate the prevalence of neural axis malformations and the clinical relevance of MRI in the evaluation of patients with idiopathic scoliosis undergoing surgical intervention.

SUMMARY OF BACKGROUND DATA

With the development of MRI, neural axis abnormalities such as syringomyelia or Chiari malformations are increasingly being found in patients with "idiopathic" scoliosis. The risk of neurologic complications during correction of scoliosis without prior decompression surgery for syringomyelia has been documented; however, there have been no prospective studies for identifying the risk of neurologic complications as a result of scoliosis surgery in patients with asymptomatic neural axis malformations.

METHODS

A total of 250 patients who were classified as having "idiopathic" scoliosis at first presentation and admitted for spinal surgery were evaluated. All patients were examined for neural axis abnormalities using MRI. The presence of neurologic symptoms and abnormal neurologic signs was also examined before and after surgical intervention. Neurologic complications during scoliosis surgery were reviewed in patients with neural axis abnormalities.

RESULTS

There were 44 (18%) patients (13 males and 31 females) who had neural axis abnormalities on MRI, including syringomyelia with Chiari malformations in 22 patients, syringomyelia with tonsillar ectopia in 2, Chiari malformations in 13, tonsillar ectopia in 6, and low conus medullaris in 1. On clinical examination, 44 (18%) patients had abnormal neurologic signs and 26 (7%) patients complained of headache or back pain. There were significant differences between patients with and without neural axis abnormalities regarding the age at first visit, gender, curve pattern, sagittal profile of thoracic spine, presence of neurologic deficit, and complaint of pain. Only 12 of 44 patients needed neurosurgical treatment for foramen magnum decompression before correction of scoliosis. Neurologic status temporarily worsened in 3 patients, including 2 patients with neurosurgical treatment and 1 patient without neurosurgical treatment; however, there were no permanent neurologic complications as a result of scoliosis surgery. All patients without neurologic deficits or complaints of pain did not receive neurosurgical treatment, while they had no permanent neurologic complications.

CONCLUSIONS

Foramen magnum decompression for neural axis malformations could prevent permanent neurologic complications during scoliosis surgery. There is little risk of neurologic complications in patients with "idiopathic" scoliosis whose neurologic status is normal, even if these patients have a neural axis malformation on MRI.

Chiari I malformation with syrinx

The Chiari I congenital malformation is characterized by caudal displacement of the cerebellar tonsils through the cervical canal. Although this malformation is often asymptomatic, coexisting syringomyelia can result in neurologic symptoms. We report a case of progressive ataxia with brainstem dysfunction in an adolescent female manifesting a severe Chiari I malformation with syrinx. Chiari decompression 4 years after initial presentation led to rapid improvement in most of her long-term symptoms. This case demonstrates the importance of consideration of Chiari I with syringomyelia in the differential diagnosis of progressive ataxia and brainstem symptoms.

Surgical experience in 130 pediatric patients with Chiari I malformations

OBJECT

The aim of this study was to present the long-term findings of a surgical series of pediatric patients with Chiari I malformations.

METHODS

One hundred thirty symptomatic pediatric patients with Chiari I malformations underwent posterior fossa decompression. The age in this group of patients ranged from 2 months to 20 years (mean 11 years). The length of the hospital stay extended from 2 to 7 days (mean 2.7 days), and follow up was from 3 months to 15 years (mean 4.2 years). Patients most often presented with headache/neck pain (38%) and scoliosis (18%). Examples of associated diagnoses included neurofibromatosis Type 1 (5.5%), hydrocephalus (11%), idiopathic growth hormone deficiency (5.5%), and Klippel-Feil anomaly (5%). Syringes were present in 58% of patients. Seventeen percent of patients had caudal displacement of the brainstem and fourth ventricle. Postoperative relief of preoperative pathologies was experienced in 83% of patients. Of the most common presenting symptoms--headache/neck pain and scoliosis--12 and 17%, respectively, were not alleviated postoperatively. Complications occurred in 2.3% of this group and included the development of acute hydrocephalus postoperatively and severe life-threatening signs of brainstem compression that necessitated a transoral odontoidectomy. Nine patients have had to undergo repeated operations for continued symptoms or persistent large syringes. During surgery 10 patients (7.7%) were found to have arachnoid veils occluding the fourth ventricular outlet, and nine of these had syringomyelia. In our experience almost all syringes will stabilize or improve with posterior fossa decompression and duraplasty.

CONCLUSIONS

The authors believe this to be the largest reported series of pediatric patients who have undergone posterior fossa decompression for Chiari I malformations.

Arnold-Chiari malformation type I and sleep-disordered breathing: an uncommon manifestation of an important pediatric problem

A case review of a healthy 3-year-old toddler with a chief complaint of sleep-disordered breathing is presented. The child underwent a pneumogram sleep study with significant abnormal findings. Magnetic resonance imaging led to a diagnosis of Arnold-Chiari type I malformation and the need for posterior fossa decompression. The child has been monitored, and 1 year postoperatively, her sleep apnea has resolved and day-time function and development remain normal. Definitions of the different types of Arnold-Chiari malformation are discussed, with sleep apnea presenting as the only symptom. The importance of a sleep history as part of the practitioner's pediatric assessment is explored.

Rapid development of Chiari I malformation in an infant with Seckel syndrome and craniosynostosis. Case report and review of the literature

To illustrate the rapidity with which a child can develop a severe, symptomatic Chiari I malformation, the authors present the case of a 3-month-old infant with Seckel syndrome (microcephaly, micrognathia, craniosynostosis, and multiple other abnormalities) and posterior sagittal and bilateral lambdoid synostosis. The infant underwent magnetic resonance (MR) imaging shortly after birth; the initial image demonstrated the cerebellar tonsils in the posterior fossa, with no herniation. He subsequently developed severe apneic episodes and bradycardia; repeated MR imaging at 3 months demonstrated severe tonsillar herniation with compression of the brainstem. The child underwent posterior fossa remodeling surgery, including release of the posterior sagittal and lambdoid sutures and decompression of the Chiari I malformation. The patient's apnea gradually improved; however, he died of complications of pneumonia and sepsis several weeks later. The authors identified from the literature 21 patients in whom there was a documented MR image or other neuroimage that did not reveal evidence of a Chiari I malformation, followed by a subsequent study with clear documentation of the presence of Chiari I malformation. The interval between the initial study and the development of the tonsillar herniation ranged from 11 days to 18.5 years. In most cases, a lumbar cerebrospinal fluid (CSF) diversion had been performed. This patient developed a severely symptomatic Chiari I malformation during a 3-month period. These reports illustrate that the Chiari I malformation can develop rapidly in the face of increased intracranial pressure, craniosynostosis, and spinal CSF diversion.

Idiopathic scoliosis as a presenting sign of familial neurologic abnormalities

STUDY DESIGN

Familial cases of "idiopathic" scoliosis associated with neurologic abnormalities are reported with a review of the literature.

OBJECTIVE

To investigate the prevalence of neurologic abnormalities such as syringomyelia, Chiari 1 malformation, and tonsillar ectopia in patients with genetically determined "idiopathic" scoliosis.

SUMMARY OF BACKGROUND DATA

Idiopathic scoliosis is widely considered to be a genetic disorder of unknown etiology. Magnetic resonance imaging (MRI) studies have shown that several cases of "idiopathic" scoliosis show neurologic abnormalities including syringomyelia and Chiari 1 malformation. Recently, several familial cases of either syringomyelia or Chiari malformation were reported, and it is suspected that genetic factors may influence the development of the craniovertebral malformation. It was hypothesized that some cases of "idiopathic" scoliosis include a craniovertebral malformation that is genetically determined.

METHODS

This study, using clinical examinations and MRI, investigated 71 patients with scoliosis and a family history of "idiopathic" scoliosis in third-degree relatives for the presence of neurologic abnormalities. If neurologic abnormalities were confirmed with MRI, the relatives affected with scoliosis were also examined.

RESULTS

Nine (13%) patients showed neurologic abnormalities on MRI. Magnetic resonance imaging showed syringomyelia with Chiari 1 malformation in four patients, Chiari 1 malformation in three patients, and tonsillar ectopia in two patients. Among the relatives of these patients, 4 of 15 individuals affected with scoliosis also showed neurologic abnormalities on MRI.

CONCLUSIONS

It is suggested that familial neurologic abnormalities may have a wide range of expression, and that some patients with "idiopathic" scoliosis present with genetically determined craniovertebral malformations such as syringomyelia, Chiari 1 malformation, and tonsillar ectopia.

Chiari I malformation in the very young child: the spectrum of presentations and experience in 31 children under age 6 years

INTRODUCTION

The entity of hindbrain herniation without myelodysplasia in the very young child has been poorly described. A retrospective analysis of children diagnosed with Chiari I malformation (CM I) before their sixth birthday is presented.

METHODS

Since 1985, 31 children with CM I (0.3-5.8) years of age have been diagnosed at University of Iowa Hospitals and Clinics. Their records were reviewed for presenting symptoms, signs, radiographic findings, treatment, complications, and outcome.

RESULTS

The average age at diagnosis was 3.3 years. Sixteen patients were under age 3. Chief presenting complaints included impaired oropharyngeal function (35%), scoliosis (23%), headache or neck pain (23%), sensory disturbance (6%), weakness (3%), and other (10%). Sixty-nine percent of children under age 3 had abnormal oropharyngeal function. Three patients under age 3 (19%) had undergone fundoplication and/or gastrostomy before diagnosis of CM I. Common physical findings included abnormal tendon reflexes (68%), scoliosis (26%), abnormal gag reflex (13%), and normal examination (13%). Vocal cord dysfunction (26%, all under age 3) and syringohydromyelia (52%) were also seen. Twenty-five patients were treated surgically at our institution with posterior fossa decompression, duraplasty, and cerebellar tonsillar shrinkage. Three patients were lost to follow-up. Ninety-one percent of patients reported improved symptomatology at last follow-up (mean: 3.9 years). Three patients required reoperation for recurrence of symptoms. Syringomyelia improved in all patients. Scoliosis resolved in 2 of 8 patients, improved in 5, and stabilized in 1. There was no permanent morbidity from surgery.

DISCUSSION

We show that children with Chiari I abnormality are very likely to present with oropharyngeal dysfunction if under age 3, and either scoliosis or headache or neck pain worsened by valsalva if age 3 to 5. These symptoms are very likely to improve after Chiari decompression, which can be done with low morbidity.

CONCLUSIONS

Very young children presenting with oropharyngeal dysfunction, pain worsened by valsalva, or scoliosis should prompt the clinician to consider CM I as a possible cause.

Curve progression in scoliosis associated with Chiari I malformation following suboccipital decompression

Nine children with scoliosis and Chiari I malformations were followed 1-11 years after suboccipital decompression. Eight also had syringomyelia. Despite initial curve stabilization, at final follow-up eight curves were of the magnitude to require spinal fusion. Neither bracing nor secondary neurosurgical procedures arrested progressive curves.

[Chiari type I malformation in children: presentation in 34 cases]

Incidental diagnoses of Chiari I malformation are more and more frequent in pauci or asymptomatic children. The value of neurophysiological investigations for surgical indications is discussed.

OBJECTIVE

To determine clinical presentations of Chiari I malformation and relative frequencies of severe and incidental forms, and to evaluate the usefulness of neurophysiological investigations for surgical indications.

METHODS

This retrospective study included 34 patients admitted from 1984 to 2000, with Chiari I malformation diagnosis in different pediatric (intensive care, neurology and neurosurgery) units of a university hospital.

RESULTS

The clinical presentation was severe (two children died) in four cases (12%). Signs of brain stem compression were found in 41% of cases, scoliosis in 21%, and incidental diagnosis in 26%. The polysomnography, performed in 12 cases, showed sleep-apneas in six cases. One child with an incidental diagnosis of Chiari I malformation had many sleep-apneas which required a surgical treatment. A surgical decompression was performed in 69% of cases, with clinical improvement in 77%.

CONCLUSION

The high incidence (12%) of severe forms revealing Chiari I malformations justifies systematic neurophysiological investigations for the initial evaluation and the follow-up of Chiari 1 malformations, including the less symptomatic forms.

Chiari I malformation associated with syringomyelia and scoliosis: a twenty-year review of surgical and nonsurgical treatment in a pediatric population

STUDY DESIGN

Retrospective review of patients with Chiari I malformation with or without associated scoliosis.

OBJECTIVES

Determine the effect of decompression of Chiari I malformation with syringomyelia on stabilization or improvement of associated scoliosis.

SUMMARY OF BACKGROUND DATA

Chiari malformations are often associated with spinal deformities, including scoliosis. Studies have suggested a causal relation between syringomyelia and scoliosis.

METHODS

Patients with Chiari I malformation and syringomyelia with or without scoliosis treated over the last 20 years were reviewed. Patients with any other anomalies were excluded. Scoliotic curves were classified by magnitude and curve type. All patients were treated with surgical decompression of the Chiari malformation with or without drainage of the syringomyelia.

RESULTS

Twenty-five patients were identified, ranging in age from 19 months to 16.5 years. Nineteen patients (76%) had associated scoliosis. The majority of the patients with scoliosis (13 of 19) sought treatment for spinal deformity, and only 6 had for pain or neurologic symptoms. Eleven of 19 patients with scoliosis (58%) underwent fusion. Eight of 19 (42%) patients have not undergone fusion: 3 have experienced progress, 1 remains in a stable condition, and 4 have experienced improvement of curvature since undergoing decompression. The mean age of patients who experienced progress after decompression was 14.5 years, compared to 6 years for patients who experienced improvement.

CONCLUSION

Early decompression of Chiari I malformation with syringomyelia and scoliosis resulted in improvement or stabilization of the spinal deformity in 5 cases. Each of these patients underwent decompression before 8 years of age and before the curve was severe. However, this series represents a few patients demonstrating this trend, and further follow-up and investigation are warranted.

Surgical treatment of Chiari I malformation: indications and approaches

Chiari I malformation is a well-described entity characterized by hindbrain herniation through the foramen magnum. Although the exact origin of congenital Chiari I malformation is unknown, it appears to be caused by a mismatch between the volume of the posterior fossa neural elements and the posterior fossa cranial content. Several theories have been proposed to describe the resultant pathophysiology of this mismatch. It is clear, however, that abnormal cerebrospinal fluid flow and velocity play a role in the symptoms and signs associated with this disorder. The authors will review the pathophysiology, clinical presentation, and treatment options for patients with Chiari I malformation.