Chiari Type I Malformation in a Pediatric Population

Abstract

Objective The natural history of Chiari I malformation in children remains unclear. Methods In this population-based retrospective cohort study, we searched radiology reports from all head and spine MRI scans (n=5248) performed among 741, 815 children under age 20 within Kaiser Northern California, 1997–1998, for Chiari I. We reviewed medical records and imaging studies to determine clinical and radiographic predictors of significant neurologic symptoms defined as moderate to severe headache, neck pain, vertigo or ataxia. Results The 51 patients identified with Chiari I represented 1% of children who had head or spine MRI 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 time of initial diagnosis; no new syrinxes developed during follow-up. Older age at time of diagnosis was associated with increased risk of headache (OR 1.3, 95% CI 1.1–1.5) and significant neurologic symptoms (OR 1.2, 95% CI 1.04–1.4). Conclusions Chiari I, an under-recognized 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.

Long-term clinical data and molecular defects in the STAR gene in five Greek patients

“…In a study carried out in a general population sample of individuals younger than 20 years (nZ5248), the prevalence of Chiari-1 malformation was 0.7/10.000, whereas in subjects who had an MRI for CNS symptoms, it was 1% (40). Of note is the report that 37% of the subjects with Chiari-1 younger than 20 years were asymptomatic at the time of diagnosis, as were our two patients with Chiari-1 malformation.…”

Incidental Findings on Brain and Spine Imaging in Children

“…[135][136][137] The prevalence of syringomyelia in the setting of CM estimated from imaging databases has been reported to be between 12% and 23%. 138,139 Syringes are less likely to be found associated with CM in children younger than 5 years but may develop later in childhood. 139 Lower position of the cerebellar tonsils in CM is associated with a greater likelihood of syringomyelia.…”

“…139,140,151 If the current imaging definition of tonsils 5 mm below the foramen magnum is used, CM is not rare. 78,[138][139][140]153,154 CM is found in approximately 0.8% to 1% of all patients undergoing MRI when age is not considered. 78,138,153 When prevalence is stratified by age, it is clear that the prevalence in children and young adults is greater.…”

“…78,[138][139][140]153,154 CM is found in approximately 0.8% to 1% of all patients undergoing MRI when age is not considered. 78,138,153 When prevalence is stratified by age, it is clear that the prevalence in children and young adults is greater. 152 As many as 3.6% of children undergoing MRI of the brain or cervical spine have CM by imaging criteria; most children who meet the definition of CM by imaging criteria are asymptomatic.…”

Chiari 1 Malformation and Holocord Syringomyelia in Hunter Syndrome

“…CM1 is an uncommon condition (about 1 % in the pediatric population) (Aitken et al 2009) due to underdevelopment of mesenchymal structures forming the clivus and posterior cranial fossa bones (Milhorat et al 2010). The abnormal position of the cerebellar tonsils disrupts the normal CSF flow dynamics (Shah et al 2011) at the cranio-cervical junction and may result in spinal cord damage.…”