Skip to main content
  • Chiari I Malformations and Other Intracranial Radiographic Abnormalities in Autism Spectrum Disorder

    Final Number:

    Mayur Jayarao MD, MSc; Kristin Sohl MD; Tomoko Tanaka MD

    Study Design:

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2014 Annual Meeting

    Introduction: Children with Autism Spectrum Disorder (ASD) have a higher incidence of intracranial radiographic abnormalities compared to the normal population. Here we report on the Magnetic Resonance Imaging (MRI) findings from our ASD database and the outcomes of five ASD children with symptomatic Chiari I malformations.

    Methods: Institution review board approval was obtained for this retrospective study. Over 13.5 years (1999-2013), 125 children (younger than 18 years of age) with a diagnosis of ASD underwent cranial MRI surveillance. All children met DSM-IV criteria for ASD and were assessed using the Autism Diagnostic Observation Schedule, Autism Diagnostic Interview, Child Behavior Checklist, Teachers Report Form or Pediatric Quality of Life Inventory.

    Results: Thirty-eight children had intracranial MRI abnormalities (30.4%). Nine had evidence of cerebellar tonsil ectopia (7%), of whom, four were asymptomatic with ectopia less than 4 mm. Five children with symptomatic Chiari I malformations presented with features of headache, neck pain, lower cranial nerve dysfunction, cerebellar or spinal cord compromise. These children underwent surgical decompression with suboccipital craniectomy, C1 laminectomy and duraplasty, with resolution of symptoms postoperatively. (Figure 1) Other MRI abnormalities included: Arachnoid cyst (7), Cavum septum pellucidum (4), Non-specific white matter signal change (4), Developmental venous abnormality (4), Pineal cyst (4), Mega cisterna magna (3), Corpus callosum abnormality (2) and Septum pellucidum cyst (1). Table I summarizes these findings.

    Conclusions: Cerebellar ectopia was the most frequent MRI abnormality encountered (7%) in these children with more than half of them being symptomatic, requiring surgical decompression. This is greater than the current observed frequency of Chiari I malformations in the pediatric and adult population (1%). It is imperative that the physician be alert to the history, observed clinical findings, and to corroborate these aspects with the sensible utilization of further testing and management.

    Patient Care: This research attempts to illuminate the likely under-diagnosed and therefore, under-treated association of symptomatic Chiari I malformations in children with ASD. Due to the young age and clinical heterogeneity of patients with the ASD, it can be extremely difficult to identify co-existing symptomatic Chiari I malformations. Features of headache, neck pain, lower cranial nerve dysfunction, cerebellar or spinal cord compromise are frequently attributed to being secondary to ASD and consequently not investigated further. Awareness of the co-existence of symptomatic Chiari I malformations and other intracranial abnormalities in children with ASD necessitates clear communication between primary care physicians, autism specialists, pediatric neurologists and pediatric neurosurgeons so that appropriate management may be instituted early.

    Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the frequent intracranial MRI abnormalities encountered in children with Autism Spectrum Disorder (ASD). 2) Discuss, in small groups, the importance of identifying ASD children with symptomatic intracranial abnormalities. 3) Identify an effective treatment for ASD children with symptomatic intracranial abnormalities such as Chiari I malformations.

    References: 1. Autism, Developmental Disabilities Monitoring Network Surveillance Year Principal I, Centers for Disease C, Prevention: Prevalence of autism spectrum disorders--Autism and Developmental Disabilities Monitoring Network, 14 sites, United States, 2008. MMWR Surveill Summ 61:1-19, 2012. 2. Aitken LA, Lindan CE, Sidney S, Gupta N, Barkovich AJ, Sorel M, et al: Chiari type I malformation in a pediatric population. Pediatr Neurol 40:449-454, 2009. 3. Meadows J, Kraut M, Guarnieri M, Haroun RI, Carson BS: Asymptomatic Chiari Type I malformations identified on magnetic resonance imaging. J Neurosurg 92:920-926, 2000. 4. Salmond CH, de Haan M, Friston KJ, Gadian DG, Vargha-Khadem F: Investigating individual differences in brain abnormalities in autism. Philos Trans R Soc Lond B Biol Sci 358:405-413, 2003. 5. Volkmar FR, Reichow B, McPartland J: Classification of autism and related conditions: progress, challenges, and opportunities. Dialogues Clin Neurosci 14:229-237, 2012.

We use cookies to improve the performance of our site, to analyze the traffic to our site, and to personalize your experience of the site. You can control cookies through your browser settings. Please find more information on the cookies used on our site. Privacy Policy