Chiari I Malformation in Nephropathic Cystinosis.

OBJECTIVE: To determine the relative incidence of Chiari I malformations in children with cystinosis compared with those in the general population. STUDY DESIGN: Magnetic resonance imaging scans were performed on 53 patients with nephropathic cystinosis and 120 controls, age range 3-18 years. RESULTS: Ten of 53 (18.9%) patients with cystinosis had Chiari I or tonsillar ectopia, and only 2 of 120 controls (1.6%) had a similar finding. At least 2 of the patients had symptoms or signs thought to be related to the malformation, and one had surgical decompression. Two had an associated cervical syrinx. CONCLUSIONS: Children with cystinosis have a 12-fold higher prevalence of Chiari I malformations than the general pediatric population. Chiari I malformations should be high on the differential diagnosis when individuals with cystinosis develop neurologic signs and symptoms, and magnetic resonance imaging scans should be performed on children with cystinosis who present with new-onset headache, ataxia, incontinence, or other unexplained neurologic symptoms.