Agenesis of the Arcuate Fasciculi in Congenital Bilateral Perisylvian Syndrome A Diffusion Tensor Imaging and Tractography Study

Objective: To describe the absence of the arcuate fasciculi in 2 cases of congenital bilateral perisylvian syndrome (CBPS). Design: Case series. Setting: Pediatric referral hospital-based study. Patients: Two patients with CBPS, referred to our institution as candidates for surgical treatment of epilepsy. Intervention: Diffusion tensor imaging (1.5-T scanner; 15 encoding directions; b= 800 s/mm(2)) and deterministic tractography of the main projection and association tracts. Main Outcome Measures: Neuropsychology evaluation; fractional anisotropy, apparent diffusion coefficients, and anatomical aspect of the tracts. Results: Absence of the arcuate fasciculus was observed in both subjects. Ancillary findings were complete absence of the superior longitudinal fasciculi in 1 case and underdevelopment in the other. Low fractional anisotropy of the left inferior occipitofrontal fasciculus was found in both cases. The same tract was maloriented in 1 of the cases. Conclusion: Agenesis of the arcuate fasciculus may accompany CBPS.