Case Report: Sustained Cognitive Improvement and Reversible Brain Hypoperfusion in the Context of Posterior Fossa Arachnoid Cyst Shunting Procedure in KBG Syndrome.

Résumé

KBG syndrome is a genetic syndrome characterized by developmental delay, mild autism spectrum disorder (ASD), variable cognitive disorders and distinctive craniofacial and skeletal features. Posterior fossa arachnoid cysts (PFACs) have been reported in this condition as in other syndromic forms of ASD, but their impact remains uncertain. Here, we report a ten-year follow-up of a patient with KBG syndrome and PFAC shunted for progressive cyst enlargement and his clinical symptoms, who showed important cognitive and behavior improvement post-drainage. Preoperative neuropsychological assessment revealed severe ASD, heterogeneous cognitive profile with below-average IQ (82, average ≥90), slow processing speed (66, cut-off