Speech and Language Delays Associated With New-Onset Seizures Revealing Dandy-Walker Variant

Abstract

Dandy-Walker malformation or syndrome is a rare congenital deformity in which the cerebellar vermis is hypoplastic and upwardly rotated, the fourth ventricle enlarged, and the posterior fossa cystically dilated. It represents the most common type of posterior fossa malformations that are usually diagnosed before the age of one year old. We present a seven-year-old boy with a history of neonatal hypotonia and delayed walking, who presented with speech and language difficulties. His physical examination and cognitive tests were unremarkable. The patient's brain magnetic resonance imaging showed a partial defect of the inferior part of the cerebellar vermis and communication between a normal-sized cisterna magna and the fourth ventricle. There were no other coexisting central nervous system or systemic anomalies. This isolated inferior vermian hypoplasia was compatible with an uncommon variant of the Dandy-Walker syndrome. The aim of this report is to provide insight into the importance of implementing a pediatrician-psychiatrist collaboration in the clinical decision-making process of such developmental delay cases. What makes the present case further interesting are the new-onset unprovoked seizures that developed and recurred in the setting of such isolated and less severe posterior fossa anomaly, raising both diagnostic and therapeutic challenges.

Keywords: dandy-walker syndrome; dandy-walker variant; developmental delay; new-onset seizure; posterior fossa malformations.

Figure 1. Brain MRI showing an inferior cerebellar vermian hypoplasia (white arrow), with communication between a normal-sized fourth ventricle (yellow arrow) and cisterna magna (red arrows). There was no hypoplasia, anterior rotation, upward displacement of the remaining vermis, or anterolateral displacement of the cerebellar hemispheres. The forebrain appeared normal. (A) Axial, (B) sagittal, and (C) coronal MRI images.