Bilateral Idiopathic Frontal Transalar Herniation: A Case Report

A bstract Idiopathic frontal brain herniation, a considerable displacement of tissue without an identifiable cause, is rare, and only focal herniations have been described in the past. The lack of documented cases of bilateral transalar herniation in the literature poses difficulties in patient counseling. Here, we present the case of a 5-year-old child with no relevant past medical history who sustained a minor traumatic brain injury. Initial imaging revealed a nonspecific left frontal hypodensity. Furthermore, evaluation with magnetic resonance imaging showed bilateral frontal–basal parenchymal protrusions across intact sphenoid wings into the middle cranial fossa. Complete assessments, including neurocognitive and ophthalmological evaluations, revealed normal findings. We propose the descriptive term “idiopathic transalar herniation” for this radiological finding to distinguish it from herniations of known cause. Longitudinal studies are essential to document its benign nature and guide management. Follow-up in pediatric patients is required until the natural history of this rare anomaly is fully elucidated.