Tonsillar contusion associated with benign tonsillar ectopia following minor head trauma

Purpose: The relationship between tonsil position and symptomatic cerebellar contusion is unclear. To date, there are no reports of symptomatic traumatic brain injury associated with benign tonsillar ectopia. Reported cases are limited to prominent cerebellar tonsillar displacement by ≥5 mm (i.e., Chiari malformations). Methods: The authors describe a case of symptomatic concussion in a toddler with unusual computerized tomography (CT) presentation and incidental finding of benign tonsillar ectopia, hemorrhagic contusion of the tonsils, blood-brain barrier (BBB) disruption and delayed atrophy shown using magnetic resonance imaging (MRI) studies. The radiological presentation and the clinical challenges are discussed through a review of the literature. Conclusion: This case suggests that damage to cerebellar structures is not limited only to overt tonsillar herniation. Benign tonsillar ectopia may predispose to cerebellar contusion even after minor concussion and thus has a clinical significance. The current paradigm viewing only noticeable tonsillar herniation as a risk factor for hindbrain injury should be revisited.