Abstract
Congenital defects in the tentorium cerebelli are quite rare occurrences and are often too small and asymptomatic. This is a case report of a female patient aged 11 years, complaining of headache, vertigo, and vomiting. Her computed tomography (CT) images show transtentorial herniation of occipital gyri across a developmental defect involving the anterior free margin of the tentorium cerebelli. Similar cases have been reported in the past as "incidental" and "potentially symptomatic" findings, and in at least one case as a proven pathological findings. Our case is unique in terms of the asymmetric bilateral configuration and comparatively larger size of the defect. We have included a review of the existing medical literature in order to derive learning points for the betterment of our understanding of a rare entity that can have significant implications.