Subdural Hygroma: A Rare Complication of a Common Brain Malformation.

Introduction Arachnoid cysts are a common incidental finding on head imaging. While the natural history of these cysts in poorly described, hemorrhage with subdural hygroma formation is rare. We review the clinical course of a patient who developed a subdural hygroma following trauma. Case The patient was a previously healthy 14-month-old male who presented to the Emergency Department with vomiting after a fall and was found to have esotropia without other focal neurological deficits and a CT scan consistent with a subdural cerebrospinal fluid collection with midline shift. The patient was treated conservatively and his symptoms resolved. Discussion Arachnoid cyst rupture is a rare complication which can lead to increased intracranial pressure with devastating consequences. Clinical manifestation can be similar to that of other intracranial pathologies. Prompt diagnosis is required to avoid life-threatening symptoms. Conclusion Arachnoid cyst rupture should be considered when evaluating patients with non-specific neurological symptoms following trauma.