Supplementary Material for: Idiopathic Intraventricular Aneurysm Presenting with Intraventricular Hemorrhage: Case Report and Review of the Literature

Intraventricular hemorrhage (IVH) is a relatively commonly encountered problem in neurosurgical practice. The underlying causes could include hypertension, arteriovenous malformations (AVM), angiomas, trauma, tumors, aneurysms and moyamoya disease. Truly idiopathic intraventricular aneurysms (IVA) are rare. A high index of suspicion needs to be maintained since, with the appropriate treatment, the outcome is generally good. We report the case of a 14-year-old boy who presented with sudden onset headache and vomiting. CT angiogram pointed to the possibility of an IVA. This was confirmed by MRI with three-dimensional constructive interference in steady state (CISS-3D) sequences and digital subtraction angiography. The patient underwent microsurgical excision of the aneurysm and is doing well on follow-up. Idiopathic IVA can present with IVH at any age. MRI with CISS-3D and MR angiography would be the imaging modality of choice since it can also rule out other causes of intraventricular bleeding such as tumors and AVM. These lesions could be managed effectively by microsurgical excision/clipping. The necessity of investigating every patient who presents with IVH is debatable.