Case Report of an Obstructive Hydrocephalus Caused by an Unruptured Mesencephalic Arteriovenous Malformation in a Boy and a Review of Literature.

Objective: Arteriovenous malformation (AVM) is the most common form of intracranial vascular malformations in adults. Intracranial pediatric AVMs are rare. AVM located in the vicinity of the brain stem in children are even more rare.

Case report: This study reports a rare case of acute obstructive hydrocephalus following aqueductal stenosis caused by an unruptured grade IV perimesencephalic arteriovenous malformation. An 11-year-old boy admitted to the hospital with progressive headache, nausea and vomiting throughout a month. A Computerized Tomography (CT) showed an obstructive hydrocephaly. A Magnetic Resonance (MR) imaging revealed a mesencephalic AVM compressing the aqueduct. The patient deteriorated in hours and an emergency ventriculoperitoneal shunting was performed. He did well in the early postoperative period. AVM examined with Digital Subtraction Angiography (DSA) in detail for maintaining the definitive treatment by means of endovascular embolization, microsurgery and stereotactic radiosurgery; but the patient was lost to follow up.

Conclusion: A Pubmed search revealed 34 cases of hydrocephalus caused by an unruptured AVM in the literature, and only four cases were less than 18 years old with unruptured AVM locating in brain stem or posterior fossa. Although focal neurologic deficit, seizure and headache are the most common symptoms, acute neurologic deterioration due to hydrocephalus may be the presenting symptom in these cases. The decrease in intracranial pressure by changing the flow of cerebrospinal fluid (CSF) via an emergency ventriculoperitoneal (VP) shunting or Endoscopic Third Ventriculostomy (ETV) can be a lifesaving procedure that gives a chance for further treatment modalities.