Large intraparenchymal hematoma revealing an intracranial pseudoaneurysm in a newborn discovered during surgery

Intracranial pseudoaneurysms are rare and account for approximately 1% of all intracranial aneurysms. They can occur at any age, including in children usually post-trauma. Their presence in newborns is extremely rare. This case describes a spontaneous ruptured pseudoaneurysm of the middle cerebral artery in a newborn. A 25-day-old female infant, born from a consanguineous marriage, was admitted following a generalized tonic-clonic seizure. There was no history of head trauma or infection. Neurologically, she had a Blantyre coma score of 5/5, no motor deficits, and a bulging anterior fontanelle. A transfontanellar ultrasound revealed a mixed right-sided mass displacing midline structures. This was confirmed by a brain CT scan which showed a large right frontoparietal hematoma. A cerebral CT angiography showed a probable fusiform aneurysm in the distal right middle cerebral artery (M3 segment). The patient was referred to our neurosurgery department for hematoma evacuation and aneurysm clipping. Under general anesthesia and after a linear incision was made, the bone flap was cut using a Metzenbaum scissor. The dura was opened then the large intraparenchymal hematoma was progressively evacuated. No aneurysmal sac was found, only the feeding branch with brisk arterial bleeding and clot, confirming the presence of an intracranial pseudoaneurysm. The bleeding vessel was coagulated. The patient had no postoperative deficits, possibly due to adequate collateral circulation. Pseudoaneurysms in neonates are rare. They should be suspected in infants with intraparenchymal hematoma and imaging suggestive of aneurysm. Careful imaging review is vital to guide treatment.