Ruptured Intracranial Aneurysm in a 60-Day-Old Infant: An Extreme Case.

The prevalence of aneurysms in children is low when compared to adults, being even rarer in the first year of life. They can be secondary to infections, traumatic brain injury, autoimmune diseases, or connective tissue diseases. Dissecting etiology is rare. A 60-day-old female infant, previously healthy, presented to the emergency department (ED) with irritability and loss of appetite since the preceding day, a fever of one-hour duration, and vomiting. Laboratory analysis revealed a hemoglobin level of 6.5 g/dL, without elevation of inflammatory markers. In the ED, she experienced two episodes, with a one-hour interval, of clonic movements of the upper eyelid and right upper limb, along with conjugate gaze deviation to the same side, which resolved after intravenous diazepam. Levetiracetam was initiated after the second episode. The anterior fontanelle became progressively tense. Brain computed tomography (CT) showed a voluminous intraparenchymal and subarachnoid hemorrhage with an aneurysm at the bifurcation of the left middle cerebral artery (MCA). Initially, an endovascular approach was tried but was not successful due to technical problems. Consequently, a Vaso-CT scan was performed that confirmed a dissecting aneurysm/pseudoaneurysm (8 mm × 10 mm × 10 mm) of the left MCA, originating from the upper wall of the M1 segment. Next, she underwent microsurgical exclusion of the aneurysm using microclips. Post-surgery brain CT showed acute ischemia in the entire MCA region. Follow-up angiography showed complete exclusion of the aneurysm. She evolved to grade 3 monoparesis of the upper limb at the six-month interval follow-up, which has been gradually improving with physical rehabilitation. The next-generation sequencing (NGS) panel for aneurysms and arterial dissections did not detect any pathogenic variants. Clinical presentation of cerebral aneurysms in infants can be subtle, and a high index of suspicion is required in cases of irritability, altered consciousness, seizures, bulging fontanelle, and motor deficits. Early detection is of utmost importance as it is associated with moderate mortality. Surgical treatment with the use of clips proved to be effective in this case.