Intracranial aneurysms in children under 1 year of age: a systematic review of the literature

OBJECTIVE: Intracranial aneurysms are very rare in early childhood. Because the location, morphology as well as the clinical and radiological presentation of these aneurysms seem to be different from those in adults, we performed a systematic review of the literature to discuss the clinical, morphological, and radiological features of intracranial aneurysms in the first year of life. MATERIALS AND METHODS: A computerized search of both Pubmed and EMBASE from before 1966 to 2005 was performed. Included were all articles that dealt with cases in which an intracranial aneurysm was demonstrated in children under 1 year of age. RESULTS: We found 110 articles in which 131 cases of an intracranial aneurysm in children under 1 year were presented. The mean age at diagnosis of the aneurysm was 4.9+/-3.5 months with a male to female ratio of 1.1. There was a hemorrhagic presentation in 73% (n=96). The patients presenting with a hemorrhage were younger (mean 4.3 vs 6.7 months, P<0.001) and tended to have smaller-sized (i.e.<2.5 cm) aneurysms (P=0.07). The aneurysm was defined as traumatic or infectious in 15 and 13 cases, respectively. In 21% (n=27), there was various vascular or congenital co-morbidity. In 76%, the aneurysm was located in the anterior circulation. The prevalence of aneurysms on the middle cerebral artery (MCA) was nearly three times higher than on any other vessel. The mean aneurysm size was 1.8+/-1.4 cm, with 30 giant aneurysms (>2.5 cm). The giant aneurysms were significantly more often located in the posterior circulation (43 vs 16%, P=0.01). The mean period of follow-up was 13.6+/-24.8 months. The Glasgow Outcome Scale (GOS) could be derived in 106 cases: 50% had an excellent outcome (GOS of 5). CONCLUSIONS: The presentation of arterial aneurysms in children under the age of 1 year differs from that in adults with a significantly higher prevalence of giant aneurysms in the posterior circulation. The prevalence of aneurysms on the MCA is nearly three times higher than on any other vessel. The patients presenting with a hemorrhage were younger and tended to have smaller-sized aneurysms. Our study did not confirm the male predominance that has thus far been associated with pediatric aneurysms. The outcome is comparable or slightly better than in adults.