Giant cerebral arterial aneurysm in an infant: report of a case and review of 42 previous cases in infants with cerebral arterial aneurysm.

A giant cerebral aneurysm with subarachnoidal hemorrhage in a 4-month-old female infant is reported. The clinical course was complicated by an electrolyte imbalance and unexpected intoxication by phenobarbital. She died as a result of the third episode of rerupture of the aneurysm on the 16th day after onset. Histological findings showed that the aneurysm was of the saccular type, 35 x 20 x 22 mm in size, arising from the basilar artery. The aneurysmal wall consisted microscopically of fibrous tissue with partial absence or fragmentation of the internal elastic lamina and muscular lamina. Forty-three cases of cerebral aneurysms during the first year of life including the present case were summarized and it was found that they could be characterized as follows: (i) a high incidence of onset in early infancy; (ii) larger than 10 mm; (iii) a large number arose from the posterior circulation of the circle of Willis; and (iv) a poor prognosis of non-operated groups, especially in the posterior circulation.