OBJECTIVE: Marfan's syndrome is a heritable connective tissue disorder that has 
been associated with intracranial aneurysms. However, the prevalence of 
intracranial aneurysms in Marfan's syndrome is unknown and pathological studies 
of affected vessels have not been reported. We therefore examined the 
neuropathological findings in a group of patients with Marfan's syndrome.
METHODS: We identified all patients with Marfan's syndrome in whom postmortem 
examination had been performed at the Mayo Clinic between 1969 and 1993.
RESULTS: Autopsy included examination of the brain in seven patients with 
Marfan's syndrome (five men and two women with a mean age of 28 yr). Each of two 
patients had one or more intracranial aneurysms. The first patient, a 
32-year-old man who died as a result of aortic dissection, was observed to have 
an incidental saccular supraclinoid carotid artery aneurysm (7 mm). Microscopic 
examination of the remainder of the cerebral arteries revealed duplication and 
fragmentation of the internal elastic lamina. The second patient, a 20-year-old 
man who died as a result of a subarachnoid hemorrhage, had ruptured saccular 
supraclinoid carotid artery (3 mm) and anterior cerebral artery (20 mm) 
aneurysms as well as unruptured fusiform middle cerebral artery (18 mm) and 
posterior cerebral artery (13 mm) aneurysms. Microscopic examination of the 
cerebral arteries revealed widespread changes consisting of intimal 
proliferation, medial degeneration, and fragmentation of the internal elastic 
lamina.
CONCLUSION: These findings confirm an association between Marfan's syndrome and 
intracranial aneurysms. Microscopic involvement of cerebral arteries in Marfan's 
syndrome may be variable, even among those with intracranial aneurysms.