Cerebral amyloid angiopathy and intracerebral hemorrhage with special reference to the pons.

Cerebral amyloid angiopathy accounts for approximately 10% of spontaneous intracerebral hemorrhage, typically in the cortex and subcortical white matter. Its contribution to primary pontine hemorrhage is not known. The present study was designed to determine if amyloid angiopathy occurs in the pons and whether primary pontine hemorrhages are associated with amyloid infiltration of nearby vessels. Two groups of patients were identified. Group A included 30 patients with proven CAA in whom special blocks of the pons were taken, group B consisted of 10 primary pontine hemorrhages in whom transverse blocks were available. A congo red stain and an A4 immunohistochemical technique were used. Only 1 patient from group A and none from group B had amyloid angiopathy in the pons. It is concluded that pontine angiopathy is rare and an exceptional cause of primary pontine hemorrhage.