Apoptosis of endothelial cells in vessels affected by cerebral vasospasm.

Background: Cerebral vasospasm after subarachnoid hemorrhage is a prolonged contraction that leads to cerebral ischemia or infarction. Morphological studies of cerebral arteries during vasospasm have shown extensive necrosis of smooth-muscle cells and desquamation and dystrophy of endothelial cells. The mechanism of cellular death is unknown.

Methods: We report an observation of apoptotic changes in the cerebral arteries of a patient who died after suffering severe cerebral vasospasm caused by aneurysmal rupture. Subarachnoid hemorrhage and cerebral vasospasm were confirmed by computed tomography scanning and angiogram. Histological and immunohistological examinations for apoptosis were performed in cerebral arteries. For control, the arteries from another patient, who died of trauma without head injury, were used.

Results: Corrugation of the internal elastic lamina and increased amounts of connective tissue was demonstrated by light microscopy. Apoptotic changes, characterized by condensation of chromatin of the nucleus and detachment from the basal membrane, were found on transmission electron microscopy in endothelial cells. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling reaction revealed positive staining of the nuclei of the endothelial cells.

Conclusions: This study demonstrates that apoptosis occurred in the cerebral arteries in a patient who died of cerebral vasospasm. The possible role of apoptosis in cerebral vasospasm is discussed.