BACKGROUND AND PURPOSE: A chronic compromise of cerebral hemodynamics has been shown to identify a group of patients at an increased risk for stroke. Because a "steal phenomenon" induced by a vasodilatory challenge has characterized the group at greatest risk, it was hypothesized that these individuals would also have a severe compromise of primary collaterals and an increased dependence on leptomeningeal collaterals. METHODS: Twenty-three patients with symptomatic cerebrovascular disease underwent angiography and xenon-enhanced computed tomographic cerebral blood flow studies before and after 1 g IV acetazolamide within 6 months of each other. Cerebral blood flow vasoreactivity was classified by whether cerebral blood flow increased (> 5%) or was unchanged (+/- 5%) (group 1) or fell by > 5% (group 2) in any vascular territory. Angiographic collateralization was classified into four types: normal (type 1), willisian (type 2), ophthalmic (type 3), and leptomeningeal (type 4). RESULTS: Twenty percent (2/10) of group 1 patients and 69% (9/13) of group 2 patients (P = .0009) had leptomeningeal collaterals. CONCLUSIONS: A negative flow reactivity is significantly associated with a dependence on leptomeningeal collaterals and implies a state of maximal hemodynamic compromise.
BACKGROUND AND PURPOSE: A chronic compromise of cerebral hemodynamics has been shown to identify a group of patients at an increased risk for stroke. Because a "steal phenomenon" induced by a vasodilatory challenge has characterized the group at greatest risk, it was hypothesized that these individuals would also have a severe compromise of primary collaterals and an increased dependence on leptomeningeal collaterals. METHODS: Twenty-three patients with symptomatic cerebrovascular disease underwent angiography and xenon-enhanced computed tomographic cerebral blood flow studies before and after 1 g IV acetazolamide within 6 months of each other. Cerebral blood flow vasoreactivity was classified by whether cerebral blood flow increased (> 5%) or was unchanged (+/- 5%) (group 1) or fell by > 5% (group 2) in any vascular territory. Angiographic collateralization was classified into four types: normal (type 1), willisian (type 2), ophthalmic (type 3), and leptomeningeal (type 4). RESULTS: Twenty percent (2/10) of group 1 patients and 69% (9/13) of group 2 patients (P = .0009) had leptomeningeal collaterals. CONCLUSIONS: A negative flow reactivity is significantly associated with a dependence on leptomeningeal collaterals and implies a state of maximal hemodynamic compromise.
Authors: Roham Moftakhar; Aquilla S Turk; David B Niemann; Sayed Hussain; Sharad Rajpal; Thomas Cook; Madeleine Geraghty; Beverly Aagaard-Kienitz; Patrick A Turski; George C Newman Journal: AJNR Am J Neuroradiol Date: 2005-08 Impact factor: 3.825
Authors: H T Ozgur; T Kent Walsh; A Masaryk; J F Seeger; W Williams; E Krupinski; M Melgar; E Labadie Journal: AJNR Am J Neuroradiol Date: 2001-05 Impact factor: 3.825