title: Significance of Development and Reversion of Collaterals on MRI in Early Neurologic Improvement and Long-Term Functional Outcome after Intravenous Thrombolysis for Ischemic Stroke.
abstract: OBJECTIVE
  Predicting response to rtPA is essential in the era of endovascular therapy for stroke. The purpose of this study was to elucidate prognostic factors of early neurologic improvement and long-term outcome with respect to the development and reversion of leptomeningeal collaterals in recanalization therapy after acute ischemic stroke.
  
  
  METHODS
  We analyzed consecutive patients with proximal MCA occlusion treated with rtPA from 2007 to 2012 at 2 hospital stroke centers. All patients routinely underwent brain MR imaging before rtPA. To assess the reversion of collateral signs, we included patients who underwent follow-up MR imaging. We assessed the development and reversion of collaterals by using a combination of 2 MR imaging collateral markers, the hyperintense vessel sign and the posterior cerebral artery laterality sign. Early neurologic improvement was defined as a decrease in the NIHSS score of ≥10 or a score of ≤2 at 24 hours of treatment.
  
  
  RESULTS
  Early neurologic improvement was observed in 22 of 48 eligible patients. The development of collaterals at arrival (15/22 versus 9/26, P = .042) was significantly associated with early neurologic improvement. Multivariate analysis adjusting for other variables showed that the development of collaterals at arrival (OR, 4.82; 95% CI, 1.34-19.98; P = .015) was independently associated with early neurologic improvement. Reversion of collaterals was significantly associated with successful recanalization (P < .001), and multivariate analysis showed that the reversion of collaterals was an independent prognostic factor of long-term functional outcome (OR, 5.07; 95% CI, 1.38-22.09; P = .013).
  
  
  CONCLUSIONS
  Our results indicate that the development of leptomeningeal collaterals plays a crucial role in achieving early neurologic improvement, and reversion of collaterals predicts a favorable outcome via arterial recanalization after rtPA treatment for acute stroke.
authors.affiliation: From the Department of Neurology and Neurological Science (M.I., E.I., Y.N., S.I., and H.M.) Department of Neurology, Musashino Red Cross Hospital (M.I., T.K.), Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ichijo
authors.affiliation: From the Department of Neurology and Neurological Science (M.I., E.I., Y.N., S.I., and H.M.).
authors.forename: E
authors.initials: E
authors.lastname: Iwasawa
authors.affiliation: From the Department of Neurology and Neurological Science (M.I., E.I., Y.N., S.I., and H.M.).
authors.forename: Y
authors.initials: Y
authors.lastname: Numasawa
authors.affiliation: Department of Endovascular Surgery (K.M.).
authors.forename: K
authors.initials: K
authors.lastname: Miki
authors.affiliation: From the Department of Neurology and Neurological Science (M.I., E.I., Y.N., S.I., and H.M.) t-ishibashi.nuro@tmd.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Ishibashi
authors.affiliation: Clinical Research Center (M.T.), Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tomita
authors.affiliation: Department of Neurology, JA Toride Medical Center (H.T., S.S.), Ibaraki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tomimitsu
authors.affiliation: Department of Neurology, Musashino Red Cross Hospital (M.I., T.K.), Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kamata
authors.affiliation: Department of Internal Medicine (H.F.), Metropolitan Bokutoh Hospital, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Fujigasaki
authors.affiliation: Department of Neurology, JA Toride Medical Center (H.T., S.S.), Ibaraki, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shintani
authors.affiliation: From the Department of Neurology and Neurological Science (M.I., E.I., Y.N., S.I., and H.M.).
authors.forename: H
authors.initials: H
authors.lastname: Mizusawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply*; D003097:Collateral Circulation / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000187:drug effects; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D010959:Tissue Plasminogen Activator