title: How temporal evolution of intracranial collaterals in acute stroke affects clinical outcomes.
abstract: OBJECTIVE
  We compared intracranial collaterals on pretreatment and day 2 brain CT angiograms (CTA) to assess their evolution and relationship with functional outcomes in acute ischemic stroke (AIS) patients treated with IV tissue plasminogen activator (tPA).
  
  
  METHODS
  Consecutive AIS patients who underwent pretreatment and day 2 CTA and received IV tPA during 2010-2013 were included. Collaterals were evaluated by 2 independent neuroradiologists using 3 predefined criteria: the Miteff system, the Maas system, and 20-point collateral scale by the Alberta Stroke Program Early CT Score methodology. We stratified our cohort by baseline pre-tPA state of their collaterals and by recanalization status of the primary vessel for analysis. Good outcomes at 3 months were defined by a modified Rankin Scale score of 0-1.
  
  
  RESULTS
  This study included 209 patients. Delayed collateral recruitment by any grading system was not associated with good outcomes. All 3 scoring systems showed that collateral recruitment on the follow-up CTA from a baseline poor collateral state was significantly associated with poor outcome and increased bleeding risk. When the primary vessel remained persistently occluded, collateral recruitment was significantly associated with worse outcomes. Interestingly, collateral recruitment was significantly associated with increased mortality in 2 of the 3 grading systems.
  
  
  CONCLUSIONS
  Not all collateral recruitment is beneficial; delayed collateral recruitment may be different from early recruitment and can result in worse outcomes and higher mortality. Prethrombolysis collateral status and recanalization are determinants of how intracranial collateral evolution affects functional outcomes.
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore. leonard_ll_yeo@nuhs.edu.sg.
authors.forename: Leonard L L
authors.initials: LL
authors.lastname: Yeo
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Prakash
authors.initials: P
authors.lastname: Paliwal
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Low
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Edgar L W
authors.initials: EL
authors.lastname: Tay
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Anil
authors.initials: A
authors.lastname: Gopinathan
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Mahendran
authors.initials: M
authors.lastname: Nadarajah
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Eric
authors.initials: E
authors.lastname: Ting
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Narayanaswamy
authors.initials: N
authors.lastname: Venketasubramanian
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Raymond C S
authors.initials: RC
authors.lastname: Seet
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Aftab
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Bernard P L
authors.initials: BP
authors.lastname: Chan
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Hock L
authors.initials: HL
authors.lastname: Teoh
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Derek
authors.initials: D
authors.lastname: Soon
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Rahul
authors.initials: R
authors.lastname: Rathakrishnan
authors.affiliation: From the Division of Neurology, Department of Medicine (L.L.L.Y., P.P., R.C.S.S., A.A., B.P.L.C., H.L.T., D.S., R.R., V.K.S.), Cardiac Department (A.F.L., E.L.W.T.), and Department of Diagnostic Imaging (A.G., E.T.), National University Health System; Department of Neuroradiology (M.N.), National Neuroscience Institute; and Raffles Neuroscience Centre (N.V.), Raffles Medical Group, Singapore.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Sharma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology; D003097:Collateral Circulation / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000401:mortality; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D014057:Tomography, X-Ray Computed / Q000401:mortality / Q000639:trends; D016896:Treatment Outcome
chemical_list: D010959:Tissue Plasminogen Activator