title: Early Fiber Number Ratio Is a Surrogate of Corticospinal Tract Integrity and Predicts Motor Recovery After Stroke.
abstract: OBJECTIVE
  The contribution of imaging metrics to predict poststroke motor recovery needs to be clarified. We tested the added value of early diffusion tensor imaging (DTI) of the corticospinal tract toward predicting long-term motor recovery.
  
  
  METHODS
  One hundred seventeen patients were prospectively assessed at 24 to 72 hours and 1 year after ischemic stroke with diffusion tensor imaging and motor scores (Fugl-Meyer). The initial fiber number ratio (iFNr) and final fiber number ratio were computed as the number of streamlines along the affected corticospinal tract normalized to the unaffected side and were compared with each other. The prediction of motor recovery (ΔFugl-Meyer) was first modeled using initial Fugl-Meyer and iFNr. Multivariate ordinal logistic regression models were also used to study the association of iFNr, initial Fugl-Meyer, age, and stroke volume with Fugl-Meyer at 1 year.
  
  
  RESULTS
  The iFNr correlated with the final fiber number ratio at 1 year (r=0.70; P<0.0001). The initial Fugl-Meyer strongly predicted motor recovery (≈73% of initial impairment) for all patients except those with initial severe stroke (Fugl-Meyer<50). For these severe patients (n=26), initial Fugl-Meyer was not correlated with motor recovery (R(2)=0.13; p=ns), whereas iFNr showed strong correlation (R(2)=0.56; P<0.0001). In multivariate analysis, the iFNr was an independent predictor of motor outcome (β=2.601; 95% confidence interval=0.304-5.110; P=0.031), improving prediction compared with using only initial Fugl-Meyer, age, and stroke volume (P=0.026).
  
  
  CONCLUSIONS
  Early measurement of FNr at 24 to 72 hours poststroke is a surrogate marker of corticospinal tract integrity and provides independent prediction of motor outcome at 1 year especially for patients with severe initial impairment.
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Antoine
authors.initials: A
authors.lastname: Bigourdan
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Fanny
authors.initials: F
authors.lastname: Munsch
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Pierrick
authors.initials: P
authors.lastname: Coupé
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Charles R G
authors.initials: CR
authors.lastname: Guttmann
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Sharmila
authors.initials: S
authors.lastname: Sagnier
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Pauline
authors.initials: P
authors.lastname: Renou
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Sabrina
authors.initials: S
authors.lastname: Debruxelles
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Mathilde
authors.initials: M
authors.lastname: Poli
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Vincent
authors.initials: V
authors.lastname: Dousset
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.).
authors.forename: Igor
authors.initials: I
authors.lastname: Sibon
authors.affiliation: From the Université de Bordeaux, Bordeaux, France (A.B., F.M., P.C., C.R.G.G., V.D., I.S., T.T.); CHU de Bordeaux, Neuroimagerie Diagnostique et Thérapeutique, Bordeaux, France (A.B., F.M., V.D., T.T.); INSERM, U1215, Neurocentre Magendie, Bordeaux, France (F.M., V.D., T.T.); LaBRI, UMR 5800, PICTURA, Talence, France (P.C.); Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.R.G.G.); CHU de Bordeaux, Unité Neurovasculaire, Bordeaux, France (S.S., P.R., S.D., M.P., I.S.); and INCIA, UMR 5287, Bordeaux, France (I.S.). thomas.tourdias@chu-bordeaux.fr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Tourdias
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011712:Pyramidal Tracts / Q000503:physiopathology*; D020127:Recovery of Function / Q000502:physiology*; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000503:physiopathology*
keywords: Wallerian degeneration; diffusion tensor imaging; magnetic resonance imaging; stroke; stroke volume