title: Development of movement-related intracortical inhibition in acute to chronic subcortical stroke.
abstract: OBJECTIVE
  A prospective longitudinal cohort study in stroke patients was performed to better understand the role of γ-aminobutyric acid-dependent intracortical inhibition (ICI) for recovery after stroke.
  
  
  METHODS
  Patients with acute first-ever subcortical stroke and hand paresis were recruited, and motor function as well as ICI were measured up to 1 year after stroke. Motor recovery was defined as the change in hand motor function from the acute to the chronic stage (Δ = recovery over 1 year). Primary outcome measures for hand motor function were the recovery of grip strength (ΔGS) and finger-tapping speed (ΔFT). Using double-pulse transcranial magnetic stimulation, we studied ICI in the ipsilesional primary motor cortex during the preparation of a movement with the paretic hand at different time points during recovery (first week, 7 weeks, 3 months, and 1 year after stroke).
  
  
  RESULTS
  Eleven patients were enrolled (mean age 62.9 ± 3.8 years). The results of a multiple regression analysis showed a significant association of movement-related ICI in the acute stage only (first week) with motor recovery over 1 year (ΔGS: R(2) = 0.75, F = 17.6, p = 0.006; ΔFT: R(2) = 0.55, F = 7.3, p = 0.035). More disinhibition of ICI in the acute phase of stroke predicted more improvement in ΔGS (β = -0.86, p = 0.006) and ΔFT (β = -0.74, p = 0.035), independent of the initial motor deficit.
  
  
  CONCLUSIONS
  Movement-related ICI one week after a subcortical stroke is associated with better outcome of hand motor function. Disinhibition in the ipsilesional primary motor cortex could be a mechanism of how the brain attempts to promote motor recovery after stroke.
authors.affiliation: From the Brain Imaging and Neurostimulation (BINS) Laboratory (G.L., V.H., P.L., J.H., K.H., M.Z., C.G., F.C.H.), Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; and the Department of Neurology (G.L.), University Hospital Zürich, Switzerland.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Liuzzi
authors.forename: Vanessa
authors.initials: V
authors.lastname: Hörniß
authors.forename: Patricia
authors.initials: P
authors.lastname: Lechner
authors.forename: Julia
authors.initials: J
authors.lastname: Hoppe
authors.forename: Kirstin
authors.initials: K
authors.lastname: Heise
authors.forename: Maximo
authors.initials: M
authors.lastname: Zimerman
authors.forename: Christian
authors.initials: C
authors.lastname: Gerloff
authors.forename: Friedhelm C
authors.initials: FC
authors.lastname: Hummel
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D002544:Cerebral Infarction / Q000150:complications / Q000503:physiopathology*; D002908:Chronic Disease; D005260:Female; D006225:Hand / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D010291:Paresis / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation / Q000379:methods*