title: Changes in Cerebellar Activation After Onabotulinumtoxin A Injections for Spasticity After Chronic Stroke: A Pilot Functional Magnetic Resonance Imaging Study.
abstract: OBJECTIVE
  To investigate the effect of reducing spasticity via onabotulinumtoxin A (Obtx-A) injection on cerebellar activation after chronic stroke during unilateral gripping.
  
  
  METHODS
  Pre-post, case series.
  
  
  METHODS
  Outpatient spasticity clinic.
  
  
  METHODS
  Individuals with chronic spasticity (N=4).
  
  
  METHODS
  Upper-limb Obtx-A injection.
  
  
  METHODS
  Functional magnetic resonance imaging (fMRI) was used to measure changes in cerebellar activation before and after upper-limb Obtx-A injection. During fMRI testing, participants performed the same motor task before and after injection, which was 15% and 30% of maximum voluntary isometric gripping measured before Obtx-A injection.
  
  
  RESULTS
  After Obtx-A injection, cerebellar activation increased bilaterally during gripping with the paretic hand and during rest. During both pre- and postinjection scans, the paretic hand showed larger cerebellar activation during gripping compared with the nonparetic hand. Cerebellar activation during gripping with the nonparetic hand did not change significantly after Obtx-A injection.
  
  
  CONCLUSIONS
  Reducing spasticity via Obtx-A injection may increase cerebellar activation both during gripping tasks with the paretic hand and during rest. To our knowledge, this is the first study that examines changes in cerebellar activation after spasticity treatment with Obtx-A.
authors.affiliation: Department of Kinesiology, University of San Francisco, San Francisco, CA. Electronic address: changchialin@gmail.com.
authors.forename: Chia-Lin
authors.initials: CL
authors.lastname: Chang
authors.affiliation: Defense Advanced Research Projects Agency, Arlington, VA.
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Weber
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Munin
mesh_terms: D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D002531:Cerebellum / Q000187:drug effects*; D002908:Chronic Disease; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009128:Muscle Spasticity / Q000209:etiology / Q000503:physiopathology*; D009465:Neuromuscular Agents / Q000494:pharmacology*; D020521:Stroke / Q000150:complications / Q000503:physiopathology*; D034941:Upper Extremity / Q000503:physiopathology
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: Botulinum toxins, type A; Cerebellum; Magnetic resonance imaging; Muscle spasticity; Rehabilitation; Stroke