title: Sensorimotor modulation by botulinum toxin A in post-stroke arm spasticity: Passive hand movement.
abstract: BACKGROUND
  In post-stroke spasticity, functional imaging may uncover modulation in the central sensorimotor networks associated with botulinum toxin type A (BoNT) therapy. Investigations were performed to localize brain activation changes in stroke patients treated with BoNT for upper limb spasticity using functional magnetic resonance imaging (fMRI).
  
  
  METHODS
  Seven ischemic stroke patients (4 females; mean age 58.86) with severe hand paralysis and notable spasticity were studied. Spasticity was scored according to the modified Ashworth scale (MAS). fMRI examination was performed 3 times: before (W0) and 4 (W4) and 11weeks (W11) after BoNT. The whole-brain fMRI data were acquired during paced repetitive passive movements of the plegic hand (flexion/extension at the wrist) alternating with rest. Voxel-by-voxel statistical analysis using the General Linear Model (GLM) implemented in FSL (v6.00)/FEAT yielded group session-wise statistical maps and paired between-session contrasts, thresholded at the corrected cluster-wise significance level of p<0.05.
  
  
  RESULTS
  As expected, BoNT transiently lowered MAS scores at W4. Across all the sessions, fMRI activation of the ipsilesional sensorimotor cortex (M1, S1, and SMA) dominated. At W4, additional clusters transiently emerged bilaterally in the cerebellum, in the contralesional sensorimotor cortex, and in the contralesional occipital cortex. Paired contrasts demonstrated significant differences W4>W0 (bilateral cerebellum and contralesional occipital cortex) and W4>W11 (ipsilesional cerebellum and SMA). The remaining paired contrast (W0>W11) showed activation decreases mainly in the ipsilesional sensorimotor cortex (M1, S1, and SMA).
  
  
  CONCLUSIONS
  The present study confirms the feasibility of using passive hand movements to map the cerebral sensorimotor networks in patients with post-stroke arm spasticity and demonstrates that BoNT-induced spasticity relief is associated with changes in task-induced central sensorimotor activation, likely mediated by an altered afferent drive from the spasticity-affected muscles.
authors.affiliation: Department of Neurology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Veverka
authors.affiliation: Department of Neurology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic; Department of Radiology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Hluštík
authors.affiliation: Department of Neurology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Hok
authors.affiliation: Department of Neurology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Otruba
authors.affiliation: Department of Biophysics, Biometry and Statistics, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Zapletalová
authors.affiliation: Department of Radiology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Zbyněk
authors.initials: Z
authors.lastname: Tüdös
authors.affiliation: Department of Physiotherapy, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Alois
authors.initials: A
authors.lastname: Krobot
authors.affiliation: Department of Neurology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Kaňovský
mesh_terms: D000368:Aged; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007699:Kinesthesis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D009498:Neurotoxins / Q000627:therapeutic use*; D010100:Oxygen / Q000097:blood; D011782:Quadriplegia / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology*; D018709:Statistics, Nonparametric; D020521:Stroke / Q000150:complications*
chemical_list: D009498:Neurotoxins; D019274:Botulinum Toxins, Type A; D010100:Oxygen
keywords: Botulinum toxin; Functional magnetic resonance imaging; Hand weakness; Neuronal plasticity; Spasticity; Stroke