title: Separating coordinative and executive dysfunction in cerebellar patients during motor skill acquisition.
abstract: OBJECTIVE
  Patients with cerebellar stroke are impaired in motor skill acquisition and cognitive/executive performance. The aim was to test whether skill acquisition in cerebellar patients is influenced by executive demands such as the intermittent exercise of a conflicting motor task.
  
  
  METHODS
  Patients with cerebellar stroke and healthy controls were tested in two serial reaction time experiments. In Experiment 1, participants performed practice runs (always same sequence) and interference runs (new sequence for each run) in a strictly alternating fashion. In Experiment 2, participants rested between successive practice runs; the duration of rests was adapted to the duration of interference runs in the other experiment. Participants of Experiment 1 were also tested for cognitive-executive functions (Wisconsin Card Sort, Word Fluency, Trail Making, Digit Span backwards).
  
  
  RESULTS
  (1) Patients in Experiment 1, although always slower than controls, acquired motor skills in the first run before interference but in contrast to controls failed to improve their performance in subsequent runs. (2) Patients in Experiment 2 improved their performance consistently over several runs. (3) Patients of Experiment 1 were worse than controls in several cognitive-executive functions; however, these deficits did not correlate with the degree of interference in motor skill acquisition.
  
  
  CONCLUSIONS
  Simple movement coordination and higher order context-related movement organisation are separate cerebellar functions. In cerebellar patients, impaired movement coordination is associated with generally slower reaction times whereas organisational deficits are associated with a specific impairment to change between motor sets. Motor-executive functions responsible for the latter impairment might be independent from cognitive-executive functions.
authors.affiliation: Department of Neurology, Medical University of Vienna, Wahringer Gurtel 18-20, 1090 Wien, Austria. georg.dirnberger@weizmann.ac.il
authors.forename: Georg
authors.initials: G
authors.lastname: Dirnberger
authors.forename: Judith
authors.initials: J
authors.lastname: Novak
authors.forename: Christian
authors.initials: C
authors.lastname: Nasel
authors.forename: Miriam
authors.initials: M
authors.lastname: Zehnter
mesh_terms: D000328:Adult; D000368:Aged; D001259:Ataxia / Q000175:diagnosis* / Q000453:epidemiology*; D002526:Cerebellar Diseases / Q000453:epidemiology* / Q000503:physiopathology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007858:Learning; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009483:Neuropsychological Tests; D011930:Reaction Time; D012691:Serial Learning; D012720:Severity of Illness Index; D055815:Young Adult