title: Robot-aided neurorehabilitation in sub-acute and chronic stroke: does spontaneous recovery have a limited impact on outcome?
abstract: BACKGROUND
  Robotic neurorehabilitation, thanks to high dosage/intensity training protocols, has the potential for a greater impact on impairment.
  
  
  OBJECTIVE
  We aimed to analyze how time since the acute event may influence the motor recovery process during robot-assisted rehabilitation of the upper limb.
  
  
  METHODS
  A total of 41 patients after stroke were enrolled: 20 in subacute phase, i.e. ≤ 6 months elapsed since their unilateral cerebrovascular accident (CVA), and 21 at chronic stage, i.e. > 6 months since CVA. All subjects underwent 30 minutes of robot-aided rehabilitation twice a day, 5 days a week for at least three weeks of training. Patients were evaluated at the start and end of treatment using the Fugl-Meyer and Modified Ashworth clinical scales and by a set of robot measured kinematic parameters. The time interval from stroke was considered as a grouping factor to analyze its impact on time course of recovery.
  
  
  RESULTS
  After training both groups significantly improved their impairment (F = 44.25, p < 0.001) but sub-acute patients showed a greater improvement on the Fugl-Meyer scale than chronic patients. The time course of recovery of the kinematic variables showed higher time constants of motor improvement in the sub-acute than chronic group, but they were one order lower than spontaneous recovery time constants.
  
  
  CONCLUSIONS
  Spontaneous recovery seems to have a limited impact on the improvement of sub-acute patients, most of their changes being likely due to re-learning during rehabilitation. In addition, a longer recovery time was required to maximize outcome in sub-acute than in chronic patients.
authors.affiliation: "Salvatore Maugeri" Foundation, IRCCS, Service of Bioengineering, Pavia, Italy "Salvatore Maugeri" Foundation, IRCCS, Service of Bioengineering, Veruno (NO), Italy.
authors.forename: R
authors.initials: R
authors.lastname: Colombo
authors.affiliation: "Salvatore Maugeri" Foundation, IRCCS, Service of Bioengineering, Pavia, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Sterpi
authors.affiliation: "Salvatore Maugeri" Foundation, IRCCS, Service of Bioengineering, Veruno (NO), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mazzone
authors.affiliation: "Salvatore Maugeri" Foundation, IRCCS, Division of Neurologic Rehabilitation, Veruno (NO), Italy.
authors.forename: C
authors.initials: C
authors.lastname: Delconte
authors.affiliation: "Salvatore Maugeri" Foundation, IRCCS, Division of Neurologic Rehabilitation, Veruno (NO), Italy.
authors.forename: F
authors.initials: F
authors.lastname: Pisano
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015915:Motion Therapy, Continuous Passive / Q000295:instrumentation*; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology*; D012371:Robotics; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome; D034941:Upper Extremity / Q000502:physiology
keywords: Robotic therapy; motor recovery; neurorehabilitation; spontaneous recovery; stroke