title: Concurrent motor and cognitive function in multiple sclerosis: a motor overflow and motor stability study.
abstract: OBJECTIVE
  The interplay between motor and cognitive functions during performance of concurrent tasks is not fully understood but is known to vary depending on task characteristics and across clinical populations. Our controlled study examined how a concurrent digit span task affected a motor stability and motor overflow task in patients with multiple sclerosis (MS).
  
  
  METHODS
  We asked 22 patients with MS and 22 matched controls to exert force on a transducer using 1 index finger at a time. We measured their motor stability (accuracy of voluntary force production) and motor overflow (involuntary force produced by the opposite, inactive finger). During half of the trials, the participants concurrently performed a digit span task.
  
  
  RESULTS
  Overall, the patients with MS had more motor overflow and less motor stability than the controls; these measures correlated with the patients' disease severity. Adding the concurrent task affected motor stability; this relationship varied with the required level of exerted force. Motor overflow was lower during trials with the concurrent task. The concurrent task affected patients and controls similarly for both motor stability and overflow.
  
  
  CONCLUSIONS
  This study demonstrates preserved motor function in a concurrent-task paradigm in patients with MS, and sheds further light on the relationship between attention and motor function in both the patients and controls. This research may help to inform rehabilitation for everyday life situations in which patients routinely perform cognitive and motor tasks simultaneously.
authors: *Experimental Neuropsychology Research Unit †Ocular Motor Research Laboratory, School of Psychological Sciences, Monash University, Clayton Campus, Victoria, Australia ‡Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia §Institute of Sport, Exercise, and Active Living, Victoria University, Footscray Park Campus, Victoria, Australia.
authors: Anne-Marie
authors: AM
authors: Ternes
authors: Joanne
authors: J
authors: Fielding
authors: Patricia K
authors: PK
authors: Addamo
authors: Owen
authors: O
authors: White
authors: Nellie
authors: N
authors: Georgiou-Karistianis
mesh_terms: D000328:Adult; D001288:Attention; D016022:Case-Control Studies; D003071:Cognition; D005260:Female; D005385:Fingers; D007839:Functional Laterality; D006801:Humans; D008297:Male; D009068:Movement; D009103:Multiple Sclerosis / Q000503:physiopathology*; D009119:Muscle Contraction; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D046608:Synkinesis