title: The influence of a concurrent cognitive task on lower limb reaction time among stroke survivors with right- or left-hemiplegia.
abstract: OBJECTIVE
  To determine the impact of cognitive interference on foot pedal reaction time among stroke survivors with right- (RH) or left-hemiplegia (LH).
  
  
  METHODS
  Cross-sectional comparison without randomization.
  
  
  METHODS
  10 patients post-stroke with RH, 10 with LH; 10 age-matched controls.
  
  
  METHODS
  Foot pedal response times were measured using three different reaction time (RT) paradigms: simple RT, dual-task RT (counting backward by serial 3 seconds), and choice RT (correct response contingent on stimuli to eliminate pre-programing). RH and LH used the non-paretic leg for all trials. Three 3 (RT task) × 3 (group) mixed-model factorial ANOVAs were used to compare RT, movement time (MT), total response time (TRT).
  
  
  RESULTS
  Overall controls demonstrated faster RT than RH (332 ± 73 versus 474 ± 144 ms, P < 0.001) or LH (402 ± 127 ms, P < 0.05); LH group demonstrated faster RT than those with RH (P < 0.05). Control subjects demonstrated significantly faster RT than RH for all RT conditions (P < 0.05 for all). In contrast, controls achieved significantly faster RT than LH for the choice RT condition only (P < 0.05), but not for the simple (P = 0.12) or dual-task RT conditions (P = 0.25).
  
  
  CONCLUSIONS
  Compared to controls, response time was significantly impaired among LH and RH when the response could not be pre-programmed. While current simple RT testing commonly employed by driver rehab specialists may be sufficient for detecting RT deficits in patients with RH, simple or dual-task RT tests alone may fail to detect RT deficiencies among LH, even when testing the non-paretic limb. Choice RT should be added to post-stroke driver fitness assessment, particularly for patients with LH.
authors.forename: Tim
authors.initials: T
authors.lastname: Pauley
authors.forename: Chetan P
authors.initials: CP
authors.lastname: Phadke
authors.forename: Adam
authors.initials: A
authors.lastname: Kassam
authors.forename: Farooq
authors.initials: F
authors.lastname: Ismail
authors.forename: Chris
authors.initials: C
authors.lastname: Boulias
authors.forename: Michael
authors.initials: M
authors.lastname: Devlin
mesh_terms: D000368:Aged; D001334:Automobile Driving / Q000523:psychology; D002755:Choice Behavior; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D007839:Functional Laterality; D006429:Hemiplegia / Q000503:physiopathology* / Q000523:psychology / Q000534:rehabilitation; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D011930:Reaction Time; D020521:Stroke / Q000503:physiopathology* / Q000523:psychology; D000071939:Stroke Rehabilitation
keywords: Dual-task,; Left-hemiplegia,; Movement time,; Reaction time,; Right-hemiplegia,; Total response time