title: Freezing of gait in Parkinson disease is associated with impaired conflict resolution.
abstract: BACKGROUND
  Freezing of gait (FOG) in Parkinson disease (PD) may involve executive dysfunction. This study examined whether executive functioning and attention are more affected in patients with FOG compared with those without and determined whether these processes are influenced by anti-Parkinson medication.
  
  
  METHODS
  A total of 11 PD patients with FOG, 11 without FOG, and 10 healthy control subjects, matched for age, gender, and education, participated. General motor, mental and cognitive screening tests, as well as specific neuropsychological assessment of executive functions and the Attention Network Test (ANT) were administered. The ANT was conducted in both ON and OFF phases in a counterbalanced design to determine medication-specific effects.
  
  
  RESULTS
  FOG showed a clear association with impairment in the executive control network for conflict resolution (inhibition of unwanted responses and impaired response selection), compared with nonfreezers and healthy controls, F(2, 28) = 5.41, P = .01. Orienting and alerting function did not differ between groups, F < 1. Other executive functions, such as abstract problem solving and mental flexibility were not associated with FOG (P > .10). Anti-Parkinson medication did not ameliorate conflict resolution (P > .10), although orienting attention improved with medication, F(1, 17) = 9.81, P < .01.
  
  
  CONCLUSIONS
  This study shows an association between impaired conflict resolution and FOG, important in understanding the interplay between cognitive and motor problems, which can lead to specific rehabilitation strategies.
authors.affiliation: Vrije Universiteit Brussel, Brussels, Belgium. jochen.vandenbossche@vub.ac.be
authors.forename: Jochen
authors.initials: J
authors.lastname: Vandenbossche
authors.forename: Natacha
authors.initials: N
authors.lastname: Deroost
authors.forename: Eric
authors.initials: E
authors.lastname: Soetens
authors.forename: Joke
authors.initials: J
authors.lastname: Spildooren
authors.forename: Sarah
authors.initials: S
authors.lastname: Vercruysse
authors.forename: Alice
authors.initials: A
authors.lastname: Nieuwboer
authors.forename: Eric
authors.initials: E
authors.lastname: Kerckhofs
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D016022:Case-Control Studies; D004185:Disability Evaluation; D056344:Executive Function / Q000502:physiology*; D005260:Female; D046352:Freezing Reaction, Cataleptic / Q000502:physiology*; D020233:Gait Disorders, Neurologic / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D011930:Reaction Time; D013223:Statistics as Topic; D011795:Surveys and Questionnaires