title: A new quantitative method for evaluating freezing of gait and dual-attention task deficits in Parkinson's disease.
abstract: People with Parkinson's disease (PD) can exhibit disabling gait symptoms such as freezing of gait especially when distracted by a secondary task. Quantitative measurement method of this type of cognitive-motor abnormality, however, remains poorly developed. Here we examined whether stepping-in-place (SIP) with a concurrent mental task (e.g., subtraction) can be used as a simple method for evaluating cognitive-motor deficits in PD. We used a 4th generation iPod Touch sensor system to capture hip flexion data and obtain step height (SH) measurements (z axis). The accuracy of the method was compared to and validated by kinematic video analysis software. We found a general trend of reduced SH for PD subjects relative to controls under all conditions. However, the SH of PD freezers was significantly worse than PD non-freezers and controls during concurrent serial 7 subtraction and SIP tasking. During serial 7 subtraction, SH was significantly associated with whether or not a PD patient was a self-reported freezer even when controlling for disease severity. Given that this SIP-based dual-task paradigm is not limited by space requirements and can be quantified using a mobile tracking device that delivers specifically designed auditory task instructions, the method reported here may be used to standardize clinical assessment of cognitive-motor deficits under a variety of dual-task conditions in PD.
authors.affiliation: Department of Clinical Neurosciences, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. tgchomia@ucalgary.ca.|1C46 HRIC, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. tgchomia@ucalgary.ca.
authors.forename: Taylor
authors.initials: T
authors.lastname: Chomiak
authors.affiliation: Department of Clinical Neurosciences, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
authors.forename: Fernando Vieira
authors.initials: FV
authors.lastname: Pereira
authors.affiliation: Department of Clinical Neurosciences, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
authors.forename: Nicole
authors.initials: N
authors.lastname: Meyer
authors.affiliation: Department of Kinesiology, University of Lethbridge, 4401 University Drive, Lethbridge, AB, T1K 3M4, Canada.
authors.forename: Natalie
authors.initials: N
authors.lastname: de Bruin
authors.affiliation: Movement Disorders Clinic, Foothills Medical Centre, Alberta Health Services, Health Sciences Building, First Floor, Area 3, 1403 29 Street NW, Calgary, AB, T2N 2T9, Canada.
authors.forename: Lorelei
authors.initials: L
authors.lastname: Derwent
authors.affiliation: Department of Clinical Neurosciences, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
authors.forename: Kailie
authors.initials: K
authors.lastname: Luan
authors.affiliation: Department of Clinical Neurosciences, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Cihal
authors.affiliation: Department of Kinesiology, University of Lethbridge, 4401 University Drive, Lethbridge, AB, T1K 3M4, Canada.
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Brown
authors.affiliation: Department of Clinical Neurosciences, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. hub@ucalgary.ca.|1C46 HRIC, 3280 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. hub@ucalgary.ca.
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
mesh_terms: D000368:Aged; D001288:Attention; D001696:Biomechanical Phenomena; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology; D034201:Computers, Handheld; D003937:Diagnosis, Differential; D005260:Female; D020233:Gait Disorders, Neurologic / Q000175:diagnosis / Q000503:physiopathology; D006615:Hip; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D057566:Self Report; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014741:Video Recording; D059015:Wireless Technology
keywords: Disease; Dual; Parkinson’s; Recall; Serial; Stepping-in-place; Subtract; Tasking