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.

Effects of Auditory Rhythm and Music on Gait Disturbances in Parkinson’s Disease

“…The long-term impact of RAS on gait impairment and other motor and cognitive deficits should be objectively assessed by randomizing subjects to either participate in RAS by a trained therapist at least once a week for 6 months or participate in routine gait training. Novel methods and instruments, such as quantitative stepping-in-place with a concurrent mental task using a fourth generation iPod Touch sensor system ( 130 ), are needed to assess the effects of RAS on gait and mental function. The type of music and rhythm needed to optimize response to RAS should also be further evaluated.…”

A training approach to improve stepping automaticity while dual-tasking in Parkinson's disease

“…[ 1 – 5 ] In Parkinson's disease (PD), subtle cognitive and cognitive-motor dual-task (DT) deficits are prevalent and are an early and consistent hallmark of declines in cognitive function associated with impairments in gait functioning, poor health outcome, increased fall risk, and a poor quality of life. [ 1 , 4 – 7 ]…”

“…We recently developed and validated a home-based amenable method for screening general cognitive-motor DT deficits and evaluating cognitive-motor rehabilitation training while SIP. [ 4 ] In the current pilot study, we sought to build on these findings by testing the feasibility and potential efficacy of a home-based 4-week music-contingent SIP training program for the improvement of DT performance. Here, repetitive stepping is positively reinforced with pleasurable music playback.…”

“…Here, repetitive stepping is positively reinforced with pleasurable music playback. [ 4 ] Our rationale is based on the evidence that musical cues, enriched with rhythm, vocal singing, and uplifting emotional salience stimulate cognitive and arousal systems which in turn can influence motor learning and automaticity (i.e., the ability to perform a skilled movement with minimal executive control). [ 11 , 18 , 19 ] Modern attentional theories of learning predict that long-term motor memory of automatic gait control may benefit from cueing approaches that activate reward and attentional networks.…”

Long-Term Task- and Dopamine-Dependent Dynamics of Subthalamic Local Field Potentials in Parkinson’s Disease

“…In these controlled environments, brief recordings are performed with subjects in a reclined operating table or hospital bed and may not be representative of the variable recordings that will be present in a real-world setting. As PD symptoms are dependent on the patient’s attention, alertness and behavior, the STN-LFP activity likely varies with these factors, as well [39,40,41,42,43]. Therefore, inter-day variability will be a challenge that must be addressed in a closed-loop DBS system.…”