COGNITIVE IMPAIRMENT IN PD: UNDERSTANDING AND UNLOCKING FREEZING OF GAIT
Daniel Peterson, Ph.D
Fay Horak, PT, Ph.D
Mike Studer, PT, MHS, NCS, CEEAA, CWT, CSST
DESCRIPTION: Over 80% of persons with Parkinson's Disease (PD) will eventually experience Freezing of Gait (FOG). People who experience FOG not only have
many more falls than people with PD without FOG, but they also exhibit more severe cognitive impairments1,2 - These cognitive impairments involve executive
function critical for safe mobility and quality of life. Understanding the types of cognitive deficits associated with FOG and their relationship to mobility can yield insights
into effective rehabilitation. To bridge this gap, this presentation discusses: 1) the cognitive changes associated with FOG and possible neural underpinnings, 2) how to
assess FoG with clinical tools and wearable technology, and 3) possible approaches to ameliorate FOG in the environments that trigger freezing.
Cognitive impairment (D. Peterson): People with PD who freeze exhibit poorer cognition in global assessments such as the Scales for Outcomes in Parkinson’s diseasecognition (SCOPA-COG). However, recent work has begun to identify specific domains in which people with PD exhibit poorer cognitive performance, including response
inhibition, attentional control, visuospatial skills, and learning3, 4, 5. The physiological changes underlying these cognitive deficits are not fully understood, but may relate
to connectivity among the brainstem locomotor areas with the basal ganglia and frontal cortex. Importantly, recent evidence suggests that cognitive training may
improve performance on many of these domains. However, there is limited work on whether improvements via cognitive training results in improved mobility
performance or whether improvement in mobility improve cognition.
Assessment (F. Horak): Self-reporting freezing with the New Freezing of Gait questionnaire and in-clinic assessments, such as observation of FoG while turning and dualtasking, are both useful but don’t always agree. Technological advances in wearable technology afford us the opportunity to improve the quantification of gait and
severity of FOG both in prescribed tasks and during natural activities with continuous monitoring. Wearable technology is also being tested to provide biofeedback to
reduce FOG and provide real-time gait feedback to therapists and patients.
Treatment (M. Studer): The limited research on the effects of physical therapy on FoG supports a two-fold approach:
1) Rehabilitative- through restitutive dual- task and cognitive training6,7,8; and
2) Compensatory- through education (cueing, awareness and prioritization)9.
Therapy must take into account the specific environmental influences affecting each person with FoG. For some, FOG is triggered by upcoming sequential motor tasks
(turn to sit, pass through doorways, ambulate over a change in flooring) and for others FOG is triggered by a secondary manual, cognitive, auditory, or visual distractions
from the environment. Stress from fear of falling and from temporal demands (hurrying to a phone, to cross a street, to the restroom) are among the
cognitive/psychological demands that are associated with FOG and must be addressed in therapy.
References
2017 APTA CSM
Property of Peterson, Horak, Studer
San Antonio
Not to be copied without permission
1) Peterson DS, et al. 2016. Cognitive Contributions to Freezing of Gait in Parkinson Disease- Implications for Physical Rehabilitation. Physical Therapy Journal.
[Epub ahead of print] PMID: 26381808.
2) Heremans E et al. 2013. Cognitive aspects of freezing of gait in Parkinson’s disease: a challenge for rehabilitation. J Neural Trans. 120:543-557.
3) Vandenbossche J et al. 2012. Freezing of gait in Parkinson’s disease: disturbances in automaticity and control. Front Human Neuroscience. Vol 6.
4) Cohen R et al. 2014. Inhibition, Executive Function, and Freezing of Gait. J Parkinson’s Disease. Vol 4. 111-122.
5) Nantel J, et al. 2012. Deficits in visuospatial processing contribute to quantitative measures of freezing of gait in Parkinson’s Disease. Neuroscience. 221:151156.
6) Yogev-Seligmann G et al. 2012. A Training Program to Improve Gait While Dual Tasking in Patients With Parkinson’s Disease: A Pilot Study. Arch Phys Med
Rehabil. Vol 93.
7) King L et al. 2013. Exploring Outcome Measures for Exercise Intervention in People with Parkinson’s Disease. Parkinson’s Disease. Vol 2013.
8) Reuter I et al. 2012 Efficacy of a multimodal cognitive rehabilitation including psychomotor and endurance training in Parkinson’s disease. J Age Res. Vol 2012
9) Yogev-Seligman 2013 Do We Always Prioritize Balance When Walking? Towards an Integrated Model of Task Prioritization. Mov Dis. Vol 27, No.6
2017 APTA CSM
Property of Peterson, Horak, Studer
San Antonio
Not to be copied without permission