Understanding Freezing of Gait and Cognition in Parkinson’s
Understanding Freezing of Gait and Cognition in Parkinson’s
Freezing of gait (FoG) is one of the most complex and debilitating symptoms experienced by individuals with Parkinson’s disease (PD). Characterised by brief episodes where the feet appear “glued to the floor,” FoG often occurs during turning, navigating narrow spaces, or in stressful situations. For neuro rehab clinicians, understanding the link between cognition and FoG is essential for delivering effective assessment and rehab.
The Neurophysiology Behind Freezing of Gait
FoG is believed to result from a breakdown in the integration of motor, cognitive, and sensory systems. In PD there is impaired processing in the basal ganglia, disrupting automatic movement control. Dopamine deficits lead to bradykinesia and difficulty with gait initiation and transitions. In addition, altered connections in the cortico-striatal-thalamic circuits impairs the integration of sensory and motor commands. Executive dysfunction is linked to FoG, specifically affecting attention switching and pre motor planning. These cognitive impairments may disrupt the automaticity of gait, requiring increased conscious control, which can be overwhelming in complex environments or under dual-task conditions, resulting in more frequent FoG episodes.
A systematic review by Monaghan et al (2023) concluded that non-motor symptoms are more prevalent in those who experience FOG and people with PD that present with FoG typically will have worse cognitive impairment. This highlights the importance of early cognitive screening to identify even mild cognitive impairment and possible modifiable factors.
FoG Assessment
Key tools and strategies include:
- FoG Questionnaires: Use the FoG/CFOG to help identify FoG and educate the client about it and screen for cognitive impairments that may exacerbate FoG.
- PD Cognitive Rating Scale: our PD Special Interest Group (SIG) discovered this cognitive screening tool for OTs. It has a higher ceiling effect than many other measures. It may be good to use for people in the earlier stages of PD which other tests may not pick up on. However, they acknowledged that this is less researched than other measures.
- Functional Observation: Objective, functional assessment is essential as the questionnaire scores do not always correlate with the frequency or duration of freezing “in real life”. Observe gait under varied conditions (turning, confined spaces, textured surfaces). Turning is a key trigger (Conde et al, 2023) and should be assessed at multiple angles (180°, 360°, 540°). Video gait analysis is highly valuable.
- The Modified Timed Gait Assessment: This protocol is a reliable measure of FoG and can be used to clinically assess for FoG. It is important to video all assessments and assess the client turning in both directions.
- Dual-task Testing: Incorporate motor and/or cognitive dual tasks to reveal hidden deficits and assess how cognitive load affects gait. Often these assessments raise awareness of underlying cognitive difficulties to people with PD when they had perhaps been unaware or experiencing a very gradual decline in dual tasking ability which they are able to mask/compensate for.
- The Parkinson’s Anxiety Scale: helps flag the need for psychological referral—FoG and anxiety often co-occur.
- OT Assessments: Explore how FoG affects ADLs and safety within the home and community, as well as conducting more specific cognitive assessments e.g. the Trail Making Test. Cognitive screening questions – identifies reasons to refer on to OT e.g. do you find it harder to concentrate and remember what you talked about with friends or your therapists or ‘do you always remember to take your medications’?
Treatment Approaches
1. Cognitive Strategies
Early intervention supports both remedial (e.g., memory training) and compensatory strategies (e.g., calendars, cue cards). Refer early while the patient retains learning capacity.
2. Treadmill Training
Treadmill walking has strong evidence supporting its use in improving gait speed and stride length in people with PD and FoG. It provides consistent somatosensory and visual cues, which may help bypass ineffective internal cueing mechanisms. Incorporating variations such as sideways walking and exaggerated “big steps” and “ball kicks” can further enhance outcomes.
3. Dual-Task and Obstacle Training
Challenging patients with obstacle navigation, especially when combined with dual tasks (e.g. passing objects hand-to-hand), can improve dynamic balance and reduce freezing episodes. These activities promote weight shifting and step initiation, key components often impaired in FoG.
The “Clock Yourself” app exemplifies how cognitive and motor training can be integrated. Patients respond to visual or verbal prompts by stepping to corresponding positions on a clock face. Progressions include removing visual cues, using months or compass directions, and applying “opposite” rules to increase cognitive demand. These exercises not only target FoG but also enhance cognitive flexibility and working memory.
4. Assistive Technology
Several devices are proving beneficial in clinical practice and may be worth trialling:
- Pathfinder: A shoe-mounted laser that projects a visual cue to aid step initiation
- U-Step Walker & Laser Cane: Visual and auditory cueing devices
- CUE1: Vibrotactile stimulation device to improve step initiation
5. Balance and Falls Prevention
Targeted balance training, including reactive stepping and perturbation training, addresses high fall risk associated with FoG. Therapists are encouraged to use both standardised tools and functional assessments/interventions to evaluate and improve balance.
Multidisciplinary is Key
Reflection Questions for Clinicians:
- What assessment strategies do you find most useful when evaluating FoG in your clients with Parkinson’s
- How have cognitive interventions or dual-task training influenced outcomes for your patients with FoG?
- What role has assistive technology played in your clinical practice for people with PD?
Responses