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April: Freezing of Gait

Updated: Apr 13



Written by: Dr. Caitlin A. Bender, OTR/L


Dopamine’s Role

In a healthy person, the primary automatic mode of motor control is intact. Different brain networks are largely segregated, and the corticostriatal motor network results in gait being an automatic function. However with Parkinson’s Disease the dopamine producing neurons that fuel the corticostriatal motor network are impaired, which results in the cardinal motor symptoms seen in Parkinson’s Disease: rigidity, bradykinesia, tremor, and postural instability, all of which can impact ambulation performance. It is theorized that as control of the motor networks is affected, other complementary networks of the brain, such as the sensory network, integrate and compensate in order to have improved performance of gait. Relatively early on in the disease, processing across different networks is able to control gait well. As degradation of the corticostriatal motor network continues however, the once complementary input from other brain networks begins to compete with the corticostriatal motor networks, resulting in dysfunctional “cross talk”. At this stage, freezing episodes may occur occasionally, particularly during complex situations where the demand for gait control exceeds the combined processing capacity of the motor-cognitive circuits, such as during turning a corner. Abnormal inputs from the limbic circuit, specifically during more stressful conditions may put a further strain on processing and thereby exacerbate freezing (Gilat, 2021).


Green circle: intact corticostriatal motor network; Dashed green circle: impaired corticostriatal motor network; Yellow circle: sensory network; Purple circle: limbic network; Blue circle;cognitive network. Black double-sided triangle arrows represent a simplified schematic illustration of the functional integration between the different brain regions (which is presumably much more complex than depicted); Dashed arrows indicate the impaired function of the primary motor circuitry in PD; Thickness of the dark-grey equilateral barb arrows represents the neuromodulatory activity of the locus coeruleus (depicted here in the rostral pons as a small dark-grey ellipse) (Tosserams, 2023).


Freezing

‘Start hesitation’, also referred to as a motor block, occurs at the start of an action, for example, when beginning to speak, or start walking. ‘Freezing’ is a term used to describe the experience of stopping suddenly and without intending to do so, as may commonly occur while walking. Both lead to being unable to proceed for several seconds or minutes. Freezing of gait is reported as feeling as if the feet are ‘frozen’ or stuck to the ground, while often the top half of the body is still able to continue to move forward (leading to a risk of falling if this happens). Freezing often occurs in small, crowded spaces, and can result in difficulty navigating environments, especially areas such as grocery stores or airports, where more multitasking may be required. While freezing may manifest as a motor symptom, it is important to note its correlation with both cognitive dysfunction, and “on/off” fluctuations, and how that may impact its presentation throughout the disease’s progression.

Common triggers for FOG include:

  • Turning

  • Performing cognitive challenges while walking (i.e., dual-tasking)

  • Overcoming environmental challenges, such as navigating through doorways

  • Approaching destinations, such as a chair to sit

  • Reduced visual input, such as when walking in the dark

  • High anxiety situations, such as being rushed

FOG increases the risk of falls for PD patients and has a large impact on the motor function and daily life of the patients. This can severely impact independence, and quality of life in those diagnosed with Parkinson’s Disease (Herman, 2023). 


Medication Management

While freezing episodes tend to last only a few seconds, ‘on/off’ fluctuations can continue for several minutes, or even hours. The terms ‘on’ and ‘off’ are used to describe the abrupt changes in mobility of some people with long- standing Parkinson’s Disease. The ‘on/off’ syndrome can best be described as an unpredictable shift from relative wellness and mobility, being ‘on’, to a sudden inability to move, going ‘off’ – although ‘off’ to ‘on’ can occur just as suddenly. The speed of this shift can be dramatic, and leads to increased episodes of freezing, particularly during gait. Proper medication management can reduce the effects of “on/off” shifts, with studies showing levodopa can significantly improve freezing of gait; specifically, high dosage levodopa can reduce the number of episodes of FOG, and akinesia. Similarly, the frequency and duration of “off” related FOG can be reduced by Levodopa (Zhang, 2016). Studies also found DBS proves effective for FOG symptoms in PD patients, especially those who are poorly responsive to medication,  however further studies may be needed to determine if FOG improvements persist with disease progression (Huang, 2018). If experiencing FOG or “on/off” fluctuations then discuss possible medication changes with your physician or neurologist. 

OT Tips and Tricks

  • Visualization: Use self cueing strategies like envisioning yourself stepping over a log, or turning in a wide U shape, to act as a stimulus for movement.

  • Visual cues: Implement visual cues such as floor markers at the entryways or turning points to help with the flow of movement.

  • Auditory cues: Studies using metronomes have been conducted for overcoming start- hesitation, and freezing, or motor blocks, occurring during movement. These studies show encouraging responses to the sound of a metronome where the individual is sensitive to this form of stimulus. Research supports that the playing of a person’s favorite music can increase dopamine production in the basal ganglia which assists in initiating movement and decreases freezing, while the beat can act as an auditory cue for gait tempo (Lim et al 2005a, 2005b, Rochester et al 2005). 

  • Assistive devices: Transitioning to a walking aid can be difficult for some, but it can help to keep you independent for longer by keeping you safer during freezing episodes. 

  • Footwear: Evaluate current shoes for fit and sole type as this can play a role in difficulty with curling toes which ultimately affects our ability to stabilize ourselves. 

  • Scheduling: Plan important events or times when you will have to navigate public spaces with your medication “on/off” periods to enhance gait performance and reduce freezing. Try to limit multi-tasking within your tasks as this can influence gait. Be aware of stressful conditions within your schedule, as freezing can also increase when fatigued or anxious. 

  • 5 S method: If having trouble breaking out of a freezing episode then try the 5 S method. Firstly, stop; fighting freezing can sometimes make it worse, and increase anxiety. Next stand tall; proper posture will help you to get into optimal position to begin movement again. After that try to shake it off and take some deep breaths to help shake off any feelings of frustration, release tension, and boost your focus. Next shift your weight so you are shifting the weight forward and backward between your right and left foot; if you are seated and frozen then rock your torso back and forth so that you feel the weight shift from hips to feet. Finally use the momentum of the weight shift to drive the knee of your back leg forward to take a huge marching step forward; if seated then drive your nose over your toes, reach forward, and shoot up to come to standing. 

-Stop

-Stand Tall

-Shake it off (relax)

-Shift your weight

-Shoot forward/up

  • Exercises: 

-Criss-Cross-Applesauce: practice high marching knees and auditory self- cuing

-Ski step: practice weight shifting and initiating large steps

-Walking/Cycling: practice walking on an incline, which can help to improve stride length, or cycling which has good carry-over to gait reciprocation. 

-Sit to stand: maintain functional mobility and practice 5 “S” method



References


Gilat, M., Ginis, P., Zoetewei, D., De Vleeschhauwer, J., Hulzinga, F., D'Cruz, N., & Nieuwboer, A. (2021). A systematic review on exercise and training-based interventions for freezing of gait in Parkinson's disease. NPJ Parkinson's disease, 7(1), 81. https://doi.org/10.1038/s41531-021-00224-4


Herman, T., Barer, Y., Bitan, M. et al. (2023). A meta-analysis identifies factors predicting the future development of freezing of gait in Parkinson’s disease. npj Parkinsons Dis. 9, 158. https://doi.org/10.1038/s41531-023-00600-2 


Huang, C., Chu, H., Zhang, Y., & Wang, X. (2018). Deep Brain Stimulation to Alleviate Freezing of Gait and Cognitive Dysfunction in Parkinson's Disease: Update on Current Research and Future Perspectives. Frontiers in neuroscience, 12, 29. https://doi.org/10.3389/fnins.2018.00029


Lim LIIK, Van Wegen EEH, De Goede CJT, Deutekom M, Nieuwboer AM, Willems AM, Jones D, Rochester L, Kwakkel G (2005b) Effects of external rhythmical cueing on gait in patients with Parkinson’s disease: a systematic review. Clinical Rehabilitation, 19(7), 695–713.


Rochester L, Hetherington V, Jones D, Nieuwboer A, Willems AM, Kwakkel G, Van Wegen E (2005) The effect of external rhythmical cues (auditory and visual) on walking during a functional task in homes of people with Parkinson’s disease. Archives of Physical Medicine and Rehabilitation, 86(5), 999–1006. 


Tosserams, A., Bloem, B.R., Ehgoetz Martens, K.A. et al. (2023) Modulating arousal to overcome gait impairments in Parkinson’s disease: how the noradrenergic system may act as a double-edged sword. Transl Neurodegener 12, 15 (2023). 


Zhang, L. L., Canning, S. D., & Wang, X. P. (2016). Freezing of Gait in Parkinsonism and its Potential Drug Treatment. Current neuropharmacology, 14(4), 302–306. https://doi.org/10.2174/1570159x14666151201190040 

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2 Comments


Great article! Thanks Doctor :)

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Thank you very good very informative article . Going to practice the five s

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