What is Freezing of Gait and can NexStride help?

Freezing of gait (FOG) is a common motor disorder in Parkinson’s disease (PD). It is characterised by sudden, unanticipated interruptions in gait, lasting from seconds to minutes, in which people feel that their feet are stuck to the floor and unable to move forward despite trying hard.

FOG episodes can occur in other neurological diseases too. The phenomenon is particularly debilitating and often requires physical support from another person to get unstuck and start walking again. Treatment strategies developed for managing gait disorders and freezing include medications, deep brain stimulation (DBS), physical therapy interventions and external visual cues.

Anatomical Concepts offer a neat product called NexStride that uses cueing technology to help overcome the freezing of gait.

What is Freezing of Gait?

In formal language, freezing of Gait (or FOG) is a symptomatic motor disorder characterised by Parkinson's disease (PD) patients who often experience difficulty in initiating or maintaining walking. FOG episodes are sudden, unanticipated interruptions in gait, lasting from seconds to minutes, in which people feel that their feet are stuck to the floor, unable to move forward, despite trying hard. The phenomenon can be seen in other neurological diseases too, however, it occurs most commonly in Parkinson's disease patients. What causes this is not fully understood.

The classic presentation of gait freezing is sudden and dramatic stops and starts while walking, but some patients describe that they feel like their feet are glued to the floor with an inability to take the next step. These episodes often occur when crossing doorways, turning around, or approaching an obstacle. The severity is very variable from person to person with some experiencing only occasional episodes and rarely, some individuals will experience almost continuous FOG preventing useful ambulation.

Freezing of Gait obviously impairs mobility but also increases the risk of, and causes, falls and significantly reduces quality of life. Gait disorders, including freezing, affect 60-80% of PD patients, often presenting in the later stages of the disease.

This short video explains the experience of some individuals with Parkinson's and introduces the NexStride product.

What is Parkinson's disease?

Parkinson's disease is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The underlying pathophysiology is the progressive death of dopaminergic neurons that normally produce dopamine in the substantia nigra, a region in the midbrain. The deficiency of dopamine leads to characteristic PD symptoms such as tremors, rigidity, bradykinesia, and postural instability, which subsequently impact gait and balance. Gait freezing is a common motor symptom of PD.

Several factors can cause or worsen the freezing of gait, including fatigue, distraction, anxiety, stress, visual clutter, transitions from one walking surface to another, and narrow spaces. Patients who have freezing of gait also tend to experience more severe postural instability and other motor symptoms of the disease.

Studies have shown that more advanced PD patients who show primarily a freezing of gait phenotype tend to have less benefit from dopaminergic medication and have more potential side effects, including motor fluctuations. Thus, there is a growing clinical focus on novel therapeutic interventions, not only for FOG but working on the significant non-dopaminergic pathology that exists in the primary progressive freezing gait syndrome.

Patients with severe Fog episodes are often candidates for deep brain stimulation (DBS), a neurosurgical procedure which is beyond the scope of this article

Physical therapy, particularly a program that involves balance and gait training, is an essential non-pharmacological intervention to improve gait freezing and associated motor symptoms. Standardized gait questionnaires and structured physical activity programs have been used to assess patients' motor and cognitive function, providing a baseline to evaluate this and guide clinical intervention.

The inner ear plays a crucial role in balance and gait control; hence some research is focusing on developing novel treatment paradigms that target the vestibular system. Vestibular stimulation techniques such as galvanic vestibular stimulation, can provide short-lived relief from FOG by significantly reducing the freezing of gait prevalence and severity.

Visual cues are known to be an effective method for improving freezing episodes. The presence of sensory feedback may be useful for overcoming a "motor block" and promoting movement. Various external visual cues, such as laser lines, stripes on the floor, or footstep rhythms, can be an effective way to overcome freezing, providing the patient with a predictable sequence to follow. Additionally, tasks such as mental imaging and rhythmic audio cues can also effectively trigger gait initiation in PD patients.

The NexStride product combines both visual and rhythmic audio cues, makes them adjustable and adaptable to different types of walking aids

The short video shows how the NexStride works and explains how the device can be attached to any walking cane or frame. Fundamentally by using the visual and auditory cueing you are able to bypass the blocked neural pathway that is causing the freezing of gait.

Conclusion

In conclusion, freezing of gait (FOG) is a common motor disorder that affects Parkinson's disease (PD) patients. FOG episodes are sudden, unanticipated interruptions in gait, lasting from seconds to minutes, in which people feel that their feet are stuck to the floor, unable to move forward, despite trying hard.

Researchers recognise that the various presentations of freezing need to be better characterised to provide targeted and personalized treatments. They have also likened freezing episodes to an iceberg; visible when surfaces but only a small fraction of the underlying disease process.

FOG is a symptom that often requires physical support to start walking again. Various treatment strategies have been developed to manage gait disorders and freezing, including medication, neurological procedures, deep brain stimulation (DBS), and physical therapy. Additionally, external visual cues, vestibular stimulation, audio cues, and rhythmic imaging.

The NexStride can effectively trigger gait initiation in many persons who have difficulty with FOG.

You can purchase the NexStride in our webstore at (https://store.anatomicalconcepts.com/rehab-tech)or contact us for more information. The product page also has information showing how to use NexStride

Reference

Nutt JG, Bloem BR, Giladi N, Hallett M, Horak FB, Nieuwboer A. Freezing of gait: moving forward on a mysterious clinical phenomenon. Lancet Neurol. 2011 Aug;10(8):734-44. doi: 10.1016/S1474-4422(11)70143-0. PMID: 21777828; PMCID: PMC7293393.