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Strategies to Combat Freezing in Parkinson’s Patients

Strategies to Combat Freezing

Freezing” is when an individual suddenly feels like they’re glued to the ground. Parkinson’s disease patients often experience freezing during the late stages of the disease. It can occur while the person is in motion or after they’ve been stationary and then attempt to move. It’s associated with complicated movements like dodging obstacles or getting up from a chair.

The loss of automatic motor skills affects one’s sense of control and even their safety, as about 38 percent of Parkinson’s patients fall each year. Tracking when your struggles occur can help you to manage them, allowing you to challenge how frequently freezing occurs.

What causes freezing?

Not everyone with Parkinson’s experiences freezing, and the exact cause of freezing is unknown. But our relationship to balance gives insight into potential causes. Parkinson’s patients experience changes in the brain that affect the way they walk.

Dr. Howard Weiss, in his blog for the Parkinson Foundation of the National Capital Area, writes, “’Freezing of gait’ is often triggered by specific activities or circumstances that demand switching between motor actions.” While learning to walk, we strengthen the neural pathways that allow us to balance. But Parkinson’s patients see a degradation of these pathways, leading to difficulty in stabilization.

What freezing is like for my dad

Like many Parkinson’s patients, my dad notices that he usually only freezes when he’s not on his medication. It usually happens while he’s moving through doors: “When you pivot you’re worried about losing your balance. That’s why we shuffle our feet and take baby steps initially. Once I’m moving I’m fine,” he says.

Since he’s worried about maintaining balance while navigating, it’s possible that there’s a connection between fear and freezing. Continuous motion seems to bypass the risk of freezing, while shifting motion types can present challenges.

But curiously, stairs are rarely problematic: “I freeze just before I’m ready to go down the stairs. But when I’m actually walking downstairs I don’t have a problem. I can practically hop down them once I’m in motion. And going upstairs is fine,” he says. Getting started can prove challenging, but the act of walking up and down the stairs is still relatively easy.

So, what can you do to manage freezing?

  • If you find yourself getting stuck in particular places, try changing the layout of your living space. Freezing can occur because you have to pivot around furniture.
  • Exploring rhythm helps you to maintain momentum where you previously got stuck. Some Parkinson’s patients explore strategies like dancing, counting, marching, and shifting their weight from side to side.

Thinking outside of the box can assist you in unfreezing yourself. Dad finds that his posture can affect whether or not he’s able to unfreeze himself: “When I freeze, I stand up straight. If I move away from gravity, I can unfreeze. But if I’m hunching over, gravity pulls me toward the floor and it takes longer to get out of the freeze. And once I move my left foot forward, I can unfreeze. Freezing’s scary. That’s why a lot of Parkinson’s patients fall.”

Exercise and physical therapy can be game changers

Joining a Parkinson’s-specific fitness program like Rock Steady Boxing helps you to strengthen your motor functions. This ultimately allows you to stabilize with more ease. Since Parkinson’s patients often see a decline in motor skills, exercise can offer a good option for strengthening those skills. Rock Steady also uses portions of the class to teach Parkinson’s patients how to fall.

According to Dad, “About once a month or so, they’ll put mats on the floor and show you proper falling and rolling technique. They try to do things in boxing that’ll help people with different stages of Parkinson’s.”

While the exercise portion of Rock Steady Boxing is valuable in itself, learning how to fall helps mitigate risk as much as possible.

Freezing is a frightening phenomenon, but there are ways you can manage this symptom. Stay positive! Try to find Parkinson’s fitness classes or challenge yourself with rhythmic solutions to freezing. Other patients have found that these strategies can assist in the management of motor-related functions.

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Note: Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The opinions expressed in this column are not those of Parkinson’s News Today or its parent company, BioNews Services, and are intended to spark discussion about issues pertaining to Parkinson’s disease.

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Changes in Neuronal Communication Linked to Falls and Freezing of Gait in Parkinson’s, Study Finds

neuronal communication changes, Parkinson's motor symptoms

Parkinson’s disease-related falls and freezing of gait — when patients are unable to move their feet forward when trying to walk — are associated with changes in a specific type of neuronal communication in different brain regions, a study reports.

The study, “Cholinergic system changes of falls and freezing of gait in Parkinson disease,” was published in Annals of Neurology.

Many people with Parkinson’s disease will experience falling and freezing of gait, which tend to become more frequent as the disease progresses. In some cases, symptoms cannot be controlled with dopaminergic therapy, suggesting that non-dopamine mechanisms contribute to Parkinson’s disease motor symptoms.

Previous studies have shown that the brainstem (region that connects the brain to the spinal cord) and basal forebrain (important in the production of acetylcholine) regions with degenerated acetylcholine-releasing neurons projecting to the thalamus and cerebral cortex are associated with falls and slow gait speed in Parkinson’s patients.

Acetylcholine is a brain chemical (neurotransmitter) released by nerve cells to send signals to other cells (neurons, muscles, and glands). The thalamus is involved in several important processes, including consciousness, sleep, and sensory interpretation; the cerebral cortex plays a key role in memory, attention, perception, awareness, thought, language, and consciousness.

Scientists have also observed reduced dopaminergic nerve terminals in the striatum, reduced cholinergic (meaning “acetylcholine-releasing”) nerve terminals in the cortex, and more severe beta-amyloid accumulation in Parkinson’s disease “freezers” compared with “non-freezers.”

The striatum coordinates multiple aspects of cognition, including both motor and action planning; the cholinergic system contains nerve cells that use acetylcholine to propagate a nerve impulse, and has been associated with a number of cognitive functions, including memory, selective attention, and emotional processing.

University of Michigan researchers hypothesized that distinct patterns of cholinergic projection system changes in the brain are associated with freezing of gait and falls in Parkinson’s patients.

The team examined and performed [18F]FEOBV positron emission tomography (PET) scans on 94 Parkinson’s patients (72 men and 22 women) with a history of falling and “freezing.” Most subjects were taking dopamine agonists, carbidopa-levodopa or combinations of both.

[18F]FEOBV is a radioactive marker that selectively binds to the vesicular acetylcholine transporter (VACht) that loads acetylcholine into synaptic vesicles — sac-like structures in neurons that store chemical messengers before releasing them into the gap between nerve cells (synapse), enabling neuronal communication.

A PET scan is a non-invasive imaging technique to visualize metabolic processes in the body. Before the scan, [18F]FEOBV is administered via injection; doctors wait for the radiotracer to be distributed throughout the body, and then scan the patient to detect and quantify the patterns of its accumulation in the body.

Because the marker binds to VACht, scientists use it to quantify active cholinergic nerve terminals in the brain.

“Participants were asked about a history of falling. A fall was defined as an unexpected event during which a person falls to the ground. The presence or absence of (freezing of gait) was based on clinical examination and directly observed by the clinician examiner,” according to The Movement-Disorder Society Sponsored-Unified Parkinson’s Disease Rating Scale (MDSUPDRS), the researchers wrote.

They reported that 35 participants (37.2%) had a history of falls, and 15 (16%) had observed freezing of gait.

Compared with non-fallers, fallers had a significant decrease in VACht expression within the right thalamus, specifically in the lateral geniculate nucleus, which is the primary center for processing visual information. This suggests that the visual information processing required for walking around safely might be compromised in Parkinson’s patients with a history of falling.

On the other hand, patients with freezing of gait had significantly reduced VACht expression in the bilateral striatum and hippocampus — required for learning and memory — compared with non-freezers.

The team found that a history of falls was associated with cholinergic projection system changes that relay to the thalamus, while the neural signals behind freezing of gait transmit to the caudate nucleus — a brain region associated with motor processing.

They also found that Parkinson’s fallers had a lower density of thalamic cholinergic nerve terminals compared with non-fallers.

Freezing of gait was related to longer disease duration, more severe parkinsonian motor ratings, and higher levodopa levels.

These results suggest that changes in acetylcholine-mediated neuronal communication are linked to falls or freezing behavior, depending on the affected brain region.

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Freezing of Gait Linked to More Severe Disability, Advanced Disease in Parkinson’s Study

gait and Parkinson's

Freezing of gait — the description for a Parkinson’s symptom in which a person’s feet become briefly “glued to the floor,” preventing forward movement despite an intention to walk — is associated with more severe disease and worse motor and non-motor disability, a study reports.

The study, “Factors associated with freezing of gait in patients with Parkinson’s disease,” was published in Neurological Sciences.

Such freezing, a form of akinesia or abnormal movement, while walking is estimated to affect about 50 percent of Parkinson’s patient in later, more advanced, disease stages. Freezing of gait (FOG) is a well-known cause of falls, and a loss of independence and lower quality of life in these patients, but can be difficult for clinicians to assess and treat.

“FOG measurement is quite challenging as objective FOG assessment requires a continuous ambulatory system that can monitor locomotion and FOG episodes,” the researchers wrote.

Studies have suggested that FOG is related to an array of contributing factors, including longer disease duration, more severe disability, wearing off of levodopa treatment, and urinary plus cardiovascular symptoms.

Given this variety, scientists at the Chonnam National University Hospital in Gwangju, South Korea, wanted to estimate the prevalence of FOG and pinpoint factors that could independently contribute to its occurrence in a population of Parkinson’s patients.

A total of 157 patients (ages 62 to 77) were recruited. All “had a positive response to levodopa and did not have clinically significant brain lesions, as seen by magnetic resonance imaging,” tje researchers wrote.

Patients’ age at symptom onset, disease duration, and past plus current medications were all evaluated.

A series of scales/questionnaires were used to assess distinct domains:

Results showed that 70.7 percent — 111 of 157 — of examined patients had FOG.

Researchers reported that “patients with FOG were older [mean age of 71.1], had long disease duration, were taking higher doses of dopaminergic agents, and had higher motor and non-motor scores than those without FOG.” Higher scores mean greater disability.

Among non-motor symptoms, those affecting the cardiovascular, gastrointestinal and urinary systems were more frequent in patients with FOG than in those without. In accordance, cardiovascular, gastrointestinal, urinary and miscellaneous NMSS domain scores were significantly higher in patients with FOG.

Results showed that higher mHYS and UPDRS part II scores — the section of the scale that refers to motor experiences in daily living — and NMSS total scores were significant predictors of  greater freezing of gait severity and frequency.

Evidence indicates that non-motor symptoms like anxiety, fatigue, and pain impact mobility in PD patients, but this study found no difference between mood/cognition scores in patients with and without FOG.

The cause or mechanism of action for freezing of gait in Parkinson’s patients “remains unclear,” the study concluded. But its researchers saw  possible association between FOG and both motor and non-motor disabilities. They suggest that physicians “consider the non-motor features, the motor, and activities of daily living states of the patients for the proper management of FOG.”

And they recommended further studies “to fully assess the role of non-motor symptoms in the mechanism of action during FOG.”

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Low-frequency Deep Brain Stimulation Reduces Freezing of Gait, Study Shows

gait

Low-frequency subthalamic deep brain stimulation (STN-DBS), but not high-frequency STN-DBS, reduces freezing of gait in Parkinson’s patients while preserving their ability to simultaneously process motor and cognitive information, a recent study shows.

The study, “Decreasing subthalamic deep brain stimulation frequency reverses cognitive interference during gait initiation in Parkinson’s disease,” was published in the journal Clinical Neurosphysiology.

Many Parkinson’s patients (50-70 percent) will develop freezing of gait, which occurs when a patient temporarily feels as if his/her feet are glued to the floor and hesitates before stepping forward.

Freezing of gait mainly occurs when a patient wants to start walking or change direction, but also can occur in double-task situations, such as crossing the street or talking while walking. This often leads to falls and affects patients’ quality of life, making freezing of gait a major burden.

Increasing evidence suggests an association between freezing of gait and impaired attention, executive function, and cognitive control, supporting the additional involvement of non-motor brain regions in this motor symptom.

Deep brain stimulation often is used to treat patients with advanced Parkinson’s whose motor problems no longer improve with medication.

The technique involves surgically implanting an electrode in the brain that is connected to an implanted pulse generator through subcutaneous wires. The pulse generator is programmed to deliver charge-balanced, voltage-controlled electric pulses that stimulates the subthalamic nucleus, an area of the brain involved in motor function and which becomes hyperactive in Parkinson’s patients.

Several studies have shown that STN-DBS eases motor symptoms, reduces the necessary daily dose of medication, and improves patients’ quality of life.

While some studies have shown that high-frequency STN-DBS strongly alleviates motor symptoms in Parkinson’s patients, others suggest that it worsens freezing of gait and executive function, compared to low frequency STN-DBS.

French researchers now evaluated the therapeutic effects of low (80-Hz) and high (130-Hz) frequency STN-DBS on the walking initiation performance of Parkinson’s patients, with or without the combination of a cognitive task.

This cognitive interference task consisted of initiating walking according to a visual cue, which involved  integrating an environmental cue and executing the motor task.

The study included 19 people (15 men and four women) with advanced Parkinson’s disease and a mean age of 59 years, and 20 healthy people (15 men and five women) with a mean age of 62 years.

While initiation of walking was recorded in all participants, only nine Parkinson’s patients performed the walking test combined with the cognitive interference task. The tests were conducted before DBS surgery, with or without dopaminergic medications, and after surgery without dopaminergic medications.

In the simple walking initiation task, Parkinson’s patients showed significant improvements in their walking ability after STN-DBS with either frequency and with prior dopaminergic treatment.

However, when coupled with the cognitive interference task, treatment with high frequency STN-DBS significantly impaired patients’ walking performance. These changes were not observed in patients treated with low-frequency STN-DBS, with or without prior dopaminergic medication, or in healthy people.

These findings suggest that “high frequency STN-DBS reduces the ability to simultaneously process motor and cognitive information while this seems preserved with low frequency STN-DBS,” researchers wrote.

Thus, the results support the use of low frequency STN-DBS to ease freezing of gait in Parkinson’s patients.

The team noted that different frequencies may act differently in the brain networks that regulate motor and cognitive functions, and that additional studies are necessary to clarify the mechanisms behind these different effects.

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Source: Parkinson's News Today

Brain Training Decreases Severity of Parkinson’s Freezing of Gait, Study Reports

brain training

Brain training reduces the severity and duration of freezing of gait and improves cognition and daytime sleepiness in Parkinson’s patients, a study shows.

The study, “Cognitive training for freezing of gait in Parkinson’s disease: a randomized controlled trial,” appeared in the journal npj Parkinson’s Disease.

Freezing of gait is a symptom of Parkinson’s disease and occurs when patients temporarily feel as if their feet are glued to the floor and hesitate before stepping forward. This often leads to falls and lower quality of life. Studies have shown a connection between freezing of gait and impaired attention and cognitive control.

Researchers in Australia conducted a double-blind trial with Parkinson’s patients who self-reported freezing of gait and had no signs of dementia. Patients were randomly assigned to either cognitive training intervention (20 patients) or an “active control” (18 patients).

Cognitive training consisted of exercises where participants were asked to get up from a chair and walk to a spot marked with a box 5 meters away. Conditions in which patients completed different tasks involving the box were evaluated. Two trials of each condition were completed, one with a left turn and one to the right.

The conditions included: one in which participants walked to the box, turned 180 degrees, and returned to their chair; one where they completed a 540-degree turn in the box before returning to the chair; one in which they shuffled around the box, keeping their inside foot to the outside of the box; and a dual task, where they did the same exercise as the first 180-degree condition, but also completed a cognitive task as they walked, either naming aloud the months backwards or multiples of nine or seven.

Study interventions were conducted twice weekly for seven weeks. Each session took two hours.

The initial 30-45 minutes were common to both groups and included education about a number of topics related to Parkinson’s. Patients undergoing cognitive training then conducted computer tasks targeting processes such as attention, working memory, and brain processing speed. Patients in the active control group completed nonspecific computer tasks.

Investigators primarily evaluated the percentage of time spent frozen during cognitive training, which was analyzed while subjects were both on and off dopaminergic medications. Researchers also assessed several other measures, including mood, well-being, anxiety and depression, sleep quality, and quality of life.

For patients on dopaminergic medication, results showed that those on cognitive training had a significant decrease in the severity of their freezing of gait compared with patients in the active control group. Cognitive training also led to improvements in processing speed and reduced daytime sleepiness.

In contrast, no differences were found when comparing patients not taking regular dopaminergic treatment.

“These results add to the growing body of evidence showing that [cognitive training] is a useful therapeutic technique worthy of continued exploration in [Parkinson’s],” the researchers wrote in the study.

“We believe there is reason to be hopeful for the use of these trials in the future,” Simon Lewis, MD, the study’s senior author and a professor of cognitive neuroscience at the University of Sydney’s Brain and Mind Centre, said in a press release.

He also emphasized the positive feedback from participants and family members, and added that “the results of this pilot study highlight positive trends, and the importance of nonpharmacological trials involving cognitive training has become increasingly clear.”

The researchers also noted the importance of their finding that improvements only occur in patients on dopaminergic medication, “the normal day-day state for patients with Parkinson’s,” said Courtney Walton, PhD, the study’s lead author, who is now at the University of Queensland.

“While more research is needed to better understand and establish these findings, it’s likely that participants in the off- dopaminergic state were too impaired to benefit from any of the potential changes initiated through cognitive training,” Walton said.

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Source: Parkinson's News Today

Electrical-pulse Brain Stimulation Improves Parkinson’s Patients’ Mid-step Freezing

Brain stimulation study

Electrical-pulse brain stimulation eases a common mobility problem that Parkinson’s patients face — their walk freezing in mid-step, a study reports.

The research in the journal Movement Disorders involved using low-current pulses to alleviate what Parkinson’s experts call gait freezing. The title of the study is “Multitarget transcranial direct current stimulation for freezing of gait in Parkinson’s disease.

Researchers at Tel Aviv University tried the stimulation with 20 Parkinson’s patients whose gait freezes. Patients used a head cap to receive 20 minutes of stimulation on three visits.

This technique delivered electric current to the primary motor cortex of the brain or to both this cortex and the left dorsolateral prefrontal cortex. The study included a control group that received placebo stimulation — a tingling sensation but negligible stimulation.

Before and after each round of stimulation, patients took a number of gait-related and cognition-related tests. One dealt with gait freezing. Another, Timed Up and Go, evaluated patients’ risk of falling. Another was the Stroop cognition test. It evaluated patients’ information processing speed, attention and other factors.

After 20 minutes of simultaneous stimulation of the primary motor cortex and left dorsolateral prefrontal cortex, patients’ gait freezing decreased and their mobility and cognition improved more than those who received sham stimulation or stimulation to the primary motor cortex only.

“What we found was quite encouraging,” Professor Jeffrey Hausdorff of Tel Aviv University’s Sackler School of Medicine said in a press release. “The participants’ walking improved after simultaneous stimulation of the primary motor cortex and left dorsolateral prefrontal cortex, but not after primary motor cortex only or sham stimulation,” said Hausdorff, the study’s lead author.

“The results of the study reveal that transcranial direct current stimulation designed to simultaneously target motor and cognitive regions apparently induces immediate aftereffects in the brain that translate into reduced freezing of gait and improvements” in function and mobility, he added.

Overall, the findings suggest that brain stimulation of both motor and cognitive areas improves Parkinson’s patients’ gait freezing.

Tel Aviv University and Harvard Medical School researchers are collaborating on a clinical trial evaluating the long-term benefits of brain stimulation on gait freezing and other Parkinson’s symptoms. The randomized, controlled trial (NCT02656316) is currently recruiting participants.

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Source: Parkinson's News Today