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The 9th International Congress of Parkinson's Disease and Movement Disorders - Part Three: Balance and Gait in Parkinson's Disease

The Parkinson Alliance/DBS-STN Research Team

The summary to follow includes information presented by Nir Giladi, MD from the Department of Neurology at Tel Aviv Sourasky Medical Center; Fay Horak, PT, MS, Ph.D. from the Neurological Science Institute at Oregon Health Sciences University in Beaverton, Oregon; and Robert Iansek, MMEDSCI, MBBS, Ph.D. from Kingston Centre in Australia. Additionally, some information that was included in some of the poster sessions is cited.

Among the cardinal features of PD, including bradykinesia, rigidity, resting tremor, and abnormal postural reflexes and gait disturbance, gait disturbances and falls are a leading cause of disability and functional dependence. Of interest, Dr. Horak cited that PD patients have 3 times the falls and 5 times the injuries when compared to age-matched individuals who do not have PD. Thus, gaining further understanding about gait disturbance and its cause are of great importance.

Dr. Giladi eloquently described the relationship between locomotion gait disturbances and the progression of PD. He indicated that in the early stages, gait disturbance manifests itself in decreased arm swing, shorter stride, slower speed, and short and transient hesitation or festination (involuntary shortening of stride and quickening of gait that tend to occur while turning or ambulating through spatially restricted areas -“ e.g., doorways). In the advanced stages of PD, one is more likely to experience postural instability, akinesia (inability to move the muscles) when off medications, dyskinesia (excessive movement of the body), significant festination, and significantly reduced stride-length and ground clearance (which results in shuffling of feet while walking). An illustration of how the progression of PD can impact the prevalence of a specific gait disturbance was provided. Freezing spells were reported to occur in approximately 7% of PD patients within the first year of diagnosis, approximately 26% around 18 months, and over 50% after several years.

"Iatrogenic" locomotion gait disturbances were also described by Dr. Giladi. "Iatrogenic" means a condition caused by treatment. Thus, in the context of gait disturbances in PD patients, medications often have side effects (e.g., dopaminergic side effects) that impact mobility, such as dyskinesia, freezing spells, festination, sudden off periods, light headedness, and double vision.

Cognition and Gait:

There was an important delivery about the effects of cognitive inefficiency on gait performance. Specifically, some research has found that as the brain has more to process gait speed is slowed down and gait rhythm is disturbed. Some research conducted by Hausdorff and colleagues (2005) indicated that routine walking relies upon higher levels of cognitive abilities called executive function (such as attention, planning, sequencing, organizing, initiating activity, solving problems, etc.). In fact, as these higher-order functions become dysfunctional, gait disturbance and fall risk are likely to result. For example, Bernal and co-investigators (2005) assessed 39 patients with PD to gain further understanding about cognition and gait disturbance. They found that cognitive activities are able to modify gait speed in patients. Specifically, demands on attention mediate gait performance in such a way that as the demands on attention increase, increased likelihood of gait disturbance ensues.

Treatment:

With regard to treatment options, multiple studies and techniques were addressed by Drs. Horak and Iansek.

Jobges and colleagues (2004) examined repetitive training of compensatory steps to help treat postural instability in PD. They noted that dopaminergic medication is of negligible use for postural instability and a positive effect of deep brain stimulation on this issue has not been reported. Their goal was to develop a method of repetitive training of compensatory steps to enhance protective postural responses by using training strategies based on recent neurophysiological research. Fourteen patients with PD trained for 14 days in an ambulant setting consisting of two daily sessions. The results revealed that after training, the length of compensatory steps increased, gait length increased, and gait speed improved. These effects were stable for two months without additional training.

Herman and colleagues (2005) assessed gait and quality of life. They conducted a study with 9 patients with PD wherein the patients were examined before and after they participated in an intensive treadmill training program. The rehabilitation-like program was designed to retrain gait pacing, which will improve motor performance, gait steadiness, and quality of life in patients with PD. Patients walked on the treadmill for 30 minutes each session, 4 training sessions per week, for 6 weeks. Once a week walking speed was re-evaluated and the treadmill speed was adjusted accordingly. The results of the study demonstrated the potential to enhance gait rhythmicity in patients with PD and suggest that a treadmill can be used as a powerful tool to minimize impairments in gait, reduce fall risk, and increase quality of life.

As was mentioned above, cognitive processes are very important in ambulation. There are some medications that may assist in improving gait performance via improving cognition. Uriel and his colleagues (2005) evaluated the impact of a psychostimulant (Methylphenidate, also known as Ritalin) on gait performance. Their premise was to evaluate the effect of Ritalin on cognitive function (e.g., attention, memory, planning, organizing, initiation, flexibility in thinking, problem solving), gait, and fall risk in patients with PD. They assessed 14 patients with PD and evaluated gait and cognitive capabilities before and after the administration of the medication. The results revealed that Ritalin was associated with a differential improvement in attention and other higher order cognitive functions (but not memory) and gait performance. They concluded that this unique dual effect of this medication opens a new potential mode of intervention to decrease falls in PD.

Dr. Horak discussed some of her research as it relates to the effects of deep brain stimulation and levodopa on postural sway in PD. A recent study conducted by Rocchi, Chiari, & Horak (2002) aimed to quantify postural sway in subjects with Parkinson's disease and elderly controls, and determine the effects of PD, deep brain stimulation, levodopa, and their interactions on postural control during a quiet stance. The participants included 11 controls and 6 patients with PD. The results revealed that area of postural sway was larger than normal in subjects with Parkinson's disease in the off condition, increased further with levodopa, and significantly decreased with deep brain stimulation. They concluded that subjects with PD have abnormal postural sway in stance. Treatment with levodopa increases postural sway abnormalities, whereas treatment with deep brain stimulation improves postural sway.

Dr. Horak indicated that rehabilitation for mobility and stability improves function, and she stated that exercise may even be neuroprotective. She emphasized that goals for rehabilitation should include facilitating appropriate strategies for mobility and stability and learning compensatory strategies for musculoskeletal problems. Furthermore, she indicated that rehabilitation earlier in the disease is better.

Dr. Iansek provided his conceptualization of a specific gait disturbance often seen in PD patients. He stated that there is an inability, or at least difficulty, to maintain and correct the height and speed of stepping while ambulating. He indicated that the sequence of ambulating becomes corrupted at some point during the action, and subsequently, movements become smaller and slower. He indicated that inattention and occasional unawareness of the difficulties perpetuates the problem once it is started.

Subsequent to this declaration, he provided some strategies that he has found helpful for treating gait disturbances. He indicated that the use of external cues (e.g., visual cues: lines on the floor to identify/dictate stride length) have been helpful in stride length and reducing festination. He also mentioned that the lack of internal referencing may result in gait disturbance. In other words, the inability to cue oneself to carry-on with a movement may occur, thus causing a gait disturbance. He suggested that family members or others assisting the patient provide him or her with a cue. Specifically, when a patient is unable to initiate a step, one should provide a verbal cue (go ahead and take a step). Dr. Iansek reported that the verbal cue should not be vague; rather, it should be specific. For example, when a patient freezes or has difficulty initiating the next step, provide a specific cue, such as "Take a step that is 12 inches long."

Additionally, Dr. Iansek described the importance of managing the environment in which patients ambulate. Specifically, one can maintain an environment at home that eliminates or at least minimizes obstacles that may influence gait disturbance. For example, making sure that the areas through which the patient may be walking are spacious and free of hazardous objects on the floor. When venturing into the community, PD patients should plan ahead, avoid crowded locations, and avoid engaging in dual tasks (e.g., simplify tasks and take them one step at a time to avoid cognitive overload).

Furthermore, Dr. Iansek indicated that the response to medications needs to be optimized, as some medications may be helpful while others may exacerbate gait difficulties. He emphasized the importance of good management of medications and sound assessment of how it affects gait performance. He also strongly recommended participating in a multidisciplinary treatment team to help improve overall functioning and quality of life (e.g., neurologists, neuropsychologist, physical therapist, occupational therapist, speech therapist, etc.).

References
Bernal, A., Arango, G., Grandados, A., & Fernandez, W. (2005). Gait assessment in parkinsonism, dementia, and normal aging. Poster presentation at the 9thInternational Congress of Parkinson's Disease & Movement Disorders, New Orleans.

Hausdorff, J., Yogev, G., Springer, S., Simon, E., & Giladi (2005). Walking is more like catching than tapping: Gait in the elderly as a complex cognitive task. Poster presentation at the 9th International Congress of Parkinson's Disease & Movement Disorders, New Orleans.

Herman, T., Giladi, N., Erlich, L., Gruendlinger, L., & Hasudorff, J. (2005). Six weeks intensive treadmill training improves gait and quality of life in patients with Parkinson's disease: A pilot study. Poster presentation at the 9th International Congress of Parkinson's Disease & Movement Disorders, New Orleans.

Jobges, M., Heuschkel, G., Pretzel, C., Illhardt, C., Renner, C., & Hummelsheim H. (2004). Repetitive training of compensatory steps: a therapeutic approach for postural instability in Parkinson's disease. Journal of Neurology, Neurosurgery, and Psychiatry, 75(12),1682-1687.

Rocchi, L, Chiari, L, & Horak, F. (2002). Effects of deep brain stimulation and levodopa on postural sway in Parkinson's disease. Journal of Neurology, Neurosurgery, and Psychiatry, 73 (3), 267-274.



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