Walking is an activity that many of us can carry out instinctively. Recently, the use of smartwatches to count the number of steps taken each day has become a popular way to measure fitness. But by and large, individuals who are mobile, walk without thinking about walking, similar to how people with healthy eyesight, see without consciously thinking about seeing.
In reality, walking is a complex act that requires close coordination between different systems, such as the neurological system and the neuromuscular system. If there is an aberration somewhere along the pathway from the brain (in which a decision to initiate walking has been made) to the feet and toes (to carry out that movement), the simple act of walking cannot be carried out.
Regardless of the underlying medical cause, studies indicate that the loss of ambulation/coordination has a notably negative impact on an individual’s health-related quality of life. In 1 of my medical textbooks, the editors thought it appropriate to include a short poem from a man who had his feet amputated because of diabetes. In the short poem, the man laments that his days of running carefree along the hills are now decidedly in the past. It is a type of mourning that takes effect only when the object of the mourning is long gone.
The loss of ambulation can be classified as a “disability,” according to CDC guidelines. There are, of course, different levels of disability, but all disabilities entail some changes in the way an individual interacts with their home, social, and work environments.
Needless to say, physicians have an obligation to ensure that every able-bodied patient retains their ability to ambulate for as long as is medically possible.
The Link Between Wilson Disease and Gait
Wilson disease is a rare disorder in which copper accumulates toxically in the body. Copper intoxication can reach the central nervous system, causing a broad spectrum of neurological abnormalities, such as a parkinsonian gait, dysarthria, and dystopias.
Read more about Wilson disease etiology
Fortunately, copper elimination therapy can ameliorate many of the neurological symptoms and brain dysfunction brought about by excessive copper accumulation. A study indicates that patients treated with copper chelating agents are free from abnormal gait in 4 out of every 5 cases; sadly, this also means that 20% of patients experience gait abnormalities despite the best treatment.
“Gait is a complex bipedal motor task which is under the control of several [central nervous system] structures, especially the basal ganglia, the cerebellum, and the brainstem nuclei,” Samadzadeh and colleagues wrote in Sports. “Therefore, gait disturbances have to be expected in neurological [Wilson disease].”
The authors of the study hypothesized that slight instabilities in gait could be amplified by running since running is a more complex activity, with the center of gravity intermittently supported by 1 leg followed by the other. The additional difficulties in running should expose any lingering gait abnormalities experienced by patients with Wilson disease, even if their walking gait appears to be normal.
The research team recruited patients who were diagnosed with Wilson disease and subsequently treated at the Neurological Clinic of the University of Düsseldorf. Selected patients must be on regular treatment for Wilson disease for at least 2 years and be able to walk for 40 m without walking aids. Age- and sex-matched controls were recruited among the healthy population.
The participants of this study underwent detailed neurological tests that encompassed 7 motor symptoms and 3 nonmotor symptoms. The research team also split the group of participants into those who could run (n=25) and those who could not (n=5). Participants in the “could run” group was further split into smaller subcategories according to the clinical severity of their Wilson disease.
Read more about Wilson disease treatment
The research team carefully designed the running course, informing participants that safety was a greater priority than running speed. Participants were asked to run for more than 40 m along a predetermined distance. The participants had to conduct the run with 10 running steps with both the left and right leg each for the run to count.
“Only 16% of the [Wilson disease]-patients were unable to run under our test conditions,” Samadzadeh and colleagues wrote. “This is in line with the previously reported observation that the central pattern generator of walking appears to be unimpaired in about 80% of the long-term treated [Wilson disease]-patients.”
These findings are significant in a number of ways. First, it clarifies existing evidence that the majority of patients with Wilson disease who receive treatment can walk/run normally. This is an important point, as many of our patients are young and view the ability to walk/run normally as a prerequisite for the participation in sports/physical activity. Physicians would be wise to use the evidence from this and other studies to assure patients of the high likelihood of gait normalcy should they abide by the treatment course as prescribed.
Second, these findings suggest that any residual gait abnormalities do not significantly impact running for the 80% of patients with Wilson disease treated with copper chelating agents. This means that individuals with this condition can, in all likelihood, participate in able-bodied sports without significant risk of injury.
References
Samadzadeh S, Hefter H, Tezayak O, Rosenthal D. Analysis of running in Wilson’s disease. Sports (Basel). Published online January 7, 2022. doi:10.3390/sports10010011
Scura D, Piazza VM. Disability evaluation. StatPearls. Published online April 21, 2022.
