Two scores that evaluate gait characteristics may help differentiate between those who have Charcot-Marie-Tooth (CMT) disease and those who are not affected, according to a study.
The scores could also help evaluate the severity of the disease, the joints most affected, and the benefits provided by physiotherapy and orthotics, the researchers said.
The study, “Quantifying gait impairment in individuals affected by the Charcot-Marie-Tooth disease: the usefulness of gait profile score and gait variable score,” was published in the journal Disability and Rehabilitation.
Patients with CMT often have gait impairments and experience difficulties with walking, running and jumping. Since no effective medications are available yet, physiotherapy and orthotics are the standard clinical approach. This makes it important to have reliable methods that can measure patients’ levels of disability both in clinical practice and in research.
Currently, the gold standard to assess movement impairment is the CMT neuropathy score, a 36-point scale based on symptoms, signs, and neurophysiological measures. Recently, a revised version (CMTNS2) became available.
However, this score has a low sensitivity to functional disability, and it is not ideal for the evaluation of patient rehabilitation.
Gait parameters could be useful in characterizing walking issues both quantitatively and qualitatively, but the large amount of data generated from this approach makes it too complex.
Researchers have proposed the use of the gait profile score (GPS), a measure that more simply combines and expresses gait parameters. This score has been validated in other diseases that cause impaired movement.
The GPS is calculated by another value called the gait variable score (GVS) that comprises nine values related to the movement of body parts such as the pelvis, hip, knee, ankle, and foot. Each movement gives a GVS that is then compared with the pattern of non-affected individuals.
The combination of all GVS values allows for the calculation of GPS, which is a measure of how much the gait of a patients differs from a normal gait. The higher the value, the more affected the individual.
“Our study intended to test the use of GPS (and its sub-scores) to quantify CMT gait impairment,” the researchers wrote. “For this reason, we evaluated whether GPS and GVS (gait variable score) are able to distinguish between normal and CMT gait patterns and if GPS can be used to define the grade of gait impairment by evaluating its relationship with CMTNS2.”
They calculated CMTNS2, GPS, and GVS in 20 adults with CMT, with a mean age of 48.9 years, and compared them with an otherwise similar group of 20 healthy individuals used as controls.
Results showed that gait scores varied significantly between affected individuals and healthy controls. Additionally, they were useful in evaluating the severity of the disease and the most affected joints.
Overall, CMT patients walked slower, with smaller steps and spent more time with both feet on the ground, probably to improve their stability and reduce the risk of falling.
In addition, gait scores showed a positive relationship with CMTNS2 scores, which further demonstrates that gait scores can effectively evaluate movement impairment in CMT patients.
“The GPS/GVS scoring is able to identify and quantify the typical features of CMT. … Our major finding is that GPS is able to differentiate patients with CMT from healthy controls. GPS showed a high linear relationship with CMTNS2 and thus can quantify disability caused by CMT. Moreover, by using the GVS, it may be possible to detail joint movement, not only quantifying but also characterizing it,” the researchers concluded.
They emphasized that future studies should confirm the usefulness of this approach for specific issues such as the use of orthoses and foot surgery.