Foot tapping test in thoracic myelopathy as a quantitative assessment method reflecting corticospinal tract disorders.

This study aimed to establish the utility of FTT as a quantitative measure of corticospinal tract (CST) disorders. 

This study evaluated 43 patients with thoracic myelopathy who underwent surgery. FTT, JOA score for lower limb motor function was measured preoperatively and at two weeks, three months, and six months postoperatively. Participants measured FTT with the hip and knee joints flexed at 90 degrees. The FTT value was measured bilaterally by tapping the sole of the foot as many times as possible for 10 s while keeping the heel in contact with the floor. The mean number of repetitions was used for data analysis. P values less than 5% were considered to be statistically significant. 

The correlations between FTT and JOA scores for lower limb motor function were as follows: preoperative ρ=0.70, two weeks postoperative ρ=0.74, three months postoperative ρ=0.56, and six months postoperative ρ=0.43. All the correlations were statistically significant.

FTT showed significant correlations with gait function at all time points, with stronger correlations in the early postoperative period that decreased over time. Our results suggest that FTT is a reliable quantitative assessment of corticospinal tract impairment. The correlation coefficients between FTT and gait function were significant in all cases. However, the correlation coefficients showed a decreasing trend over time, as FTT reflects corticospinal tract impairment. Gait impairment in patients with spinal cord disorders has been reported to be dependent on corticospinal tract impairment. Therefore, the correlation was strong during the perioperative period and decreased over time.

Previous studies reported that foot control reflects CST disorders. CST injuries are generally assessed using instruments such as Transcranial Magnetic Stimulation (TMS) but are difficult to assess in a clinical setting. Assessing corticospinal tract impairment using FTT may help segment gait impairment in patients with compression myelopathy, potentially facilitating more effective rehabilitation.