Wearable device allows neuromotor assessment of leukoencephalopathy patients

Gait and balance measures in patients with leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) can be reliably monitored using wearable accelerometers, according to a recent study.

“The gait and balance results appear to reflect the contribution of both cerebellar and dorsal column pathology to ataxia in LBSL, which is useful information with the potential to inform clinical therapeutic interventions,” the researchers said.                                                   

A total of eight LBSL patients (median age 10 years, five males) with confirmed mutations in the DARS2 gene participated in the study. Patients, along with age- and sex-matched controls, were given the wearable device, a laptop, and a web camera. Neuromotor tests were conducted remotely, with study staff guiding participants through Zoom.

Overall, patients had mild-to-moderate ataxia, with a mean score of 8.7 on the Scale for the Assessment and Rating of Ataxia (SARA). Most of them showed mild impairment in gross and fine motor function. Muscle weakness, hypotonia, and hyperreflexia were all also common in the study sample. [Ann Clin Transl Neurol 2022;doi:10.1002/acn3.51509]

Walk Test results showed that LBSL patients did not differ from controls in terms of stride length, gait cycle duration, cadence, or stride velocity. However, patients were slower by an average of 0.09 m/sec. While this difference in stride velocity did not reach statistical significance, researchers pointed out that this might be due to the small sample size.

Moreover, lateral step variability (LSV) was significantly greater in LBSL patients than controls (p<0.001), as was the elevation of the foot at mid-swing (p=0.02).

LBSL patients also showed worse balance relative to controls, with significantly greater sway path length and area and sway jerk. These differences in various balance measures remained true across different feet placements and whether eyes were opened or closed.

Notably, SARA scores correlated significantly and positively with LSV (p<0.01) and with sway area when the participants’ feet were together and their eyes were closed (p=0.01). No link between ataxia and magnetic resonance imaging score was reported (p=0.65).

“This study describes a novel and feasible approach for performing clinical rating scales and assessing quantitative gait and balance measures using wearable technology at home without the assistance of any on-site staff. This approach is accessible, because data acquisition requires only minimal set up and basic instructions,” the researchers said.

Indeed, all participants in the study were able to follow online instructions and perform the remote neuromotor tests without issue. The portable nature of the device was also an advantage and could allow use in many different situations or across serial visits.

In addition, this device-based approach “can be applied to related rare diseases that feature ataxia, in which study numbers are low, and removing barriers to participation is critical for research and biomarker development to continue,” the researchers said.