Balance Impairments in People with Early-Stage Multiple Sclerosis: Boosting the Integration of Instrumented Assessment in Clinical Practice

Abstract

The balance of people with multiple sclerosis (PwMS) is commonly assessed during neurological examinations through clinical Romberg and tandem gait tests that are often not sensitive enough to unravel subtle deficits in early-stage PwMS. Inertial sensors (IMUs) could overcome this drawback. Nevertheless, IMUs are not yet fully integrated into clinical practice due to issues including the difficulty to understand/interpret the big number of parameters provided and the lack of cut-off values to identify possible abnormalities. In an attempt to overcome these limitations, an instrumented modified Romberg test (ImRomberg: standing on foam with eyes closed while wearing an IMU on the trunk) was administered to 81 early-stage PwMS and 38 healthy subjects (HS). To facilitate clinical interpretation, 21 IMU-based parameters were computed and reduced through principal component analysis into two components, sway complexity and sway intensity, descriptive of independent aspects of balance, presenting a clear clinical meaning and significant correlations with at least one clinical scale. Compared to HS, early-stage PwMS showed a 228% reduction in sway complexity and a 63% increase in sway intensity, indicating, respectively, a less automatic (more conscious) balance control and larger and faster trunk movements during upright posture. Cut-off values were derived to identify the presence of balance abnormalities and if these abnormalities are clinically meaningful. By applying these thresholds and integrating the ImRomberg test with the clinical tandem gait test, balance impairments were identified in 58% of PwMS versus the 17% detected by traditional Romberg and tandem gait tests. The higher sensitivity of the proposed approach would allow for the direct identification of early-stage PwMS who could benefit from preventive rehabilitation interventions aimed at slowing MS-related functional decline during neurological examinations and with minimal modifications to the tests commonly performed.

VISIBL-MS: A bilingual educational framework to increase awareness of early multiple sclerosis

“…Changes in balance and gait initiation are seen in early-stage patients due to alteration of motor modulation of stance limb kinetics during gait initiation. 27 Finally, exercise-induced gait deterioration is an early symptom that limits ambulation, becoming more prominent with increasing neurological disease and also observed with the get-up and go test. 28,29 Limb numbness and weakness (L): Motor deficits and muscle function impairment are cardinal features of MS from the beginning of the disease.…”

Multiple Sclerosis in the Digital Health Age: Challenges and Opportunities - A Systematic Review

“…While suggested as suitable for remote MS monitoring 77 , measures can be different in unsupervised settings 75 . Over and above, authors in 78 highlighted that PwMS showed a reduction in sway complexity paired with an increase in sway intensity while performing an altered Romberg test (patient stands on foam), which could point to a less automatic postural control strategy, albeit the correlation between EDSS and balance scores was only significant for EDSS > 3 78 .…”

Assessing Free-Living Postural Sway in Persons With Multiple Sclerosis

“…To address these challenges, studies have shown that postural sway can be assessed using data from just a sacral or chest accelerometer [ 10 ], [ 14 ], [ 15 ], [ 16 ]. Sensor-derived postural sway measures have been used to classify fall risk in PwMS [ 14 ], distinguish between disease states [ 10 ], [ 13 ], [ 16 ], [ 17 ], [ 18 ] and to augment current assessment techniques [ 19 ], thereby achieving similar clinical utility to the force platform.…”