Profiling cognitive–motor interference in a large sample of persons with progressive multiple sclerosis and impaired processing speed: results from the CogEx study

• Published in: Journal of neurology Vol. 270; no. 6; pp. 3120 - 3128
• Main Authors: Veldkamp, R., D’hooge, M., Sandroff, B. M., DeLuca, J., Kos, D., Salter, A., Feinstein, A., Amato, M. P., Brichetto, G., Chataway, J., Farrell, R., Chiaravalloti, N. D., Dalgas, U., Filippi, M., Freeman, J., Motl, R. W., Meza, C., Inglese, M., Rocca, M. A., Cutter, G., Feys, P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2023; Springer Nature B.V
• Subjects: Cognition; Cognitive ability; Cognitive Dysfunction - etiology; Gait; Humans; Medicine; Medicine & Public Health; Multiple Sclerosis; Multiple Sclerosis, Chronic Progressive - complications; Neurology; Neuroradiology; Neurosciences; Original Communication; Processing Speed; Retinoids; Walking; Progressive; Multiple sclerosis; Gait; Dual task; Cognitive–motor interference
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-023-11636-y

Background
Performing cognitive–motor dual tasks (DTs) may result in reduced walking speed and cognitive performance. The effect in persons with progressive multiple sclerosis (pwPMS) having cognitive dysfunction is unknown.
Objective
To profile DT-performance during walking in cognitively impaired pwPMS and examine DT-performance by disability level.
Methods
Secondary analyses were conducted on baseline data from the CogEx-study. Participants, enrolled with Symbol Digit Modalities Test 1.282 standard deviations below normative value, performed a cognitive single task ([ST], alternating alphabet), motor ST (walking) and DT (both). Outcomes were number of correct answers on the alternating alphabet task, walking speed, and DT-cost (DTC: decline in performance relative to the ST). Outcomes were compared between EDSS subgroups (≤ 4, 4.5–5.5, ≥ 6). Spearman correlations were conducted between the DTC
motor
with clinical measures. Adjusted significance level was 0.01.
Results
Overall, participants (n = 307) walked slower and had fewer correct answers on the DT versus ST (both
p
 < 0.001), with a DTC
motor
of 15.8% and DTC
cognitive
of 2.7%. All three subgroups walked slower during the DT versus ST, with DTC
motor
different from zero (
p
’s < 0.001). Only the EDSS ≥ 6 group had fewer correct answers on the DT versus ST (
p
 < 0.001), but the DTC
cognitive
did not differ from zero for any of the groups (
p
 ≥ 0.039).
Conclusion
Dual tasking substantially affects walking performance in cognitively impaired pwPMS, to a similar degree for EDSS subgroups.