The importance of pyramidal tract integrity for cortical plasticity and related functionality in patients with multiple sclerosis

Carolin Balloff; Philipp Albrecht; Arved-Sebastian Stucke; Lina Scala; Sveva Novello; Christian Johannes Hartmann; Sven Günther Meuth; Alfons Schnitzler; Iris-Katharina Penner; Stefan Jun Groiss

doi:10.3389/fneur.2023.1266225

The importance of pyramidal tract integrity for cortical plasticity and related functionality in patients with multiple sclerosis

Front Neurol. 2023 Nov 24:14:1266225. doi: 10.3389/fneur.2023.1266225. eCollection 2023.

Authors

Carolin Balloff^#^{1

2}, Philipp Albrecht^#^{1

2}, Arved-Sebastian Stucke¹, Lina Scala¹, Sveva Novello¹, Christian Johannes Hartmann^{1

3}, Sven Günther Meuth¹, Alfons Schnitzler^{1

3}, Iris-Katharina Penner^{1

4}, Stefan Jun Groiss^{1

3

5}

Affiliations

¹ Department of Neurology, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany.
² Department of Neurology, Kliniken Maria Hilf GmbH, Mönchengladbach, Germany.
³ Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany.
⁴ Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
⁵ Neurocenter Düsseldorf, Düsseldorf, Germany.

^# Contributed equally.

Abstract

Background: Cortical plasticity induced by quadripulse stimulation (QPS) has been shown to correlate with cognitive functions in patients with relapsing-remitting multiple sclerosis (RRMS) and to not be reduced compared to healthy controls (HCs).

Objective: This study aimed to compare the degree of QPS-induced plasticity between different subtypes of multiple sclerosis (MS) and HCs and to investigate the association of the degree of plasticity with motor and cognitive functions. We expected lower levels of plasticity in patients with progressive MS (PMS) but not RRMS compared to HCs. Furthermore, we expected to find positive correlations with cognitive and motor performance in patients with MS.

Methods: QPS-induced plasticity was compared between 34 patients with PMS, 30 patients with RRMS, and 30 HCs using linear mixed-effects models. The degree of QPS-induced cortical plasticity was correlated with various motor and cognitive outcomes.

Results: There were no differences regarding the degree of QPS-induced cortical plasticity between HCs and patients with RRMS (p = 0.86) and PMS (p = 0.18). However, we only found correlations between the level of induced plasticity and both motor and cognitive functions in patients with intact corticospinal tract integrity. Exploratory analysis revealed significantly reduced QPS-induced plasticity in patients with damage compared to intact corticospinal tract integrity (p < 0.001).

Conclusion: Our study supports the notion of pyramidal tract integrity being of more relevance for QPS-induced cortical plasticity in MS and related functional significance than the type of disease.

Keywords: cortical plasticity; motor function; pyramidal tract integrity; quadripulse stimulation; repetitive transcranial magnetic stimulation.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the research commission of the medical faculty of the Heinrich Heine University Düsseldorf (project No. 2019-14). The funder had no role in the design and conduct of the study, collection, management, analysis, and interpretation of the data, preparation, review, or approval of the manuscript.