Myelin content changes in Clinically Isolated Syndrome and Relapsing- Remitting Multiple Sclerosis: Associations with lesion type and severity of visuomotor impairment

Τheodora Panou; Eleftherios Kavroulakis; Vasileios Mastorodemos; Styliani Pouli; Georgios Kalaitzakis; Eirini Spyridaki; Thomas G Maris; Panagiotis Simos; Efrosini Papadaki

doi:10.1016/j.msard.2021.103108

Myelin content changes in Clinically Isolated Syndrome and Relapsing- Remitting Multiple Sclerosis: Associations with lesion type and severity of visuomotor impairment

Mult Scler Relat Disord. 2021 Sep:54:103108. doi: 10.1016/j.msard.2021.103108. Epub 2021 Jun 23.

Authors

Τheodora Panou¹, Eleftherios Kavroulakis², Vasileios Mastorodemos³, Styliani Pouli², Georgios Kalaitzakis⁴, Eirini Spyridaki¹, Thomas G Maris⁵, Panagiotis Simos⁶, Efrosini Papadaki⁷

Affiliations

¹ Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece.
² Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece.
³ Department of Neurology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece.
⁴ Department of Medical Physics, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece.
⁵ Department of Medical Physics, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece; Institute of Computer Science, Foundation of Research and Technology-Hellas, Voutes, Heraklion, Greece.
⁶ Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece; Institute of Computer Science, Foundation of Research and Technology-Hellas, Voutes, Heraklion, Greece.
⁷ Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece; Institute of Computer Science, Foundation of Research and Technology-Hellas, Voutes, Heraklion, Greece. Electronic address: fpapada@otenet.gr.

PMID: 34198031
DOI: 10.1016/j.msard.2021.103108

Abstract

Background: Cognitive disturbances occur in patients with Relapsing Remitting Multiple Sclerosis (RR-MS) and Clinically Isolated Syndrome (CIS). The Multi-Echo-Spin-Echo (MESE) T2-weighted sequence quantifies demyelination, the pathological hallmark of MS, but has not been used for the documentation of the potential relationship between anatomically specific demyelinating changes and cognitive impairment in MS.

Purpose: To identify markers of regional demyelination in patients with RR-MS and CIS in relation to clinical variables and severity of cognitive impairment.

Methods and materials: 37 RR-MS patients, 39 CIS patients and 52 healthy controls (HC) were examined using the MESE sequence. Long T2 and myelin water fraction (MWF) values were measured, serving as indices of intra/extracellular water content and myelin content, respectively, in focal white matter lesions and 12 normal appearing white matter (NAWM) areas of the patients and HC. A comprehensive neuropsychological assessment was administered to all patients.

Results: RR-MS patients showed widespread long T2 increases and MWF reductions in NAWM, compared to the respective values of HC (p < 0.001), which correlated with total lesion volume. Among RR-MS patients illness duration correlated negatively with MWF in right hemisphere frontal and periventricular NAWM areas (and positively with corresponding long T2 values). MWF values were lower in the CIS, as compared to the HC group, in the temporal, frontal and periventricular NAWM areas. Focal demyelinating lesions displayed variable higher T2 and lower MWF values, compared to NAWM, closely corresponding to their intensity on T1 sequences. Reduced MWF values and increased long T2 values in right periventricular NAWM were significantly associated with poor visuomotor performance.

Conclusion: The MESE sequence affords accurate estimation of myelin and water content in NAWM and focal lesions in RR-MS and CIS patients, by means of the MWF and long T2 values, respectively, providing a sensitive index of demyelination associated with visuomotor deficits.

Keywords: CIS; MS; Magnetic Resonance Imaging (MRI); T2 relaxometry; Visuomotor capacity.

MeSH terms

Brain / diagnostic imaging
Demyelinating Diseases* / complications
Demyelinating Diseases* / diagnostic imaging
Humans
Magnetic Resonance Imaging
Multiple Sclerosis*
Multiple Sclerosis, Relapsing-Remitting* / complications
Multiple Sclerosis, Relapsing-Remitting* / diagnostic imaging
Myelin Sheath
White Matter* / diagnostic imaging