Page 256 - MEGIN Book Of Abstracts - 2023

De Tiège, Xavier functioning alterations. It highlights the potential value
of electrophysiological intrinsic rsFC for monitoring the
Laboratoire de Cartographie fonctionnelle du Cerveau, UNI- cognitive impairment in patients with MS.
ULB Neuroscience Institute, Université libre de Bruxelles (ULB),
Brussels, Belgium; Department of Functional Neuroimaging, Keywords: cognitive fatigue, cognitive impairment, func-
Service of Nuclear Medicine, CUB-Hôpital Erasme, Université tional connectivity, magnetoencephalography, multiple
libre de Bruxelles (ULB), Brussels, Belgium; National MS Center, sclerosis
Belgium; Center for Neurosciences, Vrije Universiteit Brussel,
Brussels, Belgium; Oxford Centre for Human Brain Activity, Human brain mapping (2021), Vol. 42, No. 3 (33242237)
Wellcome Centre for Integrative Neuroimaging, Department (14 citations)
of Psychiatry, University of Oxford, Oxford, UK; St Edmund
Hall, University of Oxford, Oxford, UK
Structural correlates of atypical visual and motor
ABSTRACT The pathophysiology of cognitive dys- cortical oscillations in pediatric-onset multiple
function in multiple sclerosis (MS) is still unclear. This sclerosis (2020)
magnetoencephalography (MEG) study investigates
the impact of MS on brain resting-state functional Waldman, Amy T; Sollee, John R; Datta, Ritobrato;
connectivity (rsFC) and its relationship to disability and Lavery, Amy M; Liu, Geraldine; Aleman, Tomas S;
cognitive impairment. We investigated rsFC based on Banwell, Brenda L; Gaetz, William C
power envelope correlation within and between differ-
ent frequency bands, in a large cohort of participants Department of Neurology and Pediatrics, Perelman School
consisting of 99 MS patients and 47 healthy subjects. of Medicine at the University of Pennsylvania, Philadelphia,
Correlations were investigated between rsFC and out- Pennsylvania, USA; Division of Neurology, Children's Hospital
comes on disability, disease duration and 7 neuropsy- of Philadelphia, Philadelphia, Pennsylvania, USA; Division of
chological scores within each group, while stringently Ophthalmology, Children's Hospital of Philadelphia, Philadel-
correcting for multiple comparisons and possible con- phia, Pennsylvania, USA; Department of Radiology, Children's
founding factors. Specific dysconnections correlating Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
with MS-induced physical disability and disease dura-
tion were found within the sensorimotor and language ABSTRACT We have previously demonstrated that
networks, respectively. Global network-level reductions pediatric-onset multiple sclerosis (POMS) negatively
in within- and cross-network rsFC were observed in the impacts the visual pathway as well as motor processing
default-mode network. Healthy subjects and patients speed. Relationships between MS-related diffuse struc-
significantly differed in their scores on cognitive fatigue tural damage of gray and white matter (WM) tissue and
and verbal fluency. Healthy subjects and patients cortical responses to visual and motor stimuli remain
showed different correlation patterns between rsFC poorly understood. We used magnetoencephalogra-
and cognitive fatigue or verbal fluency, both of which phy in 14 POMS patients and 15 age- and sex-matched
involved a shift in patients from the posterior default- healthy controls to assess visual gamma (30-80 Hz), mo-
mode network to the language network. Introducing tor gamma (60-90 Hz), and motor beta (15-30 Hz) corti-
electrophysiological rsFC in a regression model of cal oscillatory responses to a visual-motor task. Then,
verbal fluency and cognitive fatigue in MS patients sig- 3T MRI was used to: (a) calculate fractional anisotropy
nificantly increased the explained variance compared (FA) of the posterior visual and corticospinal motor WM
to a regression limited to structural MRI markers (rela- pathways and (b) quantify volume and thickness of the
tive thalamic volume and lesion load). This MEG study cuneus and primary motor cortex. Visual gamma band
demonstrates that MS induces distinct changes in the power was reduced in POMS and was associated with
resting-state functional brain architecture that relate reduced FA of the optic radiations but not with loss of
to disability, disease duration and specific cognitive cuneus volume or thickness. Activity in the primary

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C