Resting state networks change in clinically isolated syndrome
Brain. 2010-03-30; 133(6): 1612-1621
DOI: 10.1093/brain/awq058
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1. Brain. 2010 Jun;133(Pt 6):1612-21. doi: 10.1093/brain/awq058. Epub 2010 Mar 30.
Resting state networks change in clinically isolated syndrome.
Roosendaal SD(1), Schoonheim MM, Hulst HE, Sanz-Arigita EJ, Smith SM, Geurts JJ,
Barkhof F.
Author information:
(1)VU University Medical Centre, Department of Radiology, PO Box 7057, 1007 MB
Amsterdam, the Netherlands.
Task-functional magnetic resonance imaging studies have shown that early cortical
recruitment exists in multiple sclerosis, which can partly explain the
discrepancy between conventional magnetic resonance imaging and clinical
disability. The study of the brain ‘at rest’ may provide additional information,
because task-induced metabolic changes are relatively small compared to the
energy use of the resting brain. We therefore questioned whether functional
changes exist at rest in the early phase of multiple sclerosis, and addressed
this question by a network analysis of no-task functional magnetic resonance
imaging data. Fourteen patients with symptoms suggestive of multiple sclerosis
(clinically isolated syndrome), 31 patients with relapsing remitting multiple
sclerosis and 41 healthy controls were included. Resting state functional
magnetic resonance imaging data were brought to standard space using non-linear
registration, and further analysed using multi-subject independent component
analysis and individual time-course regression. Eight meaningful resting state
networks were identified in our subjects and compared between the three groups
with non-parametric permutation testing, using threshold-free cluster enhancement
to correct for multiple comparisons. Additionally, quantitative measures of
structural damage were obtained. Grey and white matter volumes, normalized for
head size, were measured for each subject. White matter integrity was
investigated with diffusion tensor measures that were compared between groups
voxel-wise using tract-based spatial statistics. Patients with clinically
isolated syndrome showed increased synchronization in six of the eight resting
state networks, including the default mode network and sensorimotor network,
compared to controls or relapsing remitting patients. No significant decreases
were found in patients with clinically isolated syndrome. No significant resting
state synchronization differences were found between relapsing remitting patients
and controls. Normalized grey matter volume was decreased and white matter
diffusivity measures were abnormal in relapsing remitting patients compared to
controls, whereas no atrophy or diffusivity changes were found for the clinically
isolated syndrome group. Thus, early synchronization changes are found in
patients with clinically isolated syndrome that are suggestive of cortical
reorganization of resting state networks. These changes are lost in patients with
relapsing remitting multiple sclerosis with increasing brain damage, indicating
that cortical reorganization of resting state networks is an early and finite
phenomenon in multiple sclerosis.
DOI: 10.1093/brain/awq058
PMID: 20356855 [Indexed for MEDLINE]