Elisabetta Pagani1, Maria Assunta Rocca1,2, Alessandro D'Ambrosio1,3, Gianna Carla Riccitelli1, Bruno Colombo2, Mariaemma Rodegher2, Andrea Falini4, Giancarlo Comi2, and Massimo Filippi1,2
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3I Division of Neurology, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Naples, Italy, 4Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
Synopsis
Aim of the
study was to assess the role of cerebellar global and sub-regional
involvement on motor and cognitive impairment in multiple sclerosis
(MS) patients. Cerebellar
segmentation and lobular parcellation was performed on T1 weighted
images from 95 MS patients and 32 healthy controls using SUIT tool.
The Nine Hole Peg Test was obtained as a measure of motor
performance; patients also underwent cognitive evaluation. Cerebellar
posterior-inferior volume accounted for variance in cognitive
measures in MS patients, whereas anterior cerebellar volume accounted
for variance in motor performance, supporting a critical contribution
of regional cerebellar damage to clinical manifestations of MS.Background
The
cerebellum plays a role in a wide variety of complex behaviors. Many
evidences support a topographic division into “motor” and
“non-motor” regions mapped to the anterior and posterior lobe of
the cerebellum, respectively (1). Currently, no study has
investigated the impact of structural cerebellar sub-regional
involvement on motor and cognitive manifestations in
multiple
sclerosis (MS)
patients.
Purpose
To
assess the role of cerebellar global and sub-regional involvement on
motor and cognitive performance in MS patients.
Methods
Cerebellar
segmentation and lobular parcellation was performed on high
resolution 3D T1 weighted brain images from 95 MS patients (53
relapsing remitting [RR] MS, 20 benign MS and 22 secondary
progressive [SP] MS) and 32 healthy controls (HC) using the SUIT tool
(2) from SPM12. For all subjects, the Nine Hole Peg Test (9-HPT) was
obtained as a measure of motor performance. MS patients also
underwent cognitive evaluation, including the Paced Auditory Serial
Addition Test (PASAT), Symbol Digit Modalities Test (SDMT) and
Wisconsin Card Sorting Test (WCST). The SUIT tool automatically
isolates the cerebellum, which is then non-linearly transformed with
Dartel (3) onto the standard space. A probabilistic atlas is
available, based on the anatomy of 20 healthy subjects, whose lobules
were segmented according to Schmahmann et al. (4). Through the
application of the atlas, the volumes of the anterior and posterior
regions were obtained, after combining lobules I-V and VI-X
respectively (Figure 1). Volumes were then normalized for the
intracranial volume. Spearman’s correlations between normalized
cerebellar volumes vs motor and cognitive scores were estimated
(p<0.05).
Results
Global and
regional cerebellar volumes
did
not differ between MS patients and HC. In MS patients, better 9-HPT
performance correlated with higher global and regional cerebellar
volumes, with stronger correlation with the anterior regions (lobules
I-V) (p=0.02, r=0.24) (Figure 2). In RRMS patients, better cognitive
performance (SDMT, WCST) correlated with higher global and
posterior-inferior (lobules VI-X) cerebellar volumes (p range:
0.008-0.01, r range: 0.30-0-32) (Figure 3).
Conclusions
Cerebellar
posterior-inferior volume accounted for variance in cognitive
measures in MS patients, whereas anterior cerebellar volume accounted
for variance in motor performance, supporting a critical contribution
of regional cerebellar damage to the clinical manifestations of MS.
Acknowledgements
This
study has been partially supported by a grant from FISM 2011/R/19 and
Italian Ministry of Health (GR-2009-1529671).References
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