MRI correlates of clinical disability and hand-motor performance in multiple sclerosis phenotypes

Claudio Cordani, M. Hidalgo de la Cruz, A. Meani, P. Valsasina, F. Esposito, E. Pagani, M. Filippi and M. A Rocca

Must Scler. 2020 Sep 14. doi: 10.1177/1352458520958356

Selezionato dal Lettore: Alessia Giugno - Università degli Studi Magna Graecia, Catanzaro

MOTIVAZIONE: In this study, authors investigated the contribution of structural and functional damage in motor-related areas to global clinical disability and hand-motor impairment in multiple sclerosis (MS) patients through a clinical and multimodal MRI approach. 

Although walking is believed to be the main contributor to clinical disability, upper limb motor impairment may influence quality of life, with functional and neuropsychological consequences. To characterize the correlation between structural and functional MRI observations and clinical findings, an extensive cohort of 364 MS patients, stratified according to relapsing-remitting (RR)-MS and to progressive MS (PMS) phenotype, and a group of healthy control subjects (164) were enrolled. Hand-motor dexterity and fine motor control were tested with nine-hole peg test and electronic finger tapping rate respectively. EDSS score evaluated global disability. After clinical evaluation, a 3T brain MRI was acquired, including structural and functional MRI study. The MRI study investigated the presence of atrophy of sensorimotor gray matter regions, of microstructural damage in motor-related white matter tracts and resting state (RS) functional connectivity (FC) abnormalities of left and right-hand motor related networks. In RR-MS, disability may be predicted only by structural damage, in terms of global measures of atrophy, lesions and structural damage of motor-related regions, in absence of RS FC alterations. In PMS patients, both structural and functional MRI parameters, including the atrophy of sensorimotor and cerebellar networks, the impairment of left cerebellar peduncle and an increased RS FC between left motor cortex and inferior frontal gyrus, seems to predict disability.

The study has an original finding which is supported by a robust methodology which includes a large cohort of patients and an extensive description of the methods applied.

The study highlights the importance of evaluation of hand-dexterity in clinical practice. Structural and functional MRI findings appear fundamental, since these evidences may reveal early biomarkers of disability and guide the choose of disease modifying and rehabilitative treatment.