Brain and Cervical Spinal Cord MRI Correlates of Motor Impairment and Vibratory Sensation in Patients with Multiple Sclerosis
Tetsu Morozumi1, Paolo Preziosa2, Alessandro Meani1, Giorgia Pessina1, Matteo Azzimonti2, Massimo Filippi3, Maria Rocca2
1Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 2Neuroimaging Research Unit, Division of Neuroscience; and Neurology Unit, 3Neuroimaging Research Unit, Division of Neuroscience; Neurology Unit; Neurorehabilitation Unit; and Neurophysiology Service, IRCCS San Raffaele Scientific Institute; and Vita-Salute San Raffaele University
Objective:
To identify MRI features of cervical spinal cord (cSC) damage able to predict a more severe clinical disability and impairment in motor and sensory functions in multiple sclerosis (MS) patients.
Background:
cSC focal lesions and volume loss represent pathological processes that strongly contribute to clinical disability in MS. However, how different MS-related cSC abnormalities may be associated with specific motor and sensory dysfunctions still needs to be fully explored. 
Design/Methods:

One hundred fifty-one MS patients and 69 age- and sex-matched healthy controls (HC) underwent brain and cSC 3T MRI acquisition and a comprehensive clinical assessment including evaluation of Expanded Disability Status Scale (EDSS), 9-hole peg test (9-HPT), finger tapping test (FTT), timed 25-foot walk test (T25FWT) and vibration detection threshold (VDT). Using random forest analyses, we investigated whether brain and cSC MRI measures (T2-hyperintense lesion volume [T2-LV] and total, gray matter [GM] and white matter [WM] cross-sectional areas [CSA] at C2-C3 level) were informative predictors of EDSS disability milestones (EDSS≥3.0, 4.0 and 6.0), impairment at pyramidal and sensory functional systems (P-FS and S-FS ≥2), as well as at 9-HPT, FTT and T25FWT (z-scores≤5th percentile of HC), and higher VDT.

Results:

Different combinations of brain and cSC MRI measures were informative predictors of EDSS milestones (out-of-bag [OOB]-area under the curve [AUC]=0.879-0.900), VDT (OOB-R2=0.194), and impairment at P-FS (OOB-AUC=0.820), S-FS (OOB-AUC=0.795), 9-HPT (OOB-AUC=0.793), FTT (OOB-AUC=0.740), T25FWT (OOB-AUC=0.825). For all these clinical outcomes, cSC GM CSA was identified as the most relevant predictor, except for 9-HPT, for which cSC T2-LV was the best predictor.

Conclusions:

A multiparametric approach including brain and cSC MRI measures may explain a more severe clinical disability in MS with high accuracy. cSC GM atrophy represents an impactful pathological substrate specifically contributing to motor and sensory impairment in MS.

10.1212/WNL.0000000000205037