Lesion symptom map of cognitive-postural interference in multiple sclerosis.
To investigate the disease-altered structure-function relationship underlying the cognitive-postural interference (CPI) phenomenon in multiple sclerosis (MS).



We measured postural sway of 96 patients and 48 sex-/age-matched healthy controls by force platform in quiet standing (single-task (ST)) while performing the Stroop test (dual-task (DT)) to estimate the dual-task cost (DTC) of balance. In patient group, binary T2 and T1 lesion masks and their corresponding lesion volumes were obtained from magnetic resonance imaging (MRI) of brain. Normalized brain volume (NBV) was also estimated by SIENAX. Correlations between DTC and lesion location were determined by voxel-based lesion symptom mapping (VLSM) analyses.



Patients had greater DTC than controls ( p < 0.001). Among whole brain MRI metrics, only T1 lesion volume correlated with DTC ( r = -0.27; p < 0.01). However, VLSM analysis did not reveal any association with DTC using T1 lesion masks. By contrast, we found clusters of T2 lesions in distinct anatomical regions (anterior and superior corona radiata, bilaterally) to be correlated with DTC ( p < 0.01 false discovery rate (FDR)-corrected). A multivariable stepwise regression model confirmed findings from VLSM analysis. NBV did not contribute to fit the model.



Our findings suggest that the CPI phenomenon in MS can be explained by disconnection along specific areas implicated in task-switching abilities and divided attention.
Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy/Department of Neurosciences, San Camillo Forlanini Hospital, Rome, Italy.
Serena
S
Ruggieri
Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
Fulvia
F
Fanelli
Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
Letizia
L
Castelli
Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy/IRCCS Santa Lucia Foundation, Rome, Italy.
Nikolaos
N
Petsas
Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
Laura
L
De Giglio
Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
Luca
L
Prosperini
D000328:Adult; D000067289:Behavior Observation Techniques; D002552:Cerebral Ventricles / Q000000981:diagnostic imaging; D003071:Cognition; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D056344:Executive Function; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015999:Multivariate Analysis; D004856:Postural Balance; D012384:Rome; D000078783:Standing Position; D018709:Statistics, Nonparametric; D057190:Stroop Test; D066127:White Matter / Q000473:pathology
MRI; Multiple sclerosis; T2 lesions; atrophy; balance; cognitive–motor interference