Daams M, Steenwijk MD, Wattjes MP, Geurts JJ, Uitdehaag BM, Tewarie PK, Balk LJ, Pouwels PJ, Killestein J, Barkhof F.Unraveling the neuroimaging predictors for motor dysfunction in long-standing multiple sclerosis.Neurology. 2015 . pii: 10.1212/WNL.0000000000001756. [Epub ahead of print]
OBJECTIVE:To find the strongest neuroimaging predictors for motor dysfunction using conventional and quantitative imaging measures focusing on the corticospinal tract (CST) in a large cohort of patients with long-standing multiple sclerosis (MS).
METHODS:In this cross-sectional study, a wide spectrum of neuroimaging measures at the whole-brain, cervical, and CST level were analyzed in 195 patients with MS and 54 healthy controls. Motor function was assessed using the Expanded Disability Status Scale (EDSS), 9-Hole Peg Test, Timed 25-Foot Walk Test, and Multiple Sclerosis Walking Scale. Associations between damage in different parts of the motor system and motor functioning were assessed using stepwise linear regression.
RESULTS:Patients had an average disease duration of 19.98 (±6.99) years and a median EDSS score of 4 (range: 1.0-8.0). EDSS score was associated with number of infratentorial and cervical cord lesions, lesion volume in the CST, and mean upper cervical cord area (adjusted R2 = 0.403). Timed 25-Foot Walk Test score was associated with number of infratentorial lesions and cerebellar volume (adjusted R2 = 0.150), 9-Hole Peg Test score with number of infratentorial lesions and thickness of the cortex connected to the CST (adjusted R2 = 0.245), and Multiple SclerosisWalking Scale with number of infratentorial and cervical lesions, thickness of the cortex connected to the CST, and mean upper cervical cord area (adjusted R2 = 0.354).
CONCLUSIONS:Motor dysfunction in MS has a complex substrate that cannot be ascribed to a single neuroimaging finding, but is the consequence of infratentorial and spinal cord damage, as well as damage in the CST
The corticospinal tract is tract in the spinal cord where nerves run to the brain that controls movement. In this study they looked at a number of behavioural outcomes and at imaging outcomes in the CST an the cord in the neck and the brain. Not a single imaging outcome could be linked to the movement problems, so begs he question of what these imaging outcomes really mean