Measurement of spinal cord area in clinically isolated syndromessuggestive of multiple sclerosis

摘要

Atrophy of the spinal cord is known to occur in multiple sclerosis but the cause and the timing of its onset are not clear. Recent evidence suggests that atrophy may start to occur early in the disease. The aim was to determine whether atrophy of the spinal cord could be detected in vivo using MRI techniques, in patients presenting with a clinically isolated syndrome, which in many cases is the earliest clinical stage of multiple sclerosis. The cross sectional area of the spinal cord was measured in 43patients presenting with a clinically isolated syndrome and 15matched controls. T2 weighted imaging of the brain was also performed to determine the number and volume of high signal lesions consistent with disseminated demyelination. Both patients and controls were restudied after 1 year. The spinal cord area was significantly smaller in the 74% of patients with an abnormal brain MRI at presentation than in controls (mean areas 73.9 mm² and 78.1 mm² respectively, p=0.03). No significant difference was found in the spinal cord area between controls and patients with normal baseline brain imaging. The annual rate of change in patients did not differ significantly from controls. Inconclusion, the finding of asmaller cord area in the subgroup of patients with clinically isolatedsyndrome with the highest risk of developing multiple sclerosis—thatis, with an abnormal brain MRI, suggests that atrophy has developed insome patients with multiple sclerosis even before their first clinicalsymptoms. However, the lack of a detectable change in cord area over 1 year of follow up contrasts strikingly with the results of an earlierstudy of patients with relapsing-remitting multiple sclerosis,suggesting that the rate of atrophy increases as the disease becomesmore established.