Absence of diffuse cervical cord tissue damage in early, non-disabling relapsing-remitting MS: a preliminary study

Background Magnetization transfer (MT) magnetic resonance imaging (MRI) can provide quantitative information about the severity of tissue damage in the cervical cord of patients with multiple sclerosis (MS). MT MRI-derived measures of cord damage are correlated with the severity of diseaserelated locomotor disability. Objectives The objective of this study was to investigate whether MT MRI-detectable cervical cord damage is present in early relapsing-remitting (RR) MS. Subjects and methods We studied 23 patients with 'early' RR MS (i.e., with a disease duration shorter than 5 years) and 10 age-matched healthy control subjects. During a single session, the following sequences were acquired using a 1.5 T scanner: (a) brain dual-echo turbo spin echo; (b) cervical cord fast short-tau inversion recovery; (c) cervical cord gradient echo, without and with MT pulse. Brain T2 lesion volume was measured. Cervical cord lesions were counted and normalized histograms of cord MT ratio (MTR) were produced. Results One or more cervical cord lesions were found in nine patients (39%). The average cord MTR and the mean histogram peak height values did not differ between patients and controls. There was no significant correlation between brain T2 lesion volume and cervical cord MTR histogram-derived metrics. Conclusions Cervical cord tissue damage seems to be limited to macroscopic lesions in patients with early, non-disabling RR MS. Longitudinal studies are warranted to define the dynamics of MSrelated cord damage accumulation over time later on in the course of the disease.