Effect of corpus callosum damage on ipsilateral motor activation in patients with multiple sclerosis: a functional and anatomical study

Functional MRI (fMRI) studies have shown increased activation of ipsilateral motor areas during hand movement in patients with multiple sclerosis (MS). We hypothesized that these changes could be due to disruption of transcallosal inhibitory pathways. We studied 18 patients with relapsing-remitting MS. Conventional T1- and T2-weighted images were acquired and lesion load (LL) measured. Diffusion tensor imaging (DTI) was performed to estimate fractional anisotropy (FA) and mean diffusivity (MD) in the body of the corpus callosum (CC). fMRI was obtained during a right-hand motor task. Patients were studied to evaluate transcallosal inhibition (TCI, latency and duration) and central conduction time (CCT). Eighteen normal subjects were studied with the same techniques. Patients showed increased MD (P < 0.0005) and reduced FA (P < 0.0005) in the body of the CC. Mean latency and duration of TCI were altered in 12 patients and absent in the others. Between-group analysis showed greater activation in patients in bilateral premotor, primary motor (M1), and middle cingulate cortices and in the ipsilateral supplementary motor area, insula, and thalamus. A multivariate analysis between activation patterns, structural MRI, and neurophysiological findings demonstrated positive correlations between T1-LL, MD in the body of CC, and activation of the ipsilateral motor cortex (iM1) in patients. Duration of TCI was negatively correlated with activation in the iM1. Our data suggest that functional changes in iM1 in patients with MS during a motor task partially represents a consequence of loss of transcallosal inhibitory fibers.     

MRI-based analysis of the natalizumab therapeutic window in multiple sclerosis

The recommended natalizumab dosage is 300 mg every 4 weeks. We evaluated radiological activity at various times from the last natalizumab infusion by examining 386 magnetic resonance imaging (MRI) scans from 166 natalizumab-treated patients with relapsing-remitting MS. Of 113 scans performed >4 weeks after last natalizumab infusion, 26 were active (i.e. had ≥1 contrast-enhancing lesions). Risk of radiological activity increased by 1.34 fold for each week of delay with respect to the recommended 4-week dosing interval, compared with schedule-adherent patients (p<0.0001). Our data suggest that an increased MRI activity ≥7 weeks from the last infusion of natalizumab should be considered in cases of therapy discontinuation.     

Pulse monthly steroids during an elective interruption of natalizumab: a post-marketing study

Background and purpose: Temporary discontinuation of natalizumab is sometimes considered as the observed risk of progressive multifocal leukoencephalopathy (PML) in patients with multiple sclerosis (MS). However, interruption of natalizumab may result in a re‐start of disease activity. Methods: In this prospective post‐marketing study, 23 patients with MS treated with natalizumab elected a trial of treatment interruption (90–150 days) because of safety concerns on the risk of developing PML. To reduce the risk of disease activity return, patients received monthly intravenous (i.v.) steroid pulses before natalizumab re‐start. Results: Despite the steroid coverage, seven patients (30.4%) had an active scan during the natalizumab interruption period; of these, four also had a concomitant clinical exacerbation. Conclusions: Our findings suggest that i.v. steroids are not currently recommendable as drug coverage during a scheduled treatment interruption period.     

Observations during an elective interruption of natalizumab treatment: a post-marketing study

In this prospective post-marketing study, 21 patients with multiple sclerosis treated with natalizumab for 24 consecutive months elected a trial of treatment interruption (90-180 days). During a mean duration of treatment interruption of 111.5 days 4 patients (19.0%) experienced a relapse and 9 out of 19 (47.4%) had MRI activity. Number of contrast-enhancing lesions at baseline was lower than during treatment interruption, but the difference was not significant. These findings suggest that disease activity may return after the last infusion of natalizumab. Patients should have regular MRI assessment during treatment interruption to rapidly identify any return of disease activity. The aim of this study was to determine the optimal duration for temporary interruption of natalizumab therapy in patients who have received continuous therapy with natalizumab for 24 months.     

Natalizumab treatment in multiple sclerosis: the experience of S. Andrea MS Centre in Rome

We reported a post-marketing experience of 190 patients affected by relapsing multiple sclerosis on treatment with natalizumab. Clinical findings during pre-treatment period and throughout the study were documented. Magnetic resonance imaging (MRI) scans were performed at baseline and at 6, 12, and 24 months of therapy. Cumulative proportions of patients disease activity free (i.e. absence of relapses, disability progression, MRI activity) were measured as efficacy endpoints. Despite that the baseline characteristics suggested a more severe course of disease in our sample than that of the AFFIRM trial, data on effectiveness of natalizumab were comparable. At 1 year of treatment we found 80 and 70% patients free from relapses and MRI activity, respectively, that is similar to 75 and 62% detected in the AFFIRM trial. Moreover, only 5% of our patients showed a progression of disability after a mean follow-up time of 15 months. Finally, the presence of antibodies anti-Natalizumab was strongly related to the occurrence of relapses (p = 0.002) and MRI activity (p < 0.001) even in the post-marketing experience.

     

Extra-mammary findings in breast MRI

Objectives  

Incidental extra-mammary findings in breast Magnetic Resonance Imaging (MRI) may be benign in nature, but may also represent a metastasis or another important lesion. We aimed to analyse the prevalence and clinical relevance of these unexpected findings.