Disease Dissemination In Space Research Articles

Demyelinating Disease

The diagnosis of multiple sclerosis (MS) relies on the demonstration of disease dissemination in space and time, and the exclusion of other neurological disorders. However, it is often difficult to exclude alternative diagnoses with a single MRI examination or during a short clinical course. "Red flags" are recommended as clinical and paraclinical indicators that could help suggest alternative diagnoses to MS, and may improve diagnostic accuracy.

Application and a proposed modification of the 2010 McDonald criteria for the diagnosis of multiple sclerosis in a Canadian cohort of patients with clinically isolated syndromes

Background: The 2005 and 2010 McDonald criteria utilize magnetic resonance imaging (MRI) to provide evidence of disease dissemination in space (DIS) and time (DIT) for the diagnosis of multiple sclerosis (MS) in patients who have clinically isolated syndromes (CIS). Methods: Data from 109 CIS patients not satisfying the 2005 criteria at entry into a randomized controlled minocycline trial were analyzed to determine the proportion who would have been diagnosed with MS at screening based on 2010 criteria. The impact of including symptomatic, as well as asymptomatic, MRI lesions to confirm DIT was also explored. Results: Thirty percent (33/109) of patients, retrospectively, met the 2010 criteria for a diagnosis of MS at baseline. When both symptomatic and asymptomatic lesions were used to confirm DIT, three additional patients met the 2010 criteria. There was a significant 10.1% increase in the proportion of patients who met the 2010 DIS criteria, compared with the 2005 DIS criteria; however, two patients satisfied the 2005 DIS but not 2010 DIS criteria. Conclusion: Using 2010 McDonald criteria, 30% of the CIS patients could be diagnosed with MS using a single MRI scan. Inclusion of symptomatic lesions in the DIT criteria further increases this proportion to 33%.

Guidelines from The Italian Neurological and Neuroradiological Societies for the use of magnetic resonance imaging in daily life clinical practice of multiple sclerosis patients

MRI is highly sensitive in detecting focal white matter lesions in multiple sclerosis (MS). For this reason, it has been formally included in the diagnostic workup of patients with clinically isolated syndromes suggestive of MS, through the definition of ad hoc sets of criteria to show disease dissemination in space and time. MRI is used in virtually all clinical trials of the disease as a surrogate measure of treatment response. Several guidelines have been published to help characterizing the imaging features on conventional MR sequences of "typical" MS lesions and work has also been performed to identify "red flags" which should alert the clinicians to exclude possible alternative conditions. Despite this, the application of the available guidelines and criteria in daily life clinical practice is still limited and varies among and within countries (including Italy) due to regulatory issues and heterogeneity of MRI facilities. It is crucial for neurologists and neuroradiologists to become familiar with these criteria to improve the quality of their diagnostic assessment. In patients with established MS, the main problem is to define standard procedures for monitoring the course of the disease and treatment response. This review aims at providing daily life guidelines to clinicians for a correct application of MRI in the workup of patients suspected of having MS as well as in the monitoring of disease evolution in those with established MS. It also offers clues for the standardization of MRI studies and relative reporting to be applied at a national level.

Clinically isolated syndromes suggestive of multiple sclerosis: an optical coherence tomography study.

BackgroundOptical coherence tomography (OCT) is a simple, high-resolution technique to quantify the thickness of retinal nerve fiber layer (RNFL), which provides an indirect measurement of axonal damage in multiple sclerosis (MS). This study aimed to evaluate RNFL thickness in patients at presentation with clinically isolated syndromes (CIS) suggestive of MS.MethodologyThis was a cross-sectional study. Twenty-four patients with CIS suggestive of MS (8 optic neuritis [ON], 6 spinal cord syndromes, 5 brainstem symptoms and 5 with sensory and other syndromes) were prospectively studied. The main outcome evaluated was RNFL thickness at CIS onset. Secondary objectives were to study the relationship between RNFL thickness and MRI criteria for disease dissemination in space (DIS) as well as the presence of oligoclonal bands in the cerebrospinal fluid.Principal FindingsThirteen patients had decreased RNFL thickness in at least one quadrant. Mean RNFL thickness was 101.67±10.72 µm in retrobulbar ON eyes and 96.93±10.54 in unaffected eyes. Three of the 6 patients with myelitis had at least one abnormal quadrant in one of the two eyes. Eight CIS patients fulfilled DIS MRI criteria. The presence of at least one quadrant of an optic nerve with a RNFL thickness at a P<5% cut-off value had a sensitivity of 75% and a specificity of 56% for predicting DIS MRI.ConclusionsThe findings from this study show that axonal damage measured by OCT is present in any type of CIS; even in myelitis forms, not only in ON as seen up to now. OCT can detect axonal damage in very early stages of disease and seems to have high sensitivity and moderate specificity for predicting DIS MRI. Studies with prospective long-term follow-up would be needed to establish the prognostic value of baseline OCT findings.

Intracortical lesions

To generate and validate new MRI diagnostic criteria for multiple sclerosis (MS) taking into account not only white matter lesions but also intracortical lesions (ICLs). Brain double inversion recovery and brain and cord T2- and postcontrast T1-weighted scans were acquired in a training (80 patients with clinically isolated syndromes [CIS], median follow-up = 55.3 months) and a validation (39 patients with CIS, median follow-up = 28.0 months) sample. In the training sample, regression analysis and Cox proportional hazard model were used to identify MRI variables independently predicting the evolution to clinically definite (CD) MS. The best criterion selected was then validated. The performance of the new and previously available MRI criteria for disease dissemination in space (DIS) and time (DIT) were tested. The final multivariate model showed that ≥1 ICL (p < 0.001), ≥1 infratentorial (p = 0.03), and ≥ 1 gadolinium-enhancing or ≥1 spinal cord lesion (p = 0.004) were independent predictors of CDMS. The presence of at least 2 of these variables was the best DIS criterion in both samples. New ICLs had a poor sensitivity for DIT. The combination of the new DIS criterion with the MAGNIMS criteria for DIT yielded to an accuracy of 81%, which was higher than those of the other available criteria. The accuracy of MRI diagnostic criteria for MS is increased when considering the presence of ICLs on baseline scans from patients at presentation with CIS suggestive of MS. If confirmed by other studies, ICL detection might be considered in future diagnostic algorithms for MS.

A three-year, multi-parametric MRI study in patients at presentation with CIS

To define the extent of overall brain damage in patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) and to identify non-conventional magnetic resonance (MR) metrics predictive of evolution to definite MS. Brain conventional and magnetization transfer (MT) MRI scans were obtained from 208 CIS patients and 55 matched healthy controls, recruited in four centres. Patients were assessed clinically at the time of MRI acquisition and after a median period of 3.1 years from disease onset. The following measures were derived: T2, T1 and gadolinium (Gd)- enhancing lesion volumes (LV), normalized brain volume (NBV), MTR histogram-derived quantities of the normal-appearing white matter (NAWM) and grey matter (GM). During the follow-up, 43 % of the patients converted to definite MS. At baseline, a significant inter-centre heterogeneity was detected for T2 LV (p = 0.003), T1 LV (p = 0.006), NBV (p < 0.001) and MTR histogram-derived metrics (p < 0.001). Pooled average MTR values differed between CIS patients and controls for NAWM (p = 0.003) and GM (p = 0.01). Gdactivity and positivity of International Panel (IP) criteria for disease dissemination in space (DIS), but not NAWM and GM MTR and NBV, were associated with evolution to definite MS. The final multivariable model retained only MRI IP criteria for DIS (p = 0.05; HR = 1.66, 95 % CI = 1.00-2.77) as an independent predictor of evolution to definite MS. Although irreversible tissue injury is present from the earliest clinical stages of MS, macroscopic focal lesions but not "diffuse" brain damage measured by MTR are associated to an increased risk of subsequent development of definite MS in CIS patients.

CD8 + T cell activation correlates with disease activity in clinically isolated syndromes and is regulated by interferon-β treatment

An increased percentage of blood CD8 + T cells from patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) was found to express CD26 and CD69. The percentage of CD26 or CD69 positive CD8 + T cells was higher in patients with MRI evidence of disease dissemination in space or with active MRI lesions than in the remaining patients. Treatment of MS with interferon (IFN)-β resulted in a decrease in the percentage of CD26 and CD71 positive CD8 + T cells and an increase in the percentage of CD8 + T cells that expressed interleukin (IL)-10 and IL-13. CD8 + T cell activation in MS may be linked to disease activity already at disease onset, and is regulated by treatment with IFN-β.

Axonal injury in early multiple sclerosis is irreversible and independent of the short-term disease evolution

To define the nature and the temporal evolution of neuronal/axonal injury in patients at the earliest clinical stage of multiple sclerosis (MS), using whole brain N-acetylaspartate (WBNAA) proton MR spectroscopy (1H-MRS). Thirty-five patients at presentation with clinically isolated syndromes (CIS) and MRI evidence of disease dissemination in space were studied. The following scans of the brain were acquired within 3 months from the onset of the disease and after 12 months: 1) dual-echo; 2) WBNAA 1H-MRS; 3) pre- and postcontrast T1-weighted. The same scans were obtained in 12 age-matched healthy subjects, without contrast administration. In patients, conventional MRI scans were also repeated 3 months after the first scanning session, to assess the presence of early disease dissemination in time (DIT). Over the study period, 24 patients showed MRI evidence of disease DIT, thus fulfilling the criteria for a diagnosis of MS. The average WBNAA amount was lower in CIS patients than in controls both at baseline (13.7 vs 16.9 mM, p < 0.001) and at 1-year follow-up (12.6 vs 16.2 mM, p < 0.001), but the average yearly percentage change of WBNAA did not differ between the two groups. No MRI or 1H-MRS quantities were significantly associated with the disease DIT over the study period. Irreversible brain damage associated with axonal dysfunction occurs at a very early stage in patients with clinically isolated syndromes, but it does not seem to be related with the disease evolution in the subsequent short-term period.

Diffusion-Tensor Magnetic Resonance Imaging Detects Normal-Appearing White Matter Damage Unrelated to Short-term Disease Activity in Patients at the Earliest Clinical Stage of Multiple Sclerosis

Diffusion-tensor (DT) magnetic resonance imaging (MRI) has the potential to elucidate some characteristics of tissue microstructure inaccessible to other MRI techniques. To investigate whether normal-appearing brain tissue abnormalities occur in patients with multiple sclerosis at the earliest clinical stage and whether their severity is predictive of a short-term disease evolution by using DT MRI. Forty-five patients and 22 healthy control subjects were studied. All patients had had a clinically isolated syndrome within the 3 months preceding study enrollment and paraclinical evidence of disease dissemination in space. During a single session, dual-echo, pulsed-gradient spin-echo echo-planar, and postgadolinium T1-weighted images of the brain were obtained from each subject. In patients, dual-echo and enhanced images were obtained after 3 and 12 months, to detect MRI signs of disease dissemination in time. An on-study neurological examination was also conducted to ascertain the occurrence of clinical relapses. Mean diffusivity and fractional anisotropy maps were derived from DT images. Normal-appearing white matter (NAWM) and normal-appearing gray matter mean diffusivity and fractional anisotropy histograms were produced and analyzed. During the study period, 29 patients showed MRI evidence of disease dissemination in time. When compared with healthy controls, patients showed higher average NAWM mean diffusivity (P = .01), lower average NAWM mean diffusivity peak height (P < .001), and fractional anisotropy (P < .001). The DT MRI characteristics of patients did not differ between those with and those without disease dissemination in time at follow-up. In patients with multiple sclerosis at the earliest clinical stage, the severity of NAWM damage does not predict new lesion formation in the short term, suggesting that the "diffuse" component of tissue damage is, at least partially, independent of the "discrete," predominantly inflammatory aspects of the disease since its clinical onset.

Frontline: Epitope recognition on the myelin/oligodendrocyte glycoprotein differentially influences disease phenotype and antibody effector functions in autoimmune demyelination.

Preliminary observations of humoral immunity against the myelin oligodendrocyte glycoprotein (MOG) in experimental allergic encephalomyelitis (EAE) and human multiple sclerosis (MS) suggest that a subset of anti-MOG autoantibodies directed against conformational epitopes is of pathogenic predominance. Here, we provide proof that in marmoset EAE, autoantibodies reactive against conformational epitopes of MOG are not only responsible for aggravating demyelination, but also an essential factor for disease dissemination in space within the central nervous system, a hallmark for typical forms of human MS. In terms of effector mechanisms, IgG deposition and complement activation occur exclusively in association with presence of these conformational antibodies, while microglial/macrophage activation appears to be a common immunopathological finding regardless of the fine determinant specificity of anti-MOG antibodies. These findings highlight for the first time the complex heterogeneity of function and pathogenicity in the polyclonal anti-MOG antibody repertoire of outbred species. Because the linear and conformational antibody determinants of MOG are shared between marmosets and humans, these results are directly relevant to understanding effector mechanisms of organ damage in MS.