Eleonora Tavazzi

Postinfectious inflammatory disorders Subgroups based on prospective follow-up

Background: Acute disseminated encephalomyelitis (ADEM) refers to a monophasic acute multifocal inflammatory CNS disease. However, both relapsing and site-restricted variants, possibly associated with peripheral nervous system (PNS) involvement, are also observed, and a systematic classification is lacking. Objective: To describe a cohort of postinfectious ADEM patients, to propose a classification based on clinical and instrumental features, and to identify subgroups of patients with different prognostic factors. Methods: Inpatients of a Neurologic and Infectious Disease Clinic affected by postinfectious CNS syndrome consecutively admitted over 5 years were studied. Results: Of 75 patients enrolled, 60 fulfilled criteria for ADEM after follow-up lasting from 24 months to 7 years. Based on lesion distribution, patients were classified as encephalitis (20%), myelitis (23.3%), encephalomyelitis (13.3%), encephalomyeloradiculoneuritis (26.7%), and myeloradiculoneuritis (16.7%). Thirty patients (50%) had a favorable outcome. Fifteen patients (25%) showed a relapsing course. Poor outcome was related with older age at onset, female gender, elevated CSF proteins, and spinal cord and PNS involvement. All but two patients received high-dose steroids as first-line treatment, with a positive response in 39 (67%). Ten of 19 nonresponders (53%) benefited from high-dose IV immunoglobulin; 9 of 10 had PNS involvement. The data were not controlled. Conclusions: A high prevalence of “atypical variants” was found in this series, with site-restricted damage or additional peripheral nervous system (PNS) involvement. Prognosis and response to steroids were generally good, except for some patient subgroups. In patients with PNS involvement and steroid failure, a favorable effect of IV immunoglobulin was observed.

Diffusion-weighted imaging predicts cognitive impairment in multiple sclerosis

Following a previous study with diffusion tensor imaging, we investigated the correlation between diffusion-weighted imaging (DWI) and cognitive dysfunction in multiple sclerosis (MS). We studied 60 MS patients (mean age 45.8±9.0 years) using 1.5-T MRI. Disease course was RR=40 and SP = 20. Mean disease duration was 12.8±8.7 years. Mean EDSS was 3.4±1.7. Whole brain, gray and white matter normalized volumes were calculated on 3D SPGR T1-WI using a fully automated Hybrid SIENAX method. Parenchymal mean diffusivity (PMD) maps were created after automated segmentation of the brain parenchyma and cerebrospinal fluid using T2-WI and DW images. Histogram analysis was performed and DWI indices of peak position (PP), peak height (PH), mean parenchymal diffusivity (MPD) and entropy were obtained. Neuropsychological (NP) evaluation emphasized auditory/verbal and visual/spatial memory, as well as processing speed and executive function. We found significant correlations between DWI and performance in all cognitive domains. Overall, stronger correlations emerged for MPD and entropy than other DWI measures, although all correlations were in the expected direction. The strongest association was between DWI entropy and performance on the Symbol Digit Modalities Test, which assesses processing speed and working memory (r = -0.54). Fisher r to z transformations revealed that DWI, gray matter (GMF) and whole brain (BPF) atrophy, T1-lesion volume (LV) and T2-LV all accounted for similar amounts of variance in NP testing. Stepwise regression models determined whether multiple MRI measures predicted unique additive variance in test performance. GMF (R2 = 0.35, F =30.82, P <0.01) and entropy (ΔR2 =0.06, ΔF=5.47, P <0.05) both accounted for unique variance in processing speed. Our data make a stronger case for the clinical validity of DWI in MS than heretofore reported. DWI has very short acquisition times, and the segmentation method applied in the present study is reliable and fully automated. Given its overall simplicity and moderate correlation with cognition, DWI may offer several logistic advantages over more traditional MRI measures when predicting the presence of NP impairment. Multiple Sclerosis 2007; 13: 722-730. http://msj.sagepub.com

Oligoclonal bands in Devic’s neuromyelitis optica and multiple sclerosis: differences in repeated cerebrospinal fluid examinations:

We studied repeated cerebrospinal fluids of patients with Devic’s neuromyelitis optica (NMO) and multiple sclerosis (MS). Variations of oligoclonal bands (OBs) had opposite trends in the two groups. In MS, O Bs were detected in 399 of 411 patients (97%) and never disappeared. In NMO, O Bs were detected in three of 11 patients (27%) and always disappeared. The hypothesis that NMO and MS follow distinct patho genetic pathways is supported by our findings, which can be useful for the differentiatio n of NMO from MS.

Cytokines and chemokines in cerebrospinal fluid and serum of adult patients with acute disseminated encephalomyelitis.

Cytokines and chemokines contribute to the pathogenesis of acute disseminated encephalomyelitis (ADEM). Using a multiplex immunochemiluminescence ELISA, we measured 8 Th1/Th2 cytokines and 18 chemokines in the cerebrospinal fluid (CSF) and serum of 17 ADEM patients, 14 multiple sclerosis (MS) patients, and 7 healthy controls (HCs). Relative to HCs, ADEM patients had significantly high mean CSF concentrations of chemokines with attractant/activating properties towards neutrophils (CXCL1 and CXCL7), monocytes/T cells (CCL3 and CCL5), Th1 cells (CXCL10), and Th2 cells (CCL1, CCL22, and CCL17). Mean CSF concentrations of CXCL7, CCL1, CCL22, and CCL17 were higher in ADEM than in MS, whereas those of CCL11 were lower in MS than in ADEM and HCs. CSF pleocytosis correlated with CSF concentrations of CXCL1, CXCL10, CCL1, CCL17, and CCL22. Most of the functionally homologous chemokines correlated with each other. CSF Th1/Th2 cytokines were not detectable in most samples. Their mean concentrations did not differ in the three groups, and the same held for serum cytokines and chemokines. Our data suggest that the upregulation of chemokines active on neutrophils and Th2 cells differentiates ADEM from MS inflammation, and that both Th1 and Th2 chemokines might be produced in ADEM. Chemokines upregulated in ADEM could become CSF biomarkers after a posteriori evaluations in unselected case series.

Quantitative diffusion weighted imaging measures in patients with multiple sclerosis.

Diffusion-weighted imaging (DWI) has been proposed as a sensitive measure of disease severity capable of detecting subtle changes in gray matter and white matter brain compartments in patients with multiple sclerosis (MS). However, DWI has been applied to the study of MS clinical subtypes in only a few studies. The objective of this study was to demonstrate the validity of a novel, fully automated method for the calculation of quantitative DWI measures. We also wanted to assess the correlation between whole brain (WB)-DWI variables and clinical and MRI measures of disease severity in a large cohort of MS patients. For this purpose we studied 432 consecutive MS patients (mean age 44.4+/-10.2 years), 16 patients with clinically isolated syndrome (CIS) and 38 normal controls (NC) using 1.5 T brain MRI. Clinical disease subtypes were as follows: 294 relapsing-remitting (RR), 123 secondary-progressive (SP) and 15 primary-progressive (PP). Mean disease duration was 12+/-10 years. Mean Expanded Disability Status Scale (EDSS) was 3.3+/-2.1. Brain parenchymal fraction (BPF), gray matter fraction (GMF) and white matter fraction (WMF) were calculated using a fully automated method. Mean parenchymal diffusivity (MPD) maps were created. DWI indices of peak position (PP), peak height (PH), MPD and entropy (ENT) were obtained. T2- and T1-lesion volumes (LV), EDSS, ambulation index (AI) and nine-hole peg test (9-HPT) were also assessed. MS patients had significantly lower BPF (d=1.26; p<0.001) and GMF (d=0.61; p=0.003), and higher ENT (d=1.2; p<0.0001), MPD (d=1.04; p<0.0001) and PH (d=0.47; p=0.045) than NC subjects. A GLM analysis, adjusted for age and multiple comparisons, revealed significant differences between different clinical subtypes for BPF, GMF, ENT, PH, PP, T2-LV and T1-LV (p<0.0001), WMF (p=0.001) and MPD (p=0.023). In RR and SP MS patients, ENT showed a more robust correlation with other MRI (r=0.54 to 0.67, p<0.0001) and clinical (r=0.31 to 0.36, p<0.0001) variables than MPD (r=0.23 to 0.41, p<0.001 for MRI and r=0.13 to 0.18; p=0.006 to p<0.001 for clinical variables). The GMF and BPF showed a slightly stronger relationship with all clinical variables (r=0.33 to 0.48; p<0.0001), when compared to both lesion and DWI measures. ENT (R2=0.28; p<0.0001) and GMF (R2=0.26; p<0.001) were best related with SP disease course. This study highlights the validity of DWI in discerning differences between NC and MS patients, as well as between different MS subtypes. ENT is a sensitive marker of overall brain damage that is strongly related to clinical impairment in patients with SP MS.

Early prediction of the long term evolution of multiple sclerosis: the Bayesian Risk Estimate for Multiple Sclerosis (BREMS) score

Aim: To propose a simple tool for early prediction of unfavourable long term evolution of multiple sclerosis (MS). Methods: A Bayesian model allowed us to calculate, within the first year of disease and for each patient, the Bayesian Risk Estimate for MS (BREMS) score that represents the risk of reaching secondary progression (SP). Results: The median BREMS scores were higher in 158 patients who reached SP within 10 years compared with 1087 progression free patients (0.69 vs 0.30; p<0.0001). The BREMS value was related to SP risk in the whole cohort (p<0.0001) and in the subgroup of 535 patients who had never been treated with immune therapies, thus reasonably representing the natural history of the disease (p<0.000001). Conclusions: The BREMS score may be useful both to identify patients who are candidates for early or for more aggressive therapies and to improve the design and analysis of clinical therapeutic trials and of observational studies.

Advanced magnetic resonance imaging of neuromyelitis optica: a multiparametric approach

Background: Several authors have used advanced magnetic resonance imaging (MRI) techniques to investigate whether patients with neuromyelitis optica (NMO) have occult damage in normal-appearing brain tissue, similarly to multiple sclerosis (MS). To date, the literature contains no data derived from the combined use of several advanced MRI techniques in the same NMO subjects. Objective: We set out to determine whether occult damage could be detected in the normal-appearing brain tissue of a small group of patients with NMO using a multiparametric MRI approach. Methods: Eight female patients affected by NMO (age range 44–58 years) and seven sex- and age-matched healthy controls were included. The techniques used on a 1.5 T MRI imaging scanner were magnetization transfer imaging, diffusion tensor imaging, tract-based spatial statistics, spectroscopy and voxel-based morphometry in order to analyse normal-appearing white matter and normal-appearing grey matter. Results: Structural and metabolic parameters showed no abnormalities in normal-appearing white matter of patients with NMO. Conversely, tract-based spatial statistics demonstrated a selective alteration of the optic pathways and the lateral geniculate nuclei. Diffusion tensor imaging values in the normal-appearing grey matter were found to be significantly different in the patients with NMO versus the healthy controls. Moreover, voxel-based morphometry analysis demonstrated a significant density and volume reduction of the sensorimotor cortex and the visual cortex. Conclusions: Our data disclosed occult structural damage in the brain of patients with NMO, predominantly involving regions connected with motor and visual systems. This damage seems to be the direct consequence of transsynaptic degeneration triggered by lesions of the optic nerve and spine.

Severe steroid-resistant post-infectious encephalomyelitis: General features and effects of IVIg

Based on their presumed immuno-mediated etiology, post-infectious CNS disorders are commonly treated with high-dose steroids. Factors influencing treatment effectiveness, possible alternative options for steroid-resistant cases, and their outcome profiles, remain unclear. We here describe the clinical features, the prognosis and the efficacy of i. v. immunoglobulins (IVIg) in a series of severe ADEM refractory to steroids. We performed an inception cohort study on inpatients of the Neurologic and Infectious Disease Clinics, consecutively admitted over eight years, with a minimum two-year follow-up. Nineteen patients affected by classic and site-restricted ADEM were treated with IVIg after steroid failure. Five other patients received IVIg as first-line treatment due to steroids contraindications: although not included in the analysis, they were monitored for anecdotal comparison. Steroids were administered as IV 6-methylprednisolone (6-MP) 500/1000 mg daily until a maximum dose of 6–8 g; IVIg were administered at 0.4 g/kg/day for 5 days. The outcome was assessed by the Scripps Neurological Rating Scale (SNRS) score with determined periodicity. We observed that steroid-resistant patients showed high prevalence of PNS damage (89%) and myelitis (95 %). Other features were old age, severe disability at onset, and moderate to severe blood-brain-barrier (BBB) damage on CSF. In 10/19 patients (53 %) IVIg were effective, the clinical improvement beginning within the end of the five-day cycle,without relapses. Prominent effects of IVIg were detectable on motor dysfunction. Milder onset disability (p = 0.013) and lower CSF albumin (p = 0.006) were the predictors of IVIg response.Among steroid-free patients, 3/5 were responsive to IVIg. We conclude that IVIg can be useful in a portion of patients with severe steroid-resistant ADEM and prominent motor dysfunction. Unsolved issues regard the usefulness of IVIg in less selected groups, and the spectrum of their clinical effects.

Immunomodulatory therapies delay disease progression in multiple sclerosis.

Background: Few studies have analysed long-term effects of immunomodulatory disease modifying drugs (DMDs). Objective: Assessment of the efficacy of DMDs on long-term evolution of multiple sclerosis, using a Bayesian approach to overcome methodological problems related to open-label studies. Methods: MS patients from three different Italian multiple sclerosis centres were divided into subgroups according to the presence of treatment in their disease history before the endpoint, which was represented by secondary progression. Patients were stratified on the basis of the risk score BREMS (Bayesian risk estimate for multiple sclerosis), which is able to predict the unfavourable long-term evolution of MS at an early stage. Results: We analysed data from 1178 patients with a relapsing form of multiple sclerosis at onset and at least 10 years of disease duration, treated (59%) or untreated with DMDs. The risk of secondary progression was significantly lower in patients treated with DMDs, regardless of the initial prognosis predicted by BREMS. Conclusions: DMDs significantly reduce the risk of multiple sclerosis progression both in patients with initial high-risk and patients with initial low-risk. These findings reinforce the role of DMDs in modifying the natural course of the disease, suggesting that they have a positive effect not only on the inflammatory but also on the neurodegenerative process. The study also confirms the capability of the BREMS score to predict MS evolution.

Postinfectious neurologic syndromes A prospective cohort study

Objectives: Postinfectious neurologic syndromes (PINSs) of the CNS include heterogeneous disorders, sometimes relapsing. In this study, we aimed to a) describe the spectrum of PINSs; b) define predictors of outcome in PINSs; and c) assess the clinical/paraclinical features that help differentiate PINSs from multiple sclerosis (MS). Methods: In this prospective cohort study, adult inpatients with PINSs underwent extensive diagnostic assessment and therapeutic protocols at inclusion and during a minimum 2-year follow-up. We compared them with newly diagnosed, treatment-naive patients with MS, also prospectively recruited. Results: The study sample comprised 176 patients with PINSs aged 59.9 ± 17.25 years (range: 18–80 years) divided into 2 groups: group 1 (CNS syndromes, 64%)—encephalitis, encephalomyelitis, or myelitis; and group 2 (CNS + peripheral nervous system [PNS] syndromes, 36%)—encephalomyeloradiculoneuritis or myeloradiculoneuritis. We observed the patients for 24 to 170 months (median 69 months). Relapses, almost invariably involving the spinal cord, occurred in 30.5%. PNS involvement was an independent risk factor for relapses (hazard ratio 2.8). The outcome was poor in 43% of patients; risk factors included older age, greater neurologic disability at onset, higher serum-CSF albumin percentage transfer, myelitis, and PNS involvement. Steroid resistance occurred in 30% of the patients, half of whom responded favorably to IV immunoglobulins. Compared with MS, PINSs were characterized by older age, lower tendency to relapse, and distinct CSF findings. Conclusions: The category of PINSs should be revised: most of the clinical variants have a poor prognosis and are not readily classifiable on the basis of current knowledge. PNS involvement has a critical role in relapses, which seem to affect the spine only.