Carla Tortorella

Course and prognosis in early-onset MS Comparison with adult-onset forms

Objectives: To establish the prognostic role of clinical and demographic factors in a hospital-based cohort of MS patients categorized by age at clinical onset and clinical course. Methods: Eighty-three patients with MS had a clinical onset of the disease in childhood (age <16 years; early-onset MS [EOMS]) and 710 in adult age (between 16 and 65 years; adult-onset MS [AOMS]). Patients were followed for a mean period of observation of 5 years. Univariate and multivariate analyses of clinical and demographic predictors for rapid progression and disability were performed using a stepwise Cox regression model with time-dependent covariates. Results: In EOMS, the Expanded Disability Status Scale (EDSS) evaluated at last clinical examination was lower than in AOMS, despite a longer disease duration. The probability to reach growth disability and progression was significantly lower in EOMS than in AOMS. Median times to reach EDSS score of 4 and secondary progression were longer in EOMS than in AOMS, but the age at both endpoints was significantly lower in EOMS. In EOMS and AOMS, an irreversible disability was related to a secondary progressive course, a sphincteric system involvement at onset, and an older age at onset (in EOMS only for the group >14 years); in AOMS, other unfavorable factors were a pyramidal involvement at onset and a high relapse frequency in the first 2 years. The risk of entering secondary progression was significantly influenced by a high number of relapses in EOMS and by a higher age at onset and a short interattack interval in AOMS. Conclusion: A slower rate of progression of disease characterized EOMS patients, suggesting more plasticity to recover in developing CNS, but the early clinical manifestation cannot be considered a positive prognostic factor.

Comparison of MS clinical phenotypes using conventional and magnetization transfer MRI.

Objective: To identify differences in pathology between the principal clinical phenotypes of MS using conventional and magnetization transfer (MT) MRI. Methods: T1-weighted and T2-weighted images as well as MT scans were obtained from 20 controls, 21 patients presenting with clinically isolated syndromes suggestive of MS, and 93 MS patients with relapsing-remitting, secondary progressive, benign, or primary progressive course. Metrics considered: hypointense T1 and T2 lesion volumes, average lesion MT ratio, average brain MT ratio, peak height and position from MT histograms. Results: MS patients had lower MT metrics than controls. Patients with clinically isolated syndromes had MT measures similar to controls, whereas primary progressive MS patients had lower histogram peak height with normal peak position. Relapsing-remitting MS patients had lower MT measures, higher T2 lesion load and ratio of hypointense T1 to T2 lesion volumes than patients with clinically isolated syndromes, and lower MT ratio and peak height than benign MS patients. Benign MS patients were similar to controls and patients with clinically isolated syndromes. Secondary progressive MS patients had the lowest MT measures and highest lesion loads. Conclusions: Pathology in patients with clinically isolated syndromes is confined to modest tissue damage in the lesions seen on T2-weighted scans. Severe damage is important for the later development of disability. However, microscopic damage in normal-appearing white matter may be a major contributor to disability in primary progressive MS.

Changes in the normal appearing brain tissue and cognitive impairment in multiple sclerosis

OBJECTIVES To assess (a) whether the changes in the normal appearing brain tissue (NABT), as revealed by magnetisation transfer (MT) histogram analysis, correlates with cognitive dysfunction in patients with multiple sclerosis and (b) the relative contribution of these changes by comparison with that of multiple sclerosis lesions visible on conventional MRI. METHODS Dual echo, T1 weighted and MT scans of the brain were obtained in 12 patients with multiple sclerosis with cognitive impairment and in seven without cognitive impairment. Lesion loads were assessed from T2 and T1 weighted scans. To create MT histograms of the NABT, multiple sclerosis lesion outlines from dual echo scans were superimposed automatically and nulled out from the coregistered and scalp stripped MTR maps. Average lesion MT ratio (MTR) and brain size were also measured. RESULTS T2 and T1 lesion loads were significantly higher and the average lesion MTR and brain size were significantly lower in the group of cognitively impaired patients. Patients with cognitive deficits also had significantly lower average MTR and peak location of the NABT histogram. Logistic regression analysis showed that 68% of the total variance was explained by average NABT-MTR alone. A multivariable regression model showed that NABT-MTR was the only factor that significantly correlated with cognitive impairment in these patients (p=0.001). CONCLUSIONS The extent of abnormalities which go undetected when using conventional MRI is relevant in determining cognitive impairment in multiple sclerosis.

A magnetization transfer histogram study of normal-appearing brain tissue in MS

Objective: To evaluate 1) the ability of magnetization transfer ratio (MTR) histogram analysis to detect the extent of changes occurring outside MS lesions seen on conventional scans, 2) whether such changes vary in the different MS clinical phenotypes, 3) whether the changes are associated with the extent and severity of the macroscopic lesion load, and 4) the contribution to brain atrophy. Methods: Dual-echo, T1-weighted, and MT scans of the brain were obtained from 77 patients with varying MS courses and 20 age- and sex-matched control subjects. To create MT histograms of the normal-appearing cerebral tissue, MS lesions were segmented from dual-echo scans, superimposed automatically, and nulled out from the coregistered and scalp-stripped MTR maps. Average MTR, peak height, and peak position were considered. T2 and T1 lesion loads, average lesion MTR, and brain volume were also measured. Results: Average histogram MTR (p < 0.0001) and peak position (p < 0.0001) from patients with relapsing–remitting MS (RMMS) were lower than those from control subjects. Patients with primary progressive MS (PPMS) had lower average histogram MTR (p = 0.002) and histogram peak height (p = 0.01) than control subjects. Patients with secondary progressive MS (SPMS) had a lower peak height (p = 0.05) than those with RRMS. Average lesion MTR (p < 0.0001) correlated highly with the histogram MTR. Average histogram MTR (p < 0.0001) and T2 lesion load (p = 0.001) correlated highly with brain volume. Conclusions: The amount of microscopic changes account for an important fraction of the lesion load in MS. They may contribute to the development of brain atrophy and tend to be more evident in patients with secondary progressive MS.

Geographical variations in sex ratio trends over time in multiple sclerosis

Background A female/male (F/M) ratio increase over time in multiple sclerosis (MS) patients was demonstrated in many countries around the world. So far, a direct comparison of sex ratio time-trends among MS populations from different geographical areas was not carried out. Objective In this paper we assessed and compared sex ratio trends, over a 60-year span, in MS populations belonging to different latitudinal areas. Methods Data of a cohort of 15,996 (F = 11,290; M = 4,706) definite MS with birth years ranging from 1930 to 1989 were extracted from the international MSBase registry and the New Zealand MS database. Gender ratios were calculated by six decades based on year of birth and were adjusted for the F/M born-alive ratio derived from the respective national registries of births. Results Adjusted sex ratios showed a significant increase from the first to the last decade in the whole MS sample (from 2.35 to 2.73; p = 0.03) and in the subgroups belonging to the areas between 83° N and 45° N (from 1.93 to 4.55; p<0.0001) and between 45° N to 35° N (from 1.46 to 2.30; p<0.05) latitude, while a sex ratio stability over time was found in the subgroup from areas between 12° S and 55° S latitude. The sex ratio increase mainly affected relapsing-remitting (RR) MS. Conclusions Our results confirm a general sex ratio increase over time in RRMS and also demonstrate a latitudinal gradient of this increase. These findings add useful information for planning case-control studies aimed to explore sex-related factors responsible for MS development.

Aquaporin-4 orthogonal arrays of particles are the target for neuromyelitis optica autoantibodies

Neuromyelitis optica (NMO) is an inflammatory autoimmune demyelinating disease of the central nervous system (CNS) which in autoantibodies produced by patients with NMO (NMO‐IgG) recognize a glial water channel protein, Aquaporin‐4 (AQP4) expressed as two major isoforms, M1‐ and M23‐AQP4, in which the plasma membrane form orthogonal arrays of particles (OAPs). AQP4‐M23 is the OAP‐forming isoform, whereas AQP4‐M1 alone is unable to form OAPs. The function of AQP4 organization into OAPs in normal physiology is unknown; however, alteration in OAP assemblies is reported for several CNS pathological states. In this study, we demonstrate that in the CNS, NMO‐IgG is able to pull down both M1‐ and M23‐AQP4 but experiments performed using cells selectively transfected with M1‐ or M23‐AQP4 and native tissues show NMO‐IgG epitope to be intrinsic in AQP4 assemblies into OAPs. Other OAP‐forming water‐channel proteins, such as the lens Aquaporin‐0 and the insect Aquaporin‐cic, were not recognized by NMO‐IgG, indicating an epitope characteristic of AQP4‐OAPs. Finally, water transport measurements show that NMO‐IgG treatment does not significantly affect AQP4 function. In conclusion, our results suggest for the first time that OAP assemblies are required for NMO‐IgG to recognize AQP4.

Real-life impact of early interferonβ therapy in relapsing multiple sclerosis

Recent findings support greater efficacy of early vs. delayed interferon beta (IFNβ) treatment in patients with a first clinical event suggestive of multiple sclerosis (MS). We aimed to evaluate the effectiveness of early IFNβ treatment in definite relapsing‐remitting MS (RRMS) and to assess the optimal time to initiate IFNβ treatment with regard to the greatest benefits on disability progression.

Localised 1H-MR spectroscopy for metabolic characterisation of diffuse and focal brain lesions in patients infected with HIV

OBJECTIVES To evaluate the role of proton MR spectroscopy (1H-MRS) in detecting metabolic changes in diffuse or focal lesions in the brain of patients infected with HIV. METHODS Sixty HIV seropositive patients (25 with HIV related encephalopathies, 20 with toxoplasmosis, eight with progressive multifocal leukoencephalopathies (PMLs), and seven with lymphomas) and 22 HIV seronegative neurological controls were examined with a combined MRI and1H-MRS technique using a Siemens 1.5 Tesla Magnetom. Spectra (Spin Echo sequence, TE 135 ms) were acquired by single voxel, localised on focal lesions in toxoplasmosis, PML, lymphomas, and HIV encephalopathies and on the centrum semiovale of neurological controls. Choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate, and lipids were evaluated in each spectrum and NAA/Cr, NAA/Cho, and Cho/Cr ratios were calculated. RESULTS A significant decrease in NAA/Cr and NAA/Cho ratios were found in all HIV diagnostic groups in comparison with neurological controls (p<0.003), suggesting neuronal or axonal damage independent of brain lesion aetiology. However, the NAA/Cr ratio was significantly lower in PML and lymphomas than in HIV encephalopathies (p<0.02) and toxoplasmosis (p<0.05). HIV encephalopathies, lymphomas, and toxoplasmosis showed a significant increase in the Cho/Cr ratio in comparison with neurological controls (p<0.03) without between group differences. The presence of a lipid signal was more frequent in lymphomas (71%) than in other HIV groups (Fisher’s test, p=0.00003). The presence of mobile lipid resonance together with a high Cho/Cr ratio in lymphomas may be related to an increased membrane synthesis and turnover in tumour cells. A lactate signal (marker of inflammatory reaction), was found in all but one patient with PML lesions (75%), but had a lower incidence in the other HIV diagnostic groups (Fisher’s test, p=0.00024). CONCLUSION 1H-MRS shows a high sensitivity in detecting brain involvement in HIV related diseases, but a poor specificity in differential diagnosis of HIV brain lesions. Nevertheless, the homogeneous metabolic pattern that characterises PML suggests the usefulness of 1H-MRS as an adjunct to MRI in differentiating CNS white matter lesions, such as HIV encephalopathies, from PML.

Serum MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in multiple sclerosis: relationships with different magnetic resonance imaging measures of disease activity during IFN-beta-1a treatment

Matrix metalloproteinase-9 (MMP-9) is involved in blood-brain barrier (BBB) disruption in active multiple sclerosis (MS), while MMP-2 seems to be associated with the chronic progressive phase of the disease. Recombinant interferon beta-1a (rIFNβ-1a) is effective in restoring the BBB. We studied the relationships between serum MMP-9, MMP-2, TIMP-1 and TIMP-2 and different magnetic resonance imaging (MRI) measures of disease activity in MS patients during treatment with rIFNβ-1a. Twenty-one relapsing-remitting (RR) MS patients underwent longitudinally simultaneous blood withdrawals and MRI (before and after standard dose (SD) and triple dose (TD) of gadolinium (Gd)) examinations before and during 48 weeks of rIFNβ-1a (Rebif® 22 mcg three times a week) treatment. Serum MMP-9, MMP-2, TIMP-1 and TIMP-2 were measured, MMP-9 to TIMP-1 and MMP-2 to TIMP-2 ratios were calculated and the numbers of Gd-SD, Gd-TD, new-Gd-SD, new-Gd-TD and new-T2 lesions counted. Serum MMP-9/TIMP-1 ratio (P< 0.0001), as well as the numbers of ‘active’ lesions (P ranging from 0.0004 to 0.005) decreased during treatment. Moreover, serum MMP-9/TIMP-1 ratio proved to be a good positive predictor (estimate= 0.85; P> 0.05) of the numbers of MRI Gd-TD active lesions. These data confirm that serum MMP-9/TIMP-1 ratio may be viewed as a reliable marker and may be predictive of MRI activity in RR MS.

Normal-appearing white matter changes in multiple sclerosis: the contribution of magnetic resonance techniques

Several magnetic resonance (MR) techniques have proved to be sensitive enough to detect the subtle pathological changes that post-mortem studies showed to occur in the normal-appearing white matter (NAWM) from patients with multiple sclerosis (MS). Although these abnormalities can be detected in other neurological conditions, they seem to be more frequent and diffuse in MS. However, the contribution of NAWM changes to the diagnosis is still unclear. Their nature is also unknown and perhaps differs in different phases and clinical manifestations of the disease. Nevertheless, the extent and severity of NAWM damage seems to be relevant in causing disability and influencing the clinical evolution in MS patients. This review will summarize the present knowledge about MR-detected NAWM changes in MS and their relevance to the diagnosis and the understanding of disease evolution.