Longitudinal Metabolite Changes in Progressive Multiple Sclerosis: A Study of 3 Potential Neuroprotective Treatments

BACKGROUND

1H-magnetic resonance spectroscopy (1H-MRS) may provide a direct index for the testing of medicines for neuroprotection and drug mechanisms in multiple sclerosis (MS) through measures of total N-acetyl-aspartate (tNAA), total creatine (tCr), myo-inositol (mIns), total-choline (tCho), and glutamate + glutamine (Glx). Neurometabolites may be associated with clinical disability with evidence that baseline neuroaxonal integrity is associated with upper limb function and processing speed in secondary progressive MS (SPMS).

PURPOSE

To assess the effect on neurometabolites from three candidate drugs after 96-weeks as seen by 1H-MRS and their association with clinical disability in SPMS.

STUDY-TYPE

Longitudinal.

POPULATION

108 participants with SPMS randomized to receive neuroprotective drugs amiloride [mean age 55.4 (SD 7.4), 61% female], fluoxetine [55.6 (6.6), 71%], riluzole [54.6 (6.3), 68%], or placebo [54.8 (7.9), 67%].

FIELD STRENGTH/SEQUENCE

3-Tesla. Chemical-shift-imaging 2D-point-resolved-spectroscopy (PRESS), 3DT1.

ASSESSMENT

Brain metabolites in normal appearing white matter (NAWM) and gray matter (GM), brain volume, lesion load, nine-hole peg test (9HPT), and paced auditory serial addition test were measured at baseline and at 96-weeks.

STATISTICAL TESTS

Paired t-test was used to analyze metabolite changes in the placebo arm over 96-weeks. Metabolite differences between treatment arms and placebo; and associations between baseline metabolites and upper limb function/information processing speed at 96-weeks assessed using multiple linear regression models. P-value<0.05 was considered statistically significant.

RESULTS

In the placebo arm, tCho increased in GM (mean difference = -0.32 IU) but decreased in NAWM (mean difference = 0.13 IU). Compared to placebo, in the fluoxetine arm, mIns/tCr was lower (β = -0.21); in the riluzole arm, GM Glx (β = -0.25) and Glx/tCr (β = -0.29) were reduced. Baseline tNAA(β = 0.22) and tNAA/tCr (β = 0.23) in NAWM were associated with 9HPT scores at 96-weeks.

DATA CONCLUSION

1H-MRS demonstrated altered membrane turnover over 96-weeks in the placebo group. It also distinguished changes in neuro-metabolites related to gliosis and glutaminergic transmission, due to fluoxetine and riluzole, respectively. Data show tNAA is a potential marker for upper limb function.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 4.

Predictive value of retinal atrophy for cognitive decline across disease duration in multiple sclerosis

BACKGROUND

We investigated the association between changes in retinal thickness and cognition in people with MS (PwMS), exploring the predictive value of optical coherence tomography (OCT) markers of neuroaxonal damage for global cognitive decline at different periods of disease.

METHOD

We quantified the peripapillary retinal nerve fibre (pRFNL) and ganglion cell-inner plexiform (GCIPL) layers thicknesses of 207 PwMS and performed neuropsychological evaluations. The cohort was divided based on disease duration (≤5 years or >5 years). We studied associations between changes in OCT and cognition over time, and assessed the risk of cognitive decline of a pRFNL≤88 µm or GCIPL≤77 µm and its predictive value.

RESULTS

Changes in pRFNL and GCIPL thickness over 3.2 years were associated with evolution of cognitive scores, in the entire cohort and in patients with more than 5 years of disease (p<0.01). Changes in cognition were related to less use of disease-modifying drugs, but not OCT metrics in PwMS within 5 years of onset. A pRFNL≤88 µm was associated with earlier cognitive disability (3.7 vs 9.9 years) and higher risk of cognitive deterioration (HR=1.64, p=0.022). A GCIPL≤77 µm was not associated with a higher risk of cognitive decline, but a trend was observed at ≤91.5 µm in PwMS with longer disease (HR=1.81, p=0.061).

CONCLUSIONS

The progressive retinal thinning is related to cognitive decline, indicating that cognitive dysfunction is a late manifestation of accumulated neuroaxonal damage. Quantifying the pRFNL aids in identifying individuals at risk of cognitive dysfunction.

What contributes to disability in progressive MS? A brain and cervical cord-matched quantitative MRI study

BACKGROUND

We assessed the ability of a brain-and-cord-matched quantitative magnetic resonance imaging (qMRI) protocol to differentiate patients with progressive multiple sclerosis (PMS) from controls, in terms of normal-appearing (NA) tissue abnormalities, and explain disability.

METHODS

A total of 27 patients and 16 controls were assessed on the Expanded Disability Status Scale (EDSS), 25-foot timed walk (TWT), 9-hole peg (9HPT) and symbol digit modalities (SDMT) tests. All underwent 3T brain and (C2-C3) cord structural imaging and qMRI (relaxometry, quantitative magnetisation transfer, multi-shell diffusion-weighted imaging), using a fast brain-and-cord-matched protocol with brain-and-cord-unified imaging readouts. Lesion and NA-tissue volumes and qMRI metrics reflecting demyelination and axonal loss were obtained. Random forest analyses identified the most relevant volumetric/qMRI measures to clinical outcomes. Confounder-adjusted linear regression estimated the actual MRI-clinical associations.

RESULTS

Several qMRI/volumetric differences between patients and controls were observed (p < 0.01). Higher NA-deep grey matter quantitative-T1 (EDSS: beta = 7.96, p = 0.006; 9HPT: beta = -0.09, p = 0.004), higher NA-white matter orientation dispersion index (TWT: beta = -3.21, p = 0.005; SDMT: beta = -847.10, p < 0.001), lower whole-cord bound pool fraction (9HPT: beta = 0.79, p = 0.001) and higher NA-cortical grey matter quantitative-T1 (SDMT = -94.31, p < 0.001) emerged as particularly relevant predictors of greater disability.

CONCLUSION

Fast brain-and-cord-matched qMRI protocols are feasible and identify demyelination - combined with other mechanisms - as key for disability accumulation in PMS.

Treatment reduces the incidence of newly appearing multiple sclerosis lesions evolving into chronic active, slowly expanding lesions: A retrospective analysis

BACKGROUND AND PURPOSE

Newly appearing lesions in multiple sclerosis (MS) may evolve into chronically active, slowly expanding lesions (SELs), leading to sustained disability progression. The aim of this study was to evaluate the incidence of newly appearing lesions developing into SELs, and their correlation to clinical evolution and treatment.

METHODS

A retrospective analysis of a fingolimod trial in primary progressive MS (PPMS; INFORMS, NCT00731692) was undertaken. Data were available from 324 patients with magnetic resonance imaging scans up to 3 years after screening. New lesions at year 1 were identified with convolutional neural networks, and SELs obtained through a deformation-based method. Clinical disability was assessed annually by Expanded Disability Status Scale (EDSS), Nine-Hole Peg Test, Timed 25-Foot Walk, and Paced Auditory Serial Addition Test. Linear, logistic, and mixed-effect models were used to assess the relationship between the Jacobian expansion in new lesions and SELs, disability scores, and treatment status.

RESULTS

One hundred seventy patients had ≥1 new lesions at year 1 and had a higher lesion count at screening compared to patients with no new lesions (median = 27 vs. 22, p = 0.007). Among the new lesions (median = 2 per patient), 37% evolved into definite or possible SELs. Higher SEL volume and count were associated with EDSS worsening and confirmed disability progression. Treated patients had lower volume and count of definite SELs (β = -0.04, 95% confidence interval [CI] = -0.07 to -0.01, p = 0.015; β = -0.36, 95% CI = -0.67 to -0.06, p = 0.019, respectively).

CONCLUSIONS

Incident chronic active lesions are common in PPMS, and fingolimod treatment can reduce their number.

Diffusion-based structural connectivity patterns of multiple sclerosis phenotypes

BACKGROUND

We aimed to describe the severity of the changes in brain diffusion-based connectivity as multiple sclerosis (MS) progresses and the microstructural characteristics of these networks that are associated with distinct MS phenotypes.

METHODS

Clinical information and brain MRIs were collected from 221 healthy individuals and 823 people with MS at 8 MAGNIMS centres. The patients were divided into four clinical phenotypes: clinically isolated syndrome, relapsing-remitting, secondary progressive and primary progressive. Advanced tractography methods were used to obtain connectivity matrices. Then, differences in whole-brain and nodal graph-derived measures, and in the fractional anisotropy of connections between groups were analysed. Support vector machine algorithms were used to classify groups.

RESULTS

Clinically isolated syndrome and relapsing-remitting patients shared similar network changes relative to controls. However, most global and local network properties differed in secondary progressive patients compared with the other groups, with lower fractional anisotropy in most connections. Primary progressive participants had fewer differences in global and local graph measures compared with clinically isolated syndrome and relapsing-remitting patients, and reductions in fractional anisotropy were only evident for a few connections. The accuracy of support vector machine to discriminate patients from healthy controls based on connection was 81%, and ranged between 64% and 74% in distinguishing among the clinical phenotypes.

CONCLUSIONS

In conclusion, brain connectivity is disrupted in MS and has differential patterns according to the phenotype. Secondary progressive is associated with more widespread changes in connectivity. Additionally, classification tasks can distinguish between MS types, with subcortical connections being the most important factor.

Cardiovascular risk factors in secondary progressive multiple sclerosis: A cross-sectional analysis from the MS-STAT2 randomized controlled trial

BACKGROUND AND PURPOSE

There is increasing evidence that cardiovascular risk (CVR) contributes to disability progression in multiple sclerosis (MS). CVR is particularly prevalent in secondary progressive MS (SPMS) and can be quantified through validated composite CVR scores. The aim was to examine the cross-sectional relationships between excess modifiable CVR, whole and regional brain atrophy on magnetic resonance imaging, and disability in patients with SPMS.

METHODS

Participants had SPMS, and data were collected at enrolment into the MS-STAT2 trial. Composite CVR scores were calculated using the QRISK3 software. Prematurely achieved CVR due to modifiable risk factors was expressed as QRISK3 premature CVR, derived through reference to the normative QRISK3 dataset and expressed in years. Associations were determined with multiple linear regressions.

RESULTS

For the 218 participants, mean age was 54 years and median Expanded Disability Status Scale was 6.0. Each additional year of prematurely achieved CVR was associated with a 2.7 mL (beta coefficient; 95% confidence interval 0.8-4.7; p = 0.006) smaller normalized whole brain volume. The strongest relationship was seen for the cortical grey matter (beta coefficient 1.6 mL per year; 95% confidence interval 0.5-2.7; p = 0.003), and associations were also found with poorer verbal working memory performance. Body mass index demonstrated the strongest relationships with normalized brain volumes, whilst serum lipid ratios demonstrated strong relationships with verbal and visuospatial working memory performance.

CONCLUSIONS

Prematurely achieved CVR is associated with lower normalized brain volumes in SPMS. Future longitudinal analyses of this clinical trial dataset will be important to determine whether CVR predicts future disease worsening.

Feasibility of in vivo multi-parametric quantitative magnetic resonance imaging of the healthy sciatic nerve with a unified signal readout protocol

Magnetic resonance neurography (MRN) has been used successfully over the years to investigate the peripheral nervous system (PNS) because it allows early detection and precise localisation of neural tissue damage. However, studies demonstrating the feasibility of combining MRN with multi-parametric quantitative magnetic resonance imaging (qMRI) methods, which provide more specific information related to nerve tissue composition and microstructural organisation, can be invaluable. The translation of emerging qMRI methods previously validated in the central nervous system to the PNS offers real potential to characterise in patients in vivo the underlying pathophysiological mechanisms involved in a plethora of conditions of the PNS. The aim of this study was to assess the feasibility of combining MRN with qMRI to measure diffusion, magnetisation transfer and relaxation properties of the healthy sciatic nerve in vivo using a unified signal readout protocol. The reproducibility of the multi-parametric qMRI protocol as well as normative qMRI measures in the healthy sciatic nerve are reported. The findings presented herein pave the way to the practical implementation of joint MRN-qMRI in future studies of pathological conditions affecting the PNS.

Relationship between paramagnetic rim lesions and slowly expanding lesions in multiple sclerosis

BACKGROUND

Magnetic resonance imaging (MRI) markers for chronic active lesions in MS include slowly expanding lesions (SELs) and paramagnetic rim lesions (PRLs).

OBJECTIVES

To identify the relationship between SELs and PRLs in MS, and their association with disability.

METHODS

61 people with MS (pwMS) followed retrospectively with MRI including baseline susceptibility-weighted imaging, and longitudinal T1 and T2-weighted scans. SELs were computed using deformation field maps; PRLs were visually identified. Mixed-effects models assessed differences in Expanded Disability Status Scale (EDSS) score changes between the group defined by the presence of SELs and or PRLs.

RESULTS

The median follow-up time was 3.2 years. At baseline, out of 1492 lesions, 616 were classified as SELs, and 80 as PRLs. 92% of patients had ⩾ 1 SEL, 56% had ⩾ 1 PRL, while both were found in 51%. SELs compared to non-SELs were more likely to also be PRLs (7% vs. 4%, p = 0.027). PRL counts positively correlated with SEL counts (ρ= 0.28, p = 0.03). SEL + PRL + patients had greater increases in EDSS over time (beta = 0.15/year, 95% confidence interval (0.04, 0.27), p = 0.009) than SEL+PRL-patients.

CONCLUSION

SELs are more numerous than PRLs in pwMS. Compared with either SELs or PRLs found in isolation, their joint occurrence was associated with greater clinical progression.

Slowly expanding lesions relate to persisting black-holes and clinical outcomes in relapse-onset multiple sclerosis

BACKGROUND

Slowly expanding lesions (SELs) are MRI markers of chronic active lesions in multiple sclerosis (MS). T1-hypointense black holes, and reductions in magnetization transfer ratio (MTR) are pathologically correlated with myelin and axonal loss. While all associated with progressive MS, the relationship between these lesion's metrics and clinical outcomes in relapse-onset MS has not been widely investigated.

OBJECTIVES

To explore the relationship of SELs with T1-hypointense black holes, and longitudinal T1 intensity contrast ratio and MTR, their correlation to brain volume, and their contribution to MS disability in relapse-onset patients.

METHODS

135 patients with relapsing-remitting MS (RRMS) were studied with clinical assessments and brain MRI (T2/FLAIR and T1-weighted scans at 1.5/3 T) at baseline and two subsequent follow-ups; a subset of 83 patients also had MTR acquisitions. Early-onset patients were defined when the baseline disease duration was ≤ 5 years (n = 85). SELs were identified using deformation field maps from the manually segmented baseline T2 lesions and differentiated from the non-SELs. Persisting black holes (PBHs) were defined as a subset of T2 lesions with a signal below a patient-specific grey matter T1 intensity in a semi-quantitative manner. SELs, PBH counts, and brain volume were computed, and their associations were assessed through Spearman and Pearson correlation. Clusters of patients according to low (up to 2), intermediate (3 to 10), or high (more than 10) SEL counts were determined with a Gaussian generalised mixture model. Mixed-effects and logistic regression models assessed volumes, T1 and MTR within SELs, and their correlation with Expanded Disability Status Scale (EDSS) and confirmed disability progression (CDP).

RESULTS

Mean age at study onset was 35.5 years (73% female), disease duration 5.5 years and mean time to last follow-up 6.5 years (range 1 to 12.5); median baseline EDSS 1.5 (range 0 to 5.5) and a mean EDSS change of 0.31 units at final follow-up. Among 4007 T2 lesions, 27% were classified as SELs and 10% as PBHs. Most patients (n = 65) belonged to the cluster with an intermediate SEL count (3 to 10 SELs). The percentage of PBHs was higher in SELs than non-SELs (up to 61% vs 44%, p < 0.001) and within-patient SEL volumes positively correlated with PBH volumes (r = 0.53, p < 0.001). SELs showed a decrease in T1 intensity over time (beta = -0.004, 95%CI -0.005 to -0.003, p < 0.001), accompanied by lower cross-sectional baseline and follow-up MTR. In mixed-effects models, EDSS worsening was predicted by the SEL log-volumes increase over time (beta = 0.11, 95%CI 0.03 to 0.20, p = 0.01), which was confirmed in the sub-cohort of patients with early onset MS (beta = 0.14, 95%CI 0.04 to 0.25, p = 0.008). In logistic regressions, a higher risk for CDP was associated with SEL volumes (OR = 5.15, 95%CI 1.60 to 16.60, p = 0.006).

CONCLUSIONS

SELs are associated with accumulation of more destructive pathology as indicated by an association with PBH volume, longitudinal reduction in T1 intensity and MTR. Higher SEL volumes are associated with clinical progression, while lower ones are associated with stability in relapse-onset MS.

Association of Slowly Expanding Lesions on MRI With Disability in People With Secondary Progressive Multiple Sclerosis

BACKGROUND AND OBJECTIVE

To explore the relationship between slowly expanding lesions (SELs) on MRI and disability in secondary progressive multiple sclerosis (SPMS).

METHODS

We retrospectively studied 345 patients with SPMS enrolled in the MS-SMART trial. They underwent brain MRI at baseline and at 24 and 96 weeks. Definite SELs were defined as concentrically expanding T2 lesions, as assessed by nonlinear deformation of volumetric T1-weighted images. Associations of SEL volumes with other MRI metrics and disability were assessed through Pearson correlations and regression analyses.

RESULTS

Averaged across patients, 29% of T2 lesions were classified as being definite SELs. A greater volume of definite SELs correlated with a higher total baseline T2 lesion volume (r = 0.55, p < 0.001) and percentage brain volume reduction (r = -0.26, p < 0.001), a higher number of new persisting T1 black holes (r = 0.19, p < 0.001), and, in a subset of 106 patients, with a greater reduction in magnetization transfer ratio (adjusted difference 0.52, p < 0.001). In regression analyses, a higher definite SEL volume was associated with increasing disability, as assessed by the Expanded Disability Status Scale (β = 0.23, p = 0.020), z scores of the Multiple Sclerosis Functional Composite (β = -0.47, p = 0.048), Timed 25-Foot Walk Test (β = -2.10, p = 0.001), and Paced Auditory Serial Addition Task (β = -0.27, p = 0.006), and increased risk of disability progression (odds ratio 1.92, p = 0.025).

DISCUSSION

Definite SELs represent almost one-third of T2 lesions in SPMS. They are associated with neurodegenerative MRI markers and related to clinical worsening, suggesting that they may contribute to disease progression and be a new target for therapeutic interventions.

Spatial patterns of brain lesions assessed through covariance estimations of lesional voxels in multiple Sclerosis: The SPACE-MS technique

Predicting disability in progressive multiple sclerosis (MS) is extremely challenging. Although there is some evidence that the spatial distribution of white matter (WM) lesions may play a role in disability accumulation, the lack of well-established quantitative metrics that characterise these aspects of MS pathology makes it difficult to assess their relevance for clinical progression. This study introduces a novel approach, called SPACE-MS, to quantitatively characterise spatial distributional features of brain MS lesions, so that these can be assessed as predictors of disability accumulation. In SPACE-MS, the covariance matrix of the spatial positions of each patient's lesional voxels is computed and its eigenvalues extracted. These are combined to derive rotationally-invariant metrics known to be common and robust descriptors of ellipsoid shape such as anisotropy, planarity and sphericity. Additionally, SPACE-MS metrics include a neuraxis caudality index, which we defined for the whole-brain lesion mask as well as for the most caudal brain lesion. These indicate how distant from the supplementary motor cortex (along the neuraxis) the whole-brain mask or the most caudal brain lesions are. We applied SPACE-MS to data from 515 patients involved in three studies: the MS-SMART (NCT01910259) and MS-STAT1 (NCT00647348) secondary progressive MS trials, and an observational study of primary and secondary progressive MS. Patients were assessed on motor and cognitive disability scales and underwent structural brain MRI (1.5/3.0 T), at baseline and after 2 years. The MRI protocol included 3DT1-weighted (1x1x1mm3) and 2DT2-weighted (1x1x3mm3) anatomical imaging. WM lesions were semiautomatically segmented on the T2-weighted scans, deriving whole-brain lesion masks. After co-registering the masks to the T1 images, SPACE-MS metrics were calculated and analysed through a series of multiple linear regression models, which were built to assess the ability of spatial distributional metrics to explain concurrent and future disability after adjusting for confounders. Patients whose WM lesions laid more caudally along the neuraxis or were more isotropically distributed in the brain (i.e. with whole-brain lesion masks displaying a high sphericity index) at baseline had greater motor and/or cognitive disability at baseline and over time, independently of brain lesion load and atrophy measures. In conclusion, here we introduced the SPACE-MS approach, which we showed is able to capture clinically relevant spatial distributional features of MS lesions independently of the sheer amount of lesions and brain tissue loss. Location of lesions in lower parts of the brain, where neurite density is particularly high, such as in the cerebellum and brainstem, and greater spatial spreading of lesions (i.e. more isotropic whole-brain lesion masks), possibly reflecting a higher number of WM tracts involved, are associated with clinical deterioration in progressive MS. The usefulness of the SPACE-MS approach, here demonstrated in MS, may be explored in other conditions also characterised by the presence of brain WM lesions.

Reduced neurite density in the brain and cervical spinal cord in relapsing-remitting multiple sclerosis: A NODDI study

BACKGROUND

Multiple sclerosis (MS) affects both brain and spinal cord. However, studies of the neuraxis with advanced magnetic resonance imaging (MRI) are rare because of long acquisition times. We investigated neurodegeneration in MS brain and cervical spinal cord using neurite orientation dispersion and density imaging (NODDI).

OBJECTIVE

The aim of this study was to investigate possible alterations, and their clinical relevance, in neurite morphology along the brain and cervical spinal cord of relapsing-remitting MS (RRMS) patients.

METHODS

In total, 28 RRMS patients and 20 healthy controls (HCs) underwent brain and spinal cord NODDI at 3T. Physical and cognitive disability was assessed. Individual maps of orientation dispersion index (ODI) and neurite density index (NDI) in brain and spinal cord were obtained. We examined differences in NODDI measures between groups and the relationships between NODDI metrics and clinical scores using linear regression models adjusted for age, sex and brain tissue volumes or cord cross-sectional area (CSA).

RESULTS

Patients showed lower NDI in the brain normal-appearing white matter (WM) and spinal cord WM than HCs. In patients, a lower NDI in the spinal cord WM was associated with higher disability.

CONCLUSION

Reduced neurite density occurs in the neuraxis but, especially when affecting the spinal cord, it may represent a mechanism of disability in MS.

In vivo imaging of chronic active lesions in multiple sclerosis

New clinical activity in multiple sclerosis (MS) is often accompanied by acute inflammation which subsides. However, there is growing evidence that a substantial proportion of lesions remain active well beyond the acute phase. Chronic active lesions are most frequently found in progressive MS and are characterised by a border of inflammation associated with iron-enriched cells, leading to ongoing tissue injury. Identifying imaging markers for chronic active lesions in vivo are thus a major research goal. We reviewed the literature on imaging of chronic active lesion in MS, focussing on ‘slowly expanding lesions’ (SELs), detected by volumetric longitudinal magnetic resonance imaging (MRI) and ‘rim-positive’ lesions, identified by susceptibility iron-sensitive MRI. Both SELs and rim-positive lesions have been found to be prognostically relevant to future disability. Little is known about the co-occurrence of rims around SELs and their inter-relationship with other emerging techniques such as dynamic contrast enhancement (DCE) and positron emission tomography (PET).

Erratum: Author Correction: High-dimensional detection of imaging response to treatment in multiple sclerosis

[This corrects the article DOI: 10.1038/s41746-019-0127-8.].

LncRNAs expression profile in peripheral blood mononuclear cells from multiple sclerosis patients

LncRNA PCR arrays containing 90 common LncRNAs were used to screen lncRNA expression levels in PBMC from a discovery population of patients with MS. Data from discovery and replications cohorts showed a generalized dysregulation of lncRNA levels in MS patients compared with controls. MALAT1, MEG9, NRON, ANRIL, TUG1, XIST, SOX2OT, GOMAFU, HULC, BACE-1AS were significantly downregulated in MS patients in comparison with controls. Therefore, we performed a validation analysis in an independent cohort of Belgian origin. In this study, NRON and TUG1 downregulations in MS patients compared with controls were confirmed (p ≤ .05 and p ≤ .0001 respectively), whereas considering the other lncRNAs, the statistical threshold was not reached. LncRNAs profiling could thus represent a new challenge in the research of easy detectable biomarkers of disease susceptibility and progression.

Four-wave-mixing experiments with seeded free electron lasers

The development of free electron laser (FEL) sources has provided an unprecedented bridge between the scientific communities working with ultrafast lasers and extreme ultraviolet (XUV) and X-ray radiation. Indeed, in recent years an increasing number of FEL-based applications have exploited methods and concepts typical of advanced optical approaches. In this context, we recently used a seeded FEL to demonstrate a four-wave-mixing (FWM) process stimulated by coherent XUV radiation, namely the XUV transient grating (X-TG). We hereby report on X-TG measurements carried out on a sample of silicon nitride (Si₃N₄). The recorded data bears evidence for two distinct signal decay mechanisms: one occurring on a sub-ps timescale and one following slower dynamics extending throughout and beyond the probed timescale range (100 ps). The latter is compatible with a slower relaxation (time decay > ns), that may be interpreted as the signature of thermal diffusion modes. From the peak intensity of the X-TG signal we could estimate a value of the effective third-order susceptibility which is substantially larger than that found in SiO₂, so far the only sample with available X-TG data. Furthermore, the intensity of the time-coincidence peak shows a linear dependence on the intensity of the three input beams, indicating that the measurements were performed in the weak field regime. However, the timescale of the ultrafast relaxation exhibits a dependence on the intensity of the XUV radiation. We interpreted the observed behaviour as the generation of a population grating of free-electrons and holes that, on the sub-ps timescale, relaxes to generate lattice excitations. The background free detection inherent to the X-TG approach allowed the determination of FEL-induced electron dynamics with a sensitivity largely exceeding that of transient reflectivity and transmissivity measurements, usually employed for this purpose.

Word and Picture Version of the Free and Cued Selective Reminding Test (FCSRT): Is There Any Difference?

The Free and Cued Selective Reminding Test (FCSRT) is the most commonly used neuropsychological test to evaluate episodic memory. Two variants of FCSRT exist, using the recall of words (FCSRT-w) or pictures (FCSRT-p). Fourteen patients with mild cognitive impairment underwent neuropsychological evaluation and brain magnetic resonance. We found differences in FCSRT-w and FCSRT-p variants scores. FCSRT-p was correlated with atrophy in areas involved in visual stimuli processing while FCSRT-w was correlated to hippocampal atrophy. Our study suggests that FCSRT-w and FCSRT-p scores are not equivalent, but a larger cohort of patients is needed to validate these results.

First Evidence of Purely Extreme-Ultraviolet Four-Wave Mixing

The extension of nonlinear optical techniques to the extreme-ultraviolet (EUV), soft and hard x-ray regime represents one of the open challenges of modern science since it would combine chemical specificity with background-free detection and ultrafast time resolution. We report on the first observation of a four-wave-mixing (FWM) response from solid-state samples stimulated exclusively by EUV pulses. The all-EUV FWM signal was generated by the diffraction of high-order harmonics of the FERMI free-electron laser (FEL) from the standing wave resulting from the interference of two crossed FEL pulses at the fundamental wavelength. From the intensity of the FWM signal, we are able to extract the first-ever estimate of an effective value of ∼6×10^{-24}   m^{2} V^{-2} for the third-order nonlinear susceptibility in the EUV regime. This proof of principle experiment represents a significant advance in the field of nonlinear optics and sets the starting point for a manifold of techniques, including frequency and phase-resolved FWM methods, that are unprecedented in this photon-energy regime.

Bilateral Breast Involvement in A 71-Year-Old White Man with Lambda Light Chain Disease. Regression after A new Chemotherapy Combination. A Case Report

A rare case of lambda light chain disease with bilateral breast involvement is described. A complete regression after a new chemotherapy combination (peptichemio + teniposide + dexa-methasone) was obtained. A previous treatment with prednisone + melphalan was ineffective.

CSF β-amyloid and white matter damage: a new perspective on Alzheimer's disease

OBJECTIVE

To assess the connection between amyloid pathology and white matter (WM) macrostructural and microstructural damage in demented patients compared with controls.

METHODS

Eighty-five participants were recruited: 65 with newly diagnosed Alzheimer's disease (AD), non-AD dementia or mild cognitive impairment and 20 age-matched and sex-matched healthy controls. β-amyloid_1-42 (Aβ) levels were determined in cerebrospinal fluid (CSF) samples from all patients and five controls. Among patients, 42 had pathological CSF Aβ levels (Aβ(+)), while 23 had normal CSF Aβ levels (Aβ(-)). All participants underwent neurological examination, neuropsychological testing and brain MRI. We used T2-weighted scans to quantify WM lesion loads (LLs) and diffusion-weighted images to assess their microstructural substrate. Non-parametric statistical tests were used for between-group comparisons and multiple regression analyses.

RESULTS

We found an increased WM-LL in Aβ(+) compared with both, healthy controls (p=0.003) and Aβ(-) patients (p=0.02). Interestingly, CSF Aβ concentration was the best predictor of patients' WM-LL (r=-0.30, p<0.05) when using age as a covariate. Lesion apparent diffusion coefficient value was higher in all patients than in controls (p=0.0001) and correlated with WM-LL (r=0.41, p=0.001). In Aβ(+), WM-LL correlated with WM microstructural damage in the left peritrigonal WM (p<0.0001).

CONCLUSIONS

WM damage is crucial in AD pathogenesis. The correlation between CSF Aβ levels and WM-LL suggests a direct link between amyloid pathology and WM macrostructural and microstructural damage.

CSF β-amyloid as a putative biomarker of disease progression in multiple sclerosis

BACKGROUND

Neurodegeneration plays a major role in determining disability in multiple sclerosis (MS) patients. Hence, there is increasing need to identify reliable biomarkers, which could serve as prognostic measure of disease progression.

OBJECTIVES

To assess whether cerebrospinal fluid (CSF) tau and β-amyloid (Aβ) levels were altered in newly diagnosed MS patients and correlated with disability. Moreover, we investigated whether these CSF biomarkers associate with macroscopic brain tissue damage measures.

METHODS

CSF Aβ and tau levels were determined by enzyme-linked immunosorbent assay in CSF samples from 48 newly diagnosed MS patients, followed-up clinically for 3 years by recording their Expanded Disability Status Scale score at 6-month intervals, and 45 controls. All patients underwent magnetic resonance imaging at baseline and at the end of follow-up to quantify their lesion load (LL).

RESULTS

CSF Aβ levels were significantly reduced in patients compared to controls ( p < 0.001). Lower CSF Aβ levels at baseline were a disability predictor at 3-year follow-up ( p = 0.009). CSF tau levels correlated with T2- and T1-LL ( p < 0.001).

CONCLUSION

CSF Aβ reduction is a promising biomarker of neurodegeneration and may predict patients' clinical outcome. Therefore, CSF Aβ should be considered as a potential biomarker of prognostic value.

Partial recovery after severe immune reconstitution inflammatory syndrome in a multiple sclerosis patient with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a rare and severe complication of natalizumab therapy in patients with multiple sclerosis and it may be accompanied by immune reconstitution inflammatory syndrome (IRIS). Here, we describe a case of abnormally severe IRIS, which occurred 2 months after natalizumab-associated PML in a 38-year-old woman affected by multiple sclerosis. The patient was John Cunningham virus-positive and was treated for 21 months when she developed PML. The subsequent IRIS diffusely afflicted the brain, producing edema and signs of intracranial hypertension, with a clinically severe form compromising the state of consciousness, requiring intensive care and high-dosage steroid treatment. Nevertheless, she survived and partially recovered. There is still difficulty in differentiating PML progression from IRIS onset and there is not a clear description in the literature about different clinical forms of IRIS, prognostic factors and guidelines to properly treat this complication in order to reduce the residual disability of the patient surviving this treatment complication.

A driving simulator study of driver performance on deceleration lanes

Deceleration lanes are important because they help drivers transition from high-speed lanes to low-speed ramps. Although they are designed to allow vehicles to depart the freeway safely and efficiently, many studies report high accident rates on exit ramps with the highest percentage of crashes taking place in deceleration lanes. This paper describes the results of a driving simulator study that focused on driving performance while approaching a divergence area and decelerating during the exiting maneuver. Three different traffic scenarios were simulated to analyze the influence of traffic volume on driving performance. Thirty drivers drove in the simulator in these scenarios while data on their lateral position, speed and deceleration were collected. Our results indicate there are considerable differences between the main assumptions of models generally used to design deceleration lanes and actual driving performance. In particular, diverging drivers begin to decelerate before arriving at the deceleration lane, causing interference with the main flow. Moreover, speeds recorded at the end of the deceleration lane exceed those for which the ramp's curves are designed; this creates risky driving conditions that could explain the high crash rates found in studies of exit ramps. Finally, statistical analyses demonstrate significant influences of traffic volume on some aspects of exiting drivers' performance: lower traffic volume results in elevated exiting speed and deceleration, and diverging drivers begin to decelerate earlier along the main lane when traffic volume is low. However, speeds at the end of the deceleration lane and the site of lane changing are not significantly influenced by traffic volume.

The use of ciclosporin in paediatric inflammatory bowel disease: an Italian experience

AIM

To asses the efficacy and safety of ciclosporin in a paediatric population with inflammatory bowel disease.

PATIENTS AND METHODS

Twenty-three Italian children treated with ciclosporin were studied retrospectively. The indications for treatment were severe unresponsive colitis, chronic active colitis or severe fistulizing Crohn's disease. The treatment duration, follow-up and causes of drug discontinuation were assessed.

RESULTS

Sixteen patients were treated intravenously for a mean time of 10 +/- 7 days (1-24 days) and 19 orally for a mean time of 133 days (17-660 days). The mean follow-up of all patients was 13.2 months. Ciclosporin was totally ineffective, being discontinued for surgery, in nine of 23 patients (39%); it was discontinued for partial response in three patients (13%). During treatment, clinical remission was achieved in eight children (35%) and maintained after drug withdrawal in four (17%). In severe unresponsive colitis, urgent colectomy was avoided in 12 (85%) of 14 patients who tolerated the drug. Side-effects appeared in six of 23 patients (26%), and three (13%) required ciclosporin to be discontinued due to neurotoxicity.

CONCLUSIONS

Ciclosporin shows disappointing long-term results in the treatment of refractory inflammatory bowel disease, but can play an important role in preventing urgent surgery in unresponsive severe colitis. Severe side-effects can occur.

Bloodstream infections can develop late (after day 100) and/or in the absence of neutropenia in children receiving allogeneic bone marrow transplantation

We retrospectively evaluated the incidence and time from transplantation of bloodstream infections occurring in children receiving bone marrow transplant (BMT) at G Gaslini Children's Hospital between September 1984 and December 1997. During this period the incidence was 35% after allogeneic and 26% after autologous BMT (P=0.08). Among these episodes, 38% after allogeneic BMT and 90% after autologous BMT were detected in the presence of neutropenia within the first 30 days from reinfusion (P < 0.001). Incidence of catheter-related bloodstream infections was 40% after allogeneic and 8% after autologous BMT (P < 0.001). Bloodstream infections in the absence of neutropenia were 55% after allogeneic BMT vs 10% after autologous BMT (P < 0.001) and occurred later after reinfusion (mean 199 vs 41 days, P <0.001). Among the episodes occurring after allogeneic BMT and in the absence of neutropenia, 61% were related to the presence of a central venous catheter, 15% were related to the presence of GVHD, but 23% were not associated with any of major risk factors for infection. Finally, 38% of episodes following allogeneic BMT were detected after day 100 vs 1% after autologous BMT. We concluded that patients receiving allogeneic BMT experience a high incidence of bloodstream infections in the absence of neutropenia and that a significant proportion of these episodes is not clearly associated with well known risk factors such as GVHD or central venous catheters. Moreover, many episodes develop a long time after the transplantation procedure. Therefore, any febrile episode following allogeneic BMT even late and/or in the absence of neutropenia should be intensively managed.

[Sepsis related to a permanent central venous catheter in children with neoplastic disease: practical implications of a continuous surveillance of the etiology]

Indwelling central venous catheter-related bacteremias are an important complication in patients with cancer. In general they are due to Staphylococcus aureus and Candida, while bacteremias caused by Gram-negatives are less common and often related to infusate contaminans. We describe a survey of etiological surveillance of Broviac catheter-related infections at G. Gaslini Children's Hospital of Genoa, Italy. In the period 1989-1992 an increase of Broviac catheter-related bacteremias due to Gram-negatives was demonstrated as compared with previous years (1985-1988). At home parental management was suspected as an important risk factor, since this complication was frequently due to infusate contaminants and no epidemic cluster or positive surveillance culture was observed in the Hospital. Therefore at home management was changed, especially regarding heparin storage. The subsequent, prospective follow-up from July 1993 to December 1995 showed a significant decrease in catheter-related bacteremias due to Gram-negatives (P = 0.003, chi-square test). In conclusion, a strict control on at home catheter management procedures must be maintained in order to reduce the risk of indwelling central venous catheter-related infections in children with cancer.

[Incidence and treatment of local recurrences after conservative surgical treatment for cancer of the breast]

Long-term survival is comparable after total mastectomy or conservative surgery for early breast cancer. Our purpose was to evaluate the rate and therapy of breast relapse at the Regional Hospital of Varese (Italy) in a 10 years period. From 1/1/1980 to 31/12/1990 a total of 606 patients with early breast cancer (Stage I or II early) were evaluated. They all were submitted to quadrantectomy, axillary dissection and radiotherapy. In case of metastases to the axillary lymph nodes, hormono or chiotherapy were performed. 425 patients were regularly followed for a period of 2.5-13 years. In 15 patients (3.2%) a local recurrence was discovered. They were treated as follows, 8 patients: mastectomy, 4 patients: conservative surgery, 4 patients: no therapy. The surgical approach of the local recurrence, mastectomy or conservative surgery, does not influence long-term survival of patients treated with conservative surgery and radiotherapy for early stage breast cancer. Conservative surgery is often possible in treating local recurrence without interfering with complete removal of the tumor and long-term survival.

Factors related to drug consumption during pregnancy

A survey on drug intake during pregnancy was carried out in a sample of 3268 women who delivered live-born infants in 11 hospitals located throughout Italy. A large questionnaire on drug use and other aspects of maternal life-style was administered within five days of delivery to 3112 women who consented to the interview. An overall mean consumption of 2.17 drugs per woman was reported. Apart from dietary supplements, the most used drugs were tocolytics, analgesics, and antibiotics. The proportion of women who did not use any drug was 17.3%. The role of some non-medical determinants of drug intake was evaluated as well. Geographic and socio-economic factors were seen to increase drug intake up to 44%, while the presence of anxiety provoked a 60% higher consumption of drugs other than dietary supplements. Other factors influencing drug use during pregnancy were rural vs. urban residence and smoking habits. The need for the recording of these socio-economic factors in surveys on drug use during pregnancy is emphasized.

Moderate maternal drinking and outcome of pregnancy

The adverse effect of light or moderate maternal drinking during pregnancy on the well being of the newborn has been investigated. The study group included 2145 live births in the obstetric units of 11 Italian cities between February 1989 and July 1990. A detailed life style questionnaire was administered to the mothers. Information on the newborn was collected from clinical records as well as from a clinical examination. Both univariate and multivariate analyses were suggestive of a decrease in mean birth weight associated with maternal drinking pregnancy, especially in women who also smoked during pregnancy. This effect was higher in male newborns. The occurrence of low birth weight (< 2500 g.) was more frequent in women drinking during pregnancy in both smokers and non-smokers (for this latter group an effect is suggested only for a daily consumption of more than 10 grams of absolute alcohol). Maternal alcohol drinking of more than 20 grams of absolute alcohol per day also increased the risk of preterm delivery (OR = 2.35; 95% CI: .98-5.59). Finally, an increase in the rate of early jaundice was found, also associated with maternal drinking (OR = 3.30; 95% CI: 1.03-10.54).

[The pediatric emergency department: assessment of clinical activity and interaction with local health authorities]

A perspective study was carried out at the Emergency Department of the Gaslini Institute on a sample of the children admitted from May to September 1990. The study aimed to describe types and modalities of admission. "G. Gaslini" Institute is a multidisciplinary children's hospital: 45% of patients admitted in the hospital come from the southern regions of Italy, while the admission at the Emergency Department were local in 82%. Among all children considered, 2080 (71.9% were admitted on request of their parents, who did not ask previously any physician; of those cases, 356 (17%) were hospitalized, 474 (25%) were either examined by specialist or treated and then discharged. In the remaining cases, no intervention was necessary. As a consequence, 58% of children were admitted without any clinically plausible reason. Parents' anxiety clearly played an important role in most cases. 840 children were addressed to the Emergency Department by a physician, 652 (22.3%) by the doctor in charge, 213 (32.7%) of which were sent back home by the doctor on duty, who did not think it necessary any treatment. Of the 120 (4.1%) children sent by different Emergency Departments, 95 (79.1%) were hospitalized. The reason why physicians addressed quite a large number of children to the Emergency Department, when they didn't need any intervention remain nucleo. Their diagnosis, in fact, agreed with those of the doctor on duty in 83% of cases. In conclusion, it is difficult to imagine a diagnostic or therapeutic problem which needs specific structures. Cooperative programs with physicians working in our region will be carried out in order to control, where possible, admission to Emergency Departments.

[Cerebral arteriovenous malformations (CAVM)]

Two infants with endocranic A-V malformations and irreversible picture of congestive cardiac failure are presented: the first is a newborn with a very large angioma, the second is a newborn with a large aneurysm of the vein of Galen. A review of the literature is presented: the salient age-related features required to make a diagnosis are discussed.

Effect of passive smoking during pregnancy on selected perinatal parameters

A prospective study of 1004 consecutive deliveries was carried out to investigate the effect of passive smoking during pregnancy on a set of perinatal parameters. The data set was a cooperative study involving 11 Italian cities, distributed nationally. The study group was divided in three categories according to the mother's cigarette smoke exposure during pregnancy, ie, not smokers, passive smokers, direct smokers. Potential confounders, including paternal characteristics, were adjusted for by multiple linear regression analysis. A mean reduction of 16 g (p less than 0.07) in birthweight and a decrease in birth length of 0.05 cm (p less than 0.08) were found for each hour of antenatal passive smoke exposure. No or slight effects were reported for the other perinatal parameters considered.

[5-Fluorouracil in the treatment of acute pancreatitis. Our experience]

A report is presented on 24 cases of acute pancreatitis treated with infusion of 5-fluorouracil. Though the action mechanism of the drug is still uncertain, fairly satisfactory results were obtained in terms of both clinical symptoms and laboratory findings, while the effect of the drug on the pain symptom could even be called spectacular. It is therefore considered that the treatment of acute pancreatitis with 5FU deserves serious consideration.

[Hypothalamo-hypophyseal metastasis: a rare initial manifestation of adenocarcinoma of the jejunum. Description of a clinical case]

A rare case of jejunal adenocarcinoma is described in which the initial clinical sign was diabetes insipidus and hypopituitarism linked to hypothalamohypophyseal metastasis. The rarity of the intestinal neoplasm and the unusual site of the metastatic lesions are underlined.