Regional differences in effects of APOE ε4 on cognitive impairment in non-demented subjects

BACKGROUND

The APOE ε4 allele is a risk factor for Alzheimer's disease (AD). APOE ε4 is common in non-demented subjects with cognitive impairment. In both healthy people and people with AD, its prevalence has a north-south gradient across Europe. In the present study, we investigated whether the relation between the APOE ε4 allele and cognitive impairment varied across Northern, Middle and Southern Europe. We also investigated whether a north-south gradient existed in subjects with subjective cognitive impairment (SCI), amnestic mild cognitive impairment (MCI) and non-amnestic MCI.

METHODS

Data from 16 centers across Europe were analyzed.

RESULTS

A north-south gradient in APOE ε4 prevalence existed in the total sample (62.7% for APOE ε4 carriers in the northern region, 42.1% in the middle region, and 31.5% in the southern region) and in subjects with SCI and amnestic MCI separately. Only in Middle Europe was the APOE ε4 allele significantly associated with poor performance on tests of delayed recall and learning, as well as with the amnestic subtype of MCI.

CONCLUSION

The APOE ε4 allele frequencies in subjects with SCI and amnestic MCI have a north-south gradient. The relation between the APOE ε4 allele and cognition is region dependent.

Age and diagnostic performance of Alzheimer disease CSF biomarkers

OBJECTIVES

Core CSF changes in Alzheimer disease (AD) are decreased amyloid β(1-42), increased total tau, and increased phospho-tau, probably indicating amyloid plaque accumulation, axonal degeneration, and tangle pathology, respectively. These biomarkers identify AD already at the predementia stage, but their diagnostic performance might be affected by age-dependent increase of AD-type brain pathology in cognitively unaffected elderly.

METHODS

We investigated effects of age on the diagnostic performance of CSF biomarkers in a uniquely large multicenter study population, including a cross-sectional cohort of 529 patients with AD dementia (median age 71, range 43-89 years) and 304 controls (67, 44-91 years), and a longitudinal cohort of 750 subjects without dementia with mild cognitive impairment (69, 43-89 years) followed for at least 2 years, or until dementia diagnosis.

RESULTS

The specificities for subjects without AD and the areas under the receiver operating characteristics curves decreased with age. However, the positive predictive value for a combination of biomarkers remained stable, while the negative predictive value decreased only slightly in old subjects, as an effect of the high AD prevalence in older ages.

CONCLUSION

Although the diagnostic accuracies for AD decreased with age, the predictive values for a combination of biomarkers remained essentially stable. The findings highlight biomarker variability across ages, but support the use of CSF biomarkers for AD even in older populations.

Disrupted modular brain dynamics reflect cognitive dysfunction in Alzheimer's disease

The relation between pathology and cognitive dysfunction in dementia is still poorly understood, although disturbed communication between different brain regions is almost certainly involved. In this study we combine magneto-encephalography (MEG) and network analysis to investigate the role of functional sub-networks (modules) in the brain with regard to cognitive failure in Alzheimer's disease. Whole-head resting-state (MEG) was performed in 18 Alzheimer patients (age 67 ± 9, 6 females, MMSE 23 ± 5) and 18 healthy controls (age 66 ± 9, 11 females, MMSE 29 ± 1). We constructed functional brain networks based on interregional synchronization measurements, and performed graph theoretical analysis with a focus on modular organization. The overall modular strength and the number of modules changed significantly in Alzheimer patients. The parietal cortex was the most highly connected network area, but showed the strongest intramodular losses. Nonetheless, weakening of intermodular connectivity was even more outspoken, and more strongly related to cognitive impairment. The results of this study demonstrate that particularly the loss of communication between different functional brain regions reflects cognitive decline in Alzheimer's disease. These findings imply the relevance of regarding dementia as a functional network disorder.

Efficacy of a medical food on cognition in Alzheimer's disease: results from secondary analyses of a randomized, controlled trial

OBJECTIVE

To investigate the extent that baseline cognitive impairment and intake adherence affected the 13-item Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-cog) intervention response of a medical food in Alzheimer's Disease (AD) patients. DESIGN/SETTING/PARTICIPANTS /INTERVENTION/MEASUREMENTS: This analysis was performed on data from a proof-of-concept study, consisting of a 12-week, double-blind, randomized, controlled, multicenter trial, followed by a similarly designed 12-week extension study. Patients with mild AD (Mini-Mental State Examination [MMSE] score of 20-26) were randomized to receive active or control product as a 125 ml daily drink. One of the co-primary outcome measures was the 13-item ADAS-cog. In this analysis, the study population was divided into two subgroups: patients with 'low' baseline ADAS-cog scores (<25.0) and patients with 'high' baseline ADAS-cog scores (≥25.0). Repeated Measures Models (RMM) were used to determine the relationship between ADAS-cog score and intervention.

RESULTS

A significant treatment effect (F[1,319]=4.0, p=0.046) was shown in patients with 'high' baseline ADAS-cog, but not in patients with 'low' baseline ADAS-cog (F[1,250]=1.25, p=0.265). Overall, intake adherence was significantly correlated with ADAS-cog improvement in the active product group (correlation coefficient=-0.260; p=0.019), but not the control group.

CONCLUSION

These data indicate that baseline ADAS-cog significantly influenced the effect of Souvenaid intervention on ADAS-cog outcome. A higher intake of active study product was also associated with greater cognitive benefit. These findings highlight the potential benefits of Souvenaid in AD patients and warrant confirmation in larger, controlled studies.

Effect of a medical food on body mass index and activities of daily living in patients with Alzheimer's disease: secondary analyses from a randomized, controlled trial

OBJECTIVES

To investigate the effect of a medical food (Souvenaid) on body mass index (BMI) and functional abilities in patients with mild Alzheimer's disease (AD). DESIGN/SETTING/PARTICIPANTS/INTERVENTION /MEASUREMENTS: These analyses were performed on data from a 12-week, double-blind, randomized, controlled, multicenter, proof-of-concept study with a similarly designed and exploratory 12-week extension period. Patients with mild AD (Mini-Mental State Examination score of 20-26) were randomized to receive either the active product or an iso-caloric control product. While primary outcomes included measures of cognition, the 23-item Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale was included as a secondary outcome. Both ADCS-ADL and BMI were assessed at baseline and Weeks 6, 12 and 24. Data were analyzed using a repeated-measures mixed model.

RESULTS

Overall, data suggested an increased BMI in the active versus the control group at Week 24 (ITT: p = 0.07; PP: p = 0.03), but no treatment effect on ADCS-ADL was observed. However, baseline BMI was found to be a significant treatment effect modifier (ITT: p = 0.04; PP: p = 0.05), and an increase in ADCS-ADL was observed at Week 12 in patients with a 'low' baseline BMI (ITT: p = 0.02; PP: p = 0.04).

CONCLUSIONS

These data indicate that baseline BMI significantly impacts the effect of Souvenaid on functional abilities. In addition, there was a suggestion that Souvenaid increased BMI.

Utility of imaging for nutritional intervention studies in Alzheimer's disease

Alzheimer's disease (AD) is a multi-factorial neurodegenerative disorder and the leading cause of dementia, wherein synapse loss is the strongest structural correlate with cognitive impairment. Basic research has shown that dietary supply of precursors and co-factors for synthesis of neuronal membranes enhances the formation of synapses. Daily intake of a medical food containing a mix of these nutrients for 12 weeks in humans improved memory, measured as immediate and delayed verbal recall by the Wechsler Memory Scale-revised, in patients with very mild AD (MMSE 24-26). An improvement of immediate verbal recall was noted following 24 weeks of intervention in an exploratory extension of the study. These data suggest that the intervention may improve synaptic formation and function in early AD. Here we review emerging technologies that help identify changes in pathological hallmarks in AD, including synaptic function and loss of connectivity in the early stages of AD, before cognitive and behavioural symptoms are observable. These techniques include the detection of specific biomarkers in the cerebrospinal fluid, as well as imaging procedures such as fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), amyloid PET, structural/functional magnetic resonance imaging, diffusion tensor imaging, magnetoencephalography (MEG) and electroencephalography (EEG). Such techniques can provide new insights into the functional and structural changes in the brain over time, and may therefore help to develop more effective AD therapies. In particular, nutritional intervention studies that target synapse formation and function may benefit from these techniques, especially FDG-PET and EEG/MEG employed in the preclinical or early stages of the disease.

EFNS guidelines for the diagnosis and management of Alzheimer's disease

BACKGROUND AND OBJECTIVES

In 2008 a task force was set up to develop a revision of the European Federation of the Neurological Societies (EFNS) guideline for the diagnosis and management of Alzheimer's disease (AD) and other disorders associated with dementia, published in early 2007. The aim of this revised international guideline was to present a peer-reviewed evidence-based statement for the guidance of practice for clinical neurologists, geriatricians, psychiatrists, and other specialist physicians responsible for the care of patients with AD. Mild cognitive impairment and non-Alzheimer dementias are not included in this guideline.

METHODS

The task force working group reviewed evidence from original research articles, meta-analysis, and systematic reviews, published before May 2009. The evidence was classified and consensus recommendations graded (A, B, or C) according to the EFNS guidance. Where there was a lack of evidence, but clear consensus, good practice points were provided.

RESULTS

The recommendations for clinical diagnosis, blood tests, neuropsychology, neuroimaging, electroencephalography, cerebrospinal fluid (CSF) analysis, genetic testing, disclosure of diagnosis, treatment of AD, behavioural and psychological symptoms in dementia, legal issues, counselling and support for caregivers were all revised as compared with the previous EFNS guideline.

CONCLUSION

A number of new recommendations and good practice points are made, namely in CSF, neuropsychology, neuroimaging and reviewing non-evidence based therapies. The assessment, interpretation, and treatment of symptoms, disability, needs, and caregiver stress during the course of AD require the contribution of many different professionals. These professionals should adhere to these guideline to improve the diagnosis and management of AD.

Corpus callosum atrophy as a predictor of age-related cognitive and motor impairment: a 3-year follow-up of the LADIS study cohort

The aim of this 3-year follow-up study was to investigate whether corpus callosum (CC) atrophy may predict future motor and cognitive impairment in an elderly population. On baseline MRI from 563 subjects with age-related white matter changes (ARWMC) from the Leukoaraiosis And DISability (LADIS) study, the CC was segmented and subdivided into five anterior-posterior regions (CC1-CC5). Associations between the CC areas and decline in motor performance and cognitive functions over a 3-year period were analyzed. CC atrophy at baseline was significantly associated with impaired cognitive performance (p<0.01 for CC1, p<0.05 for CC5), motor function (p<0.05 for CC2 and CC5), and walking speed (p<0.01 for CC2 and CC5, p<0.05 for CC3 and total CC), and with development of dementia at 3 years (p<0.05 for CC1) after correction for appropriate confounders (ARWMC volume, atrophy, age, gender and handedness). In conclusion, CC atrophy, an indicator of reduced functional connectivity between cortical areas, seems to contribute, independently of ARWMC load, to future cognitive and motor decline in the elderly.

Incident lacunes influence cognitive decline: the LADIS study

BACKGROUND

In cerebral small vessel disease, the core MRI findings include white matter lesions (WML) and lacunar infarcts. While the clinical significance of WML is better understood, the contribution of lacunes to the rate of cognitive decline has not been established. This study investigated whether incident lacunes on MRI determine longitudinal cognitive change in elderly subjects with WML.

METHODS

Within the Leukoaraiosis and Disability Study (LADIS), 387 subjects were evaluated with repeated MRI and neuropsychological assessment at baseline and after 3 years. Predictors of change in global cognitive function and specific cognitive domains over time were analyzed with multivariate linear regression.

RESULTS

After controlling for demographic factors, baseline cognitive performance, baseline lacunar and WML lesion load, and WML progression, the number of new lacunes was related to subtle decrease in compound scores for executive functions (p = 0.021) and speed and motor control (p = 0.045), but not for memory or global cognitive function. Irrespective of lacunes, WML progression was associated with decrease in executive functions score (p = 0.016).

CONCLUSION

Incident lacunes on MRI parallel a steeper rate of decline in executive functions and psychomotor speed. Accordingly, in addition to WML, lacunes determine longitudinal cognitive impairment in small vessel disease. Although the individual contribution of lacunes on cognition was modest, they cannot be considered benign findings, but indicate a risk of progressive cognitive impairment.

[The immune system and Alzheimer's disease]

BACKGROUND

It has still not been established unequivocally whether vascular risk factors and inflammatory reactions, determined by heredity, are a cause or a result of Alzheimer's disease

AIM

If the offspring of parents with AD have more risk factors and more frequent and severe inflammatory reactions than the offspring of parents without AD , this argues strongly in favor of a causal relationship between vascular risk factors, a pro-inflammatory cytokine response and AD.

AIM

To determine whether the offspring of parents with ad have more risk factors and more frequent and severe inflammatory reactions than the offspring of parents without ad. method Vascular risk-factors, pro-inflammatory cytokines and the apoe genotype were determined in 206 offspring of parents with ad and in 200 offspring of parents without AD.

RESULTS

Offspring of parents with ad carried more apoe epsilon4 than offspring of parents without ad (47% vs 21%). Middle-aged offspring of parents with a history of ad also had higher blood pressure and a greater atherosclerotic burden than the offspring of parents without AD. Also their response to the pro-inflammatory cytokine was significantly higher.

CONCLUSION

Hypertension and an inherited pro-inflammatory cytokine profile in middle age are early risk factors that contribute to the development of ad in old age. Offspring with a parental history of AD should therefore be offered screening and treatment for hypertension and have their blood pressure checked so that the development of AD in old age can be prevented.

New research criteria for the diagnosis of Alzheimer's disease applied in a memory clinic population

BACKGROUND

In the newly proposed research criteria for Alzheimer's disease (AD), patients are defined as having memory dysfunction in addition to either hippocampal atrophy or an abnormal cerebrospinal fluid (CSF) profile. This study applies the criteria in a memory clinic population, using clinical criteria as the reference criterion.

METHODS

138 AD patients, 145 nondemented subjects, 78 patients with other dementias and 91 patients with mild cognitive impairment (MCI) were included. Dichotomized medial temporal lobe atrophy (MTA) score on MRI and dichotomized CSF profiles (based on beta-amyloid1-42, tau and phosphorylated tau at threonine 181 levels) were used in combination with an episodic memory test to assess sensitivity, specificity and likelihood ratios (LR) of the newly proposed criteria and their components separately.

RESULTS

We found specificities of 95 and 49% for comparison with nondemented subjects and other demented patients, respectively, with a sensitivity of 86% for AD. Specificity was highest (100 and 77%, respectively, LR+ = 48) when both MTA score and CSF profile were abnormal in addition to the episodic memory test, at the cost of a low sensitivity (48%).

CONCLUSION

The newly proposed research criteria for AD yield a good specificity for comparison with nondemented subjects. When the type of dementia is clinically doubted, however, at least two supportive features should be considered (i.e. abnormal MTA score and CSF profile) in addition to memory impairment as core diagnostic criterion.

Frontal lobe white matter hyperintensities and neurofibrillary pathology in the oldest old

BACKGROUND

Current studies suggest an interaction between vascular mechanisms and neurodegenerative processes that leads to late-onset Alzheimer disease (AD). We tested whether AD pathology was associated with white matter hyperintensities (WMH) or cerebral infarcts in the oldest old individuals.

METHODS

Brains from 132 subjects over 85 years old, who came to autopsy from the Vantaa 85+ population-based cohort, were scanned by postmortem MRI and examined for neuropathologic changes. Coronal images were analyzed to determine the degree of frontal and parietal periventricular WMH (PVWMH) and deep WMH (DWMH) and cerebral infarcts. Neuropathologic variables included Consortium to Establish a Registry for Alzheimer's Disease scores for neuritic plaques and Braak staging among subjects in 5 groups: normal aging (NA), borderline with insufficient AD pathology, AD, AD plus other pathology, and other primary degenerative diseases.

RESULTS

Frontal DWMH were detected in >50% of the sample. Both frontal PVWMH and DWMH were significantly more extensive in the AD group compared to the NA group or the NA and borderline groups combined. Frontal PVWMH and DWMH were also associated with increased Braak staging (p = 0.03) and the neuritic plaque load (p = 0.01). Further analysis revealed there were a greater number of cerebral infarcts associated with frontal DWMH (p = 0.03) but not with frontal PVWMH.

CONCLUSIONS

Our study showed an association between neurofibrillary pathology and frontal PVWMH and DWMH (rather than parietal), as a surrogate of small vessel disease, particularly in very old community-dwelling individuals.

Neurological signs in relation to white matter hyperintensity volumes in memory clinic patients

PURPOSE

To determine the frequency of neurological signs in a memory clinic population and to explore their associations with white matter hyperintensity (WMH).

METHODS

We included patients with Alzheimer disease (AD; n = 210), vascular dementia (VaD; n = 34), mild cognitive impairment (MCI; n = 86) and subjective complaints (n = 153). The presence of extrapyramidal and unilateral signs was assessed from medical charts. On MRI, WMH volumes were extracted automatically.

RESULTS

Extrapyramidal signs were found in 10% and unilateral signs in 12% of the patients. Age- and sex-adjusted extrapyramidal signs occurred more often in VaD compared to patients with subjective complaints. Unilateral signs were more prevalent in all groups compared to patients with subjective complaints. Two-way analysis of variance (ANOVA) with WMH as the dependent variable showed a main effect of diagnosis (p < 0.001), but not of extrapyramidal signs (p = 0.62). In contrast, 2-way ANOVA showed main effects of diagnosis (p < 0.001) and unilateral signs (p = 0.001). Furthermore, there was an interaction between these factors (p = 0.04); if unilateral signs were present, patients with subjective complaints and VaD showed more WMH, whereas there was no relation in AD and MCI.

CONCLUSION

Extrapyramidal and unilateral signs are common in memory clinic patients, but are only modestly related to WMH.

Glycemia and levels of cerebrospinal fluid amyloid and tau in patients attending a memory clinic

OBJECTIVES

To determine the association between markers of glycemia and cerebrospinal fluid (CSF) amyloid beta 1-42 (Abeta42) and tau levels in patients attending a memory clinic.

DESIGN

Cross-sectional study.

SETTING

Memory clinic.

PARTICIPANTS

Two hundred forty-five consecutive patients attending a memory clinic. Clinical diagnoses were subjective cognitive complaints (n=91), mild cognitive impairment (n=62), Alzheimer's disease (n=58), and other dementia (n=34). Twenty-one patients had diabetes mellitus.

MEASUREMENTS

Glycosylated hemoglobin (HbA1c); fasting blood glucose levels; and CSF levels of Abeta42, total tau, and p-tau 181.

RESULTS

In regression analyses across the whole study sample adjusted for age, sex, and diagnostic group, there was no relationship between HbA1c or fasting glucose and CSF tau, p-tau 182, or Abeta42 levels. Stratification for diabetes mellitus did not change the results.

CONCLUSION

These observations do not support the hypothesis that the association between dysglycemia and impaired cognitive functioning is mediated through aberrant amyloid or tau metabolism.

Relationship between baseline white-matter changes and development of late-life depressive symptoms: 3-year results from the LADIS study

BACKGROUND

Growing evidence suggests that cerebral white-matter changes and depressive symptoms are linked directly along the causal pathway. We investigated whether baseline severity of cerebral white-matter changes predict longer-term future depressive outcomes in a community sample of non-disabled older adults.

METHOD

In the Leukoaraiosis and Disability in the Elderly (LADIS) study, a longitudinal multi-centre pan-European study, 639 older subjects underwent baseline structural magnetic resonance imaging (MRI) and clinical assessments. Baseline severity of white-matter changes was quantified volumetrically. Depressive outcomes were assessed in terms of depressive episodes and depressive symptoms, as measured by the Geriatric Depression Scale (GDS). Subjects were clinically reassessed annually for up to 3 years. Regression models were constructed to determine whether baseline severity of white-matter changes predicted future depressive outcomes, after controlling for confounding factors.

RESULTS

Baseline severity of white-matter changes independently predicted depressive symptoms at both 2 (p<0.001) and 3 years (p=0.015). Similarly, white-matter changes predicted incident depression (p=0.02). Over the study period the population became significantly more disabled (p<0.001). When regression models were adjusted to account for the influence of the prospective variable transition to disability, baseline severity of white-matter changes no longer predicted depressive symptoms at 3 years (p=0.09) or incident depression (p=0.08).

CONCLUSIONS

Our results support the vascular depression hypothesis and strongly implicate white-matter changes in the pathogenesis of late-life depression. Furthermore, the findings indicate that, over time, part of the relationship between white-matter changes and depression may be mediated by loss of functional activity.

CSF biomarkers predict rate of cognitive decline in Alzheimer disease

OBJECTIVE

CSF biomarkers amyloid beta 1-42 (Abeta(42)), total tau (tau), and tau phosphorylated at threonine 181 (p-tau-181) are useful diagnostic markers for Alzheimer disease (AD). Less is known about these biomarkers as predictors for further cognitive decline in patients with AD. We hypothesized that high tau, especially in combination with relatively low p-tau-181, is a marker of rapid decline, since it has been associated with fast neuronal degeneration.

METHODS

A total of 151 patients with AD of whom we had baseline CSF were included from our memory clinic. All patients had at least 2 Mini-Mental State Examination (MMSE) scores, obtained no less than 1 year apart. Linear mixed models were used to assess associations between CSF biomarkers and the rate of cognitive decline as measured with the MMSE. CSF biomarkers were used in quintiles, random intercept and random slope with time were assumed, and the analyses were corrected for sex and age.

RESULTS

The patients with AD (45% women, age 66 +/- 9 years, baseline MMSE 22 +/- 4) had a follow-up period of 2.0 (1.0-5.0) years. Linear mixed models revealed no relations between any CSF biomarker and baseline MMSE. However, CSF biomarkers did predict cognitive decline over time. A low p-tau-181/tau ratio was the strongest predictor with a dose-dependent effect (lowest vs highest quintile: 2.9 vs 1.3 MMSE points annual decline, p for trend <0.001). In addition, low Abeta(42), high tau, and high tau/Abeta(42)-ratio were associated with rapid cognitive decline (p < 0.05).

CONCLUSION

At the time of diagnosis, a combination of high CSF tau without proportionally elevated p-tau-181 is associated with a faster rate of cognitive decline.

Moving forward with nutrition in Alzheimer's disease

Alzheimer's disease (AD) is the epidemic of the 21st century but still relatively little is known about the causes of the disease. Nutrient deficiencies, associated with loss of cognitive function, are frequently reported in patients with AD and currently available epidemiologic evidence suggests that an increased intake of certain nutrients may lower the risk of AD. Current treatment options offer only symptomatic relief, however, there is a growing body of evidence that nutrition in general and 'nutritional intervention' in a clinical setting may be able to play a key role in the management of the disease. However, randomized clinical trials are needed to test this approach. The Souvenir study is the first randomized, controlled, double-blind, multi-centre study designed to evaluate the efficacy of a multi-nutrient dietary approach on cognitive performance in drug-naïve early AD patients.

Baseline CSF p-tau levels independently predict progression of hippocampal atrophy in Alzheimer disease

OBJECTIVE

To investigate whether baseline CSF biomarkers are associated with hippocampal atrophy rate as a measure of disease progression in patients with Alzheimer disease (AD), patients with mild cognitive impairment (MCI), and controls, controlling for baseline neuropsychological and MRI findings.

METHODS

We assessed data from 31 patients with AD, 25 patients with MCI, and 19 controls (mean age 68 +/- 8 years; 39 [52%] female) who visited our memory clinic and had received serial MRI scanning (scan interval 1.7 +/- 0.7 years). At baseline, CSF biomarkers (amyloid beta 1-42, tau, and tau phosphorylated at threonine 181 [p-tau]) were obtained, as well as neuropsychological data. Baseline MRI scans were assessed using visual rating scales for medial temporal lobe atrophy (MTA), global cortical atrophy, and white matter hyperintensities. Hippocampal atrophy rates were estimated using regional nonlinear "fluid" registration of follow-up scan to baseline scan.

RESULTS

Stepwise multiple linear regression, adjusted for age and sex, showed that increased CSF p-tau levels (beta [standard error]: -0.79 [0.35]) at baseline was independently associated with higher subsequent hippocampal atrophy rates (p < 0.05), together with poorer memory performance (0.09 [0.04]) and more severe MTA (-0.60 [0.21]). The association of memory function with hippocampal atrophy rate was explained by the link with diagnosis, because it disappeared from the model after we additionally corrected for diagnosis.

CONCLUSIONS

Baseline CSF levels of tau phosphorylated at threonine 181 are independently associated with subsequent disease progression, as reflected by hippocampal atrophy rate. This effect is independent of baseline neuropsychological and MRI predictors. Our results imply that predicting disease progression can best be achieved by combining information from different modalities.