A proof-of-concept study applying machine learning methods to putative risk factors for eating disorders: results from the multi-centre European project on healthy eating

BACKGROUND

Despite a wide range of proposed risk factors and theoretical models, prediction of eating disorder (ED) onset remains poor. This study undertook the first comparison of two machine learning (ML) approaches [penalised logistic regression (LASSO), and prediction rule ensembles (PREs)] to conventional logistic regression (LR) models to enhance prediction of ED onset and differential ED diagnoses from a range of putative risk factors.

METHOD

Data were part of a European Project and comprised 1402 participants, 642 ED patients [52% with anorexia nervosa (AN) and 40% with bulimia nervosa (BN)] and 760 controls. The Cross-Cultural Risk Factor Questionnaire, which assesses retrospectively a range of sociocultural and psychological ED risk factors occurring before the age of 12 years (46 predictors in total), was used.

RESULTS

All three statistical approaches had satisfactory model accuracy, with an average area under the curve (AUC) of 86% for predicting ED onset and 70% for predicting AN v. BN. Predictive performance was greatest for the two regression methods (LR and LASSO), although the PRE technique relied on fewer predictors with comparable accuracy. The individual risk factors differed depending on the outcome classification (EDs v. non-EDs and AN v. BN).

CONCLUSIONS

Even though the conventional LR performed comparably to the ML approaches in terms of predictive accuracy, the ML methods produced more parsimonious predictive models. ML approaches offer a viable way to modify screening practices for ED risk that balance accuracy against participant burden.

PER2 C111G polymorphism, cognitive reserve and cognition in subjective cognitive decline and mild cognitive impairment: a 10-year follow-up study

BACKGROUND AND PURPOSE

CLOCK and PER2 genes have been implicated in sleep-wake cycle alterations and neurodegenerative diseases. Our aim was to evaluate the effect of CLOCK T3111C and PER2 C111G on cognitive functioning in subjective cognitive decline (SCD) patients and mild cognitive impairment (MCI) patients at the baseline of a longitudinal study, and the effect of these two polymorphisms on the progression to Alzheimer's disease (AD) of the two groups.

METHODS

Sixty-eight subjects (41 SCD and 27 MCI) who underwent clinical evaluation, neuropsychological assessment, CLOCK and PER2 genotyping at baseline and neuropsychological follow-up every 2 years for a mean time of 10 years were included. Subjects who developed AD (SCD-c and MCI-c) and non-converters (SCD-nc, MCI-nc) were considered.

RESULTS

CLOCK T3111C was detected in 47% of cases (21 SCD, 11 MCI) and PER2 C111G in 19% of cases (eight SCD and five MCI). PER2 G carriers presented lower premorbid intelligence score (P = 0.049), fewer years of education (P = 0.007) and a lower frequency of family history of AD (P = 0.04) than G non-carriers. MCI PER2 G carriers had worse performance in tests assessing memory, executive function, language and visuospatial abilities at baseline. During follow-up, two SCD and 15 MCI subjects progressed to AD: both of the SCD-c subjects presented the PER2 G allele, while none of the SCD PER2 G non-carriers converted to AD (P = 0.003).

CONCLUSION

PER2 seems to have a role in cognitive reserve and cognition in SCD and MCI patients. Nevertheless, further studies are needed to assess the role of PER2 C111G on the risk of progression to AD.

Mediterranean Diet, Food Consumption and Risk of Late-Life Depression: The Mugello Study

OBJECTIVES

To investigate eating habits and adherence to Mediterranean Diet (MD) in relation to the risk of depression in a cohort of nonagenarians enrolled within the Mugello Study, an epidemiological study aimed at investigating both clinically relevant geriatric items and various health issues, including those related to nutritional status.

DESIGN

Cross-sectional study.

SETTING

Homes and nursing homes in the Mugello area, Florence, Italy.

PARTICIPANTS

Subjects aged 90-99 years [N=388 (271F; 117M) mean age: 92.7±3.1].

MEASUREMENTS

All subjects were evaluated through questionnaires and instrumental examinations. Adherence to MD was assessed through the Mediterranean Diet Score. A shorter version of the Geriatric Depression Scale (GDS) was used to detect the possible presence of depressive symptoms. In addition, cognitive and functional status was assessed using the Mini-Mental State Examination, the Clock Drawing Test, as well as the Basic and Instrumental Activities of Daily Living test.

RESULTS

Depressed subjects (DS) (GDS score≥5, 43.8%) were older, females and widows, than non-depressed subjects (NDS). DS reported a slightly but not statistically significant lower MD score than NDS (33.9±3.9 vs. 34.6±3.3, p=0.149). Subjects who reported to consume a greater amount of olive oil and fruit were associated with a lower risk of depression (OR=0.35, 95%CI=0.20-0.59, p<0.001 and OR=0.46, 95%CI=0.26-0.84, p=0.011, respectively) after adjustment for many possible confounders. Similar results were obtained for women, while no statistically significant differences emerged for men.

CONCLUSION

Our results support the hypothesis that a diet rich in olive oil and fruit, characteristics of MD, may protect against the development of depressive symptoms in older age.

Higher uric acid serum levels are associated with better muscle function in the oldest old: Results from the Mugello Study

BACKGROUND

Sarcopenia is the progressive loss of muscle mass and strength that occurs with advancing age and plays a pivotal role in the causal pathway leading to frailty, disability and, eventually, to death among older persons. As oxidative damage of muscle proteins has been shown to be a relevant contributory factor, in this study we hypothesized that uric acid (UA), a powerful endogenous antioxidant, might exert a protective effect on muscle function in the oldest old and we tested our hypothesis in a group of nonagenarians who participated in the Mugello Study.

METHODS

239 subjects, 73 men and 166 women, mean age 92.8years±SD 3.1, underwent the assessment of UA serum level and isometric handgrip strength, a widely used clinical measure of sarcopenia.

RESULTS

Mean UA serum level was 5.69mg/dL±SD 1.70 and mean handgrip strength was 15.0kg±SD 6.9. After adjusting for relevant confounders, higher UA serum levels remained independent positive predictors of isometric handgrip strength (β 1.24±SE(β) 0.43, p=0.005).

CONCLUSION

Our results show that higher UA serum levels are associated with better muscle function in the oldest old and, accordingly, might slow down the progression of sarcopenia.

Response to interferon-beta therapy in relapsing-remitting multiple sclerosis: a comparison of different clinical criteria

We assessed the proportion and potential predictors of response to interferon-beta (IFNβ) therapy in relapsing-remitting (RR) multiple sclerosis (MS) patients, comparing different definitions of response: a) lower relapse rate during therapy compared to the year and the two years before therapy, b) reduction of relapse rate during therapy of at least 30% compared to the two years before therapy, c) no relapse during treatment, d) no progression on the Expanded Disability Status Scale (EDSS). Among 147 RR patients treated for at least one year, 33 received IFNβ-1b subcutaneously (SC) (Betaferon), 59 IFNβ-1a intramuscularly (Avonex) and 55 IFNβ-1a SC (Rebif). Using definitions a), b) and d), 72%, 73% and 73% patients, respectively, were considered responders. Forty-four per cent of our patients were completely relapse free. In the logistic regression model, using definitions a) and b), a higher relapse rate in the two years preceding the therapy turned out to be a significant predictor of response. Considering definition c), lower baseline relapse rate was associated with a more favourable response.

Interobserver agreement on Poser’s and the new McDonald’s diagnostic criteria for multiple sclerosis

We assessed the interobserver agreement on the diagnosis of multiple sclerosis (MS) in a study sample consisting of 41 MS (15 relapsing -remitting, two secondary progressive, five primary progressive and 19 presenting their first clinical attack) and three non-MS cases. C linical and paraclinical information was recorded in standardized forms. Four neurologists were asked to make a diagnosis using Poser’s and McDonald’s criteria and to assess MRI scans according to the McDonald’s guidelines. In terms of the kappa statistic (k), we found a moderate agreement on the overall diagnosis using both Poser’s and McDonald’s criteria (k, respectively, 0.57 and 0.52). A s for distinct diagnostic categories, we observed a moderate to substantial agreement for the three McDonald categories (range of k values 0.49-0.64) and a fair to substantial agreement for the nine Poser categories (range of k values 0.37-0.67). Taking into account clinical information, the agreement on dissemination over time was substantially higher (k=0.69) than that found on dissemination over space (k=0.46). In contrast, for MRI assessment, the agreement for spatial dissemination was substantial (k=0.74) compared with the fair agreement (k=0.25) yielded by dissemination over time. The new McDonald’s criteria yield a good overall diagnostic reliability, and compare favourably with Poser’s classification in terms of agreement on distinct diagnostic categories.

Italian Frontotemporal Dementia Network (FTD Group-SINDEM): sharing clinical and diagnostic procedures in Frontotemporal Dementia in Italy

In the prospect of improved disease management and future clinical trials in Frontotemporal Dementia, it is desirable to share common diagnostic procedures. To this aim, the Italian FTD Network, under the aegis of the Italian Neurological Society for Dementia, has been established. Currently, 85 Italian Centers involved in dementia care are part of the network. Each Center completed a questionnaire on the local clinical procedures, focused on (1) clinical assessment, (2) use of neuroimaging and genetics; (3) support for patients and caregivers; (4) an opinion about the prevalence of FTD. The analyses of the results documented a comprehensive clinical and instrumental approach to FTD patients and their caregivers in Italy, with about 1,000 newly diagnosed cases per year and 2,500 patients currently followed by the participating Centers. In analogy to other European FTD consortia, future aims will be devoted to collect data on epidemiology of FTD and its subtypes and to provide harmonization of procedures among Centers.

Genetics of Alzheimer's Disease and Frontotemporal Dementia

The genetics of neurodegenerative diseases has an important role to clarify the pathogenetic mechanism, the diagnosis and finally the therapeutic and ethical implications. Moreover, the genetic approach to the study of the main clinical forms of dementia (Alzheimer's disease-AD and Frontotemporal Dementia-FTD) suggests clinical guidelines for helping families to navigate through these complexities. AD and FTD are multifactorial, genetically complex diseases involving many candidate genes. Mutations in three genes (i.e. Amyloid Precursor Protein, APP; presenilin 1, PSEN1; presenilin 2, PSEN2) have been linked to 50% of all familial forms of AD (FAD). Genome wide association studies (GWAS) have involved an increasing number of genes with a possible role in the disease pathogenesis. Up to now, the genetics of familial forms of FTD is related to 7 genes: the microtubule-associated protein tau (MAPT) progranulin (GRN), the valosin-containing protein (VCP), chromatin-modifying 2B (CHMP2B), the TARDNA binding protein 43 encoding gene (TARBDP), fused in sarcoma (FUS) and the last hexanucleotide expansion repeats in the open reading frame of chromosome 9 (C9orf72). Pre-test counseling and the identification of genetic defects are important in both patients and asymptomatic at risk family members.

Recommendations of the Sleep Study Group of the Italian Dementia Research Association (SINDem) on clinical assessment and management of sleep disorders in individuals with mild cognitive impairment and dementia: a clinical review

Clinical assessment and management of sleep disturbances in patients with mild cognitive impairment and dementia has important clinical and social implications. Poor sleep results in an increased risk of morbidities and mortality in demented patients and is a source of stress for caregivers. Sleep disturbances show high prevalence in mild cognitive impairment and dementia patients and they are often associated one to another in the same patient. A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of individuals with cognitive decline. The Sleep Study Group of the Italian Dementia Research Association (SINDem) reviewed evidence from original research articles, meta-analyses and systematic reviews published up to December 2013. The evidence was classified in quality levels (I, II, III) and strength of recommendations (A, B, C, D, E). Where there was a lack of evidence, but clear consensus, good practice points were provided. These recommendations may not be appropriate for all circumstances and should therefore be adopted only after a patient's individual characteristics have been carefully evaluated.

Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease

Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.

EFNS-ENS Guidelines on the diagnosis and management of disorders associated with dementia

BACKGROUND AND OBJECTIVES

The last version of the EFNS dementia guidelines is from 2007. In 2010, the revised guidelines for Alzheimer's disease (AD) were published. The current guidelines involve the revision of the dementia syndromes outside of AD, notably vascular cognitive impairment, frontotemporal lobar degeneration, dementia with Lewy bodies, corticobasal syndrome, progressive supranuclear palsy, Parkinson's disease dementia, Huntington's disease, prion diseases, normal-pressure hydrocephalus, limbic encephalitis and other toxic and metabolic disorders. The aim is 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 dementing disorders. It represents a statement of minimum desirable standards for practice guidance.

METHODS

The task force working group reviewed evidence from original research articles, meta-analyses and systematic reviews, published by June 2011. The evidence was classified (I, II, III, IV) 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 AND CONCLUSIONS

New recommendations and good practice points are made for clinical diagnosis, blood tests, neuropsychology, neuroimaging, electroencephalography, cerebrospinal fluid (CSF) analysis, genetic testing, disclosure of diagnosis, treatment of behavioural and psychological symptoms in dementia, legal issues, counselling and support for caregivers. All recommendations were revised as compared with the previous EFNS guidelines. The specialist neurologist together with primary care physicians play an important role in the assessment, interpretation and treatment of symptoms, disability and needs of dementia patients.

Alternative normalization methods demonstrate widespread cortical hypometabolism in untreated de novo Parkinson's disease

AIM

Previous positron emission tomography (PET) [18F]fluorodeoxyglucose ([18F]FDG) studies in Parkinson's disease (PD) demonstrated that moderate to late stage patients display widespread cortical hypometabolism, whereas early stage PD patients exhibit little or no cortical changes. However, recent studies suggested that conventional data normalization procedures may not always be valid, and demonstrated that alternative normalization strategies better allow detection of low magnitude changes. We hypothesized that these alternative normalization procedures would disclose more widespread metabolic alterations in de novo PD.

METHODS

[18F]FDG PET scans of 26 untreated de novo PD patients (Hoehn & Yahr stage I-II) and 21 age-matched controls were compared using voxel-based analysis. Normalization was performed using gray matter (GM), white matter (WM) reference regions and Yakushev normalization.

RESULTS

Compared to GM normalization, WM and Yakushev normalization procedures disclosed much larger cortical regions of relative hypometabolism in the PD group with extensive involvement of frontal and parieto-temporal-occipital cortices, and several subcortical structures. Furthermore, in the WM and Yakushev normalized analyses, stage II patients displayed more prominent cortical hypometabolism than did stage I patients.

CONCLUSION

The use of alternative normalization procedures, other than GM, suggests that much more extensive cortical hypometabolism is present in untreated de novo PD patients than hitherto reported. The finding may have implications for our understanding of the basic pathophysiology of early-stage PD.

Prevalence of sleep disturbances in mild cognitive impairment and dementing disorders: a multicenter Italian clinical cross-sectional study on 431 patients

BACKGROUND/AIMS

Sleep disturbances are common in the elderly and in persons with cognitive decline. The aim of this study was to describe frequency and characteristics of insomnia, excessive daytime sleepiness, sleep-disordered breathing, REM behavior disorder and restless legs syndrome in a large cohort of persons with mild cognitive impairment or dementia.

METHODS

431 consecutive patients were enrolled in 10 Italian neurological centers: 204 had Alzheimer's disease, 138 mild cognitive impairment, 43 vascular dementia, 25 frontotemporal dementia and 21 Lewy body dementia or Parkinson's disease dementia. Sleep disorders were investigated with a battery of standardized questions and questionnaires.

RESULTS

Over 60% of persons had one or more sleep disturbances almost invariably associated one to another without any evident and specific pattern of co-occurrence. Persons with Alzheimer's disease and those with mild cognitive impairment had the same frequency of any sleep disorder. Sleep-disordered breathing was more frequent in vascular dementia. REM behavior disorder was more represented in Lewy body or Parkinson's disease dementia.

CONCLUSION

A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of persons with cognitive decline. Instrumental supports should be used only in selected patients.

Education and occupation provide reserve in both ApoE ε4 carrier and noncarrier patients with probable Alzheimer's disease

According to the reserve hypothesis, a high educational/occupational attainment can modulate Alzheimer's disease (AD) clinical expression. The impact of the Apolipoprotein E (ApoE) ε4 allele on the reserve mechanism in AD has not been assessed. Aim of this European multicenter study was to evaluate the metabolic correlates of reserve and ApoE genotype in early probable AD. 51 AD subjects, 27 ε4 carriers, and 24 noncarriers, underwent FDG-PET brain imaging. We used the general linear model as implemented in SPM2 to test for the linear correlation of a reserve index, accounting for both educational and occupational level, with brain glucose metabolism, controlling for demographic variables (age and gender) and for cognitive performance. We found an inverse correlation between a reserve index, accounting for educational/occupational level, and metabolism in the posterior cingulate cortex and precuneus in both ε4 carriers and noncarriers, and no significant difference between the groups. We show that education and occupation act as proxies for reserve in ε4 carriers, compensating for an unfavorable genetic background; we also show that the degree of compensation does not differ significantly by ApoE ε4 status.

APOE and Alzheimer disease: a major gene with semi-dominant inheritance

Apolipoprotein E (APOE) dependent lifetime risks (LTRs) for Alzheimer Disease (AD) are currently not accurately known and odds ratios alone are insufficient to assess these risks. We calculated AD LTR in 7351 cases and 10 132 controls from Caucasian ancestry using Rochester (USA) incidence data. At the age of 85 the LTR of AD without reference to APOE genotype was 11% in males and 14% in females. At the same age, this risk ranged from 51% for APOE44 male carriers to 60% for APOE44 female carriers, and from 23% for APOE34 male carriers to 30% for APOE34 female carriers, consistent with semi-dominant inheritance of a moderately penetrant gene. Using PAQUID (France) incidence data, estimates were globally similar except that at age 85 the LTRs reached 68 and 35% for APOE 44 and APOE 34 female carriers, respectively. These risks are more similar to those of major genes in Mendelian diseases, such as BRCA1 in breast cancer, than those of low-risk common alleles identified by recent GWAS in complex diseases. In addition, stratification of our data by age groups clearly demonstrates that APOE4 is a risk factor not only for late-onset but for early-onset AD as well. Together, these results urge a reappraisal of the impact of APOE in Alzheimer 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.

Alzheimer's disease: genetic basis and amyloid imaging as endophenotype

To date, all known Alzheimer's disease genes influence amyloid β (Aβ). Imaging of Aβ deposition in the human brain using positron emission tomography (PET) tracers as [11C]Pittsburgh Compound B ([(11)C]PiB) or [18F]FDDNP offers the possibility of using cortical tracer binding as a quantitative endophenotype for genetic studies of late-onset Alzheimer's disease (AD). In this review we investigate the association between cerebral Aβ burden, as measured by amyloid PET imaging, and different genetic risk factors involved in AD. Through a look at the major genetic risk factors for both early-onset familial and late-onset sporadic forms of AD, we discuss the possible role of amyloid PET imaging as an endophenotype in AD. Several PET studies confirmed the high heritability of amyloid load estimated by PET imaging and its association with the major genetic risk factors for early and late onset AD, suggesting that cerebral binding of these amyloid tracers could represent an useful trait for large-scale genetic studies of AD.

IgM monoclonal gammopathy-associated neuropathies with different IgM specificity

BACKGROUND AND PURPOSE

  Antibodies directed against myelin-associated glycoprotein (MAG) are believed to be the most frequent biologic marker of the neuropathies associated with IgM monoclonal gammopathy of undetermined significance (MGUS). The objective of this study was to examine the prevalence of antiganglioside and/or sulfatide-positive patients and their clinical findings, including therapeutic response, compared to anti-MAG-positive or seronegative patients.

METHODS

  We prospectively followed 46 patients with MGUS who were diagnosed in our tertiary referral centers for polyneuropathy since 1997. All patients underwent nerve conduction studies and were tested for anti-MAG, gangliosides, and sulfatide antibodies. All the anagraphic and clinical data (including symptoms, disability scale, therapy, secondary malignancy development) were recorded in a database and compared between three patients' groups (anti-MAG-positive; antiganglioside/sulfatide-positive; no reactivity).

RESULTS

  Anti-MAG reactivity was present in 17 (37%) patients; other 17 patients (37%) had antiganglioside/sulfatide reactivity and 12 (26%) had no reactivity. Patients with antiganglioside/sulfatide positivity, although heterogeneous by a clinical and neurophysiological point of view, had the most severe neuropathic manifestations and a higher disability score at nadir (P < 0.001). These patients had a better response to both intravenous immunoglobulin therapy and rituximab.

CONCLUSIONS

  Our results suggest that antiganglioside/sulfatide-positive patients form a relevant portion of patients with MGUS-associated polyneuropathy seen in tertiary care centers and should be considered in future studies on treatment response.

Worldwide distribution of PSEN1 Met146Leu mutation: a large variability for a founder mutation

OBJECTIVE

Large kindreds segregating familial Alzheimer disease (FAD) offer the opportunity of studying clinical variability as observed for presenilin 1 (PSEN1) mutations. Two early-onset FAD (EOFAD) Calabrian families with PSEN1 Met146Leu (ATG/CTG) mutation constitute a unique population descending from a remote common ancestor. Recently, several other EOFAD families with the same mutation have been described worldwide.

METHODS

We searched for a common founder of the PSEN1 Met146Leu mutation in families with different geographic origins by genealogic and molecular analyses. We also investigated the phenotypic variability at onset in a group of 50 patients (mean age at onset 40.0 +/- 4.8 years) by clinical, neuropsychological, and molecular methodologies.

RESULTS

EOFAD Met146Leu families from around the world resulted to be related and constitute a single kindred originating from Southern Italy before the 17th century. Phenotypic variability at onset is broad: 4 different clinical presentations may be recognized, 2 classic for AD (memory deficits and spatial and temporal disorientation), whereas the others are expressions of frontal impairment. The apathetic and dysexecutive subgroups could be related to orbital-medial prefrontal cortex and dorsolateral prefrontal cortex dysfunction.

CONCLUSIONS

Genealogic and molecular findings provided evidence that the PSEN1 Met146Leu families from around the world analyzed in this study are related and represent a single kindred originating from Southern Italy. The marked phenotypic variability might reflect early involvement by the pathologic process of different cortical areas. Although the clinical phenotype is quite variable, the neuropathologic and biochemical characteristics of the lesions account for neurodegenerative processes unmistakably of Alzheimer nature.

ApolipoproteinE epsilon 4 allele is not associated with disease course and severity in multiple sclerosis

BACKGROUND

No study has assessed the association between apolipoproteinE (APOE) and multiple sclerosis (MS) forms grouped by also taking into account cognitive performance.

AIMS OF THE STUDY

To assess the relationship between APOE and disease course, particularly focusing on benign MS (BMS), defined as also including cognitive preservation.

METHODS

In 173 consecutive patients, we assessed the association between APOE and MS course and severity.

RESULTS

Twenty-nine APOE-epsilon4 carriers were identified. The epsilon4 allele was not associated with BMS. Moreover, it was associated neither with other disease courses nor with the time to reach disability milestones and secondary progression.

CONCLUSION

Although plausible, the association between APOE and MS course (particularly with BMS defined by including cognitive preservation) and disease severity remains controversial.

A short version of Rao's Brief Repeatable Battery as a screening tool for cognitive impairment in multiple sclerosis

Rao's Brief Repeatable Battery (BRB) is the most widely used instrument for cognitive evaluation in multiple sclerosis (MS). We assessed a short version of the BRB in 116 relapsing-remitting participants. We found that the administration of three tests, the Selective Reminding Test, the Paced Auditory Serial Addition Test-3 seconds and the Symbol Digit Modalities Test, was able to detect cognitive impairment with a sensitivity of 94%, a specificity of 84%, and an accuracy of 89%. On the basis of these results we developed a screening algorithm requiring 5 to 15 minutes, which may represent a highly sensitive and rapid tool to detect MS-associated cognitive impairment.

Mild cognitive impairment: loss of linguistic task-induced changes in motor cortex excitability

BACKGROUND

In amnestic mild cognitive impairment (aMCI), functional neuronal connectivity may be altered, as suggested by quantitative EEG and neuroimaging data. In young healthy humans, the execution of linguistic tasks modifies the excitability of the hand area of the dominant primary motor cortex (M1(hand)), as tested by transcranial magnetic stimulation (TMS). We used TMS to investigate functional connectivity between language-related cortical areas and M1(hand) in aMCI.

METHODS

Ten elderly women with aMCI and 10 age-matched women were recruited. All participants were right handed and underwent a neuropsychological evaluation. In the first TMS experiment, participants performed three different tasks: reading aloud, viewing of non-letter strings (baseline), and nonverbal oral movements. The second experiment included the baseline condition and three visual searching/matching tasks using letters, geometric shapes, or digits as target stimuli.

RESULTS

In controls, motor evoked potentials (MEP) elicited by suprathreshold TMS of the left M1(hand) were significantly larger during reading aloud (170% baseline) than during nonverbal oral movements, whereas no difference was seen for right M1(hand) stimulation. Similarly, MEP elicited by left M1(hand) stimulation during letter and shape searching/matching tasks were significantly larger compared to digit task. In contrast, linguistic task performance did not produce any significant MEP modulation in patients with aMCI, although neuropsychological evaluation showed normal language abilities.

CONCLUSIONS

Findings suggest that functional connectivity between the language-related brain regions and the dominant M1(hand) may be altered in amnestic mild cognitive impairment. Follow-up studies will reveal whether transcranial magnetic stimulation application during linguistic tasks may contribute to characterize the risk of conversion to Alzheimer disease.

The contribution of cerebrospinal fluid oligoclonal bands to the early diagnosis of multiple sclerosis

Background

McDonald Criteria (MDC) have been validated in selected patients at high risk for multiple sclerosis (MS). However, possible overdiagnosis of MS can represent critical issues in less controlled clinical settings.

Objective

To assess the contribution of oligoclonal bands (OB) to MS diagnosis in current clinical practice.

Methods

We included all the patients admitted to our Department since 2001 who had undergone diagnostic workup for a possible MS diagnosis, followed up for at least 1 year. We assessed the accuracy of MDC, OB, and two MDC definitions of dissemination in space (DIS-MRI: fulfillment of MRI criteria, DIS-OB: two MRI lesions+OB).

Results

We included 118 patients (median follow-up 4.0 years). Twenty-eight cases received an alternative diagnosis, whereas none of these presented OB, 43% fulfilled the DIS-MRI criteria. OB were present in 70% of the remaining 90 patients. By the end of the follow-up, 56% of the diagnoses had converted to clinically definite MS and OB showed higher accuracy than DIS-MRI fulfillment (70% vs 58%). Moreover, after 1 year and at the end of the follow-up, DIS-OB yielded a higher Specificity level in comparison with DIS-MRI.

Conclusion

OB can improve overall diagnostic Accuracy by increasing Specificity and negative predictive value.

Glucocorticoid Receptor Gene Polymorphisms in Italian Patients with Anorexia and Bulimia Nervosa

The etiopathogenesis of eating disorders (ED) is complex and poorly understood. The hypothalamic-pituitary-adrenal (HPA) axis, involved in the biological response to stress, could influence the onset and the course of ED.) Several variants in the Glucocorticoid receptor (GR) gene have been related to different metabolic parameters suggesting a possible role in ED. We studied if genetic variants of GR could represent potential risk factors for the development of Anorexia Nervosa (AN) and Bulimia Nervosa (BN).

We investigated the distribution of several single nucleotide polymorphisms (SNPs) of the GR including N363S (rs6195), Er22/23EK (rs6189-6190), A/G SNP in exon 9beta (rs6198) and the intronic BclI polymorphism (rs41423247), in 118 Italian patients affected by AN and in 108 patients with BN. Moreover we studied 116 normal individuals and 177 obese subjects. The distributions of genotypes and allele frequency of the SNPs in all studied groups followed Hardy-Weinberg equilibrium and did not significantly differ from that of controls. A trend towards association was observed in case-control association analysis (p=0.07) for rs6198. A correlation of metabolic parameters to the GR genotypes was performed.

We report the analysis of different GR SNPs for the first time in Italian patients with AN and BN. We failed to detect an allelic association between the studied SNPs in the GR gene and AN and BN.

None of the variants seems to influence these pathologies, not supporting a role for the GR gene as genetic risk factors for ED.

Education and occupation as proxies for reserve in aMCI converters and AD: FDG-PET evidence

BACKGROUND

Previous reports have shown that higher education is associated with more severe brain pathology in patients with Alzheimer disease (AD), suggesting that these individuals have a functional reserve provided by education, which masks the clinical expression of a higher degree of neurodegeneration. It is unknown if a similar reserve mechanism exists in patients with amnestic mild cognitive impairment (aMCI). The aim of this study was to assess the impact of education and occupation on brain glucose metabolism (rCMRglc) measured with FDG-PET in aMCI and in a very large sample of subjects with probable AD (pAD).

METHODS

A total of 242 patients with pAD, 72 with aMCI, and 144 healthy controls participated in the study. At follow-up, 21 subjects with aMCI progressed to AD. A regression analysis was conducted (SPM2), with education and occupation as independent variables, and rCMRglc as dependent variable, adjusting for demographic data, global cognitive status, and neuropsychological scores.

RESULTS

The analysis showed a significant association between higher education/occupation and lower rCMRglc in posterior temporoparietal cortex and precuneus in pAD and aMCI converters, and no correlation in aMCI nonconverters and healthy controls. This means that, when submitted to FDG-PET for diagnostic evaluation, pAD and aMCI converters with higher education/occupation had, for comparable cognitive impairment, a more severe rCMRglc reduction than the ones with lower education/occupation.

CONCLUSIONS

This study suggests that education and occupation may be proxies for brain functional reserve, reducing the severity and delaying the clinical expression of Alzheimer disease (AD) pathology. The results in aMCI converters suggest that functional reserve is already at play in the predementia phase of AD.

A comparison of unawareness in frontotemporal dementia and Alzheimer's disease

BACKGROUND

Loss of insight is a core diagnostic feature of frontotemporal dementia (FTD) and anosognosia is frequently reported in Alzheimer's disease (AD).

AIM

To compare unawareness (anosognosia) for different symptoms, measured with a discrepancy score between patient's and caregiver's assessment, in AD and FTD.

METHOD

In a prospective, multi-centre study, 123 patients with probable AD, selected according to the NINCDS-ADRDA procedure, were matched for age, sex, education, disease duration and dementia severity to patients with FTD (n = 41), selected according to international consensus criteria. A research complaint questionnaire was used to obtained patient's and caregiver's assessment concerning neuropsychological and behavioural symptoms. Data were compared in each group and between groups. Unawareness (measured by discrepancy scores) was compared between patients with AD and FTD.

RESULTS

The caregivers generally assessed symptoms more severely than did patients, but both patient groups reported changes in affect (depressive mood or irritability) as their caregivers did. Unawareness was greater in patients with FTD than in patients with AD for language and executive difficulties, and for changes in behaviour and daily activities.

CONCLUSION

The main finding is that unawareness was observed in both patients with FTD and patients with AD for most clinical domains. However, qualitative and quantitative differences showed that lack of awareness was greater in patients with FTD.

Influence of impaired T- and B-cell compartments on efficacy of IVIg in dysimmune neuropathies

Autoimmune mechanisms are postulated to play a role in the development and progression of dysimmune neuropathies (DN). We investigated the relation between lymphocyte number and marker expression, and disease activity in 20 patients with DN under intravenous immunoglobulins (IVIg) treatment. B- and T-lymphocyte markers were studied by flow cytometry of the expression of CD5, CD25, CD23 and CD38 markers on B cells and of CD3, CD4 and CD8 markers, respectively. These parameters were compared with those obtained from matched healthy volunteers. The proportions of CD38+ B cells were higher in patients compared with those of controls. Proportions of activated CD4+ and CD8+ T cells were comparable in peripheral blood mononuclear cells of patients and controls, but a significant reduction of the absolute numbers of CD3+, CD4+ and CD8+ cells were observed in DN patients. The percentages of CD25+ memory T cells were instead significantly increased in DN patients. Lastly, T-cell reduction and the CD19/CD38 ratio over total B (CD19+) cells directly correlated with a poor response to IVIg therapy. In DN, whereas T-cell number is reduced, activated T and B cells are increased, thus suggesting an intrinsic defect of the immune response.

Metabolic correlates of executive dysfunction

This study was designed to examine the correlations between resting-state brain glucose metabolism (CMRglc), as measured with Positron Emission Tomography and performance on executive function tasks in Alzheimer's disease (AD), while taking into account the severity of cognitive deterioration. We addressed this issue in 50 AD patients, classified as very mild (n = 22) and mild (n = 28) AD on the basis of an extensive neuropsychological battery. Thirteen healthy subjects were selected as controls for the neuropsychological measures. Statistical Parametric Mapping (SPM) was used to examine voxel-wise correlations between CMRglc and scores on selected cognitive tests of executive functions: the Stroop Test, the Trail Making Test, the Dual Task and the Phonemic Fluency, while correcting for age and global CMRglc. All analyses were done separately for the two AD subgroups. The very mild AD patients showed significant associations between Stroop and Trail Making Test scores and prefrontal regions metabolism, whereas the mild AD patients exhibited more widely distributed cognitive-metabolic correlations extending to the posterior brain regions. These data suggest that a large cortical network is implicated in executive dysfunction in AD, and that the pattern of cognitive-metabolic correlations varies according to disease severity.