Psychiatric and Psychosocial Characteristics of a Cohort of Spanish Individuals Attending Genetic Counseling Due to Risk for Genetically Conditioned Dementia

Background:

Predictive genetic tests are presently effective over several medical conditions, increasing the demand among patients and healthy individuals. Considering the psychological burden suspected familial dementia may carry on individuals, assessing personality, coping strategies, and mental health could aid clinicians in findings the appropriate time for delivering genetic test results and predict compliance regarding genetic counseling and expectations towards the genetic condition depending on the outcome.

Objective:

To describe the psychiatric, psychological, and coping characteristics of a sample of Spanish individuals at risk of familial dementia before genetic test results were given.

Methods:

We included 54 first degree relatives of patients diagnosed with Alzheimer’s disease, lobar frontotemporal degeneration, or prion diseases. The NEO-FFI-R, COPE, and HADS tests evaluated personality, coping strategies, and psychological distress, respectively.

Results:

Anxiety and depression were below the cut-off point for mild severity. Conscientiousness and Agreeableness were the most preponderant personality factors, while Neuroticism was the least. Positive reinterpretation and Acceptance were the most frequent coping strategies, and Denial and Alcohol and drug use were the least used. Ongoing medical pathologies increased depression, while psychiatric disorders worsened psychological distress.

Conclusion:

Contrary to our expectations, PICOGEN candidates showed psychological distress and personality traits within normative ranges, and the use of problem-focused coping strategies prevailed over avoidance coping strategies. Nevertheless, clinicians should pay particular attention to individuals attending genetic counseling who are women, aged, and present an ongoing psychiatric disorder and psychiatric history at inclusion to ensure their mental health and adherence throughout the process.

119 NeuroToolkit CSF biomarkers track the progression of Alzheimer’s disease at very early stages

Introduction

NeuroToolkit is a set of cerebrospinal fluid (CSF) biomarkers developed to identify Alzheimer’s disease co-pathologies, identify and characterize disease progression and treatment response. We assess the association between NeuroToolkit biomarkers and cerebral amyloid deposition in the ALFA+ cohort [1].

Methods

326 cognitively unimpaired individuals from the ALFA+ cohort [1] underwent a lumbar puncture and amyloid [18F]flutemetamol PET imaging. Biomarkers in NeuroToolkit (Figure 1) were determined using prototype Roche Elecsys® assays. CSF pTau levels were measured using the Elecsys® CSF assay. We cal- culated cross-correlation values between NeuroToolkit biomarkers and Centiloids. Voxel-wise associations between NeuroToolkit biomarkers and [18F]flutemetamol images were sought, accounting for the effect of various demographics. Additional analyses were performed after correcting also for the Aα42/40 ratio or Centiloid values.

Results

Figure 1. Shows associations between NeuroToolkit biomarkers and Centiloids. NeuroToolkit bio- markers were significantly associated with cerebral amyloid deposition measured by [18F]flutemetamol PET (Figure 2). Correcting for global amyloid deposition, higher levels CSF YKL-40, an astroglial activity marker, were associated to increased cerebral amyloid deposition in the inferior and lateral temporal lobe, in parietal and orbitofrontal areas, and the caudate heads (Figure 3).

Conclusions

Results of NeuroToolkit biomarkers support early involvement of the astroglial response to cerebral amyloid deposition.

Disclosure

This study was conducted through a collaboration with Roche Diagnostics International. These data will be presented at Advances in Alzheimer’s and Parkinson’s Therapies. Ref: Molinuevo. TRCI 2 (2016) 82–92

gwendlyn.kollmorgen@roche.com

The European Prevention of Alzheimer's Dementia (EPAD) Longitudinal Cohort Study: Baseline Data Release V500.0

BACKGROUND

The European Prevention of Alzheimer's Dementia (EPAD) Programme is a pan-European project whose objective is to deliver a platform, adaptive, Phase 2 proof of concept (PoC) trial for the secondary prevention of Alzheimer's dementia. A component of this platform is the Longitudinal Cohort Study (LCS) which acts as a readiness cohort for the PoC Trial as well as generating data for disease modelling work in the preclinical and prodromal phases of Alzheimer's dementia.

OBJECTIVES

The first data wave has been collected, quality checked, released and now available for analysis to answer numerous research questions. Here we describe the results from key variables in the EPAD LCS with the objective of using these results to compliment analyses of these data in the future.

DESIGN

EPAD LCS is a cohort study whose primary objective is as a readiness cohort for the EPAD PoC Trial. As such recruitment is not capped at any particular number but will continue to facilitate delivery of the EPAD PoC Trial. Research Participants are seen annually (with an additional 6 month visit in the first year).

SETTING

The EPAD Trial Delivery Network comprises currently 21 centres across Europe.

PARTICIPANTS

Research participants are included if they are over 50 years old and do not have a diagnosis of dementia.

MEASUREMENTS

All research participants undergo multiple assessments to fully characterise the biology of Alzheimer's disease and relate this to risk factors (both fixed and modifiable) and biomarker expression of disease through brain imaging, fluid samples (CSF, blood, urine and saliva), cognitive performance, functional abilities and neuropsychiatric symptomatology.

RESULTS

V500.0 represents the first 500 research participants baselined into EPAD LCS. The mean age was 66.4 (SD=6.7) and 47.8% were male. The data was split for presentation into 4 groups: [1] CDR=0 and Amyloid + (preclinical AD), [2] CDR=0 and Amyloid -, [3] CDR=0.5 and Amyloid + (prodromal AD) and [4] CDR=0.5 and Amyloid -.

CONCLUSIONS

The EPAD LCS is achieving its primary objective of trial readiness and the structured approach to data release as manifest by this first data release of V500.0 will assist researchers to describe and compare their findings as well as in systematic reviews and meta-analyses. It is anticipated given current recruitment rates that V1500.0 data release will take place in Autumn 2019. V500.1 (when the 1 year follow up is completed on the V500.0 (sub)cohort will be in Autumn 2019 also.

Anti-Tau Trials for Alzheimer's Disease: A Report from the EU/US/CTAD Task Force

Efforts to develop effective disease-modifying treatments for Alzheimer's disease (AD) have mostly targeted the amyloid β (Aβ) protein; however, there has recently been increased interest in other targets including phosphorylated tau and other forms of tau. Aggregated tau appears to spread in a characteristic pattern throughout the brain and is thought to drive neurodegeneration. Both neuropathological and imaging studies indicate that tau first appears in the entorhinal cortex and then spreads to the neocortex. Anti-tau therapies currently in Phase 1 or 2 trials include passive and active immunotherapies designed to prevent aggregation, seeding, and spreading, as well as small molecules that modulate tau metabolism and function. EU/US/CTAD Task Force members support advancing the development of anti-tau therapies, which will require novel imaging agents and biomarkers, a deeper understanding of tau biology and the dynamic interaction of tau and Aβ protein, and development of multiple targets and candidate agents addressing the tauopathy of AD. Incorporating tau biomarkers in AD clinical trials will provide additional knowledge about the potential to treat AD by targeting tau.

Comparative Analysis of Different Definitions of Amyloid-β Positivity to Detect Early Downstream Pathophysiological Alterations in Preclinical Alzheimer

Amyloid-β (Aβ) positivity is defined using different biomarkers and different criteria. Criteria used in symptomatic patients may conceal meaningful early Aβ pathology in preclinical Alzheimer. Therefore, the description of sensitive cutoffs to study the pathophysiological changes in early stages of the Alzheimer's continuum is critical. Here, we compare different Aβ classification approaches and we show their performance in detecting pathophysiological changes downstream Aβ pathology. We studied 368 cognitively unimpaired individuals of the ALFA+ study, many of whom in the preclinical stage of the Alzheimer's continuum. Participants underwent Aβ PET and CSF biomarkers assessment. We classified participants as Aβ -positive using five approaches: (1) CSF Aβ42 < 1098 pg/ml; (2) CSF Aβ42/40 < 0.071; (3) Aβ PET Centiloid > 12; (4) Aβ PET Centiloid > 30 or (5) Aβ PET Positive visual read. We assessed the correlations between Aβ biomarkers and compared the prevalence of Aβ positivity. We determined which approach significantly detected associations between Aβ pathology and tau/neurodegeneration CSF biomarkers. We found that CSF-based approaches result in a higher Aβ-positive prevalence than PET-based ones. There was a higher number of discordant participants classified as CSF Aβ-positive but PET Aβ-negative than CSF Aβ-negative but PET Aβ-positive. The CSF Aβ 42/40 approach allowed optimal detection of significant associations with CSF p-tau and t-tau in the Aβ-positive group. Altogether, we highlight the need for sensitive Aβ -classifications to study the preclinical Alzheimer's continuum. Approaches that define Aβ positivity based on optimal discrimination of symptomatic Alzheimer's disease patients may be suboptimal for the detection of early pathophysiological alterations in preclinical Alzheimer.

Multipurpose Virtual Reality Environment for Biomedical and Health Applications

Virtual reality is a trending, widely accessible, and contemporary technology of increasing utility to biomedical and health applications. However, most implementations of virtual reality environments are tailored to specific applications. We describe the complete development of a novel, open-source virtual reality environment that is suitable for multipurpose biomedical and healthcare applications. This environment can be interfaced with different hardware and data sources, ranging from gyroscopes to fMRI scanners. The developed environment simulates an immersive (first-person perspective) run in the countryside, in a virtual landscape with various salient features. The utility of the developed VR environment has been validated via two test applications: an application in the context of motor rehabilitation following injury of the lower limbs and an application in the context of real-time functional magnetic resonance imaging neurofeedback, to regulate brain function in specific brain regions of interest. Both applications were tested by pilot subjects that unanimously provided very positive feedback, suggesting that appropriately designed VR environments can indeed be robustly and efficiently used for multiple biomedical purposes. We attribute the versatility of our approach on three principles implicit in the design: selectivity, immersiveness, and adaptability. The software, including both applications, is publicly available free of charge, via a GitHub repository, in support of the Open Science Initiative. Although using this software requires specialized hardware and engineering know-how, we anticipate our contribution to catalyze further progress, interdisciplinary collaborations and replicability, with regards to the usage of virtual reality in biomedical and health applications.

Cerebrospinal fluid-induced retardation of amyloid β aggregation correlates with Alzheimer's disease and the APOE ε4 allele

Misfolding and aggregation of amyloid β (Aβ) are key features of Alzheimer's disease (AD) pathogenesis, but the molecular events controlling this process are not known in detail. In vivo, Aβ aggregation and plaque formation occur in the interstitial fluid of the brain extracellular matrix. This fluid communicates freely with cerebrospinal fluid (CSF). Here, we examined the effect of human CSF on Aβ aggregation kinetics in relation to AD diagnosis and carrier status of the apolipoprotein E (APOE) ε4 allele, the main genetic risk factor for sporadic AD. The aggregation of Aβ was inhibited in the presence of CSF and, surprisingly, the effect was more pronounced in APOE ε4 carriers. However, by fractionation of CSF using size exclusion chromatography, it became evident that it was not the ApoE protein itself that conveyed the inhibition, since the retarding species eluted at lower volume, corresponding to a much higher molecular weight, than ApoE monomers. Cholesterol quantification and immunoblotting identified high-density lipoprotein particles in the retarding fractions, indicating that such particles may be responsible for the inhibition. These results add information to the yet unresolved puzzle on how the risk factor of APOE ε4 functions in AD pathogenesis.

Evolving Evidence for the Value of Neuroimaging Methods and Biological Markers in Subjects Categorized with Subjective Cognitive Decline

There is evolving evidence that individuals categorized with subjective cognitive decline (SCD) are potentially at higher risk for developing objective and progressive cognitive impairment compared to cognitively healthy individuals without apparent subjective complaints. Interestingly, SCD, during advancing preclinical Alzheimer's disease (AD), may denote very early, subtle cognitive decline that cannot be identified using established standardized tests of cognitive performance. The substantial heterogeneity of existing SCD-related research data has led the Subjective Cognitive Decline Initiative (SCD-I) to accomplish an international consensus on the definition of a conceptual research framework on SCD in preclinical AD. In the area of biological markers, the cerebrospinal fluid signature of AD has been reported to be more prevalent in subjects with SCD compared to healthy controls; moreover, there is a pronounced atrophy, as demonstrated by magnetic resonance imaging, and an increased hypometabolism, as revealed by positron emission tomography, in characteristic brain regions affected by AD. In addition, SCD individuals carrying an apolipoprotein ɛ4 allele are more likely to display AD-phenotypic alterations. The urgent requirement to detect and diagnose AD as early as possible has led to the critical examination of the diagnostic power of biological markers, neurophysiology, and neuroimaging methods for AD-related risk and clinical progression in individuals defined with SCD. Observational studies on the predictive value of SCD for developing AD may potentially be of practical value, and an evidence-based, validated, qualified, and fully operationalized concept may inform clinical diagnostic practice and guide earlier designs in future therapy trials.

Clinical and biomarker profiling of prodromal Alzheimer's disease in workpackage 5 of the Innovative Medicines Initiative PharmaCog project: a 'European ADNI study'

BACKGROUND

In the field of Alzheimer's disease (AD), the validation of biomarkers for early AD diagnosis and for use as a surrogate outcome in AD clinical trials is of considerable research interest.

OBJECTIVE

To characterize the clinical profile and genetic, neuroimaging and neurophysiological biomarkers of prodromal AD in amnestic mild cognitive impairment (aMCI) patients enrolled in the IMI WP5 PharmaCog (also referred to as the European ADNI study).

METHODS

A total of 147 aMCI patients were enrolled in 13 European memory clinics. Patients underwent clinical and neuropsychological evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG) and lumbar puncture to assess the levels of amyloid β peptide 1-42 (Aβ42), tau and p-tau, and blood samples were collected. Genetic (APOE), neuroimaging (3T morphometry and diffusion MRI) and EEG (with resting-state and auditory oddball event-related potential (AO-ERP) paradigm) biomarkers were evaluated.

RESULTS

Prodromal AD was found in 55 aMCI patients defined by low Aβ42 in the cerebrospinal fluid (Aβ positive). Compared to the aMCI group with high Aβ42 levels (Aβ negative), Aβ positive patients showed poorer visual (P = 0.001), spatial recognition (P < 0.0005) and working (P = 0.024) memory, as well as a higher frequency of APOE4 (P < 0.0005), lower hippocampal volume (P = 0.04), reduced thickness of the parietal cortex (P < 0.009) and structural connectivity of the corpus callosum (P < 0.05), higher amplitude of delta rhythms at rest (P = 0.03) and lower amplitude of posterior cingulate sources of AO-ERP (P = 0.03).

CONCLUSION

These results suggest that, in aMCI patients, prodromal AD is characterized by a distinctive cognitive profile and genetic, neuroimaging and neurophysiological biomarkers. Longitudinal assessment will help to identify the role of these biomarkers in AD progression.

Alzheimer's disease cerebrospinal fluid biomarker in cognitively normal subjects

In a large multicentre sample of cognitively normal subjects, as a function of age, gender and APOE genotype, we studied the frequency of abnormal cerebrospinal fluid levels of Alzheimer's disease biomarkers including: total tau, phosphorylated tau and amyloid-β1-42. Fifteen cohorts from 12 different centres with either enzyme-linked immunosorbent assays or Luminex® measurements were selected for this study. Each centre sent nine new cerebrospinal fluid aliquots that were used to measure total tau, phosphorylated tau and amyloid-β1-42 in the Gothenburg laboratory. Seven centres showed a high correlation with the new Gothenburg measurements; therefore, 10 cohorts from these centres are included in the analyses here (1233 healthy control subjects, 40-84 years old). Amyloid-β amyloid status (negative or positive) and neurodegeneration status (negative or positive) was established based on the pathological cerebrospinal fluid Alzheimer's disease cut-off values for cerebrospinal fluid amyloid-β1-42 and total tau, respectively. While gender did not affect these biomarker values, APOE genotype modified the age-associated changes in cerebrospinal fluid biomarkers such that APOE ε4 carriers showed stronger age-related changes in cerebrospinal fluid phosphorylated tau, total tau and amyloid-β1-42 values and APOE ε2 carriers showed the opposite effect. At 40 years of age, 76% of the subjects were classified as amyloid negative, neurodegeneration negative and their frequency decreased to 32% at 85 years. The amyloid-positive neurodegeneration-negative group remained stable. The amyloid-negative neurodegeneration-positive group frequency increased slowly from 1% at 44 years to 16% at 85 years, but its frequency was not affected by APOE genotype. The amyloid-positive neurodegeneration-positive frequency increased from 1% at 53 years to 28% at 85 years. Abnormally low cerebrospinal fluid amyloid-β1-42 levels were already frequent in midlife and APOE genotype strongly affects the levels of cerebrospinal fluid amyloid-β1-42, phosphorylated tau and total tau across the lifespan without influencing the frequency of subjects with suspected non-amyloid pathology.

Nonlinear cerebral atrophy patterns across the Alzheimer's disease continuum: impact of APOE4 genotype

The progression of Alzheimer's disease (AD) is characterized by complex trajectories of cerebral atrophy that are affected by interactions with age and apolipoprotein E allele ε4 (APOE4) status. In this article, we report the nonlinear volumetric changes in gray matter across the full biological spectrum of the disease, represented by the AD-cerebrospinal fluid (CSF) index. This index reflects the subject's level of pathology and position along the AD continuum. We also evaluated the associated impact of the APOE4 genotype. The atrophy pattern associated with the AD-CSF index was highly symmetrical and corresponded with the typical AD signature. Medial temporal structures showed different atrophy dynamics along the progression of the disease. The bilateral parahippocampal cortices and a parietotemporal region extending from the middle temporal to the supramarginal gyrus presented an initial increase in volume which later reverted. Similarly, a portion of the precuneus presented a rather linear inverse association with the AD-CSF index whereas some other clusters did not show significant atrophy until index values corresponded to positive CSF tau values. APOE4 carriers showed steeper hippocampal volume reductions with AD progression. Overall, the reported atrophy patterns are in close agreement with those mentioned in previous findings. However, the detected nonlinearities suggest that there may be different pathological processes taking place at specific moments during AD progression and reveal the impact of the APOE4 allele.

Diagnostic validity of the Alzheimer's disease functional assessment and change scale in mild cognitive impairment and mild to moderate Alzheimer's disease

BACKGROUND

The Alzheimer's Disease Functional Assessment and Change Scale (ADFACS) is a functional assessment instrument widely used in clinical research.

AIMS

To test the diagnostic and concurrent validity of the Spanish version of this scale and to describe the functional deficit pattern for mild cognitive impairment (MCI) and Alzheimer's disease (AD) dementia.

METHODS

The ADFACS, the Interview for Deterioration in Daily Living Activities in Dementia (IDDD), and the Mini Mental State Examination (MMSE) were administered to 146 control subjects (CS) and 165 patients (67 MCI and 98 AD). Nonparametric tests were used to compare the diagnostic groups. Cronbach's α and correlations with the MMSE and the IDDD were calculated. Sensitivity, specificity and predictive values were studied.

RESULTS

The ADFACS had a high internal consistency (α = 0.95). Three cutoff points of 1, 4, and 17 were provided to separate CS and MCI patients, MCI and mild AD patients, and mild AD and moderate AD patients, respectively. The ADFACS strongly correlated with functional (IDDD, 0.927) and cognitive (MMSE, 0.747) measures. A similar pattern of dysfunction, but in different grades, was found for the MCI and AD groups.

CONCLUSION

The ADFACS is a reliable, valid, and sensitive instrument to assess functional abilities; it is useful in dementia assessment for elderly populations.

The AD-CSF-index discriminates Alzheimer's disease patients from healthy controls: a validation study

BACKGROUND

Cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) show an acceptable diagnostic sensitivity and specificity; however, their interpretation and ease of use is far from optimal.

OBJECTIVE

To study and validate the diagnostic accuracy of an easy-to-use normalized CSF biomarker index, the AD-CSF-index, in different European populations.

METHODS

A total of 342 subjects, 103 healthy controls and 239 AD patients, from four European memory clinics were included. The AD-CSF-index was constructed from the addition of normalized values between the minimum and maximum of amyloid and tau protein levels. The diagnostic accuracy, receiver operating characteristic, and regression analysis of the AD-CSF-index and other composite indices were evaluated in this study.

RESULTS

AD patients presented a significantly higher AD-CSF-index than healthy subjects (control = 0.5204; AD = 1.2272; p < 0.001). The AD-CSF-index obtained a sensitivity of 88.6% at 85% specificity and also showed a significantly higher diagnostic power (p < 0.05) than the individual CSF biomarkers and other studied indices. The performance of the AD-CSF-index was very similar between ELISA and MesoScale measurements. Cut-off values of approximately 0.75 provided the lowest achievable overall classification errors and a cut-off point of about 0.95 consistently provided specificities above 85%.

CONCLUSION

The AD-CSF-index represents a novel approach, combining normalized CSF values, for the biological diagnosis of AD. The AD-CSF-index presents an optimal AUC with high sensitivity and specificity and seems to be a simple and intuitive way to interpret AD CSF biomarker results even from different analytical platforms.

Neuroimaging and biochemical markers in the three variants of primary progressive aphasia

BACKGROUND/AIM

To investigate in variants of primary progressive aphasia (PPA) the association between current clinical and neuroimaging criteria and biochemical/genetic markers at the individual level.

METHODS

Thirty-two PPA patients were classified as non-fluent/agrammatic (nfvPPA), semantic (svPPA), or logopenic variant (lvPPA) or as unclassifiable (uPPA). In all patients, we evaluated the neuroimaging criteria (magnetic resonance imaging and/or single photon emission computed tomography/positron emission tomography) of each variant and studied serum progranulin levels, APOE genotype and Alzheimer's disease (AD)-cerebrospinal fluid (CSF) biomarkers. Cases with a first-degree family history of early-onset dementia were genetically tested.

RESULTS

Ten of 15 (66%) nfvPPA, 5/5 (100%) svPPA and 7/7 (100%) lvPPA patients showed at least one positive neuroimaging-supported diagnostic criterion. All lvPPA and 3/5 (60%) uPPA patients presented AD-CSF biomarkers, which were absent in nfvPPA and svPPA cases. Four (27%) nfvPPA patients had dementia-causing mutations: 2 carried a GRN mutation and 2 the C9ORF72 hexanucleotide expansion.

CONCLUSIONS

There was an excellent association between clinical criteria and neuroimaging-supported biomarkers in svPPA and lvPPA, as well as with AD-CSF biochemical markers in the lvPPA. Neuroimaging, biochemical and genetic findings in nfvPPA were heterogeneous. Incorporating biochemical/genetic markers into the PPA clinical diagnosis would allow clinicians to improve their predictions of PPA neuropathology, especially in nfvPPA and uPPA cases.

Decreased striatal dopamine transporter uptake in the non-fluent/agrammatic variant of primary progressive aphasia

BACKGROUND AND PURPOSE

Patients with the non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) may develop atypical parkinsonian syndromes. However, there is no current biomarker to assess which patients are at high risk of developing parkinsonism. 123I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane (123I-FP-CIT)-SPECT detects striatal dopamine dysfunction in vivo. The objective of the present study was to study whether non-fluent/agrammatic patients without parkinsonism at baseline present decreased striatal 123I-FP-CIT uptake.

METHODS

Visual and semi-quantitative assessments of the striatal 123I-FP-CIT uptake ratio were carried out in 15 patients with nfvPPA, eight patients with the logopenic variant of PPA (lvPPA) and 18 controls. To rule out progranulin mutations or underlying Alzheimer's disease (AD), serum progranulin levels and cerebrospinal fluid (CSF) biomarkers of AD (Aβ42 , total-tau, phosphorylated-tau181 ) were determined. A second 123I-FP-CIT-SPECT analysis in the biomarker-enriched groups was also carried out.

RESULTS

Patients with nfvPPA presented reduced striatal 123I-FP-CIT binding, especially in the left hemisphere (P = 0.002), compared with controls. All lvPPA patients had normal striatal 123I-FP-CIT uptake. 123I-FP-CIT striatal binding in nfvPPA patients with normal progranulin and CSF biomarker levels (nfvPPA/bio-) was also significantly reduced (P < 0.05) compared with lvPPA patients with positive AD biomarkers. Sixty-four per cent (9/14) of nfvPPA patients and 80% of nfvPPA/bio- patients (8/10) showed a diminished individual left striatal 123I-FP-CIT uptake ratio. On follow-up, seven nfvPPA/bio- patients developed parkinsonism (median 1.9 years; range 1.2-2.9), six of them with baseline reduced 123I-FP-CIT uptake.

CONCLUSIONS

Reduced striatal tracer uptake in nfvPPA patients prior to clinical parkinsonism can be detected by 123I-FP-CIT-SPECT, especially in those with nfvPPA/bio-, suggesting subclinical nigrostriatal degeneration. Decreased striatal 123I-FP-CIT binding might identify PPA patients at increased risk of developing atypical parkinsonian syndromes, probably related to tau-pathology.

Recommendations to standardize preanalytical confounding factors in Alzheimer's and Parkinson's disease cerebrospinal fluid biomarkers: an update

Early diagnosis of neurodegenerative disorders such as Alzheimer's (AD) or Parkinson's disease (PD) is needed to slow down or halt the disease at the earliest stage. Cerebrospinal fluid (CSF) biomarkers can be a good tool for early diagnosis. However, their use in clinical practice is challenging due to the high variability found between centers in the concentrations of both AD CSF biomarkers (Aβ42, total tau and phosphorylated tau) and PD CSF biomarker (α-synuclein). Such a variability has been partially attributed to different preanalytical procedures between laboratories, thus highlighting the need to establish standardized operating procedures. Here, we merge two previous consensus guidelines for preanalytical confounding factors in order to achieve one exhaustive guideline updated with new evidence for Aβ42, total tau and phosphorylated tau, and α-synuclein. The proposed standardized operating procedures are applicable not only to novel CSF biomarkers in AD and PD, but also to biomarkers for other neurodegenerative disorders.

Cognitively preserved subjects with transitional cerebrospinal fluid ß-amyloid 1-42 values have thicker cortex in Alzheimer's disease vulnerable areas

BACKGROUND

Establishing the relationship between cerebrospinal fluid (CSF) ß-amyloid 1-42 (Aß) and cortical thickness (CTh) would represent a major step forward in the understanding of the Alzheimer's disease (AD) process. We studied this relationship in a group of healthy control subjects and subjects with subjective memory complaints with preserved cognitive function at neuropsychological testing.

METHODS

In this cross-sectional study, 33 individuals (17 healthy control subjects and 16 subjects with subjective memory complaints) underwent structural 3-Tesla magnetic resonance image scanning and a spinal tap. Cerebrospinal fluid Aß was measured by enzyme-linked immunosorbent assay. The relationship between CSF Aß values and CTh in several regions of interest, both susceptible and unrelated to AD pathology, was analyzed with a curve fit analysis and CTh difference maps were derived from group comparisons.

RESULTS

Dichotomizing the whole sample according to Aß values (cutoff 500 pg/mL), we found the expected cortical thinning in Aß positive subjects in temporoparietal areas (p < .05 corrected). When analyzing the relationship between CSF Aß and CTh in AD-susceptible regions, we found a significant inverted U-shaped relationship (quadratic). Therefore, the sample was further divided into tertiles (according to CSF Aß values) to perform subsequent subgroup comparisons. Increased CTh in temporoparietal areas and precuneus (p < .05 corrected) was found in the middle Aß tertile (CSF Aß between 416 and 597 pg/mL) when compared with the high Aß tertile (616-881 pg/mL).

CONCLUSIONS

The relationship between Aß and CTh in preclinical stages may not be linear. Cortical thickness in temporoparietal and precuneus regions is greater in subjects with transitional CSF Aß values.

Clinical features and APOE genotype of pathologically proven early-onset Alzheimer disease

OBJECTIVES

Early-onset Alzheimer disease (EOAD) diagnosis often represents a challenge because of the high frequency of atypical presentations. Our aim was to describe the clinical features, APOE genotype, and its pathologic correlations of neuropathologic confirmed EOAD.

METHODS

Retrospective review of clinical data (age at onset, family history, clinical presentation, diagnostic delay, diagnosis) and APOE genotype of patients with neuropathologically confirmed EOAD (<60 years).

RESULTS

Forty cases were selected. Mean age at onset was 54.5 years (range 46-60). The mean disease duration was 11 years with a mean diagnostic delay of 3.1 years. A total of 37.5% had a nonmemory presentation. Behavioral/executive dysfunction was the most prevalent atypical presentation. Incorrect initial clinical diagnoses were common (53%) in patients with atypical presentations, but rare when anterograde amnesia was the presenting symptom (4%). The incorrect initial clinical diagnoses were 2 behavioral variant frontotemporal lobar degeneration, 2 normal pressure hydrocephalus, 1 semantic dementia, 1 primary progressive aphasia, 1 corticobasal degeneration, 1 pseudodementia with depression, and 1 unclassifiable dementia. APOE genotype was ε3/ε3 in 59%, with no significant differences between typical and atypical presentations. APOE ε4 was 3.3 times more frequent in subjects with family history of AD. A total of 97.5% of the cases presented advanced neurofibrillary pathology. A total of 45% of the patients had concomitant Lewy body pathology although localized in most cases and without a significant clinical correlate.

CONCLUSION

One third of patients with pathologic confirmed EOAD presented with atypical symptoms. Patients with EOAD with nonamnestic presentations often receive incorrect clinical diagnoses.

[Memantine: the value of combined therapy]

The symptomatic treatment of Alzheimer's disease is currently carried out using a twofold therapeutic approach involving acetylcholinesterase inhibitors, whose mechanism of action is based on the selective inhibition of this enzyme, and memantine, which acts by blocking the pathological tonic activation of NMDA receptors. Both drugs have been approved for the treatment of Alzheimer's disease and present a therapeutic indication spectrum that is shared in the moderate phase (MMSE: 10-20). Since both therapeutic approaches offer the same complementary mechanisms of action and share the same therapeutic indication over a wide symptomatic disease spectrum, the aim of this article is to review the existing evidence on the effectiveness of combined therapy so as to be able to discern its usefulness from the moment treatment begins.

Medial temporal lobe correlates of memory screening measures in normal aging, MCI, and AD

This article aimed to study the correlations for both the Memory Impairment Screen (MIS) and the Free and Cued Selective Reminding Test (FCSRT) with regard to the volumetric measures of hippocampal formation and entorhinal cortex and to explore the effect size of these measures.

METHODS

A total of 34 healthy controls, 24 participants with mild cognitive impairment (MCI), and 20 mild-to-moderate-staged Alzheimer disease (AD) participants underwent neuropsychological testing and magnetic resonance imaging (MRI). Global volumetric measures were obtained and hippocampal and entorhinal volumes were calculated. Spearman correlations were calculated between memory scores and brain volumes and an effect size analysis was performed.

RESULTS

No significant correlations with global brain volumes were found. There were dissimilar correlations among groups regarding memory and hippocampal and entorhinal volumes. No significant relationships were observed in healthy controls. The MCI group reached the higher correlation indexes, up to r = .55. In AD, only one significant correlation was observed between the delayed score of the FCSRT and the left hippocampus. Effect size values were higher for memory tests than for MRI measures, reaching d = 4.3 for the delayed score of the FCSRT.

CONCLUSIONS

Although the MIS did not reach the strong results of the FCSRT, it demonstrated a similar pattern to the FCSRT in correlational analysis. These results support the validity and usefulness of the MIS despite its brevity of application. Memory testing showed better discrimination among healthy controls, MCI, and AD participants than MRI measures by means of effect size analysis.

[New mutation in the PSEN1 (E120G) gene associated with early onset Alzheimer's disease]

OBJECTIVE

To describe a novel mutation in exon 5 of the presenilin 1 gene (E120G)associated with early-onset autosomal dominant Alzheimer's disease (AD).

PATIENT AND METHODS

The proband was a man who began with memory loss and progressive cognitive decline at the age of 34. His father and his sister suffered from early-onset cognitive decline. The genetic study performed on the blood sample using the single strand conformation polymorphism (SSCP) technique did not detect any abnormality suggestive of the presence of a mutation in PSEN1, PSEN2, and APP. In the last stage of the disease the patient had seizures and gait alteration. He died at the age of 44. Coding exons 3-12 of PSEN1 were studied by direct sequencing using isolated DNA from frozen brain tissue of the proband.

RESULTS

The neuropathological examination showed the presence of frequent amyloid plaques and neurofibrillary tangles and severe amyloid angiopathy. The direct sequencing of the PSEN1 gene disclosed the presence of the E120G mutation.

CONCLUSIONS

E120G is a novel mutation in PSEN1 that probably causes early-onset autosomal dominant AD. Absence of genetic alterations in screening techniques (SSCP) does not rule out the presence of mutations. We recommend direct sequencing for the genetic study of patients with early-onset autosomal dominant AD.

[Discriminatory validity and association of the mini-mental test (MMSE) and the memory alteration test (M@T) with a neuropsychological battery in patients with amnestic mild cognitive impairment and Alzheimer's disease]

AIMS

To establish the discriminatory validity of the mini-mental test (MMSE) and the memory alteration test (M@T) for the diagnosis of amnestic mild cognitive impairment (aMCI) and probable Alzheimer's disease (AD), and also to study the association between the results obtained in screening tests, a neuropsychological battery and a functional questionnaire in healthy persons and in patients with aMCI and AD.

SUBJECTS AND METHODS

We evaluated 27 normal controls, 27 patients with aMCI and 35 patients with AD using the MMSE and a memory screening test, the M@T, a neuropsychological battery and a questionnaire on functional activities of daily living. Pearson correlation coefficients were used to evaluate the relations between the scores on the M@T and the MMSE and the neuropsychological tests. The area below the curve, the sensitivity and the specificity were calculated for the screening tests.

RESULTS

In patients with aMCI, the scores on the M@T and the MMSE were strongly associated with the performance in the episodic memory tests in frontal tests and with the scores on the functional questionnaire, but not with tests that evaluated praxias and perceptive functions. In patients with AD, the scores on the M@T and the MMSE were associated with results in semantic memory, language, executive functions and praxias, but not with perceptive tests and functional questionnaires.

CONCLUSIONS

In patients with aMCI and AD, the association between MMSE and M@T only correlate with some cognitive functions, without there being any association with other cognitive functions. Therefore, screening tests cannot be used as the only instrument for evaluating the cognitive status in patients with suspected dementia.

[Posterior cortical atrophy. Its neuropsychological profile and differences from typical Alzheimer's disease]

INTRODUCTION

The term 'posterior cortical atrophy' (PCA) refers to a neurodegenerative syndrome that is characterised by progressive alteration of the higher visual-perceptual and/or visual-spatial functions, which often presents Alzheimer's disease (AD).

AIM

To describe the value of neuropsychological tests in the differential diagnosis of patients with PCA versus patients with typical AD.

SUBJECTS AND METHODS

The sample was made up of four patients with PCA, four patients with initial typical AD with no significant differences in the degree of cognitive impairment according to the Minimental State Examination and seven cognitively healthy controls. Subjects were administered a full neuropsychological battery of tests for memory, language, praxias, executive functions, and visual-perceptual and visual-spatial capacities. The statistical analysis was performed using the Mann-Whitney U test for non-parametric tests and independent samples.

RESULTS

In the neuropsychological study, scores were significantly lower in the group with PCA compared to the control group in verbal comprehension, praxias and visual gnosias (p < 0.05), and significantly higher with respect to the group with typical AD in episodic memory tests (p < 0.05). In contrast, patients with PCA had a significantly lower score in comparison to typical AD in visual-perceptive and visual-spatial tests (p < 0.05), and in constructive praxias (p < 0.05).

CONCLUSIONS

Results in the neuropsychological tests show subjects with PCA and typical AD have different cognitive profiles, and are useful in the differential diagnosis of the two clinical variants.

[Psychological impact of the diagnosis of Alzheimer's disease]

INTRODUCTION

The communication of the diagnosis of Alzheimer's disease (AD) may represent important emotional distress for the patient and his/her caregiver. This present work aimed to investigate if the disclosure of the diagnosis generates any emotional or psychological impact on the patient or his/her caregiver.

PATIENTS AND METHODS

Thirty-three consecutive AD patients (NINCDS/ADRDA criteria) and their main caregivers were evaluated before and after the diagnosis disclosure. Patients were evaluated with the Neuropsychiatric Inventory Questionnaire (NPI-Q) and the Geriatric Depression Scale (GDS) and caregivers were evaluated with Beck's Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), the stress subscale from the NPI-Q and Zarit's burden interview.

RESULTS

A total of 26 patients wanted to receive the diagnosis. AD diagnosis disclosure did not produce any significant clinical or emotional changes in the patient. On the contrary, the caregivers were significantly affected by AD diagnosis disclosure. This was reflected on the BDI scores, that increased from 6.9+/-6.5 to 9.7+/-7.5 (p=0.003).

CONCLUSIONS

AD diagnosis may be safely disclosed to the patient. However, the caregivers should be carefully followed-up since depressive symptoms are common after diagnosis disclosure.

Naming is associated with left temporal pole metabolite levels in neurodegenerative diseases

AIM

To investigate the relationship between performance in language tests and levels of brain metabolites in two selected left temporal lobe regions.

METHODS

Ninety-five subjects were included: 26 controls, 30 amnestic mild cognitive impairment subjects, 27 Alzheimer's disease and 12 frontotemporal lobar degeneration (FTLD) patients. Language was assessed by a naming test: Boston Naming Test (BNT) and by a semantic verbal fluency test. Other cognitive functions: verbal and visual memory, visual perception, attention and executive function, and praxis were also assessed. Single voxel magnetic resonance spectroscopy was obtained in the left temporal pole (L-TPOLE), and in the left posterior temporoparietal region (L-TPAR).

RESULTS

BNT scores were significantly associated with N-acetylaspartate/creatine ratios (r = 0.45; p < 0.001) and choline/creatine ratios (r = 0.33; p < 0.005) in the L-TPOLE. No significant associations were found between BNT and metabolite levels in the L-TPAR. No significant associations were found between the semantic verbal fluency test and other cognitive tests and metabolite levels either in the L-TPOLE or in the L-TPAR.

CONCLUSION

Naming performance is related to metabolite levels in the anterior L-TPOLE.

Whole genome analysis in a consanguineous family with early onset Alzheimer's disease

Early-onset Alzheimer's disease (EOAD) is a clinically and genetically heterogeneous condition in which the typical features appear significantly earlier in life (before 65 years). Mutations in three genes (PSEN1, PSEN2, and APP) have been identified in autosomal dominant forms of EOAD. However, in about 50% of Mendelian cases and in most of the sporadic EOAD patients, no mutations have been found. We present clinical characteristics of an Israeli family comprising two affected siblings with EOAD born to neurologically healthy parents who were first cousins (both parents died after 90 years old). Sequence analysis of PSEN1, PSEN2, APP, TAU, PGRN, and PRNP failed to reveal any mutations in the affected siblings. Because the disease in this family is consistent with an autosomal recessive mode of inheritance we identified all homozygous regions identical by descent (IBD) in both siblings, by high-density SNP genotyping. We provide here the first catalog of autozygosity in EOAD and suggest that the regions identified are excellent candidate loci for a recessive genetic lesion causing this disease.

A novel mutation in the PSEN1 gene (L286P) associated with familial early-onset dementia of Alzheimer type and lobar haematomas

The aim of this study was to describe a novel mutation in exon 8 of the presenilin gene (L286P) associated with early-onset autosomal dominant Alzheimer's disease (AD) and lobar haematomas. The proband was a woman who developed cognitive decline with predominant memory loss at the age of 35 years. The patient died at the age of 54 years and the neuropathological examination confirmed the diagnosis of AD. Three of her four siblings, one parent and one sibling of her parent had suffered from cognitive decline at ages between 35 and 42 years. Three of them also presented lobar haematomas. The neuropathological examination, available in one of them, disclosed the presence of severe amyloid angiopathy as the cause of the haematoma. The study of PSEN1 gene with single strand conformation polymorphism technique failed to show abnormalities suggestive of mutations. Direct sequencing disclosed the presence of a missense mutation in codon 286 (L286P) in the proband and her already affected descendent, which was absent in the healthy sibling. L286P is a novel mutation in PSEN1 that causes familial early-onset AD and brain haematomas related to amyloid angiopathy.

Cortical brain metabolism as measured by proton spectroscopy is related to memory performance in patients with amnestic mild cognitive impairment and Alzheimer's disease

AIMS

To investigate the relationship between verbal memory performance and brain metabolism as determined by proton spectroscopy ((1)H-MRS) in selected cortical brain regions. To characterize metabolite abnormalities across the continuum of degenerative disease from mild impairment to dementia.

METHODS

27 controls, 27 amnestic mild cognitive impairment (aMCI) patients and 35 Alzheimer's disease (AD) patients. Verbal memory was assessed with the Text Memory Test, the Wordlist Learning Test (WL-Learning Test), and with a memory screening test, the Memory Alteration Test (M@T). Single-voxel (1)H-MRS was obtained in the posterior cingulate (P-CING), left temporal pole (L-TPOLE) and left posterior temporoparietal region (L-TPAR).

RESULTS

WL-Learning Test scores were inversely associated with myoinositol/creatine ratios (mI/Cr) in the L-TPAR (r = -0.404, p < 0.002). Negative associations were also observed between M@T global scores and mI/Cr in the P-CING (r = -0.42; p < 0.001), L-TPOLE (r = -0.34; p < 0.005) and L-TPAR (r = -0.46; p < 0.001). A positive association was found between M@T scores and N-acetylaspartate concentrations in the P-CING (r = 0.33; p < 0.003).

CONCLUSION

Verbal learning performance is related to metabolic changes in cortical brain regions known to be involved in the neurodegenerative process of aMCI and AD.

[Standard values of frontal cognitive functioning tests for those over 60 years of age]

INTRODUCTION

There are some neuropsychological test with a good sensibility for cognitive disorders affecting frontal lobe damage. AIM. To provide normative data for test that assess frontal cognitive function in population over 60 years old.

SUBJECTS AND METHODS

110 neurologically healthy volunteers over 60 years old, recruited from different primary care centers from Barcelona, participated in the study and were assessed by the Trail Making Test-A (TTA), the verbal fluency test FAS and the similarities test.

RESULTS

The mean age of the sample was 71.5 years-old (DE: 6.7). The mean years of education was 8.6 (DE: 4.4). 60% of the subjects were women. The mean score obtained in TTA was 64.2 (DE: 26.0), 24.5 (DE: 11.8) in FAS and 12.5 (DE: 5.2) in similarities test. Years of education result a high significant factor for predicting the performance in all the frontal test. Gender only influenced the performance in TTA. Age did not influence the performance in any of these test.

CONCLUSIONS

These findings support the idea that years of education is the most influencing factor in the performance in frontal cognitive test in normal aged population.

MAPT gene duplications are not a cause of frontotemporal lobar degeneration

Recurrent deletions of the 17q21.31 region encompassing the microtubule-associated protein tau (MAPT) gene have recently been described in patients with mental retardation. This region is flanked by segmental duplications that make it prone to inversions, deletions and duplications. Since gain-of-function mutations of the MAPT gene cause frontotemporal lobar degeneration (FTLD) characterized by deposition of tau protein, we hypothesize that MAPT duplication affecting gene dosage could also lead to disease. Gene dosage alterations have already been found to be involved in the etiology of neurodegenerative disorders caused by protein or peptide accumulation, such as Alzheimer's and Parkinson's diseases. To determine whether MAPT gene copy number variation is involved in FTLD, 70 patients with clinical diagnosis of FTLD and no MAPT mutation (including 12 patients with pathologically proven tau-positive FTLD) were screened by using multiplex ligation probe amplification (MLPA) with specific oligonucleotide probes. No copy number variation in the MAPT gene was observed in cases. Although our study was limited by the relatively small number of patients, it does not support the theory that chromosomal rearrangements in this region are a cause of FTLD.

Brain tau expression and correlation with the H1/H1 tau genotype in frontotemporal lobar degeneration patients

Alterations in tau mRNA splicing and association with H1/H1 tau genotype have been described in some sporadic tauopathies. We evaluated the 4R/3R tau mRNA ratio in 18 patients with frontotemporal lobar degeneration (FTLD), and the effect of the H1/H1 genotype on this ratio. The 4R/3R mRNA ratio in frontal cortex was similar in FTLD patients and controls. The H1/H1 genotype carriers showed a significant increase in 4R/3R mRNA ratio, suggesting that this genotype could modulate the tau mRNA splicing.

[Perception Digital Test (PDT) for the assessment of incipient visual disorder in initial Alzheimer's disease]

INTRODUCTION

Visual perception disorders are frequent in degenerative diseases with posterior cerebral lobe involvement, such as Alzheimer's disease (AD). The main aim of this study is to create a Perception Digital Test (PDT) based on the treatment of digital photographs, and to present normative values in the elderly Spanish population. The second objective is to validate the test in a group of patients with mild AD, stage 4 in the Global Deterioration Scale (GDS) (AD-4).

SUBJECTS

The group were constituted by 86 healthy controls (CTR) and 27 AD patients.

METHOD

VPT, which was formed by 15 items with four options of answer, was administered to all subjects.

RESULTS

Mean time of administration of PDT in CTR was 85 seconds (standard desviation: 33). Mean result obtained for each groups was significantly different (CTR: 13.5 [1.4]; AD-4: 10.6 (2.9); p = 0.05). Age did not significantly influence PDT performance in any of the groups. However, years of education influenced significantly the CTR group score.

CONCLUSION

PDT is an easy, quick and sensitive test to assess visual perception disorders in initial AD.

Late-onset frontotemporal dementia associated with a novel PGRN mutation

We describe a new mutation in the PGRN gene (A303AfsX57) associated with late-onset frontotemporal dementia and with "cat's eye" shaped intranuclear and cytoplasmatic ubiquitin immunoreactive inclusions in the neuropathological exam. The A303AfsX57 mutation is consistent with a nucleotide deletion in exon 8 (c908delC). This deletion causes a frameshift at codon 303 that introduces a premature termination codon (A303AfsX57).

Screening for amnestic mild cognitive impairment and early Alzheimer's disease with M@T (Memory Alteration Test) in the primary care population

OBJECTIVES

To design and validate a new screening test for amnestic Mild Cognitive Impairment (A-MCI) and early stage Alzheimer's disease (AD).

METHODS

We develop a verbal episodic and semantic memory test: the Memory Alteration Test (M@T). Discriminative validity was assessed in a population sample of 400 aged individuals from primary care population centres in Barcelona, Spain, 50 patients with A-MCI according to Petersen et al. criteria, and 66 with early AD (Global Deterioration Scale-4 stage) according to the NINCDS-ADRDA criteria.

RESULTS

The M@T is quick, 5-min, and easy to administer and to score. M@T mean scores were significantly different between all groups: 41.4 (SD = 4.9) in the primary care population, 31.5 (SD = 3.9) in the A-MCI group and 21.8 (SD = 4.9) in early AD. A cut-off score of 37 points had a sensitivity of 96% and a specificity of 79% for A-MCI diagnosis (AUC = 0.932). A cut-off score of 28 points had a sensitivity of 92% and a specificity of 98% for early AD diagnosis (AUC = 0.99) and a sensitivity of 87 % and specificity of 82% to differentiate between A-MCI and AD patients.

CONCLUSION

The M@T provides efficient and valid screening for A-MCI and early stage AD, and discriminates between A-MCI and early AD patients.

Usefulness of neurophysiologic techniques in stereotactic subthalamic nucleus stimulation for advanced Parkinson's disease

OBJECTIVE

The objectives of this study are to determine the impact of neurophysiologic guidance on subthalamic nucleus (STN) targeting and to assess its safety and effectiveness.

METHODS

We have compared the initial theoretic anatomic target (TAT) of the STN with the final microrecording guided coordinates in 15 consecutive patients with bilaterally implanted electrodes in the STN. The clinical results and adverse effects are also reported. All comparisons were done through a paired Student's t test and Pearson's correlation test.

RESULTS

Neurophysiological guidance changed the target coordinates in 26 of the procedures. The mean correction applied to the TAT in order to place the electrode in its definite location was 0.4 mm (+/-0.8, range 0-3; P=0.03) in the medial-lateral axis, 1.6 mm (+/-1.2, range 0-5; P=0.01) in the anterior-posterior plane and 0.8 mm (+/-0.8, range 0-3; P=0.26) in the vertical axis. The mean number of microrecording tracks employed to localize each STN was 2.8+/-1.8 (range 1-8) tracks. After surgery, the total UPDRS motor score in the off medication condition improved by 65.9%; UPDRS-II scores were reduced by 71.8% and Schwab and England scores improved by 45.3%. No intraoperative hemorrhages occurred in this series.

CONCLUSIONS

Neurophysiological guidance is a safe and useful tool in order to improve and confirm target localization. The correction applied in the target resulted in a significant clinical improvement 6 months after surgery.

[Memantine]

Alzheimer's disease (AD) is the most common form of dementia in Western countries. The benefits presently observed with the approved treatments are mainly symptomatic without clear evidence of neuroprotection. N-methyl-D-aspartate (NMDA) receptor antagonists have very extensive therapeutic potential in several central nervous system disorders and can be used as neuroprotective treatment in chronic neurodegenerative diseases and as symptomatic treatment in other neurologic diseases as epilepsy. Memantine, an antagonist of the glutamatergic NMDA receptor, has been recently approved for the treatment of advanced AD. Due to its action mechanism, memantine is considered a neuroprotective drug, whose utility has been demonstrated in preclinical studies, and a useful symptomatic treatment for AD and vascular dementia. We will review both aspects as well as the basic mechanisms mediating glutamatergic neurodegeneration and the implication of glutamate in cognition.

The effect of transcranial magnetic stimulation on reaction time in progressive supranuclear palsy

OBJECTIVE

Reaction time is shortened when a startling acoustic stimulus (SAS) is delivered together with the 'go' signal in normal subjects and patients with Parkinson's disease (IPD), but not in patients with progressive supranuclear palsy (PSP). Similar shortening of reaction time has been reported in normal subjects and patients with IPD with transcranial magnetic stimulation (TMS). In this paper, we analyzed the effect of TMS on reaction time in patients with PSP.

METHODS

Six patients with PSP received the instruction to extend the wrist to a visual cue. In test trials, the visual signal was accompanied by either a SAS or a subthreshold TMS applied to the motor area. The same experimental paradigm was applied to 7 patients with IPD, and 10 normal subjects. We measured both reaction time and the slope of the initial accelerometric displacement (SAD).

RESULTS

Neither TMS nor SAS changed significantly reaction time in PSP patients. This observation was in contrast with the marked reaction time shortening induced by both stimuli in a similar amount in normal subjects and patients with IPD. Furthermore, SAS and TMS did not modify the SAD in PSP, but shortened it significantly in IPD.

CONCLUSION

The absence of an effect of TMS and SAS on reaction time in PSP patients suggests that these patients have a dysfunction in the mechanisms of facilitation of reaction time. The fact that TMS and SAS induced similar effects on reaction time in normal subjects, IPD and PSP patients indicate the possibility of common mechanisms of action for both types of stimuli.

Levodopa withdrawal after bilateral subthalamic nucleus stimulation in advanced Parkinson disease

CONTEXT

Subthalamic nucleus (STN) stimulation may be effective in ameliorating parkinsonian symptoms even to the extent to permit levodopa withdrawal.

OBJECTIVES

To analyze the efficacy of STN stimulation in patients with Parkinson disease (PD) and to determine if levodopa may be withdrawn after surgery.

DESIGN

Before-after trial.

SETTING

Referral center, hospitalized care.

PATIENTS

Fifteen patients with advanced PD.

INTERVENTIONS

Microelectrode-guided bilateral STN high-frequency stimulation.

OUTCOME MEASURES

Before surgery patients were evaluated in off-medication and on-medication conditions. Dopaminergic drug dosages were reduced after surgery, aiming for complete withdrawal. Six months after surgery, patients were reeavaluated in off- and on-medication conditions, with the stimulation turned on and off.

RESULTS

Total Unified Parkinson's Disease Rating Scale (UPDRS) motor score in the off-medication condition improved by 65.9%; and axial symptoms, bradykinesia, rigidity, and tremor improved by 65.8%, 60.4%, 66.1%, and 81.1%, respectively. UPDRS part II scores were reduced by 71.8% and Schwab and England scores improved by 45.3%. Levodopa was withdrawn in 8 patients and the overall levodopa dose was reduced 80.4%. "Off" time was reduced 89.7% and the severity of dyskinesias decreased 80.6% after surgery. All results reached significance (P<.001). Stimulation of the STN achieved antiparkinsonian effect similar to that of treatment with levodopa. No life-threatening adverse effects occurred.

CONCLUSIONS

Bilateral STN stimulation safely improves all parkinsonian symptoms, decreases or eliminates the need for levodopa, and ameliorates motor fluctuations and dyskinesias. Complete withdrawal of levodopa is feasible with this technique and the overall motor effect of STN stimulation is quantitatively comparable to that obtained with levodopa.

Progressive supranuclear palsy: earlier age of onset in patients with the tau protein A0/A0 genotype

Genetic studies have detected an association between the presence of the tau gene A0 allele and patients with progressive supranuclear palsy (PSP). This study examined whether patients with this polymorphism exhibit distinct demographic or clinical characteristics. We studied 26 patients who fulfilled clinical criteria for the diagnosis of PSP, 20 who had the A0/A0 genotype and 6 who had other genotypes. A questionnaire on demographic data, past medical history, familial history, and initial symptoms was completed as part of the consultation. A complete neurological examination was performed and PSP symptoms were quantified following Golbe's PSP disability scale. We found a significant difference in the age at onset of PSP symptoms, which was 65.9 +/- 5.3 years in the A0/A0 group and 71.2 +/- 5.6 in the non-A0/A0 group (P = 0.016). There were no significant differences in the years from disease onset between the two groups. Symptom severity did not differ significantly in patients with the different A0/A0 genotypes. The detection of significantly lower age at onset with the A0/A0 alleles is consistent with the known association of this genotype as a risk factor for PSP. No significant differences were detected in symptom severity between the two groups of patients.

[Efficacy and safety of posteroventral pallidotomy for the treatment of advanced Parkinson's disease]

OBJECTIVES

To analyze the results, efficacy and safety of unilateral microelectrode guided pallidotomy for the treatment of advanced Parkinson's disease, three months and one year after surgery.

PATIENTS AND METHODS

23 patients with advanced Parkinson's disease (mean age 58.9 years and mean disease duration 14.4 years) were submitted to pallidotomy. Neurological evaluation, three months (n = 23) and one year (n = 16) after surgery, was performed during the morning in overnight "off" condition and after receiving 100-150% of their usual l-dopa dose. Parkinsonian symptoms were evaluated in each follow up visit through motor scales, activities of daily living scales, a dyskinesia rating scale and motor timed tests.

RESULTS

Contralateral dyskinesias improved 92% three months after surgery and 89% at one year. Parkinsonian motor scores were reduced by 36.5% after three months and by 26.7% one year after surgery. In the one year follow up visit, contralateral tremor improved 48%, rigidity 36.2% and bradykinesia 37.4%. All these changes were statistically significant (p < 0.01). Adverse effects were minor or transient. Antiparkinsonian medication dosage did not significantly change during the study period.

CONCLUSION

Microelectrode guided unilateral pallidotomy is an effective and safe procedure to improve contralateral motor symptoms in Parkinson's disease, being specially useful for the treatment of l-dopa induced dyskinesias.

Pallidotomy and quality of life in patients with Parkinson's disease: an early study

The purpose of this study was to analyze the effect of stereotactic neurophysiologically guided pallidotomy on health-related quality of life (QoL) of patients with Parkinson's disease (PD). Eleven patients with PD (seven men, four women; mean age, 57.2 years; mean duration of disease, 14 years) with motor complications refractory to medical therapy underwent unilateral pallidotomy. Clinical assessment was carried out a week before surgery and 4 months after the surgical procedure and was based on the Core Assessment Program for Intracerebral Transplantations protocol. QoL was measured by means of the PDQ-39. A set of rating scales (Hoehn & Yahr, Unified Parkinson's Disease Rating Scale, Schwab and England, Northwestern University Disability Scale of Walking, Abnormal Involuntary Movement Scale), timed tests, and self-evaluations of motor function and mood were applied. Improvement was found in dyskinesias (74%) and off-period disability (42%). Cardinal motor signs improved significantly (30%-59%). Four dimensions of the PDQ-39 (Mobility, ADL, Emotions, Bodily Pain) showed a significant improvement (p <0.01-0.001). The global effect on QoL, measured through the PDQ-39 Summary Index (35.3%; 95% confidence interval: 15.60-54.97), was also significant (p<0.01) but unrelated to major clinical changes. Pallidotomy significantly improves QoL in patients with advanced PD. QoL measurement provides relevant information that is probably not attainable by clinical assessment.

Contribution of neurophysiological guidance to stereotactic posteroventral pallidotomy for Parkinson's disease

The usefulness of microrecording guidance to adequately place pallidotomy lesions is not thoroughly accepted. We have analysed in 23 consecutive Parkinsonian patients the deviation of the first recording track (FRT), which was directed to the theoretical stereotactic target, from the sensorimotor area of the internal pallidum, the internal capsule and the center of the lesion. Standard stereotactic co-ordinates were calculated applying a digitized brain atlas adapted to neuro-imaging techniques. The first recording track (FRT) was located out of the sensorimotor area of the pallidum in 13 cases and out of the internal pallidum in 11 cases. In four of these cases the FRT was within the fibers of the internal capsule. The FRT was displaced posteriorly in 9 patients, anteriorly in 11, medially in 9 and laterally in 9. The mean deviation was 1.8 mm (+/- 1.5) in the medial-lateral axis, and 2.5 mm (+/- 1.9) in the antero-posterior plane. In none of the patients the center of the lesion was co-incident with the theoretical anatomical target. The center of the lesion presented a mean deviation from the theoretical anatomical target of 1,4 mm (+/- 1,1) in the medial-lateral, plane, and 2.5 mm (+/- 1.3) in the antero-posterior plane. In addition, 8 patients presented a deviation from the theoretical anatomical target of more than 3 mm in the antero-posterior plane (mean 4.2+/-0.7 mm) and 4 patients presented deviation in the medial-lateral plane of more than 3 mm (mean 3,4+/-0,2 mm). Lesion location was checked by magnetic resonance imaging. All patients improved to a similar extent to that previously reported by the other groups performing pallidotomy under neurophysiological guidance. At 3 months follow-up, pallidotomy ameliorated contralateral bradykinesia in the off condition by 41%, rigidity by 38%, tremor by 52% and dyskinesias by 92%. No major side effects were noted. We conclude that microrecording guidance is a useful tool for avoiding damage to adjacent structures and to precisely localize the sensorimotor area of the internal pallidum in order to obtain optimal clinical results.

Identification of a novel polymorphism in the promoter region of the tau gene highly associated to progressive supranuclear palsy in humans

An intronic polymorphism and other changes in the transcribed region of the tau gene forming a haplotype have been previously described associated to progressive supranuclear palsy (PSP). These results raised the possibility that a change at or near the tau gene could be responsible for an increased risk to develop PSP. We initiated the present work in research for potential changes in the promoter region of the tau gene that could further extend the previously described haplotype. The tau promoter region was analyzed through single strand conformation polymorphism followed by direct sequencing in PSP patients (n = 35), in controls (n = 195) and in Alzheimer's disease (AD; n = 74) patients. We have been able to identify a G to C change at position -221 of the tau gene promoter region. The CC genotype has been detected to be present with a significantly higher frequency in PSP patients (91.4%; P < 0.00001; OR = 11.8), but not in AD patients, as compared with controls (49.74%). Subsequently we have detected that the CC -221 tau promoter genotype is significantly associated to the tau intronic A0/A0 genotype (P < 0.00001). The detected -221 tau G to C change occurs within a potential c-myb proto-oncogene element present in the promoter region. Thus, in addition to extending the previously described haplotype associated to PSP, this -221 G to C change is an interesting candidate that could provide a potential explanation for the association of the haplotype to increased risk for developing PSP.

Clinical outcome of patients with anti-Hu-associated encephalomyelitis after treatment of the tumor

OBJECTIVE

To evaluate 1) the effect of the tumor treatment on the clinical course of paraneoplastic encephalomyelitis (PEM) with anti-Hu antibodies, 2) the impact of immunotherapy on the tumor evolution, and 3) the outcome of the small cell lung cancer (SCLC) of PEM patients compared with that of patients without PEM.

METHODS

The authors retrospectively analyzed 51 PEM patients (42 with SCLC, 9 with other tumors) who received antineoplastic treatment with (25 patients) or without (26) concomitant immunotherapy. Tumor response was assessed at the end of the antineoplastic treatment. Progression of PEM was defined as a change of at least 1 point in the Rankin scale measured at the onset and at the end of the tumor treatment. To evaluate the outcome of SCLC, 27 PEM patients with SCLC were matched one-to-one with SCLC patients without PEM for age, performance status, tumor stage, and type of antineoplastic treatment.

RESULTS

Thirty-six (70%) patients were neurologically stable at the end of the tumor treatment. In a logistic regression analysis, tumor complete response was the only predictor of PEM stabilization (OR 7.07; 95% CI 1.68 to 29.76; p = 0.006). Immunotherapy did not modify the outcome of the tumor and PEM. Median survival was similar in SCLC patients with and without PEM, but the probability of survival at 30 months was higher in PEM patients with SCLC (OR 5.26; 95% CI 1.0004 to 27.6902; p = 0.03).

CONCLUSIONS

Complete response of the tumor seems to have a favorable influence on the course of paraneoplastic encephalomyelitis (PEM). Concomitant immunotherapy does not adversely affect the tumor outcome. The small cell lung cancer of PEM patients may have a slightly better evolution than that of patients without PEM.