Minding your steps: a cross-sectional pilot study using foot-worn inertial sensors and dual-task gait analysis to assess the cognitive status of older adults with mobility limitations.

BACKGROUND: Cognitive impairment is a critical aspect of our aging society. Yet, it receives inadequate intervention due to delayed or missed detection. Dual-task gait analysis is currently considered a solution to improve the early detection of cognitive impairment in clinical settings. Recently, our group proposed a new approach for the gait analysis resorting to inertial sensors placed on the shoes. This pilot study aimed to investigate the potential of this system to capture and differentiate gait performance in the presence of cognitive impairment based on single- and dual-task gait assessments. METHODS: We analyzed demographic and medical data, cognitive tests scores, physical tests scores, and gait metrics acquired from 29 older adults with mobility limitations. Gait metrics were extracted using the newly developed gait analysis approach and recorded in single- and dual-task conditions. Participants were stratified into two groups based on their Montreal Cognitive Assessment (MoCA) global cognitive scores. Statistical analysis was performed to assess differences between groups, discrimination ability, and association of gait metrics with cognitive performance. RESULTS: The addition of the cognitive task influenced gait performance of both groups, but the effect was higher in the group with cognitive impairment. Multiple dual-task costs, dual-task variability, and dual-task asymmetry metrics presented significant differences between groups. Also, several of these metrics provided acceptable discrimination ability and had a significant association with MoCA scores. The dual-task effect on gait speed explained the highest percentage of the variance in MoCA scores. None of the single-task gait metrics presented significant differences between groups. CONCLUSIONS: Our preliminary results show that the newly developed gait analysis solution based on foot-worn inertial sensors is a pertinent tool to evaluate gait metrics affected by the cognitive status of older adults relying on single- and dual-task gait assessments. Further evaluation with a larger and more diverse group is required to establish system feasibility and reliability in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov (identifier: NCT04587895).

An Ionic Liquid Extraction That Preserves the Molecular Structure of Cutin Shown by Nuclear Magnetic Resonance.

The biopolyester cutin is ubiquitous in land plants, building the polymeric matrix of the plant's outermost defensive barrier, the cuticle. Cutin influences many biological processes in planta; however, due to its complexity and highly branched nature, the native structure remains partially unresolved. Our aim was to define an original workflow for the purification and systematic characterization of the molecular structure of cutin. To purify cutin we tested the ionic liquids cholinium hexanoate and 1-butyl-3-methyl-imidazolium acetate. The ensuing polymeric materials are highly esterified, amorphous, and have a typical monomeric composition as demonstrated by solid-state NMR, complemented by spectroscopic, thermal, and x-ray scattering analyses. We performed a systematic study by solution-state NMR of cryogenically milled cutins extracted from tomatoes (Solanum lycopersicum 'Micro-Tom'; the wild type and the GLYCEROL-3-PHOSPHATE ACYLTRANSFERASE [GPAT6] and CUTIN SYNTHASE [CUS1] mutants). We resolved their molecular structures, relative distribution of ester aliphatics, free acid end-groups and free hydroxyl groups, differentiating between those derived from primary and secondary esters. Our data demonstrate the existence of free hydroxyl groups in cutin and provide insight into how the mutations affect the esterification arrangement of cutin. The usage of ionic liquids for studying plant polyesters has advantages over conventional approaches, since simple modifications can be applied to recover a biopolymer carrying distinct types/degrees of modifications (e.g. preservation of esters or cuticular polysaccharides), which in combination with the solution NMR methodologies developed here, constitutes essential tools to fingerprint the multifunctionality and the structure of cutin in planta.

Tracking cognitive impairment in multiple sclerosis using the Brain on Track test: a validation study.

BACKGROUND: The accurate and regular monitoring cognitive performance in multiple sclerosis (MS) patients is critical to develop new prevention and management strategies for cognitive impairment (CI). The Brain on Track (BoT) test is a self-administered web-based tool developed for cognitive screening and monitoring. The objective of this study was to validate the use of the BoT in MS, by assessing its ability to distinguish between MS patients and matched controls, as well as detect CI among MS patients, by analysing its correlation with standard cognitive tests and its reliability and learning effects in repeatable use. METHODS: The BoT was applied in 30 patients with MS consecutively selected and 30 age- and education-matched controls, first in a hospital clinic, under supervision, and then 1 week later from home. After these first two trials, MS patients repeated the test from home every 4 weeks for 3 months. A standard neuropsychological battery was also applied to MS patients at baseline. RESULTS: The Cronbach's alpha was 0.89. Test scores were significantly different between MS patients and controls (Cohen's d = 0.87; p < 0.01). Among MS patients, scores were significantly lower in those with CI documented in the standard neuropsychological battery than in their cognitively preserved counterparts (Cohen's d = 2.0; p < 0.001). The BoT scores presented a good correlation with standard neuropsychological tests, particularly for information processing speed. Regarding test-retest reliability, 10/11 subtests presented two-way mixed single intraclass consistency correlation coefficients > 0.70. CONCLUSION: The BoT showed good neuropsychological parameters in MS patients, endorsing the use of self-administered computerized tests in this setting.

Correction to: Tracking cognitive impairment in multiple sclerosis using the Brain on Track test: a validation study.

The above article was published online with an error in author name's affiliations. Affiliation 8 has to be added to Maria Pia Amato and has to be deleted from Vitor Tedim.

Regulation of the cutinases expressed by Aspergillus nidulans and evaluation of their role in cutin degradation.

Four cutinase genes are encoded in the genome of the saprophytic fungus Aspergillus nidulans, but only two of them have proven to codify for active cutinases. However, their overall roles in cutin degradation are unknown, and there is scarce information on the regulatory effectors of their expression. In this work, the expression of the cutinase genes was assayed by multiplex qRT-PCR in cultures grown in media containing both inducer and repressor carbon sources. The genes ancut1 and ancut2 were induced by cutin and its monomers, while ancut3 was constitutively expressed. Besides, cutin induced ancut4 only under oxidative stress conditions. An in silico analysis of the upstream regulatory sequences suggested binding regions for the lipid metabolism transcription factors (TF) FarA for ancut1 and ancut2 while FarB for ancut3. For ancut4, the analysis suggested binding to NapA (the stress response TF). These binding possibilities were experimentally tested by transcriptional analysis using the A. nidulans mutants ANΔfarA, ANΔfarB, and ANΔnapA. Regarding cutin degradation, spectroscopic and chromatographic methods showed similar products from ANCUT1 and ANCUT3. In addition, ANCUT1 produced 9,10-dihydroxy hexadecanoic acid, suggesting an endo-cleavage action of this enzyme. Regarding ANCUT2 and ANCUT4, they produced omega fatty acids. Our results confirmed the cutinolytic activity of the four cutinases, allowed identification of their specific roles in the cutinolytic system and highlighted their differences in the regulatory mechanisms and affinity towards natural substrates. This information is expected to impact the cutinase production processes and broaden their current biotechnological applications.

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound.

Fisetin is a natural antioxidant with a wide range of nutraceutical properties, including antidiabetic, neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out using elemental analysis, powder X-ray diffraction (PXRD), Raman, infrared and 13C{1H} CP-MAS NMR spectroscopies, and thermal analysis (TGA) to verify fisetin inclusion and to present a hypothetical structural arrangement for the host-guest units. The antioxidant activity of the γ-CD·fisetin inclusion compound is evaluated by the DPPH assay.

Web-based cognitive training: patient adherence and intensity of treatment in an outpatient memory clinic.

BACKGROUND: Cognitive training has been playing an increasing role in the treatment of patients with cognitive deficits. This type of intervention, namely its intensity, can be optimized by incorporating information technology-based systems. OBJECTIVE: The intent of the study was to determine the treatment intensity and patient adherence to home-based cognitive training strategies (Web-based cognitive training). METHODS: A cohort of 45 patients with neurologic and psychiatric diseases attending an outpatient memory clinic (average age 50.7 years, SD 17.0; average education 7.8 years, SD 4.9) was followed over 18 months. Participants were challenged to use a Web-based cognitive training system, "COGWEB", on a daily basis, and fulfilled at least four weeks of training supervised remotely. Additionally, 11 patients attended face-to-face sessions. RESULTS: The average duration of continuous cognitive training was 18.8 weeks (SD 18.9). Each patient performed on average 363.5 minutes/week (SD 136.6). At 6-month follow-up, 82.8% complied with their treatment plan. The average proportion of complete weeks was 0.75 (SD 0.22). Patients with dementia trained more intensively (444.6 minutes/week), followed by patients with static brain lesion (414.5 minutes/week; P=.01). The group that held face-to-face sessions performed more training overall (481.4 vs 366.9 minutes/week), achieving a stronger expression and statistical significance in the last week of training (652.6 versus 354.9 minutes/week, P=.027). CONCLUSIONS: Overall, the weekly training intensity was high. Patients with dementia and static lesions performed more cognitive training. Face-to-face sessions were associated with higher intensities. The combination of classical methods with information technology systems seems to ensure greater training intensity.

Validity and reliability of a digital solution for cognitive assessment: The Brain on Track®.

Background: Cognitive assessment and the early detection of cognitive impairments have been enhanced by the use of remote digital solutions. The Brain on Track® is one of these digital solutions used in clinical practice for online screening and monitoring of cognitive functioning. Objectives: This study aimed to explore the validity and reliability of the Brain on Track® computerized test on a tablet device in adults. Methods: A community sample of 54 young adults, 51 middle-aged adults, and 50 older adults were invited to attend in two assessment sessions. The first session included data collection on sociodemographic data, user digital literacy, Brain on Track® on the computer and on the tablet device, and usability from the user and moderator perspective. The second session included the Montreal Cognitive Assessment Questionnaire (MoCA) and a second completion of the Brain on Track® on tablet to assess the criterion validity and test-retest reliability. Hypothesis testing was used to assess construct validity. Results: A weak to moderate correlation was found between the Brain on Track® tablet score and the MoCA. The ICC was 0.72, 0.84, and 0.79, and Cronbach's alpha was 0.84, 0.83, and 0.89 in young adults, middle-aged adults, and older adults, respectively. Conclusions: This study suggested that the Brain on Track® administered using a tablet device has criterion validity, particularly in middle-aged and older adults, and internal consistency and test-retest reliability in adults of any age group.

Validation of a web-based self-administered test for cognitive assessment in a Swedish geriatric setting.

Computerized cognitive tests have the potential to cost-effectively detect and monitor cognitive impairments and thereby facilitate treatment for these conditions. However, relatively few of these tests have been validated in a variety of populations. Brain on Track, a self-administered web-based test, has previously been shown to have a good ability to differentiate between healthy individuals and patients with cognitive impairment in Portuguese populations. The objective of this study was to validate the differential ability and evaluate the usability of Brain on Track in a Swedish memory clinic setting. Brain on Track was administered to 30 patients with mild cognitive impairment/mild dementia and 30 healthy controls, all scheduled to perform the test from home after one week and after three months. To evaluate the usability, the patient group was interviewed after completion of the testing phase. Patients scored lower than healthy controls at both the first (median score 42.4 vs 54.1, p<0.001) and the second test (median score 42.3 vs 55.0, p<0.001). The test-retest intra-class correlation was 0.87. A multiple logistic regression model accounting for effects of age, gender and education rendered an ability of Brain on Track to differentiate between the groups with an area under the receiver operation characteristics curve of 0.90 for the first and 0.88 for the second test. In the subjective evaluation, nine patients left positive comments, nine were negative whereas five left mixed comments regarding the test experience. Sixty percent of patients had received help from relatives to log on to the platform. In conclusion, Brain on Track performed well in differentiating healthy controls from patients with cognitive impairment and showed a high test-retest reliability, on par with results from previous studies. However, the substantial proportion of patients needing help to log in could to some extent limit an independent use of the platform.

Using shoe-mounted inertial sensors and stepping exergames to assess the motor-cognitive status of older adults: A correlational study.

Objective: Stepping exergames designed to stimulate physical and cognitive skills can provide important information concerning individuals' performance. In this study, we investigated the potential of stepping and gameplay metrics to assess the motor-cognitive status of older adults. Methods: Stepping and gameplay metrics were recorded in a longitudinal study involving 13 older adults with mobility limitations. Game parameters included games' scores and reaction times. Stepping parameters included length, height, speed, and duration, measured by inertial sensors placed on the shoes while interacting with the exergames. Parameters measured on the first gameplay were correlated against standard cognitive and mobility assessments, including the Montreal Cognitive Assessment (MoCA), gait speed, and the Short Physical Performance Battery. Based on MoCA scores, patients were then stratified into two groups: cognitively impaired and healthy controls. The differences between the two groups were visually inspected, considering their within-game progression over the training period. Results: Stepping and gameplay metrics had moderate-to-strong correlations with cognitive and mobility performance indicators: faster, longer, and higher steps were associated with better mobility scores; better cognitive games' scores and reaction times, and longer and faster steps were associated with better cognitive performance. The preliminary visual analysis revealed that the group with cognitive impairment required more time to advance to the next difficulty level, also presenting slower reaction times and stepping speeds when compared to the healthy control group. Conclusion: Stepping exergames may be useful for assessing the cognitive and motor status of older adults, potentially allowing assessments to be more frequent, affordable, and enjoyable. Further research is required to confirm results in the long term using a larger and more diverse sample.

Long-term neurological complications in COVID-19 survivors: study protocol of a prospective cohort study (NeurodegCoV-19).

BACKGROUND: Evidence suggests an association between SARS-CoV-2 infection and worse performance on cognitive tests, and a higher risk of Parkinson's disease (PD) and dementia up to 6 and 12 months after infection, respectively. Longer follow-ups with comparison groups are needed to clarify the potentially increased risk of neurodegenerative diseases in COVID-19 survivors, namely those infected before mass vaccination. METHODS: A prospective study started in July 2022 with four cohorts of 150 individuals each, defined according to SARS-CoV-2 infection and hospitalisation status between March 2020 and February 2021: cohort 1-hospitalised due to SARS-CoV-2 infection; cohort 2-hospitalised, COVID-19-free; cohort 3-infected, not hospitalised; cohort 4-not infected, not hospitalised. Cohort 2 will be matched to cohort 1 according to age, sex, level of hospitalisation care and length of stay; cohort 4 will be age-matched and sex-matched to cohort 3. Baseline, 1-year and 2-year follow-up evaluations will include: cognitive performance assessed with the Montreal Cognitive Assessment (MoCA) and neuropsychological tests; the assessment of prodromal markers of PD with Rapid Eye Movement Sleep Behaviour Disorder single-question Screen and self-reported olfactory and gustative alterations; screening of PD with the 9-item PD screening questionnaire; gait evaluation with Timed Up&Go test. Suspected cases of cognitive impairment and PD will undergo a clinical evaluation by a neurologist. Frequency measures of neurological complications, prodromal markers and diagnoses of dementia and PD, will be presented. The occurrence of cognitive decline-the difference between baseline and 1-year MoCA scores 1.5 SD below the mean of the distribution of the variation-will be compared between cohorts 1 and 2, and cohorts 3 and 4 with OR estimated using multivariate logistic regression. ETHICS AND DISSEMINATION: This study received ethics approval from the Ethics Committees of the health units Unidade Local de Saúde de Matosinhos and Centro Hospitalar de Entre Douro e Vouga, and informed consent is signed for participating. Results will be disseminated among the scientific community and the public.

The impact of users' cognitive function on evaluator perceptions of usability.

To explore the association between the user's cognitive function and usability reported by the evaluator. A cross-sectional study was conducted with a community-based sample. Data about participants' age, sex, education, sleep quantity, subjective memory complaints, and cognitive function were collected. A usability session was conducted to evaluate a digital solution called Brain on Track. Independent linear-regression analyses were used to explore univariable and multivariable associations between evaluator-reported usability assessment and the users' cognitive function, age, sex, education, sleep quantity, and subjective memory complaints. A total of 238 participants entered this study, of which 161 (67.6%) were females and the mean age was 42 (SD 12.9) years old. All variables (age, education, sleep quantity, subjective memory complaints and cognitive function) except sex were significantly associated with evaluator-reported usability in the univariable analysis (p < 0.05). Cognitive function, age, education, and subjective memory complaints remained significant in the multivariable model (F = 38.87, p < 0.001) with an adjusted R2 of 0.391. Cognition scores alone showed an adjusted R2 of 0.288. This work suggests that cognitive function impacts evaluator reported usability, alongside other users' characteristics and needs to be considered in the usability evaluation.

Prevalence and pattern of cognitive impairment in rural and urban populations from Northern Portugal.

BACKGROUND: Despite worldwide recognition of the burden of dementia, no epidemiological data is yet available in Portugal. The objective of this study is to estimate the prevalence and describe the pattern of cognitive impairment with dementia or no dementia (CIND) in rural and urban populations from Northern Portugal. METHODS: Two random samples of residents aged 55 to 79 years in rural and urban communities were drawn from the health centres registries to be screened for cognitive impairment. The screening criteria for dementia were an abnormal Mini-Mental State Examination (MMSE) score or a Blessed Dementia Scale score. After excluding those who tested positive for dementia, cut-off points for CIND were set at 1 standard deviation below the mean of the MMSE according to educational level. All those who screened positive either for dementia or CIND were examined by a neurologist for establishing a definitive diagnosis. RESULTS: The prevalence of cognitive impairment was higher in rural than in urban populations, 16.8% (95% CI: 14.3-19.8%) vs. 12.0% (95%CI: 9.3-15.4%), with a rural/urban prevalence ratio (PR) of 2.16 (95% CI: 1.04-4.50) in the eldest and 2.19 (95% CI: 1.01-4.76) in persons with vascular risk factors. The prevalence of dementia was 2.7% (95% CI: 1.9-3.8%) with a rural/urban PR = 2.1 and the prevalence of CIND was 12.3% (95% CI: 10.4-14.4%) and PR = 1.3. The prevalence of dementia increases exponentially with age and in those with cerebrovascular disease or other comorbid conditions while the prevalence of CIND, besides these factors, is also higher in persons with low levels of education or vascular risk factors. Alzheimer's and vascular disease were equally likely aetiologies of dementia (38.7%), the later more common in men PR(F:M = 0.3) as opposed to the former PR(F:M = 2.0). Vascular CIND, associated either with cerebrovascular disease or vascular risk factors was more frequent (39.7%) then depression (18.4%) or any other aetiology. CONCLUSIONS: The prevalence of cognitive impairment is higher in rural compared with urban populations. This is shown in the synergy between age and rurality, with the rural/urban prevalence ratio increasing with age. In this relatively young population from Northern Portugal, cerebrovascular disease as well as vascular risk factors account for 48% of overall cognitive impairment.

Solid γ-Cyclodextrin Inclusion Compound with Gingerols, a Multi-Component Guest: Preparation, Properties and Application in Yogurt.

Gingerols from the rhizome of fresh ginger (Zingiber officinale) were obtained by a simple extraction, followed by purification. The gingerols extract was composed of 6-gingerol (54%), 8-gingerol (20%), and 10-gingerol (26%). It was included into γ-cyclodextrin by classic co-dissolution procedures. Solid-state characterisation of γ-cyclodextrin·gingerols shows that this inclusion compound features 1:1 host-to-guest stoichiometry and that it is a microcrystalline powder with a crystalline cell that belongs to the tetragonal space group 4212, having the host molecules stacked in infinite channels where the gingerols are accommodated. In chimico studies with ABTS•+ scavenging, NO• scavenging, ß-carotene peroxidation, and 5-LOX inhibition show that γ-cyclodextrin is a suitable carrier for gingerols, because it does not alter their reactivity towards these substances. Yogurt was tested as a matrix for the incorporation of gingerols and γ-cyclodextrin·gingerols into foodstuff. The colour of the fortified yogurt suffered little alterations. In the case of yogurt with the inclusion compound, γ-cyclodextrin·gingerols, as fortificant, these alterations were not perceptible to the naked eye. Moreover, yogurt with γ-cyclodextrin·gingerols showed a good antioxidant activity, thus being suitable for use in nutraceutical applications.

Tracking Cognitive Performance in the General Population and in Patients with Mild Cognitive Impairment with a Self-Applied Computerized Test (Brain on Track).

Repeated measurements could be helpful to identify patients with early cognitive decline. We compare the variation of cognitive performance over one year in patients with mild cognitive impairment (MCI) and healthy individuals using the Brain on Track self-applied computerized test (BoT). The study was initiated 30 patients with probable MCI and 377 controls from a population-based cohort, who performed the BoT test from home every three months for one year. The scores were compared using a linear mixed-effects model. All participants increased their scores in the first tests, after 120 days MCI patients started to decline, with a statistically significant higher rate. The area under the curve to detect MCI was 0.94. We identified a significant decline in cognitive performance over one year in patients with MCI using BoT and the test presented a high discriminative ability.

Portuguese version of Wechsler Memory Scale-3rd edition's utility with demented elderly adults.

The purpose of this study is to analyze the utility of the Portuguese version of the Wechsler Memory Scale-3rd edition (WMS-III) with demented elderly people, namely its capacity to detect and discriminate between subcortical vascular dementia (SVD) and Alzheimer's disease (AD). We assessed early demented patients (SVD = 16; AD = 36) aged 65 or older who were compared to a control group (n = 40). Both clinical groups were adequately matched in terms of disease severity, overall cognitive functioning, depressive symptomatology, and pre-morbid intelligence. Between-group's differences were evaluated using the Quade's rank analysis of covariance. We also computed indexes and subtests optimal cut-off scores, and the corresponding sensitivity, specificity, and positive and negative predictive values, which were able to successfully discriminate between patients and healthy subjects. The SVD patients had a better overall memory performance than AD patients on the majority of the indexes and the delayed condition subtests of the WMS-III. The AD patients only showed a better performance on digit span subtest. Several measures discriminated patients from healthy subjects. This study suggests some recommendations for the diagnostic accuracy of the Portuguese version of WMS-III in dementia and about differential diagnosis between SVD and AD.

Conversion of cheese whey into poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Haloferax mediterranei.

Haloferax mediterranei was cultivated in highly saline medium using cheese whey as the substrate for the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), P(3HB-co-3HV). Acid hydrolysis provided a simple inexpensive method to obtain a cheese whey hydrolysate that was used for cultivation of H. mediterranei. Batch bioreactor cultivation of H. mediterranei resulted in the production of an active biomass concentration of 7.54 g L(-1) with a polymer content of 53%, and a volumetric productivity of 4.04 g L(-1) day(-1). Supplementation of the cultivation medium with micronutrients favored galactose consumption that was used for polymer synthesis after exhaustion of the available glucose. P(3HB-co-3HV) with a 3-hydroxyvalerate content of 1.5 mol% was extracted from the biomass by hypo-osmotic shock. The polymer presented a molecular mass of 4.4×10(5), with a polydispersity index of 1.5. This work demonstrated the feasibility of using cheese whey for the production of a value-added biopolymer with high volumetric productivity, by using a glucose- and galactose-rich substrate obtained by acid hydrolysis of cheese whey. The use of H. mediterranei as the producing strain avoids the need for strict sterility due to the culture's high salinity requirements and, also, allows for polymer extraction by simply contacting the biomass with water.

Development of a self-administered web-based test for longitudinal cognitive assessment.

Sequential testing with brief cognitive tools has been recommended to improve cognitive screening and monitoring, however the few available tools still depend on an external evaluator and periodic visits. We developed a self-administered computerized test intended for longitudinal cognitive testing (Brain on Track). The test can be performed from a home computer and is composed of several subtests, expected to evaluate different cognitive domains, all including random elements to minimize learning effects. An initial (A) and a refined version of the test (B) were applied to patients with mild cognitive impairment or early dementia (n = 88) and age and education-matched controls. A subsample of a population-based cohort (n = 113) performed the test at home every three months to evaluate test-retest reliability. The test's final version Cronbach's alpha was 0.90, test scores were significantly different between patients and controls (p = 0.001), the area under the receiver operating characteristic curve was 0.75 and the smallest real difference (43.04) was lower than the clinical relevant difference (56.82). In the test-retest reliability analysis 9/10 subtests showed two-way mixed single intraclass consistency correlation coefficient >0.70. These results imply good internal consistency, discriminative ability and reliability when performed at home, encouraging further longitudinal clinical and population-based studies.

The Portuguese version of Addenbrooke's Cognitive Examination-Revised (ACE-R) in the diagnosis of subcortical vascular dementia and Alzheimer's disease.

The aim of this study was to investigate the accuracy of the Portuguese version of Addenbrooke's Cognitive Examination-Revised (ACE-R) in detecting and differentiating early stage subcortical vascular dementia (SVD) from early stage Alzheimer's disease (AD). Ninety-two subjects (18 SVD patients, 36 AD patients, and 38 healthy controls) were assessed using the ACE-R. Between-group's differences were evaluated using the Quade's rank analysis of covariance. The diagnostic accuracy and discriminatory ability of the ACE-R were examined via receiver operating characteristic (ROC) analysis. The ACE-R was able to successfully discriminate between patients and healthy subjects. The mean ACE-R total scores differed between SVD and AD patients; there were also significant differences in attention and orientation and in memory measures between the groups. An optimal cut-off of 72/73 was found for the detection of AD (sensitivity: 97%; specificity: 92%) and SVD (sensitivity: 100%; specificity: 92%).

Cardiac arrest: long-term cognitive and imaging analysis.

BACKGROUND: Neurological and cognitive sequelae resulting from cardiac arrest (CA), despite their potential personal and social impact, are usually not considered as major outcome measures in long-term analysis of survivors. The aim of this study is to analyze the contribution of neuropsychological testing and cerebral imaging to the development of a long-term classification of neurological impairment. PATIENTS AND METHODS: A total of 19 patients admitted over a 3 years period in an eight-bed intensive care unit of a tertiary care hospital with a diagnosis of CA were alive and attended a 6-month follow-up consultation. Eleven of these patients agreed to participate in this study carried out between 1 and 3 years after CA. Patients were classified using the Cerebral Performance Categories (CPC), neurological examination, detailed cognitive testing and computerized tomography (CT) scan with qualitative and quantitative imaging analysis. RESULTS: Six of the 11 patients had good cerebral performance. Verbal and visuo-spatial short-term memory scores were associated with CPC. All patients with at least moderate cerebral disability had abnormal verbal memory test results compared with only one survivor with CPC 1; visuo-spatial short-term memory was abnormal in four moderately affected survivors and normal in those with CPC 1. The bicaudate ratio evaluated in the CT scan was correlated with the verbal memory score while the III ventricle diameter correlated with the executive functions score, suggesting involvement of different brain areas in these functions. CONCLUSIONS: Neuropsychological and CT scan measurements are proxy measures of long-term impairment of CA survivors, providing a dichotomized global evaluation of CA survivors in close agreement with CPC.