Healthy Elderly Group Research Articles

Detection of time irreversibility in interbeat interval time series by visible and nonvisible motifs from horizontal visibility graph

The time irreversibility is a characteristic feature of biological systems and its presence in heart rate (HR) is due to the complex dynamical process involved in the controlling mechanism of cardiovascular system (CVS). In this study, we propose a novel method referred to time irreversibility using visibility motifs (TIVM) for quantifying temporal asymmetry by extracting visible and non-visible horizontal visibility graph (HVG) motifs from a time series. The method can be applied using two simple approaches for transforming original time series into visible and non-visible motifs without mapping the time series into complex networks. Kullback-Leibler divergence (KLD) is used to quantify the temporal asymmetry between visible and non-visible HVG motifs of a time series. First, we explore the structural relation between HVG motifs and ordinal patterns reveal that motifs with different structures can have the similar visibility level. Next, we apply the method to find the asymmetry in different synthetic signals and real world interbeat interval (IBI) time series from healthy and pathological subjects. The findings reveal that the proposed method provide more accurate information about the healthy biological systems and changes occurring due to aging or disease. It is an effective tool for discriminating healthy young, elderly and pathological groups.

Preliminary establishment of reference interval for non-fasting serum triglycerides among healthy middle-aged and elderly people in some communities Beijing

Objective To establish the reference interval of serum triglyceride (TG) for 4 hours after meal in healthy middle and old people of Beijing community, and to provide the diagnostic basis for the judgment of dyslipidemia after meal. Methods Selected 369 elderly people from January to October 2018 in the health examination of Guang′anmen Hospital of the Chinese Academy of Traditional Chinese Medicine. The subjects collected fasting venous blood samples in the morning the next day after fasting for 12 hours, then ate a standard breakfast that conformed to the local dietary habits, and collected venous blood samples again 4 hours after eating. Serum TG levels were measured 4 h after meal using AU5822 fully automatic biochemical analyzer and matching reagents. The comparison of postprandial TG between different age and sex groups was statistically significant using the nonparametric test of two independent samples, and the comparison between postprandial and fasting TG using the nonparametric test of two paired samples with P<0.05 as the difference. The 95% confidence interval was calculated using a nonparametric method according to the relevant requirements of the CLSI EP28-A3c file, and the reference interval was expressed as P2.5, P97.5. Results The median 4-hour post-prandial TG of the middle-aged and elderly aged 45-59 years and those aged ≥ 60 years at health checkups were 1.65 (1.25, 2.13) mmol/L and 1.58 (1.25, 2.00) mmol/L, there was no significant difference between the two groups (Z=-1.040, P>0.05). There was no statistical difference between males 1.69 (1.22, 2.31) mmol/L and females 1.63 (1.26, 2.12) mmol/L at 4 hours postprandial TG levels in the 45-59 year-old group (Z=-0.179, P>0.05),there was also no statistical difference between 1.64 (1.22, 2.06) mmol/L for men and 1.53 (1.28, 1.99) mmol/L for women aged 60 years or older (Z=-0.256, P>0.05).Compared with the median fasting TG of 1.05 (0.87, 1.29) mmol/L, the median serum TG of 1.61 (1.25, 2.09) mmol/L at 4 hours after meal was significantly increased (Z=-16.449, P<0.01). The difference between postprandial and fasting was 0.52 (0.30, 0.85) mmol/L.The reference range of serum TG at 4 hours after meal was 0.82 to 3.02 mmol/L. Conclusion In this study, the reference range of serum triglycerides for 4 hours after meal was established in some healthy elderly population groups in Beijing. Key words: Non-fasting serum Triglyceride; Healthy population; Middle-aged and elderly people; Reference range

Multifractal Detrended Fluctuation Analysis of Congestive Heart Failure Disease Based on Constructed Heartbeat Sequence

Heart rate variability (HRV) can be used as a common detection method for congestive heart failure (CHF). Existing researches regarding HRV, including both linear indicators and nonlinear characteristics, are mostly based on the RR intervals of the ECG signal. This article proposed a sequence that can reflect the regulation of sympathetic and parasympathetic nerve on heart rate, and on this basis, conducted multifractal detrended fluctuation analysis (MFDFA). We extracted multifractal features to quantitatively compare the complexity of proposed sequence between the healthy and CHF groups. Results showed that abnormal physiological and pathological conditions due to the weakening of autonomic nerve control can reduce the complexity of the heartbeat signal. Estimate the separation performance of all features, the best discrimination is obtained for the area under the mass index spectrum S1 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">τ</sub> as providing 100% accuracy in separating the Healthy Young and CHF groups, and 90.93% separation accuracy between the Healthy Elderly and CHF groups. This work provide a good basis for the diagnosis of CHF with a novel perspective.

A Preliminary Exploration of the Stability of Music- and Photo-Evoked Autobiographical Memories in People with Alzheimer’s and Behavioral Variant Frontotemporal Dementia

Music evoked autobiographical memories (MEAMs) occur in people with Alzheimer’s dementia (AD), but there is limited study of such memories in people with other dementia types such as behavioral variant frontotemporal dementia (Bv-FTD). Furthermore, there has been no study of the integrity of such memories over time, and scarce comparison with other memory cues such as photos. Our aim was to address this current gap in our knowledge and to characterize MEAMs and photo-evoked autobiographical memories (PEAMs) in healthy elderly people and people with AD and Bv-FTD on two occasions, 6 months apart. Twenty-two participants (7 with AD, 6 with Bv-FTD, and 9 healthy elderly people) reported memories following exposure to two famous songs and two famous event photographs from each decade from 1930–2010 on two occasions. All people with AD and all healthy elderly controls reported at least one MEAM or PEAM at both times. In contrast, two people with Bv-FTD reported no memories at either time. The percentage of memories over time for songs and photos remained stable for the Healthy Elderly and AD groups, whilst the percentage of memories to songs increased over time for people with Bv-FTD. Songs elicited more positive memories than photos. The specific music and photo stimuli that triggered memories, and the topic of the memories that were evoked, remained stable over a 6-month period across all groups. Our results suggest that music and photos are efficient memory cues in people with AD and Bv-FTD. Future large-scale studies of people with different dementia types over a longer time period will provide insights into the integrity of music- and photo-evoked autobiographical memories as dementia progresses.

Altered Cingulate Cortex Functional Connectivity in Normal Aging and Mild Cognitive Impairment

PurposeResting-state functional Magnetic Resonance Imaging studies revealed that the brain is organized into specialized networks constituted by regions that show a coherent fluctuation of spontaneous activity. Among these networks, the cingulate cortex appears to play a crucial role, particularly in the default mode network, the dorsal attention network and the salience network. In the present study, we mapped the functional connectivity (FC) pattern of different regions of the cingulate cortex: the anterior cingulate cortex, midcingulate cortex and posterior cingulate cortex/retro splenial cortex, which have been in turn divided into a total of 9 subregions. We compared FC patterns of the cingulate subregions in a sample of mild cognitive impairment patients and healthy elderly subjects.MethodsWe enrolled 19 healthy elders (age range: 61–72 y.o.) and 16 Mild cognitive impairment patients (age range 64–87 y.o.). All participants had comparable levels of education (8–10 years) and were neurologically examined to exclude visual and motor impairments, major medical conditions, psychiatric or neurological disorders and consumption of psychotropic drugs. The diagnosis of mild cognitive impairment was performed according to Petersen criteria. Subjects were evaluated with Mini-Mental State Examination, Frontal Assessment Battery, and prose memory (Babcock story) tests. In addition, with functional Magnetic Resonance Imaging, we investigated resting-state network activities.ResultsHealthy elderly, compared to mild cognitive impairment, showed significant increased level of FC for the ventral part of the anterior cingulate cortex in correspondence to the bilateral caudate and ventromedial prefrontal cortex. Moreover, for the midcingulate cortex the healthy elderly group showed increased levels of FC in the somatomotor region, prefrontal cortex, and superior parietal lobule. Meanwhile, the mild cognitive impairment group showed an increased level of FC for the superior frontal gyrus, frontal eye field and orbitofrontal cortex compared to the healthy elderly group.ConclusionOur findings indicate that cognitive decline observed in mild cognitive impairment patients damages the global FC of the cingulate cortex, supporting the idea that abnormalities in resting-state activities of the cingulate cortex could be a useful additional tool in order to better understand the brain mechanisms of MCI.

Neural Compensatory Response During Complex Cognitive Function Tasks in Mild Cognitive Impairment: A Near-Infrared Spectroscopy Study

The present pilot study was aimed at conducting a comparative analysis of the level of activation in the prefrontal cortex among a normal elderly group and amnestic and nonamnestic mild cognitive impairment (MCI) groups and investigating the presence of neural compensatory mechanisms according to types of MCI and different cognitive tasks. We performed functional near-infrared spectroscopy (fNIRS) along with cognitive tasks, including two-back test, Korean color word Stroop test, and semantic verbal fluency task (SVFT), to investigate hemodynamic response and the presence of neural compensation and neuroplasticity in the prefrontal cortex of patients with amnestic and nonamnestic MCI compared with a healthy elderly group. During the two-back test, there was no significant difference in the bilateral region-of-interest (ROI) analysis in the three groups. During the Stroop test, right-sided hyperactivation compared to the left side during the task was shown in the nonamnestic MCI and normal groups with statistical significance. Mean acc∆HbO2 on the right side was highest in the nonamnestic MCI group (0.30 μM) followed by the normal group (0.07 μM) and the amnestic MCI group (-0.10 μM). Otherwise, intergroup ROI analysis of acc∆HbO2 in these activated right sides showed no significant difference. During the VFT test, there was no significant difference in the bilateral region-of-interest analysis in the three groups. The highest mean acc∆HbO2 was shown in the normal group (0.79 μM) followed by the nonamnestic MCI group (0.52 μM) and the amnestic MCI group (0.21 μM). Otherwise, there was no significant difference between groups. The hemodynamic response during fNIRS showed different findings according to MCI types and cognitive tasks. Among the three tasks, the Stroop test showed results that were suggestive of neural compensatory mechanisms in the prefrontal cortex in nonamnestic MCI.

Quantification of trunk segmental coordination and head stability in laterally unstable sitting identifies aging and cerebellar ataxia

BackgroundWe quantified trunk segmental coordination and head stability in unstable sitting and investigated whether it can discriminate postural control, age-related differences and presence of coordination disorder. MethodsSubjects were a healthy younger group (n = 7), a healthy elderly group (n = 7), and a cerebellar ataxia group (n = 8). The motion sensors and surface electrodes were located on the trunk and/or head segments to measure angle displacements, acceleration and electromyograms in unstable sitting during a lateral tilt task. Trunk lateral angle cross-correlation and electromyogram cross-correlation for the trunk segmental coordination, head root mean square (RMS) for the head stability, clinical performance scales, and gait parameters (velocity, coefficient of variation, and RMS ratio) were analyzed. FindingsTrunk lateral angle cross-correlation showed a significantly negative correlation in the healthy younger group compared with the two other groups (p < 0.01). Head RMS showed a significantly larger value in the cerebellar ataxia group compared with the two other groups (p < 0.01). Trunk lateral angle cross-correlation had moderate correlation with the clinical performance scale of ataxia and gait parameters; however, it was not correlated with head RMS. Classification using trunk lateral angle cross-correlation and head RMS was validated by discriminant analysis and hierarchical cluster analysis. InterpretationWe found that trunk lateral angle cross-correlation reflected age-related differences and head RMS characterized the pathology of cerebellar ataxia. Trunk segmental coordination and head stability, as two aspects of sitting postural control, can be used to discriminate the degree of aging and cerebellar ataxia.

Correcting for Body Surface Area Identifies the True Prevalence of Abdominal Aortic Aneurysm in Screened Women

Recently, the prevalence of abdominal aortic aneurysm (AAA) using screening strategies based on elevated cardiovascular disease (CVD) risk was reported. AAA was defined as a diameter ≥30mm, with prevalence of 6.1% and 1.8% in men and women respectively, consistent with the widely reported AAA predominant prevalence in males. Given the obvious differences in body size between sexes this study aimed to re-evaluate the expanded CVD risk based AAA screening dataset to determine the effect of body size on sex specific AAA prevalence. Absolute (26 and 30mm) and relative (aortic size index [ASI] equals the maximum infrarenal aorta diameter (cm) divided by body surface area (m2), ASI≥1.5) thresholds were used to assess targeted AAA screening groups (n=4115) and compared with a self reported healthy elderly control group (n=800). Male AAA prevalence was the same using either the 30mm or ASI ≥1.5 aneurysm definitions (5.7%). In females, AAA prevalence was significantly different between the 30mm (2.4%) and ASI≥1.5 (4.5%) or the 26mm (4.4%) thresholds. The results suggest the purported male predominance in AAA prevalence is primarily an artefact of body size differences. When aortic size is adjusted for body surface area there is only a modest sex difference in AAA prevalence. This observation has potential implications in the context of the ongoing discussion regarding AAA screening in women.

Estado de salud general y perfil biopsicosocial de adultos mayores sanos o excepcionales de Santander, Colombia

El presente trabajo tuvo como objetivo evaluar el estado de salud general y perfil biopsicosocial de un grupo adultos mayores sanos o excepcionales del departamento de Santander. La muestra estuvo compuesta por 50 adultos mayores autopercibidos como sanos, de un rango de edad de 75 años en adelante y pertenecientes a las diferentes provincias del departamento. Se emplearon como instrumentos el Mini-Mental State Examination, la Escala de Barthel, el Cuestionario de salud general de Goldberg y el Mini nutricional Assesment. En los resultados encontrados se evidenciaron medias altas en el nivel cognitivo, independencia en las actividades de la vida diaria (AVD), estado nutricional y buena autopercepción de salud mental, bienestar psicológico general, funcionamiento social y afrontamiento. Esto evidencia un perfil biopsicosocial alto, relacionado a factores diferenciales en este grupo de adultos con elevado nivel de longevidad, lo cual abre paso a la exploración de las dimensiones positivas en los adultos clasificados como viejos-viejos; y además brinda una evidencia de la posibilidad de envejecer exitosamente, con salud y calidad de vida.

Influence of aging and physical frailty of elderly people on the biomechanical characteristics of trunk and lower extremities of sit to stand motion

The purpose of this study was to obtain new findings on an effective physical therapy approach to sit-to-stand (STS) motion by clarifying aging- and physical frailty-related changes in kinematic and kinetic characteristics of trunk and lower limbs of elderly people. The subjects were 17 healthy young people, 12 healthy elderly people, and 12 pre-frail elderly people. STS measurements were carried out using a three-dimensional motion analyzer (VICON MX) and ground reaction force plates (AMTI). Furthermore, the moments of the obtained hip, knee and ankle joints were summed to calculate the support moment. In the healthy elderly group, the maximum flexion angle of the trunk was significantly smaller than that in the healthy young group. There was no significant difference between the three groups in terms of the maximum flexion angle of the hip and ankle joint. In the pre-frail elderly group, the maximum flexion moment of the trunk and the hip joint was significantly lower than that of the healthy young group and the healthy elderly group, and the integral value of the extension moment and peak extension moment of the knee joint was significantly higher. Moreover, the ratio of the hip joint extension moment to the support moment was significantly lower than that in the healthy young group and the healthy elderly group, and the ratio of the knee joint extension moment to the support moment was significantly higher. It was suggested that age-related changes occur earlier in trunk movement than lower limb movement. It was also suggested that the absolute value of the kinetic data of the trunk and hip joint during STS motion declines due to the physical frailty of the elderly and that the absolute value of the kinetic data of the knee joint increases to compensate for this physical frailty.

Effects of Physical Exercise on the P300 of Elderly With Alzheimer's Disease.

Evidence regarding the benefits of physical activity on the mental processing information of patients with Alzheimer's disease assessed objectively is scarce and can be observed through event-related potentials, such as the P300. The aim of the study was to identify the effects of physical exercises on mental processing information in the elderly with Alzheimer's disease through neurophysiological measures (P300 amplitude and latency) and reaction time. A total of 31 patients with Alzheimer's disease participated in this study: 14 in functional exercise (FE) group and 17 in social gathering (SG) group who carried out three 1-hour sessions per week of FE and SG activities, respectively, for a 12-week period. All groups performed an auditory oddball task. A healthy elderly control group also participated. Significant (P < .05) improvements were observed as a reduction of reaction time after intervention in the FE group (pre = 421.5ms and post = 360.9ms). Also, an increase of P300 amplitude at central midline (pre = 5.9μV and post = 6.9μV) and parietal midline (pre = 4.7μV and post = 5.7μV) was observed in the FE. Finally, a decrease in the P300 latency at frontal midline (pre = 377ms and post = 367ms) was observed in the SG after the intervention. Physical exercise decreases reaction time and suggests a recovery in cortical activity, whereas SG activities could probably facilitate information processing.

Evaluation of the Risk of Knee Osteoarthritis and Its Predictive Factors with Emphasis on Physical Activity

Introduction: Designing programs for the prevention of osteoarthritis of the knee requires an understanding of its risk factors. The aim of the present study was to determine the relationship between the risk of knee osteoarthritis among the elderly and age, body mass index (BMI), education, depression, physical activity, and gender of the elderly. Materials and Methods: The participants consisted of 220 elderly individuals suffering from knee osteoarthritis and 220 healthy elderly individuals. The subjects were selected using voluntary sampling methods. The data collection tools included a demographic characteristics form and the Geriatric Depression Scale (GDS) and International Physical Activity Questionnaire (IPAQ). Results: The relationship of all variables with the risk of knee osteoarthritis was investigated through logistic regression analysis of a progressive model considering odds ratio (OR) and confidence interval (CI). There was a significant relationship between age and gender and the risk of developing osteoarthritis (P < 0.05); women were more susceptible to knee osteoarthritis than men (P < 0.05). The prevalence of overweight and obesity was higher among the elderly with knee osteoarthritis than the healthy subjects. Level of depression had a significant correlation with the risk of knee osteoarthritis (P < 0.05). A significant association was observed between levels of physical activity and the risk of knee osteoarthritis and the number of inactive elderly individuals in the knee osteoarthritis group was higher than the healthy elderly group. With increase in the level of education, the possibility of developing knee osteoarthritis decreased and those with an education level of lower than diploma had a greater chance of developing knee osteoarthritis (P < 0.05). Conclusion: Gender, obesity, depression, lack of physical activity, weight gain, education of lower than diploma, and lack of insight and knowledge were risk factors for susceptibility to knee osteoarthritis.

Upper Alpha Based Neurofeedback Training in Chronic Stroke: Brain Plasticity Processes and Cognitive Effects

In the present study, we investigated the effects of upper alpha based neurofeedback (NF) training on electrical brain activity and cognitive functions in stroke survivors. Therefore, two single chronic stroke patients with memory deficits (subject A with a bilateral subarachnoid hemorrhage; subject B with an ischemic stroke in the left arteria cerebri media) and a healthy elderly control group (N = 24) received up to ten NF training sessions. To evaluate NF training effects, all participants performed multichannel electroencephalogram (EEG) resting measurements and a neuropsychological test battery assessing different cognitive functions before and after NF training. Stroke patients showed improvements in memory functions after successful NF training compared to the pre-assessment. Subject B had a pathological delta (0.5–4 Hz) and upper alpha (10–12 Hz) power maximum over the unaffected hemisphere before NF training. After NF training, he showed a more bilateral and “normalized” topographical distribution of these EEG frequencies. Healthy participants as well as subject A did not show any abnormalities in EEG topography before the start of NF training. Consequently, no changes in the topographical distribution of EEG activity were observed in these participants when comparing the pre- and post-assessment. Hence, our results show that upper alpha based NF training had on the one hand positive effects on memory functions, and on the other hand led to cortical “normalization” in a stroke patient with pathological brain activation patterns, which underlines the potential usefulness of NF as neurological rehabilitation tool.

Extensive Type II Muscle Fiber Atrophy in Elderly Female Hip Fracture Patients.

Sarcopenia, or the loss of muscle mass and strength, is known to increase the risk for falls and (hip) fractures in older people. The objective of this study was to assess the skeletal muscle fiber characteristics in elderly female hip fracture patients. Percutaneous needle biopsies were collected from the vastus lateralis muscle in 15 healthy young women (20 ± 0.4 years), 15 healthy elderly women (79 ± 1.7 years), and 15 elderly women with a fall-related hip fracture (82 ± 1.5 years). Immunohistochemical analyses were performed to assess Type I and Type II muscle fiber size, and myonuclear and satellite cell content. Type II muscle fiber size was significantly different between all groups (p < .05), with smaller Type II muscle fibers in the hip fracture patients (2,609 ± 185 µm2) compared with healthy elderly group (3,723 ± 322 µm2) and the largest Type II muscle fibers in the healthy young group (4,755 ± 335 µm2). Furthermore, Type I muscle fiber size was significantly lower in the hip fracture patients (4,684 ± 211 µm2) compared with the healthy elderly group (5,842 ± 316 µm2, p = .02). The number of myonuclei per Type II muscle fiber was significantly lower in the healthy elderly and hip fracture group compared with the healthy young group (p = .011 and p = .002, respectively). Muscle fiber satellite cell content did not differ between groups. Elderly female hip fracture patients show extensive Type II muscle fiber atrophy when compared with healthy young or age-matched healthy elderly controls. Type II muscle fiber atrophy is an important hallmark of sarcopenia and may predispose to falls and (hip) fractures in the older population.

Predicting probable Alzheimer\u2019s disease using linguistic deficits and biomarkers

BackgroundThe manual diagnosis of neurodegenerative disorders such as Alzheimer’s disease (AD) and related Dementias has been a challenge. Currently, these disorders are diagnosed using specific clinical diagnostic criteria and neuropsychological examinations. The use of several Machine Learning algorithms to build automated diagnostic models using low-level linguistic features resulting from verbal utterances could aid diagnosis of patients with probable AD from a large population. For this purpose, we developed different Machine Learning models on the DementiaBank language transcript clinical dataset, consisting of 99 patients with probable AD and 99 healthy controls.ResultsOur models learned several syntactic, lexical, and n-gram linguistic biomarkers to distinguish the probable AD group from the healthy group. In contrast to the healthy group, we found that the probable AD patients had significantly less usage of syntactic components and significantly higher usage of lexical components in their language. Also, we observed a significant difference in the use of n-grams as the healthy group were able to identify and make sense of more objects in their n-grams than the probable AD group. As such, our best diagnostic model significantly distinguished the probable AD group from the healthy elderly group with a better Area Under the Receiving Operating Characteristics Curve (AUC) using the Support Vector Machines (SVM).ConclusionsExperimental and statistical evaluations suggest that using ML algorithms for learning linguistic biomarkers from the verbal utterances of elderly individuals could help the clinical diagnosis of probable AD. We emphasise that the best ML model for predicting the disease group combines significant syntactic, lexical and top n-gram features. However, there is a need to train the diagnostic models on larger datasets, which could lead to a better AUC and clinical diagnosis of probable AD.

Promising Role of Neuromodulation in Predicting the Progression of Mild Cognitive Impairment to Dementia.

The differential diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD) is not always straightforward, and the rate of progression of MCI to dementia is not negligible. Thus, there is a need for para-clinical approaches that can improve the differential diagnosis and identify patients that are at risk of progression. There is a growing interest, at present, in the role of the deterioration of brain oscillations as a predictor of MCI-to-AD conversion. For this reason, we experimentally modulated γ-band oscillations (GBO) in a sample of MCI and AD patients and an age-matched healthy elderly group, using a transcranial alternating current stimulation (tACS) protocol that was applied to different cortical sites. We correlated the after-effects of tACS on the GBO and the neuropsychological data, in an attempt to differentiate MCI from AD patients and identify, among the MCI patients, those that could be at potential risk of MCI-to-dementia conversion. MCI patients showed a partial GBO increase and improvement in some neuropsychological tests whereas AD individuals did not show significant tACS after-effects. Notably, some MCI subjects lacked significant neuropsychological and electrophysiological after-effects, similar to AD individuals. In a two-year follow-up, such MCI individuals had converted into AD. Therefore, our data suggest that tACS may support the clinical differential diagnosis of MCI and AD and identify MCI patients who could be at risk of developing dementia. This prediction index may help the clinician to adopt a better prevention/follow-up strategy in such a disabling neurodegenerative disease.

Postural Control of Healthy Elderly Individuals Compared to Elderly Individuals with Stroke Sequelae.

A stroke and aging process can modify the postural control. We aimed to compare the postural control of health elderly individuals to that of individuals with stroke sequelae. This cross-sectional transversal study was made with individuals capable of walking without any assistance and that were considered clinically stable. The study had 18 individuals in the group with stroke sequelae (SG) and 34 in the healthy elderly control group (CG). The participants were evaluated for the timed up and go test (TUG) and force platform. The SG showed the worst results in relation to the time of execution of the TUG and the force platform evaluation. The displacement of center of pressure was worse for both groups in the eyes-closed situation, especially in the anteroposterior direction for the CG. The GS showed worse results in the static and dynamic postural control. The healthy elderly showed more dependence on sight to maintain their static balance and there was no difference in the balance tests in relation to the side affected by the stroke.

4. Temporal lobe atrophy: Frequent in elderly with epilepsy of unknown etiology

Objective To evaluate the degree of temporal lobe atrophy (TLA) in elderly patients with new-onset epilepsy, and its relation to temporal epileptiform discharges. Background No etiology can be identified in as much as 30% to 50% of cases of new-onset epilepsy in the elderly, despite adequate investigation. Degenerative diseases, notably Alzheimer’s disease (AD), increase the risk of epilepsy, and are often underdiagnosed in routine clinical practice. Abnormal activity on electroencephalography (EEG) of demented epileptic individuals is most often found focally in temporal regions. Design/methods We retrospectively reviewed neuroimaging and EEG results of a consecutive cohort of 322 elders with new-onset epilepsy. The > 65 year-old patients were evaluated at the Centre Hospitalier Universitaire de Sherbrooke (CHUS) between January 2001 and October 2010. On imaging, TLA was assessed visually on axial images and graded on a 0–3 scale estimating sulcal widening and temporal horn ventricular enlargement. Measurement of the temporal horn radial width (THRW) was also acquired as a quantitative estimate of TLA. TLA was compared between subjects with epilepsy of unknown etiology (n = 127) and demented epileptic individuals of the same cohort (n = 10), as well as a healthy elderly control group (n = 31) and non-epileptic AD patients (n = 10). EEG interpretations were also analyzed, looking for correlation between temporal lobe atrophy and temporal epileptiform discharges, in the whole epileptic cohort. Results MRI (46%) or CT (93%) was available for 112 patients with epilepsy of unknown etiology. Thirty-eight percent of elderly with new-onset epilepsy of unknown cause had significant temporal atrophy, using the dichotomized 0–3 scale (0–1 vs 2–3) or THRW. This was significantly more than the healthy control group (0%) after adjustment for age and sex (p = 0.000). As expected, individuals of the same cohort with epilepsy attributed to dementia had higher prevalence of significant TLA using both THRW and the visual scale (70.4%, p = 0.026 and 76.9% p = 0.021) as did patients with established AD (70% p = 0.040 and 60% p = 0.077). EEG results were available for 297 of the 322 patients (92.2%), including 125 of the 127 subjects with epilepsy of unknown etiology. Epileptiform discharges were present in 111/297 (37.3%) and 45/125 (36%) individuals respectively, of which 68.5% and 55.5% were found in temporal leads. No correlation was found between the presence of temporal lobe atrophy, using either dichotomized THRW or the visual scale, and temporal epileptiform activity (p = 0.312 and 0.469). Conclusions A considerable proportion of elderly with new-onset epilepsy of unknown cause exhibit temporal lobe atrophy on brain imaging, which suggests that a degenerative disease such as AD could be underrecognized as a possible etiology. However, it appears there is no correlation between this atrophy and the temporal localization of epileptiform activity. Financial support University Chair.

Novel application of multi dynamic trend analysis as a sensitive tool for detecting the effects of aging and congestive heart failure on heart rate variability.

The complex fluctuations in heart rate variability (HRV) reflect cardiac autonomic modulation and are an indicator of congestive heart failure (CHF). This paper proposes a novel nonlinear approach to HRV investigation, the multi dynamic trend analysis (MDTA) method, based on the empirical mode decomposition algorithm of the Hilbert-Huang transform combined with a variable-sized sliding-window method. Electrocardiographic signal data obtained from the PhysioNet database were used. These data were from subjects with CHF (mean age = 59.4 ± 8.4), an age-matched elderly healthy control group (59.3 ± 10.6), and a healthy young group (30.3 ± 4.8); the HRVs of these subjects were processed using the MDTA method, time domain analysis, and frequency domain analysis. Among all HRV parameters, the MDTA absolute value slope (MDTS) and MDTA deviation (MDTD) exhibited the greatest area under the curve (AUC) of the receiver operating characteristics in distinguishing between the CHF group and the healthy controls (AUC = 1.000) and between the healthy elderly subject group and the young subject group (AUC = 0.834 ± 0.067 for MDTS; 0.837 ± 0.066 for MDTD). The CHF subjects presented with lower MDTA indices than those of the healthy elderly subject group. Furthermore, the healthy elderly subjects exhibited lower MDTA indices than those of the young controls. The MDTA method can adaptively and automatically identify the intrinsic fluctuation on variable temporal and spatial scales when investigating complex fluctuations in the cardiac autonomic regulation effects of aging and CHF.

Predictability effect on N400 reflects the severity of reading comprehension deficits in aphasia

Predictability effect on N400, in which low predictability words elicited a larger N400 than high predictability words did over central to posterior electrodes, has been used to index difficulty of lexical retrieval and semantic integration of words in sentence comprehension. This study examined predictability effect on N400 in aphasic patients to determine if the properties of N400 are suited to indexing the severity of reading comprehension deficits. Patients with aphasia were divided into high and low ability groups based on scores on the reading comprehension subtest in the Chinese Concise Aphasia Test (CCAT). The two aphasia groups, a group of healthy elders who were age-matched to the aphasic participants, and a group of young adults, were requested to read sentences that either ended with highly predictable words or unexpected but plausible words, while undergoing electroencephalography (EEG). The young adult and healthy elderly groups exhibited the typical centro-parietal distributed effect of predictability on N400; however, healthy elders exhibited a reduced N400 effect in a delayed time window compared to the young adults. Compared with the elderly control, the high ability aphasia group exhibited a comparable N400 effect in a more restricted time window; by contrast, the low ability aphasia group exhibited a frontal distributed N400 in a much later time window (400–700ms). These data suggest that the severity of reading comprehension deficits affects predictability effect on a set of N400 characteristics (i.e., amplitude, time window, and topographic distribution), which may be effective as ERP signatures in the evaluation of language recovery in aphasia.