Hasil untuk "Neurophysiology and neuropsychology"

Li PJ, Gong LJ, Huang ZY et al.

Pei-Jun Li,1,* Lin-Jing Gong,1,* Zi-Yang Huang,2 Xiang Zhang,3 Dan Liu,1 Zong-An Liang1 1Department of Pulmonary and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2Department of Pulmonary and Critical Care Medicine, West China School of Medicine/West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 3Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China*These authors contributed equally to this workCorrespondence: Pei-Jun Li, Department of Pulmonary and Critical Care Medicine, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan, 610041, People’s Republic of China, Email kakasinp526@163.comPurpose: Drug-induced sleep endoscopy with positive airway pressure titration (DISE-PAPT) can assess the effect of varying positive pressure levels on upper airway collapse in patients with obstructive sleep apnea (OSA) under simulated sleep condition. But it remains unclear whether DISE-PAPT can facilitate the development of personalized therapeutic interventions for OSA and further improve the therapeutic efficacy.Patients and Methods: We present three adult patients with severe OSA exhibiting distinct clinical profiles: one case of continuous positive airway pressure (CPAP) treatment failure, one case of intolerance to high CPAP, and one case of psychological resistance to CPAP therapy.Results: According to the DISE-PAPT evaluation findings, CPAP combined with positional therapy was administered in Case 1. CPAP with surgical management was performed in Case 2, resulting in significant therapeutic improvements. Additionally, real-time DISE-PAPT visualization of CPAP-mediated upper airway patency restoration enhanced CPAP adherence in Case 3.Conclusion: The personalized treatment strategies based on the DISE-PAPT technique hold promise for improving the overall therapeutic efficacy and adherence among patients with OSA.Keywords: DISE-PAPT, CPAP, obstructive sleep apnea, therapy

BaHammam AS

Ahmed Salem BaHammam1,2 1Department of Medicine, University Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia; 2University Sleep Disorders Center, King Saud University Medical City, Riyadh, Saudi ArabiaCorrespondence: Ahmed Salem BaHammam, University Sleep Disorders Center, Department of Medicine, College of Medicine, King Saud University, Box 225503, Riyadh, 11324, Saudi Arabia, Email ashammam2@gmail.comAbstract: Migratory birds demonstrate remarkable temporal plasticity, adapting their circadian rhythms and sleep patterns to meet the demands of long-distance migration. This perspective explores how insights from avian temporal adaptations could inform novel research directions in human sleep and circadian medicine. Birds’ ability to maintain precise temporal organization through multiple coordinated oscillators, particularly during migratory periods, provides a valuable framework for understanding circadian flexibility. Drawing from recent advances in avian chronobiology, we propose several research priorities for human applications, including biomarker-guided chronotherapy, circuit-specific interventions, and optimization of environmental cue timing. We explore how birds’ sophisticated control of sleep architecture and metabolic regulation during migration might inspire new approaches to managing circadian disruptions in humans. Neuroimaging studies of human temporal adaptability, guided by avian insights, could reveal network-level mechanisms underlying circadian plasticity. Of particular interest is the parallel between avian unihemispheric sleep and human hemispheric asymmetry during sleep, suggesting the evolutionary conservation of adaptive sleep mechanisms. While acknowledging the fundamental differences between avian and human circadian systems, we outline specific research directions that could translate avian temporal adaptability principles into therapeutic strategies for circadian disorders. While these avian-inspired hypotheses require rigorous validation, and some may not prove viable, embracing creative exploration remains essential for advancing our understanding of human circadian biology and guiding the development of novel therapeutic approaches.Keywords: temporal plasticity, unihemispheric sleep, circadian rhythms, sleep disorders, neuroplasticity, translational research

Leyla Baysal, Sabrina Jobi, Simone Zimmermann et al.

Myoclonic epilepsy with ragged red fibers (MERRF) syndrome is a rare mitochondrial disorder marked by myoclonus, ataxia, cognitive impairment, myopathy, and sensorineural hearing loss. Seizures in MERRF syndrome are often resistant to standard antiseizure medication. We present a unique case of an adult patient with MERRF syndrome, caused by the m.8344A > G point mutation, who developed super-refractory status epilepticus (SRSE), successfully managed by the initiation and rapid escalation of vagus nerve stimulation (VNS) therapy. Over a two-year follow-up period, the VNS therapy enabled a long-term control of generalized tonic-clonic seizures. A further status epilepticus has not yet occurred. VNS may therefore be a promising therapeutic option for managing SRSE in patients with mitochondrial epilepsy syndromes.

Dutheil F, Saint-Arroman C, Clinchamps M et al.

Frederic Dutheil,1,&ast; Chloé Saint-Arroman,1,&ast; Maëlys Clinchamps,1 Valentin Flaudias,2 Maria Livia Fantini,3 Bruno Pereira,4 Mickael Berthon,5 Catherine Laporte,6 Julien Steven Baker,7 Morteza Charkhabi,8 Pierluigi Cocco,9 Rosamaria Lecca,9 Monica Puligheddu,9 Michela Figorilli,9 Marek Zak,10 Ukadike Chris Ugbolue,11 Esther Ubago-Guisado,12 Luis Gracia-Marco,13 Jean-Baptiste Bouillon-Minois,1 Luc Vialatte14 1Université Clermont Auvergne, CNRS, Physiological and Psychosocial Stress, LaPSCo, Preventive and Occupational Medicine, University Hospital of Clermont-Ferrand, Clermont-Ferrand, F-63000, France; 2Department of Psychiatry, University Hospital of Clermont-Ferrand, University of Clermont Auvergne, Clermont-Ferrand, France; 3NPsy-Sydo, Neurology Department, University Hospital of Clermont-Ferrand, Université Clermont Auvergne, Clermont-Ferrand, France; 4Biostatistics Department, University Hospital of Clermont-Ferrand, Clermont-Ferrand, France; 5Laboratoire de Psychologie Sociale et Cognitive (LAPSCO), Université Clermont Auvergne, CNRS, Clermont-Ferrand, France; 6Clermont Auvergne INP, University Hospital of Clermont-Ferrand, CNRS, Institut Pascal, Université Clermont Auvergne, Clermont-Ferrand, F-63000, France; 7Department of Sport, Physical Education and Health, Centre for Health and Exercise Science Research, Hong Kong Baptist University, Kowloon Tong, Hong Kong; 8Université Clermont Auvergne, CNRS, Physiological and Psychosocial Stress, LaPSCo, Clermont-Ferrand, France; 9Department of Medical Sciences and Public Health, Neurology Unit, University of Cagliari and AOU Cagliari, Monserrato, Cagliari, 09042, Italy; 10Collegium Medicum, Institute of Health Sciences, Jan Kochanowski University of Kielce, Kielce, Poland; 11School of Health and Life Sciences, Institute for Clinical Exercise & Health Science, University of the West of Scotland, Glasgow, UK; 12Epidemiology and Control of Chronic Diseases, CIBER of Epidemiology and Public Health (CIBERESP), Madrid, 28029, Spain; 13Epidemiology, Prevention and Cancer Control, Instituto de Investigación Biosanitaria Ibs. Granada, Granada, 18012, Spain; 14Preventive and Occupational Medicine, University Hospital of Clermont-Ferrand, AIST – La prevention Active, University of Clermont Auvergne, Clermont-Ferrand, France&ast;These authors contributed equally to this workCorrespondence: Frederic Dutheil, Email frederic.dutheil@uca.frBackground: Socio-demographic, occupational and lifestyle variables influence total sleep time. Therefore, we aimed to evaluate the influence of those variables on sleep time, and to study risk factors of being a short sleeper.Methods: The COVISTRESS international study is an online questionnaire using the secure REDCap® software. Total sleep time was evaluated using declared bedtime and time of awakening and was analyzed as a quantitative variable and as a qualitative variable.Results: We included 549 respondents to the questionnaire, divided into 10-year age groups ranging from < 30yo to ≥ 60yo. The mean quantity of sleep was 7.11± 1.43 hours per night. Factors that reduce total sleep time were age (coefficient − 0.19, 95CI − 0.33 to 0.06), being an employee (− 0.46, − 0.85 to − 0.06), working time (− 0.18, − 0.31 to 0.05), smoking ≥ 5 cigarettes/day (− 0.5, − 0.95 to − 0.20), high stress at work (− 0.64, − 0.96 to − 0.32) and at home (− 0.66, − 0.97 to − 0.35). Being a student (0.61, 0.02 to 1.19), working less than 25h per week (0.57, 0.17 to 0.97) and telework (0.46, 0.02 to 0.89) increased total sleep time. The risk factors of being a short sleeper were age (odds ratio 1.27, 95CI 1.07 to 1.51), being an employee (2.58, 1.36 to 4.89), smoking ≥ 5 cigarettes/day (2.73, 1.54 to 4.84) and a high level of stress at work (2.64, 1.45 to 4.82) and at home (3.89, 2.25 to 6.63). Physical activity ≥ 2.5 hours/week tended to decrease the risk of being a short sleeper by 35%.Conclusion: We demonstrated the concomitant impact of sociodemographic, occupational and lifestyle behavior on sleep, which may help to build efficient preventive strategy.Keywords: total sleep time, sociodemographic variables, occupational variables, mental health

Ciro Rosario Ilardi

Abstract Neuropsychology's place in diagnosing dementia is still up for debate. With the advent of disease‐modifying therapies, the optimisation of diagnostic pathways is increasingly urgent, particularly in the early stages of Alzheimer's disease. Yet, biomarker‐driven frameworks eclipse neuropsychological testing as an ancillary tool rather than recognising it as a core component of clinical assessment. Emerging evidence indicates that relying solely on biomarkers does not provide a dependable forecast for the onset or progression of dementia. This drawback underscores how important neuropsychology is. Nonetheless, the clinical adoption of neuropsychological tests for diagnostic purposes requires a paradigm shift towards a more rigorous methodology. Despite its recognised diagnostic potential, the current neuropsychological framework is constrained by thresholds derived from normative distributions rather than Clinimetrics . Many existing tests rely on arbitrary cut‐offs that do not account for disease prevalence, personological variability, or real‐world cognitive performance. This oversimplified approach reduces the sensitivity of neuropsychological assessments and limits their integration into clinical practice. The development of population‐specific clinimetric studies that establish weighted cut‐offs for sensitivity and specificity based on clinical aims is crucial to ensure clinically meaningful decision‐making.

Claudia Pañeda, Sol Lago

Demaeyer N, Bruyneel M

Nathalie Demaeyer,1 Marie Bruyneel1,2 1Department of Pneumology, CHU Saint-Pierre, Université Libre de Bruxelles, Brussels, Belgium; 2Department of Pneumology, CHU Brugmann, Université Libre de Bruxelles, Brussels, BelgiumCorrespondence: Marie Bruyneel, Department of Pneumology, CHU Saint-Pierre, 322 rue haute, Brussels, 1000, Belgium, Tel +3225354219, Fax +3225353362, Email marie.bruyneel@stpierre-bru.beAbstract: The prevalence of obstructive sleep apnea (OSA) among the bariatric surgery population is estimated to be 45– 70%. However, weight loss obtained by bariatric surgery is not always associated with full remission of OSA, suggesting that other confounding factors are present. This article aims to review the current literature, focusing on factors that could predict the persistence of OSA after bariatric surgery. For this purpose, relevant studies of more than 50 patients that assessed pre- and post-operative presence and severity of OSA detected by poly(somno)graphy (PG/PSG) in bariatric populations were collected. Six retrospective and prospective studies were evaluated that included 1302 OSA patients, with a BMI range of 42.6 to 56 kg/m2, age range of 44.8 to 50.7 years, and percentage of women ranging from 45% to 91%. The studies were very heterogeneous regarding type of bariatric surgery, diagnostic criteria for OSA and OSA remission, and delay of OSA reassessment. OSA remission was observed in 26% to 76% of patients at 11– 12 months post-surgery. Loss to follow-up was high in all studies, leading to a potential underestimation of OSA remission. Based on this limited sample of bariatric patients, age, pre-operative OSA severity, proportion of weight loss, and type 2 diabetes (T2D) were identified as factors associated with OSA persistence but the results were inconsistent between studies regarding the impact of age and the magnitude of weight loss. Several other factors may potentially lead to OSA persistence in the bariatric surgery population, such as fat distribution, ethnicity, anatomical predisposition, pathophysiological traits, supine position, and REM-predominant hypopnea and apnea. Further well-conducted multicentric prospective studies are needed to document the importance of these factors to achieve a better understanding of OSA persistence after bariatric surgery in obese patients.Keywords: bariatric surgery, gastric sleeve, gastric bypass, obstructive sleep apnea, polygraphy, polysomnography

Carlos Ventura-Bort, Janine Wirkner, Julia Wendt et al.

Although the mediating role of the stress hormone systems in memory for single— especially emotional— events is well-stablished, less is known about the influence of stress on memory for associated contextual information (source memory). Here, we investigated the impact of acute stress on the neural underpinnings of emotional contextual source memory. Participants underwent a stress or a control manipulation before they encoded objects paired with pleasant, neutral, or unpleasant backgrounds. One week later, item and contextual source memory were tested. Acute stress modulated the neural signature of item and contextual source memory in an opposite fashion: stressed participants showed larger activation in the precuneus and the medial prefrontal cortex (mPFC) during the retrieval of items, while the retrieval of contextual unpleasant information was associated with lower activation in the angular gyrus (AG) and mPFC. Furthermore, as revealed by cross-region representational similarity analyses, stress also reduced the memory reinstatement of the previously encoded visual cortex representations of object/unpleasant background pairings in the AG and mPFC. These results suggest that pre-encoding stress induction increases the activity of memory-related regions for single items but reduces the activity of these regions during the retrieval of contextual unpleasant information. Our findings provide new insights into the dissociative effects of stress on item and contextual source memory which could have clinical relevance for stress-related disorders.

Mahgol Shojaei, َAkram Dehghani

Aim and Background: Mentalization capacity is necessary for empowering students in interpersonal interactions and consequently obtaining future success, and for this reason, it is necessary to know its correlates, Therefore The purpose of the current research was to investigate the mentalization based on attachment styles, Ego strength, Object relations and Pattern of anxiety manifestation in students. Methods and Materials: The research community was formed by the students of Isfahan National University and Azad University in 2022, according to the latest reports, their number is 35161. Based on Cochran's formula, 380 students were selected as available. The research tools were Attachment Styles Questionnaire (ASQ), Psychosocial Inventory of Ego Strengths (PIES), Bell Object Relations Inventory (BORI), Anxiety Manifestation Patterns Questionnaire and Reflective Functioning Questionnaire (RFQ) which were completed individually by students. Data analysis was done by multiple regression analysis using the twenty-sixth version of SPSS software. Findings: The results showed that secure and ambivalent attachment styles as well as ego strength can significantly predict students' mentalization capacity. (p<0.05). Conclusions: Therefore, in order to improve students' mentalization, it is necessary to pay attention to secure and ambivalent attachment styles as well as ego strength.

Zhang JL, Wang AX, Yang Y et al.

Jia-Li Zhang,1,2,&ast; An-Xin Wang,1,2,&ast; Yang Yang,2,3 Qin Xu,1,2 Xiao-Ling Liao,1,2 Wei-Guo Ma,4 Ning Zhang,2,3 Chun-Xue Wang,2,3,5 Yong-Jun Wang1,2 1Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, People’s Republic of China; 2China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, People’s Republic of China; 3Department of Neuropsychiatry and Behavioral Neurology and Clinical Psychology, Beijing Tiantan Hospital, Capital Medical University, Beijing, People’s Republic of China; 4Beijing Anzhen Hospital, Capital Medical University, Beijing, People’s Republic of China; 5Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Ning Zhang; Chun-Xue Wang, Beijing Tiantan Hospital, 119 South 4th Ring West Road, Beijing, 100070, People’s Republic of China, Emails 827582777@qq.com; snowsen@126.comBackground: Although sleep disorders significantly increase the risk of cognitive impairment, literature is relatively scarce regarding the impact of sleep status on cognitive function in patients with acute ischemic stroke (AIS). We seek to study the association between pre-stroke subjective sleep status and cognitive function at 3 months after stroke.Patients and methods: Data were analyzed for 1,759 AIS patients from the Impairment of Cognition and Sleep after Acute Ischemic Stroke or Transient Ischemic Attack in Chinese Patients Study (ICONS). Pre-stroke subjective sleep status was assessed by the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Greater sleep fragmentation was defined as waking up in the middle of the night or early morning ≥ 3 times a week. Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA) at 3 months after stroke. Primary endpoint was the incidence of post-stroke cognitive impairment (PSCI) at 3 months after stroke. The association between subjective sleep status and PSCI was evaluated using multivariable logistic regression.Results: PSCI occurred in 52.1% at 3 months after stroke. Patients with very bad sleep quality before stroke were at increased risk of PSCI (OR, 2.11; 95% CI, 1.11– 4.03; P=0.03). Subgroup analysis found that the association between very bad sleep quality and PSCI was more evident among patients with high school education or above (OR, 5.73; 95% CI, 1.92– 17.10; P for interaction=0.02). In addition, patients with greater sleep fragmentation before stroke were also at higher risk of PSCI (OR, 1.55; 95% CI, 1.20– 2.01; P< 0.01). Similarly, subgroup analysis showed that the risk of PSCI was more pronounced among patients without employment (OR, 2.45; 95% CI, 1.59– 3.77; P for interaction=0.01).Conclusion: Very bad sleep quality and greater sleep fragmentation before stroke were identified as independent risk factors for PSCI at 3 months after stroke.Keywords: subjective sleep status, cognitive impairment, ischemic stroke

Min Deng, Xing Zhang, Xiaoyan Bi et al.

Abstract Background Attachment theory demonstrates that early attachment experience shapes internal working models with mental representations of self and close relationships, which affects personality traits and interpersonal relationships in adulthood. Although research has focused on brain structural and functional underpinnings to disentangle attachment styles in healthy individuals, little is known about the spontaneous brain activity associated with self-reported attachment anxiety and avoidance during the resting state. Methods One hundred and nineteen individuals participated in the study, completing the Experience in Close Relationship scale immediately after an 8-min fMRI scanning. We used the resting-state functional magnetic resonance imaging (rs-fMRI) signal of the amplitude of low-frequency fluctuation and resting-state functional connectivity to identify attachment-related regions and networks. Results Consequently, attachment anxiety is closely associated with the amplitude of low-frequency fluctuations in the right posterior cingulate cortex, over-estimating emotional intensity and exaggerating outcomes. Moreover, the functional connectivity between the posterior cingulate cortex and fusiform gyrus increases detection ability for potential threat or separation information, facilitating behavior motivation. The attachment avoidance is positively correlated with the amplitude of low-frequency fluctuation in the bilateral lingual gyrus and right postcentral and negatively correlated with the bilateral orbital frontal cortex and inferior temporal gyrus. Functional connection with attachment avoidance contains critical nodes in the medial temporal lobe memory system, frontal-parietal network, social cognition, and default mode network necessary to deactivate the attachment system and inhibit attachment-related behavior. Conclusion and implications These findings clarify the amplitude of low-frequency fluctuation and resting-state functional connectivity neural signature of attachment style, associated with attachment strategies in attachment anxiety and attachment avoidance individuals. These findings may improve our understanding of the pathophysiology of the attachment-related disorder.

Devin M. Kellis, Kris Ford Kaigler, Eric Witherspoon et al.

Cholinergic neuromodulation plays an important role in numerous cognitive functions including regulating arousal and attention, as well as associative learning and extinction processes. Further, studies demonstrate that cholinergic inputs from the basal forebrain cholinergic system influence physiological responses in the basolateral amygdala (BLA) as well as fear extinction processes. Since rodent models display individual differences in conditioned fear and extinction responses, this study investigated if cholinergic transmission in the BLA during fear extinction could contribute to differences between extinction resistant and extinction competent phenotypes in outbred Long-Evans male rats. Experiment 1 used in vivo microdialysis to test the hypothesis that acetylcholine (ACH) efflux in the BLA would increase with presentation of an auditory conditioned stimulus (CS+) during extinction learning. Acetylcholine efflux was compared in rats exposed to the CS+, a CS- (the tone never paired with a footshock), or to a context shift alone (without CS+ tone presentation). Consistent with acetylcholine's role in attention and arousal, ACH efflux in the BLA was increased in all three groups (CS+, CS-, Shift Alone) by the initial context shift into the extinction learning chamber, but returned more rapidly to baseline levels in the Shift Alone group (no CS+). In contrast, in the group exposed to the CS+, ACH efflux in the BLA remained elevated during continued presentation of conditioned cues and returned to baseline more slowly, leading to an overall increase in ACH efflux compared with the Shift Alone group. Based on the very dense staining in the BLA for acetylcholinesterase (ACHE), Experiment 2 examined if individual differences in fear extinction were associated with differences in cholinesterase enzyme activity (CHE) in the BLA and/or plasma with a separate cohort of animals. Cholinesterase activity (post-testing) in both the BLA and plasma was higher in extinction competent rats versus rats resistant to extinction learning. There was also a significant negative correlation between BLA CHE activity and freezing during extinction learning. Taken together, our results support a role for ACH efflux in the BLA during cued fear extinction that may be modulated by individual differences in ACHE activity, and are associated with behavioral responses during fear extinction. These findings implicate individual differences in cholinergic regulation in the susceptibility to disorders with dysregulation of extinction learning, such post-traumatic stress disorder (PTSD) in humans.

Fatemeh Zare, Fahimeh Namdarpour

Aim and Background: Adolescence is an important period of development in which individuals can acquire the skills, attitudes, and abilities they need in adulthood. It seems that one of the factors that can be effective in dealing with adolescent issues is emotional intelligence. This study aims to investigate the effectiveness of Choice Theory training on emotional intelligence in adolescent girls. Methods and Materials: This is a quasi-experimental study with pretest-posttest control group design. The statistical population consists of thirteen-to-eighteen-year-old adolescent girls in the city of Isfahan. The sample consisted of 32 adolescent girls who were selected by multistage cluster sampling and were randomly and equally assigned to control and experimental groups. The experimental group received Choice Theory training in eight ninety-minute sessions. The control group was placed on the wait list. The Emotional Quotient Inventory test was used for data collection purposes and the data were analyzed using the covariance analysis test. Findings: Results showed that Choice Theory training significantly affected Emotional Intelligence and its components (adaptability, intrapersonal, interpersonal, and general mood) (p<.05). However, it was not significantly effective on stress management. Conclusions: According to the findings, it seems that Choice Theory training can be used to increase the emotional intelligence of adolescent girls in schools. Theoretical and practical implementations will be discussed in this research.

Jeffrey Cole, Marla J. Hamberger

Sheila E. Blumstein

Stephanie E. Wemm, Rajita Sinha

A number of studies have assessed the effects of psychoactive drugs on stress biology, the neuroadaptations resulting from chronic drug use on stress biology, and their effects on addiction risk and relapse. This review mainly covers human research on the acute effects of different drugs of abuse (i.e., nicotine, cannabis, psychostimulants, alcohol, and opioids) on the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) responses. We review the literature on acute peripheral stress responses in naïve or light recreational users and binge/heavy or chronic drug users. We also discuss evidence of alterations in tonic levels, or tolerance, in the latter relative to the former and associated changes in the phasic stress responses. We discuss the impact of the stress system tolerance in heavy users on their response to drug- and stress-related cue responses and craving as compared to control subjects. A summary is provided of the effects of glucocorticoid responses and their adaptations on brain striatal and prefrontal cortices involved in the regulation of drug seeking and relapse risk. Finally, we summarize important considerations, including individual difference factors such as gender, co-occurring drug use, early trauma and adversity and drug use history and variation in methodologies, that may further influence the effects of these drugs on stress biology. Keywords: Stress, Addiction, Drug, Cortisol, Autonomic nervous system, Cardiovascular

Sarah K. Lageman

Rodolfo J. Castro Salinas

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Pauline E.J. Spaan

A longstanding debate in dementia research has been whether normal aging and Alzheimer’s disease (AD) are extremes that lie along the same continuum (continuity view), or whether AD is categorically different from normal aging (discontinuity view). In other words, do only quantitative differences in neuropsychological test performance exist between normal aging and AD, or are there also qualitative differences? This question has been dominating dementia research for a century now and is characterized by inconsistent results and differences in methodological approach. In this review, I discuss studies that draw conclusions in terms of a continuous transition from normal aging to AD, followed by a discussion of studies that draw conclusions in terms of a discontinuous transition. In addition, several methodological issues are discussed that may explain the contrasting findings. This led to a proposal for investigating this topic in further research. I argue that only a latent variable (structural equation modeling) approach testing for measurement equivalence may or may not reveal structural (i.e. qualitative) differences in neuropsychological test performance between normal aging and AD. This outcome has important implications for the selection of optimal procedures of early AD assessment, particularly at very old age.

J. C. I. Belmonte, E. Callaway, P. Churchland et al.