Opportunities and Pitfalls of REM Sleep Behavior Disorder and Olfactory Dysfunction as Early Markers in Parkinson's Disease

During its pre-motor stage, Parkinson's disease (PD) presents itself with a multitude of non-motor symptoms with different degrees of specificity and sensitivity. The most important among them are REM sleep behavior disorder (RBD) and olfactory dysfunction. RBD is a parasomnia characterized by the loss of REM sleep muscle atonia and dream-enacting behaviors. Olfactory dysfunction in individuals with prodromal PD is usually described as hyposmia (reduced sense of smell) or anosmia (complete loss of olfactory function). These symptoms can precede the full expression of motor symptoms by decades. A close comprehension of these symptoms and the underlying mechanisms may enable early screening as well as interventions to improve patients' quality of life. Therefore, these symptoms have unmatched potential for identifying PD patients in prodromal stages, not only allowing early diagnosis but potentially opening a window for early, possibly disease-modifying intervention. However, they come with certain challenges. This review addresses some of the key opportunities and pitfalls of both RBD and olfactory dysfunction as early markers of PD.

The renal damage and mechanisms relevant to antitumoral drugs

Over the past few decades, significant progress has been made in the development of drugs to combat cancer. It is unfortunate that these drugs can also lead to various kidney injuries and imbalances in electrolyte levels. Nephrotoxicity caused by chemotherapy drugs can impact different parts of the kidneys, including the glomeruli, renal tubules, interstitium, or renal microvessels. Despite the existing knowledge, our understanding of the mechanisms underlying the renal damage caused by antitumoral drugs remains incomplete. In this review, we aim to provide a comprehensive overview of the specific types of kidney injury and the mechanisms responsible for the drug-mediated renal damage, and briefly discuss possible prevention and treatment measures. Sensitive blood and urine biomarkers can provide clinicians with more information about kidney injury detection and reference value for subsequent treatment options. In addition, we emphasize that both oncologists and nephrologists have a responsibility to remain vigilant against the potential nephrotoxicity of the drugs. It's crucial for experts in both fields to collaborate in early detection, monitoring and prevention of kidney damage.

[Attenuated negative symptoms in the structure of youth depression]

OBJECTIVE

To detect negative symptoms in adolescent depression, to determine their psychopathological structure and predictive significance.

MATERIAL AND METHODS

Seventy-one young in-patients (average age 19.5±2.4 years) (main group) and 52 in-patients (average age 19.8±2.7 years) (comparison group) with the diagnosis «Depressive episode» according to ICD-10 F32.1, F32.2 were examined. Inclusion criterion in the main group was attenuated negative symptoms (ANS) in adolescent depression. Clinical-psychopathological and psychometric examination was carried out using HDRS, SOPS, SANS. The statistical analysis was done by Statistica 12.

RESULTS

Adolescent depression with ANS was more persistent than depression in the comparison group (27.5±17.2 month versus 7.0±6.3, p<0.001), there was higher level of positive symptoms and disorganization symptoms on the respective SOPS sub-scales (7 [5; 9] and 4.5 [3; 8.75], p=0.002; 8 [6; 10] and 5.5 [3.25; 7], p<0.001, respectively). According to the psychopathological structure of the negative symptoms, patients in the main group were divided into a subgroup (n=38, 53.5%) with the predominance of emotional spectrum disorders and a subgroup (n=33, 46.5%) with the predominant involvement of the volition spectrum. ANS in the negative SOPS sub-scale were significantly higher (p=0.045) in patients of the subgroup with volitional disorders. Also, a total HDRS score, reflecting the severity of depressive symptoms, was significantly higher compared to a subgroup with the predominance of emotional spectrum disorders (p=0.038).

CONCLUSION

The results show that it is possible to clinically verify negative symptoms in the adolescent depression, which makes it possible to assign such patients to the risk group of manifestation of schizophrenia, and to assign depression with ANS to the model of the initial stage of schizophrenic process.

Developing Early Markers of Cognitive Decline and Dementia Derived From Survey Response Behaviors: Protocol for Analyses of Preexisting Large-scale Longitudinal Data

BACKGROUND

Accumulating evidence shows that subtle alterations in daily functioning are among the earliest and strongest signals that predict cognitive decline and dementia. A survey is a small slice of everyday functioning; nevertheless, completing a survey is a complex and cognitively demanding task that requires attention, working memory, executive functioning, and short- and long-term memory. Examining older people's survey response behaviors, which focus on how respondents complete surveys irrespective of the content being sought by the questions, may represent a valuable but often neglected resource that can be leveraged to develop behavior-based early markers of cognitive decline and dementia that are cost-effective, unobtrusive, and scalable for use in large population samples.

OBJECTIVE

This paper describes the protocol of a multiyear research project funded by the US National Institute on Aging to develop early markers of cognitive decline and dementia derived from survey response behaviors at older ages.

METHODS

Two types of indices summarizing different aspects of older adults' survey response behaviors are created. Indices of subtle reporting mistakes are derived from questionnaire answer patterns in a number of population-based longitudinal aging studies. In parallel, para-data indices are generated from computer use behaviors recorded on the backend server of a large web-based panel study known as the Understanding America Study (UAS). In-depth examinations of the properties of the created questionnaire answer pattern and para-data indices will be conducted for the purpose of evaluating their concurrent validity, sensitivity to change, and predictive validity. We will synthesize the indices using individual participant data meta-analysis and conduct feature selection to identify the optimal combination of indices for predicting cognitive decline and dementia.

RESULTS

As of October 2022, we have identified 15 longitudinal ageing studies as eligible data sources for creating questionnaire answer pattern indices and obtained para-data from 15 UAS surveys that were fielded from mid-2014 to 2015. A total of 20 questionnaire answer pattern indices and 20 para-data indices have also been identified. We have conducted a preliminary investigation to test the utility of the questionnaire answer patterns and para-data indices for the prediction of cognitive decline and dementia. These early results are based on only a subset of indices but are suggestive of the findings that we anticipate will emerge from the planned analyses of multiple behavioral indices derived from many diverse studies.

CONCLUSIONS

Survey response behaviors are a relatively inexpensive data source, but they are seldom used directly for epidemiological research on cognitive impairment at older ages. This study is anticipated to develop an innovative yet unconventional approach that may complement existing approaches aimed at the early detection of cognitive decline and dementia.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/44627.

Preschool development, temperament and genetic liability as early markers of childhood ADHD: A cohort study

Background

ADHD is associated with multiple adverse outcomes and early identification is important. The present study sets out to identify early markers and developmental characteristics during the first 30 months of life that are associated with ADHD 6 years later.

Methods

9201 participants from the prospective Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort were included. Outcome measures were parent-rated ADHD symptom scores (Strengths and Difficulties Questionnaire, SDQ) and ADHD diagnosis (Development and Wellbeing Assessment, DAWBA) at age 7. Seventeen putative markers were identified from previous literature and included: pre- and peri-natal risk factors, genetic liability (ADHD polygenic risk scores, PRS), early development, temperament scores and regulatory problems. Associations were examined using regression analysis.

Results

Univariable regression analysis showed that multiple early life factors were associated with future ADHD outcomes, even after controlling for sex and socio-economic status. In a multivariable linear regression model; temperament activity scores (B = 0.107, CI = 0.083-0.132), vocabulary delay (B = 0.605, CI = 0.211-0.988), fine motor delay (B = 0.693, CI = 0.360-1.025) and ADHD PRS (B = 0.184, CI = 0.074-0.294) were associated with future symptoms (R ² = 10.7%). In a multivariable logistic regression model, ADHD PRS (OR = 1.39, CI = 1.10-1.77) and temperament activity scores (OR = 1.09, CI = 1.04-1.16) showed association with ADHD diagnosis.

Conclusion

As well as male sex and lower socio-economic status, high temperament activity levels and motor and speech delays in the first 30 months of life, are associated with childhood ADHD. Intriguingly, given that genetic risk scores are known to explain little of the variance of ADHD outcomes, we found that ADHD PRS added useful predictive information. Future research needs to test whether predictive models incorporating aspects of early development and genetic risk scores are useful for predicting ADHD in clinical practice.

Logogenic Primary Progressive Aphasia or Alzheimer Disease: Contribution of Acoustic Markers in Early Differential Diagnosis

The logopenic variant of Primary Progressive Aphasia (lvPPA), a syndromic disorder centered on language impairment, often presents variable underlying neurodegenerative pathologies such as Alzheimer Disease (AD). Actual language assessment tests and lumbar puncture, focused on AD diagnosis, cannot precisely distinguish the symptoms, or predict their progression at onset time. We analyzed acoustic markers, aiming to discriminate lvPPA and AD as well as the influence of AD biomarkers on acoustic profiles at the beginning of the disease. We recruited people with AD (n = 8) and with lvPPA (n = 8), with cerebrospinal fluid biomarker profiles determined by lumbar puncture. The participants performed a sentence repetition task that allows assessing potential lvPPA phonological loop deficits. We found that temporal and prosodic markers significantly differentiate the lvPPA and AD group at an early stage of the disease. Biomarker and acoustic profile comparisons discriminated the two lvPPA subgroups according to their biomarkers. For lvPPA with AD biomarkers, acoustic profile equivalent to an atypical AD form with a specific alteration of the phonological loop is shown. However, lvPPA without AD biomarkers has an acoustic profile approximating the one for DLFT. Therefore, these results allow us to classify lvPPA differentially from AD based on acoustic markers from a sentence repetition task. Furthermore, our results suggest that acoustic analysis would constitute a clinically efficient alternative to refused lumbar punctures. It offers the possibility to facilitate early, specific, and accessible neurodegenerative diagnosis and may ease early care with speech therapy, preventing the progression of symptoms.

Visual Implicit Learning Abilities in Infants at Familial Risk for Language and Learning Impairments

The ability of infants to track transitional probabilities (Statistical Learning—SL) and to extract and generalize high-order rules (Rule Learning—RL) from sequences of items have been proposed as being pivotal for the acquisition of language and reading skills. Although there is ample evidence of specific associations between SL and RL abilities and, respectively, vocabulary and grammar skills, research exploring SL and RL as early markers of language and learning (dis)abilities is still scarce. Here we investigated the efficiency of visual SL and RL skills in typically developing (TD) seven-month-old infants and in seven-month-old infants at high risk (HR) for language learning impairment. Infants were tested in two visual-habituation tasks aimed to measure their ability to extract transitional probabilities (SL task) or high-order, repetition-based rules (RL task) from sequences of visual shapes. Post-habituation looking time preferences revealed that both TD and HR infants succeeded in learning the statistical structure (SL task), while only TD infants, but not HR infants, were able to learn and generalize the high-order rule (RL task). These findings suggest that SL and RL may contribute differently to the emergence of language learning impairment and support the hypothesis that a mechanism linked to the extraction of grammar structures may contribute to the disorder.

Temperament and Cognitive Regulation During the First 3 Years of Life as Predictors of Inattention and Hyperactivity/Impulsivity at 6 Years

Objective: With a wish to identify early markers of inattention and hyperactivity/impulsivity, we examined effects of temperament and cognitive regulation, during the first 3 years of life, on later inattentive and hyperactive/impulsive behavior. Method: Temperament and cognitive regulation were assessed at 12, 18, 24, and 36 months in 66 typically developing children. Teachers rated inattention and hyperactivity/impulsivity at 6 years. Results: Temperamental activity at all studied time points was predictive of later hyperactive/impulsive behavior, thus appearing as a stable marker thereof. Activity at 12 months was also predictive of inattention, whereas temperamental persistence was correlated with inattention and hyperactivity/impulsivity, but with no independent contributions. No significant relations between cognitive regulation and the outcome measures were found. Conclusion: Our findings add to the scarce literature proposing that markers of inattentive and hyperactive/impulsive behavior in early school age can be found within the first years of life, using parental ratings of child temperament.

Amnioinfusion for variable decelerations caused by umbilical cord compression without oligohydramnios but with the sandwich sign as an early marker of deterioration

We report prophylactic amnioinfusion (AI) for variable decelerations in umbilical cord compression without oligohydramnios as an early sign of deterioration. We performed a transabdominal AI in cases without oligohydramnios using the ultrasonography findings of umbilical cord compression (i.e. sandwich sign [SWS]) and variable decelerations (VD) in a foetal heart rate. Thirteen cases and 21 AIs were analysed. Nine (69%) cases were of a foetal growth restriction and 4 (31%) had umbilical hyper-coiled cords. VD frequency (p < .0001), umbilical artery pulsatility index (PI) (p < .01) and ductus venous PI (0.66 vs. 0.48; p < .05) significantly decreased, and an umbilical venous (UV) flow volume (121 vs. 197 ml/min/kg; p < .05) significantly increased after AI. The umbilical artery diastolic blood flow abnormalities and UV pulsation improved. In conclusion, AI improves the umbilical cord compression even without oligohydramnios. The SWS is an important marker of deterioration to severe oligohydramnios and latent foetal damage. IMPACT STATEMENT What is already known on this subject? Antepartum variable decelerations due to umbilical cord compression are significantly associated with the deceleration in labour. In particular, foetal hypoxia leads to other adverse events such as foetal distress, hypoxic-ischemic encephalopathy, and pulmonary arterial hypertension after birth. Amnioinfusion has been shown to be effective in patients who also have oligohydramnios. What do the results of this study add? Amnioinfusion may be effective in the cases with ultrasonography findings of umbilical cord compression (i.e. sandwich sign) and in cases with variable decelerations in foetal heart rate, but without oligohydramnios. What are the implications of these findings for clinical practice and/or further research? Amnioinfusion may be helpful to prevent adverse events including oligohydramnios and anhydroamnios.

Healthy Aging and Dementia: Two Roads Diverging in Midlife?

Dementia, particularly Alzheimer’s disease (AD), is a growing pandemic that presents profound challenges to healthcare systems, families, and societies throughout the world. By 2050, the number of people living with dementia worldwide could almost triple, from 47 to 132 million, with associated costs rising to $3 trillion. To reduce the future incidence of dementia, there is an immediate need for interventions that target the disease process from its earliest stages. Research programs are increasingly starting to focus on midlife as a critical period for the beginning of AD-related pathology, yet the indicators of the incipient disease process in asymptomatic individuals remain poorly understood. We address this important knowledge gap by examining evidence for cognitive and structural brain changes that may differentiate, from midlife, healthy aging and pathological AD-related processes. This review crystallizes emerging trends for divergence between the two and highlights current limitations and opportunities for future research in this area.

Assessment of autonomic innervation of the foot in familial amyloid polyneuropathy

BACKGROUND AND PURPOSE

Distal involvement of autonomic nerve fibers is critical in familial amyloid polyneuropathy (FAP) due to transthyretin (TTR) mutation. This study compares different methods for assessing autonomic foot innervation in TTR-FAP patients.

METHODS

Three groups of seven TTR-FAP patients were included, according to disease severity: clinically asymptomatic, moderate or advanced neuropathy. The autonomic investigation included the eutectic mixture of local anesthetics test and laser Doppler flowmetry for vasomotor aspects and the Sudoscan® (measuring electrochemical skin conductance) and Neuropad® test for sudomotor aspects. Somatic innervation was assessed by performing nerve conduction studies, quantitative sensory testing [including vibration, cold and warm detection threshold (WDT) measurements] and laser evoked potentials.

RESULTS

The results of all neurophysiological tests varied according to TTR-FAP severity (P ≤ 0.01, Kruskal-Wallis test), except for the eutectic mixture of local anesthetics test and laser Doppler flowmetry variables. In addition, the sudomotor tests (Sudoscan or Neuropad) or WDT measurement provided early markers of neuropathy in two of the seven asymptomatic carriers. Finally, all neurophysiological results correlated with the Neuropathy Impairment Score (r values between -0.88 and -0.66, P < 0.005, Spearman test), except the cold detection threshold.

CONCLUSIONS

The Neuropad test could be used to detect TTR-FAP onset, but confirmation requires electrochemical skin conductance and WDT measurement. The Sudoscan technique, but not the Neuropad test (at least assessed at a fixed time point), could be valuable to follow the progression of the neuropathy. Follow-up investigation should also include large-fiber investigation (e.g. nerve conduction studies and vibration detection threshold). Conversely, reliable tests for assessing vasomotor disturbances in limb extremities of TTR-FAP patients are still awaited.

Atypical preference for infant-directed speech as an early marker of autism spectrum disorders? A literature review and directions for further research

Autism spectrum disorders (ASD) refer to a complex group of neurodevelopmental disorders causing difficulties with communication and interpersonal relationships, as well as restricted and repetitive behaviours and interests. As early identification, diagnosis, and intervention provide better long-term outcomes, early markers of ASD have gained increased research attention. This review examines evidence that auditory processing enhanced by social interest, in particular auditory preference of speech directed towards infants and young children (i.e. infant-directed speech - IDS), may be an early marker of risk for ASD. Although this review provides evidence for IDS preference as, indeed, a potential early marker of ASD, the explanation for differences in IDS processing among children with ASD versus other children remains unclear, as are the implications of these impairments for later social-communicative development. Therefore, it is crucial to explore atypicalities in IDS processing early on development and to understand whether preferential listening to specific types of speech sounds in the first years of life may help to predict the impairments in social and language development.

Simultaneous Underexpression of let-7a-5p and let-7f-5p microRNAs in Plasma and Stool Samples from Early Stage Colorectal Carcinoma

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer death worldwide. Early detection of CRC can improve patient survival rates; thus, the identification of noninvasive diagnostic markers is urgently needed. MicroRNAs (miRNAs) have extensive potential to diagnose several diseases, including cancer. In this study, we compared the expression pattern of miRNAs from plasma and stool samples of patients with early stages of CRC (I, II) with that of healthy subjects. We performed miRNA profiling using microarrays on plasma and stool samples of eight patients with CRC and four healthy subjects. Seven miRNAs were found to be underexpressed in both plasma and stool samples of patients with CRC versus healthy subjects. Then, we aimed to verify two out of these seven differentially expressed miRNAs (let-7a-5p and let-7f-5p) by quantitative reverse transcriptase polymerase chain reaction on a larger set of plasma and stool samples of 51 patients with CRC and 26 healthy subjects. We confirmed the results of microarray analysis since their expression was significantly lower in stool and plasma samples of patients with CRC. Moreover, receiver operating characteristic curve analysis demonstrated that fecal let-7f expression levels have significant sensitivity and specificity to distinguish between patients with CRC and healthy subjects. In conclusion, if the results are confirmed in larger series of patients, underexpressed let-7a-5p and let-7f-5p miRNAs in both plasma and stool samples of patients with CRC may serve potentially as noninvasive molecular biomarkers for the early detection of CRC.

Lexical retrieval in discourse: an early indicator of Alzheimer's dementia

We examined the progression of lexical-retrieval deficits in individuals with neuropathologically determined Alzheimer's disease (AD; n = 23) and a comparison group without criteria for AD (n = 24) to determine whether linguistic changes were a significant marker of the disease. Our participants underwent multiple administrations of a neuropsychological battery, with initial administration occurring on average 16 years prior to death. The battery included the Boston Naming Test (BNT), a letter fluency task (FAS) and written description of the Cookie Theft Picture (CTP). Repeated measures analysis revealed that the AD-group showed progressively greater decline in FAS and CTP lexical performance than the comparison group. Cross-sectional time-specific group comparisons indicated that the CTP differentiated performance between the two groups at 7-9 years prior to death and FAS and BNT only at 2-4 years. These results suggest that lexical-retrieval deficits in written discourse serve as an early indicator of AD.