Motor demands of cognitive testing may artificially reduce executive function scores in individuals with spinal cord injury

Massive body-brain disconnection consequent to spinal cord injuries drives profound changes in higher-order cognitive and emotional functions: A PRISMA scoping review

Spinal cord injury (SCI) leads to a massive disconnection between the brain and the body parts below the lesion level representing a unique opportunity to explore how the body influences a person's mental life. We performed a systematic scoping review of 59 studies on higher-order cognitive and emotional changes after SCI. The results suggest that fluid abilities (e.g. attention, executive functions) and emotional regulation (e.g. emotional reactivity and discrimination) are impaired in people with SCI, with progressive deterioration over time. Although not systematically explored, the factors that are directly (e.g. the severity and level of the lesion) and indirectly associated (e.g. blood pressure, sleeping disorders, medication) with the damage may play a role in these deficits. The inconsistency which was found in the results may derive from the various methods used and the heterogeneity of samples (i.e. the lesion completeness, the time interval since lesion onset). Future studies which are specifically controlled for methods, clinical and socio-cultural dimensions are needed to better understand the role of the body in cognition.

Cognitive Impairment in Individuals With Spinal Cord Injury: Findings of a Systematic Review With Robust Variance and Network Meta-analyses

BACKGROUND AND OBJECTIVES

Estimates of the prevalence (10%-60%) of cognitive impairment in individuals with spinal cord injury (SCI) are too broad, and which domains of cognition are most affected is unclear. We performed a meta-analysis to investigate impairments across domains of cognitive functioning to provide a nuanced picture of research conducted to date into cognitive impairment after SCI.

METHODS

Results of peer-reviewed studies published in English between 1980 and 2021 comparing ≥20 participants with SCI with able-bodied controls were synthesized using meta-analysis. The primary outcomes were neurocognitive test scores categorized into 5 cognitive domains as listed in the Diagnostic and Statistical Manual of Mental Disorders: Complex Attention, Executive Functioning, Learning and Memory, Language, and Perceptual Motor Function. Two researchers independently assessed and verified extracted data to comply with meta-analytic reporting guidelines. Robust variance estimation meta-analysis was conducted to determine an overall pooled effect size across all cognitive domains using data extracted from studies. Using network meta-analysis, we synthesized eligible studies and made comparisons with the 5 domains of cognitive functioning serving as the outcomes and SCI as the condition.

RESULTS

Of 4,783 potential studies, 13 met final inclusion criteria. Studies met 6 of 8 quality assessment criteria generally. Results suggested that adults with SCI experience reduced cognitive functioning (effect size: -0.84; 95% CI -1.24 to -0.44, p < 0.001) compared with able-bodied individuals, with deficits mostly in attention (g = -0.64; 95% CI -0.92 to -0.38) and executive functioning (g = -0.61, 95% CI -0.89 to -0.04). Publication bias and high heterogeneity (I2: 86%) qualify these findings and highlight the need to improve research methods in this area.

DISCUSSION

Adults with SCI seem more likely than adults who are able-bodied to display cognitive impairments mostly in areas of attention and executive functioning. Research practices must become consistent to reduce heterogeneity so that the validity and reliability of the results of future studies into cognitive impairment after SCI improves.

Sympathetic Vagal Balance and Cognitive Performance in Young Adults during the NIH Cognitive Test

Compromised cognitive function is associated with increased mortality and increased healthcare costs. Autonomic nervous system arousal, as measured by an electrocardiogram (ECG), has received recent attention because of its association with the blood perfusion of brain regions involved with cognitive function. The purposes of this study were to determine whether the ECG HR variation, as measured by the standard deviation of the heart rate N-to-N intervals (SDNN), and sympathetic vagal tone, as estimated by the low-frequency/high-frequency ratio (LF/HF), are increased with cognitive performance during the NIH Cognitive Test (Picture Sequence, Dimensional Change Card Sort, Flanker, and List Sorting). A total of 62 young people without cognitive impairment participated in this study. We discovered that the ECG LF/HF ratio was increased in the top 50% of participants who could: (1) inhibit information and stay attentive to a desired task during the Flanker Test; (U = 329, p = 0.03; R² = 0.76); and (2) promote cognitive function flexibility during the DCCS Test; (U = 55, p = 0.007; R² = 0.98). Taken together, these findings support that the arousal level influences performance during a cognitive test.

Uses of the NIH Toolbox® in Clinical Samples: A Scoping Review

Background and Objectives

The NIH Toolbox® for the Assessment of Neurologic and Behavioral Function is a compilation of computerized measures designed to assess sensory, motor, emotional, and cognitive functioning of individuals across the life span. The NIH Toolbox was initially developed for use with the general population and was not originally validated in clinical populations. The objective of this scoping review was to assess the extent to which the NIH Toolbox has been used with clinical populations.

Methods

Guided by the Joanna Briggs Methods Manual for Scoping Reviews, records were identified through searches of PubMed MEDLINE, PsycINFO, ClinicalTrials.gov, EMBASE, and ProQuest Dissertations and Theses Global (2008-2020). Database searches yielded 5,693 unique titles of original research that used at least one NIH Toolbox assessment in a sample characterized by any clinical diagnosis. Two reviewers screened titles, abstracts, and full texts for inclusion in duplicate. Conflicts at each stage of the review process were resolved by a group discussion.

Results

Ultimately, 281 publication records were included in this scoping review (nJournal Articles = 104, nConference Abstracts = 84, nClinical Trial Registrations = 86, and nTheses/Dissertations = 7). The NIH Toolbox Cognition Battery was by far the most used of the 4 batteries in the measurement system (nCognition = 225, nEmotion = 49, nMotor = 29, and nSensation = 16). The most represented clinical category was neurologic disorders (n = 111), followed by psychological disorders (n = 39) and cancer (n = 31). Most (96.8%) of the journal articles and conference abstracts reporting the use of NIH Toolbox measures with clinical samples were published in 2015 or later. As of May 2021, these records had been cited a total of nearly 1,000 times.

Discussion

The NIH Toolbox measures have been widely used among individuals with various clinical conditions across the life span. Our results lay the groundwork to support the feasibility and utility of administering the NIH Toolbox measures in research conducted with clinical populations and further suggest that these measures may be of value for implementation in fast-paced clinical settings as part of routine practice.

Extracellular to Intracellular Body Water and Cognitive Function among Healthy Older and Younger Adults

Compromised cognitive function is associated with increased mortality and increased healthcare costs. Physical characteristics including height, weight, body mass index, sex, and fat mass are often associated with cognitive function. Extracellular to intracellular body water ratio offers an additional anthropometric measurement that has received recent attention because of its association with systemic inflammation, hypertension, and blood−brain barrier permeability. The purposes of this study were to determine whether extracellular to intracellular body water ratios are different between younger and older people and whether they are associated with cognitive function, including executive function and attention, working memory, and information processing speed. A total of 118 healthy people (39 older; 79 younger) participated in this study. We discovered that extracellular to intracellular body water ratio increased with age, was predictive of an older person’s ability to inhibit information and stay attentive to a desired task (Flanker test; R2 = 0.24; p < 0.001), and had strong sensitivity (83%) and specificity (91%) to detect a lower executive function score. These findings support that extracellular to intracellular body water ratio offers predictive capabilities of cognitive function, even in a healthy group of elderly people.

Cognitive function, quality of life, and aging: relationships in individuals with and without spinal cord injury

Background: Correlations between aging, cognitive impairment and poor quality of life (QOL) have been observed for many patient populations.Objective: The purpose of this study was to examine these correlations in individuals with and without spinal cord injury (SCI).Methods: 23 individuals with complete SCI and 20 individuals without SCI ("NON") underwent assessment of cognitive function via the NIH Toolbox for Neurological and Behavioral Function. Participants self-rated QOL via global and symptom/domain-specific measures.Results: SCI rated global QOL to be lower than NON for the EQ-5D QALY (p < .001), but not the EQ-5D VAS, which imposes no penalty for wheeled mobility. Low QOL clustered mainly in domains pertaining to physical function/symptoms. Participants with SCI reported high QOL for positive affect/well-being and resilience. Cognitive function in SCI did not differ from NON. However, strong correlations between age and cognition observed in NON (all R² > 0.532) were absent in SCI. Significant correlations between cognition and QOL were prevalent for NON but not for SCI.Conclusions: Dissociation of age, cognition and QOL occurred with SCI. Divergence between EQ-5D QALY and VAS suggests that individuals with SCI may recalibrate personal assessments of QOL in ways that minimize the importance of mobility impairment.

The treatment of neurogenic lower urinary tract dysfunction in persons with spinal cord injury: An open label, pilot study of anticholinergic agent vs. mirabegron to evaluate cognitive impact and efficacy

STUDY DESIGN

Pre-post intervention.

OBJECTIVES

1. To test whether replacement of oral anticholinergic (AC) agents with mirabegron for neurogenic lower urinary tract dysfunction (NLUTD) yields improved cognitive function in older persons with spinal cord injury (SCI). 2. To test whether mirabegron is safe and as efficacious as AC.

SETTING

USA.

METHODS

Pilot study: Twenty older (>60 y/o) persons with SCI taking chronic (>6 months) AC medication for NLUTD were enrolled. All participants were first studied on AC at baseline then switched to mirabegron for 6 months. Primary outcomes were cognitive tests of (1) executive function (TEXAS, SDMT); (2) attention (SCWT); and (3) memory (SLUMS and WMS-IV Story A/B). Secondary outcomes assessed efficacy and safety including Neurogenic Bladder Symptom Score (NBSS), bladder diary, neurogenic bowel dysfunction (NBD) survey, heart rate (HR), electrocardiogram (EKG), and mean arterial pressure (MAP).

RESULTS

When switching from AC to mirabegron for NLUTD, older persons with SCI exhibited statistically significant improvements in immediate Story A recall (p = 0.01), delayed story A and B recall (p = 0.01, 0.004), and in TEXAS (p = 0.04). Three subscores within NBSS significantly improved (p = 0.001) and the frequency of incontinence decreased (p = 0.03) on mirabegron. NBD, HR, MAP, and EKGs were unchanged.

CONCLUSIONS

Older persons with SCI on AC for NLUTD demonstrated improved short-term and delayed memory (WMS-IV Story A/B) as well as executive function (TEXAS) when switched to mirabegron. Efficacy of mirabegron for NLUTD symptoms was superior to AC with no adverse effects on bowel or cardiovascular function.

SPONSORSHIP

Claude D. Pepper Older Americans Independence Center.