Synergistic associations of cognitive and motor impairments with functional outcome in covert cerebral small vessel disease

Long-term cognitive and neurovascular changes after carotid endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) has been associated with both cognitive decline and improvement, but the underlying neurovascular mechanisms are unclear. The aim of this study was to investigate the relationship between neurovascular indices and cognitive changes after CEA.

METHODS

We studied 55 patients with severe (≥70%) symptomatic or asymptomatic carotid stenosis before and six months after CEA. A wide array of neuropsychological tests was arranged in eight cognitive domains and cognitive functions specific to hemisphere ipsilateral to operation. Differences in cognitive performance between patients and 38 matching healthy controls were studied with linear mixed models. Neurovascular functioning and microembolic signals were assessed with transcranial Doppler ultrasound of the middle cerebral artery. Associations between neurovascular indices and cognitive change were assessed with linear regression analyses.

RESULTS

On group level, the CEA patients improved more than controls in working memory, whereas no cognitive deterioration was detected. Also on individual level, improvement was most frequently observed in working memory. Worse preoperative cerebrovascular reactivity was related with improvement in cognitive functions of the ipsilateral hemisphere. Low preoperative pulsatility index was associated with improvement in executive functioning and ipsilateral cognitive functions. Poorer preoperative blood flow velocity associated with improvement in complex attention. Microembolic signals were rare.

CONCLUSION

The present findings suggest that CEA may have beneficial long-term effects on cognition. These effects may specifically involve patients with impaired preoperative circulatory adaptive mechanisms.

A Novel Computerized Flexible Attention Test in Detecting Executive Dysfunction of Patients with Early-Onset Cognitive Impairment and Dementia

OBJECTIVE

The number of computer-based cognitive tests has increased in recent years, but there is a need for tests focusing on the assessment of executive function (EF), as it can be crucial for the identification of early-onset neurodegenerative disorders. This study aims to examine the ability of the Flexible Attention Test (FAT), a new computer-based test battery for detecting executive dysfunction of early-onset cognitive impairment and dementia patients.

METHOD

We analyzed the FAT subtask results in memory clinic patients with cognitive symptom onset at ≤65 years. The patients were divided into four groups: early onset dementia (EOD, n = 48), mild cognitive impairment due to neurological causes (MCI-n, n = 34), MCI due to other causes (MCI-o, n = 99), and subjective cognitive decline (SCD, n = 14). The test accuracy to distinguish EOD patients from other groups was examined, as well as correlations with pen-and-paper EF tests. We also reported the 12-months follow-up results.

RESULTS

The EOD and MCI-n patients performed significantly poorer (p ≤ .002) than those in the MCI-o and SCD groups in most of the FAT subtasks. The accuracies of the FAT subtasks to detect EOD from other causes were mainly moderate (0.34 ≤ area under the curve < 0.74). The FAT subtasks correlated logically with corresponding pen-and-paper EF tests (.15 ≤ r ≤ .75). No systematic learning effects were detected in the FAT performance at follow-up.

CONCLUSIONS

The FAT appears to be a promising method for the precise evaluation of EF and applicable distinguishing early-onset neurodegenerative disorders from patients with other causes of cognitive problems.

Performance of the walking trail making test in older adults with white matter hyperintensities

BACKGROUND

Several studies have reported that the walking trail making test (WTMT) completion time is significantly higher in patients with developmental coordination disorders and mild cognitive impairments. We hypothesized that WTMT performance would be altered in older adults with white matter hyperintensities (WMH).

AIM

To explore the performance in the WTMT in older people with WMH.

METHODS

In this single-center, observational study, 25 elderly WMH patients admitted to our hospital from June 2019 to June 2020 served as the WMH group and 20 participants matched for age, gender, and educational level who were undergoing physical examination in our hospital during the same period served as the control group. The participants completed the WTMT-A and WTMT-B to obtain their gait parameters, including WTMT-A completion time, WTMT-B completion time, speed, step length, cadence, and stance phase percent. White matter lesions were scored according to the Fazekas scale. Multiple neuropsychological assessments were carried out to assess cognitive function. The relationships between WTMT performance and cognition and motion in elderly patients with WMH were analyzed by partial Pearson correlation analysis.

RESULTS

Patients with WMH performed significantly worse on the choice reaction test (CRT) (0.51 ± 0.09 s vs 0.44 ± 0.06 s, P = 0.007), verbal fluency test (VFT, 14.2 ± 2.75 vs 16.65 ± 3.54, P = 0.012), and digit symbol substitution test (16.00 ± 2.75 vs 18.40 ± 3.27, P = 0.010) than participants in the control group. The WMH group also required significantly more time to complete the WTMT-A (93.00 ± 10.76 s vs 70.55 ± 11.28 s, P < 0.001) and WTMT-B (109.72 ± 12.26 s vs 82.85 ± 7.90 s, P < 0.001). WTMT-A completion time was positively correlated with CRT time (r = 0.460, P = 0.001), while WTMT-B completion time was negatively correlated with VFT (r = -0.391, P = 0.008). On the WTMT-A, only speed was found to statistically differ between the WMH and control groups (0.803 ± 0.096 vs 0.975 ± 0.050 m/s, P < 0.001), whereas on the WTMT-B, the WMH group exhibited a significantly lower speed (0.778 ± 0.111 vs 0.970 ± 0.053 m/s, P < 0.001) and cadence (82.600 ± 4.140 vs 85.500 ± 5.020 steps/m, P = 0.039), as well as a higher stance phase percentage (65.061 ± 1.813% vs 63.513 ± 2.465%, P = 0.019) relative to controls.

CONCLUSION

Older adults with WMH showed obviously poorer WTMT performance. WTMT could be a potential indicator for cognitive and motor deficits in patients with WMH.

Gait Parameters can Reflect Cognitive Performance in Older Adults with Cerebral Small Vessel Disease: A Cross-sectional Research

BACKGROUND

Cerebral small vessel disease (CSVD) is a common chronic progressive disease. It remains unclear whether high gait variability is a marker of cognitive cortical dysfunction.

METHODS

This study included 285 subjects (aged from 60 to 85 years, 60.3% female) including 37 controls, 179 presented as Fazekas II, and 69 presented as Fazekas III. The severity of white matter hyperintensities was assessed by the Fazekas Rating Scale. Gait parameters were assessed using a vision-based artificial intelligent gait analyzer. Cognitive function was tested by MMSE, MoCA, DST, and VFT.

RESULTS

Three gait parameters including gait speed, gait length, and swing time were associated with cognitive performance in patients with CSVD. Gait speed was associated with cognitive performance, including MMSE (β 0.200; 95%CI 1.706-6.018; p <.001), MoCA (β 0.183; 95%CI 2.047-7.046; p <.001), DST (order) (β 0.204; 95%CI 0.563-2.093; p =.001) and VFT (β 0.162; 95%CI 0.753-4.865; p =.008). Gait length was associated with cognitive performance, including MMSE (β 0.193; 95%CI 3.475-12.845; p =.001), MoCA (β 0.213; 95%CI 6.098-16.942; p <.001), DST (order) (β 0.224; 95%CI 1.056-4.839; P <.001) and VFT (β 0.149; 95%CI 1.088- 10.114; p =.015). Swing time was associated with cognitive performance, including MMSE (β - 0.242; 95%CI -2.639 to -0.974; p<.001), MoCA (β -0.211; 95%CI -2.989 to -1.034; p <.001) and DST (reverse order) (β -0.140; 95%CI -0.568 to -0.049; p =.020).

CONCLUSION

This study revealed that the relationship between gait parameters and cognitive performance in patients with CSVD and the deteriorated gait parameters can reflect cognitive impairment and even dementia in older people with CSVD.

Subjective vs informant-reported cognitive complaints have differential clinical significance in covert cerebral small vessel disease

Objective

Subjective cognitive complaints are common in patients with cerebral small vessel disease (cSVD), yet their relationship with informant evaluations, objective cognitive functions and severity of brain changes are poorly understood. We studied the associations of subjective and informant reports with findings from comprehensive neuropsychological assessment and brain MRI.

Method

In the Helsinki SVD Study, 152 older adults with varying degrees of white matter hyperintensities (WMH) but without stroke or dementia were classified as having normal cognition or mild cognitive impairment (MCI) based on neuropsychological criteria. The measures also included continuous domain scores for memory and executive functions. Cognitive complaints were evaluated with the subjective and informant versions of the Prospective and Retrospective Memory Questionnaire (PRMQ) and Dysexecutive Questionnaire (DEX); functional abilities with the Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL); and depressive symptoms with the Geriatric Depression Scale (GDS-15).

Results

Subjective cognitive complaints correlated significantly with informant reports (r=0.40-0.50, p<0.001). After controlling for demographics, subjective and informant DEX and PRMQ were not related to MCI, memory or executive functions. Instead, subjective DEX and PRMQ significantly associated with GDS-15 and informant DEX and PRMQ with WMH volume and A-IADL.

Conclusions

Neither subjective nor informant-reported cognitive complaints associated with objective cognitive performance. Informant-evaluations were related to functional impairment and more severe WMH, whereas subjective complaints only associated with mild depressive symptoms. These findings suggest that awareness of cognitive impairment may be limited in early-stage cSVD and highlight the value of informant assessments in the identification of patients with functional impairment.

Altered neuroimaging patterns of cerebellum and cognition underlying the gait and balance dysfunction in cerebral small vessel disease

Background

The mechanism of gait and balance dysfunction (GBD) in cerebral small vessel disease (CSVD) remains unclear. Evidence supports cognition engages in GBD of CSVD. The cerebellum is important in motor and cognition, while little is known about the influence of the cerebellum on GBD in CSVD.

Methods

This study is a retrospective cohort study. All participants of this study were enrolled from the CSVD individuals in Nanjing Drum Tower Hospital from 2017 to 2021. The GBD of CSVD patients was defined as Tinetti Test score ≤ 23. Cerebral cortical thickness, cerebellar gray matter volume, the amplitude of low-frequency fluctuation, functional connectivity, and modular interaction were calculated to determine the cortical atrophy and activity patterns of CSVD patients with GBD. The effect of cognitive domains during GBD in CSVD patients was explored by correlation analyses.

Results

A total of 25 CSVD patients were recruited in CSVD patients with GBD group (Tinetti Test score ≤ 23, mean age ± standard deviation: 70.000 ± 6.976 years), and 34 CSVD patients were recruited in CSVD patients without GBD group (Tinetti Test score &gt; 23, mean age ± standard deviation: 64.029 ± 9.453 years). CSVD patients with GBD displayed worse cognitive performance and cortical atrophy in the right cerebellum VIIIa and bilateral superior temporal gyrus than those without GBD. The right postcentral gyrus, left inferior temporal gyrus, right angular gyrus, right supramarginal gyrus and right middle frontal gyrus were functionally overactivated and showed decreased modular interaction with the right cerebellum. Tinetti Test scores were negatively related to the volume of the right cerebellum VIIIa in CSVD patients with GBD. Notably, memory, especially visuospatial memory, was greatly associated with GBD in CSVD.

Conclusion

The cortical atrophy and altered functional activity in sensorimotor area and ventral attention network in the cerebellum and cerebrum may underlying the GBD in CSVD. Memory might be critically cognitively responsible for GBD in CSVD.

Neurofilament light level correlates with brain atrophy, and cognitive and motor performance

Background

The usefulness of neurofilament light (NfL) as a biomarker for small vessel disease has not been established. We examined the relationship between NfL, neuroimaging changes, and clinical findings in subjects with varying degrees of white matter hyperintensity (WMH).

Methods

A subgroup of participants (n = 35) in the Helsinki Small Vessel Disease Study underwent an analysis of NfL in cerebrospinal fluid (CSF) as well as brain magnetic resonance imaging (MRI) and neuropsychological and motor performance assessments. WMH and structural brain volumes were obtained with automatic segmentation.

Results

CSF NfL did not correlate significantly with total WMH volume (r = 0.278, p = 0.105). However, strong correlations were observed between CSF NfL and volumes of cerebral grey matter (r = -0.569, p < 0.001), cerebral cortex (r = -0.563, p < 0.001), and hippocampi (r = -0.492, p = 0.003). CSF NfL also correlated with composite measures of global cognition (r = -0.403, p = 0.016), executive functions (r = -0.402, p = 0.017), memory (r = -0.463, p = 0.005), and processing speed (r = -0.386, p = 0.022). Regarding motor performance, CSF NfL was correlated with Timed Up and Go (TUG) test (r = 0.531, p = 0.001), and gait speed (r = -0.450, p = 0.007), but not with single-leg stance. After adjusting for age, associations with volumes in MRI, functional mobility (TUG), and gait speed remained significant, whereas associations with cognitive performance attenuated below the significance level despite medium to large effect sizes.

Conclusion

NfL was strongly related to global gray matter and hippocampal atrophy, but not to WMH severity. NfL was also associated with motor performance. Our results suggest that NfL is independently associated with brain atrophy and functional mobility, but is not a reliable marker for cerebral small vessel disease.

Aged Patients With Severe Small Vessel Disease Exhibit Poor Bimanual Coordination During the Anti-Phase Horizontal Line Drawing Task

The present study explores whether SVD affects bimanual coordination, which is easier to detect than by conventional, MRI-based methods. We tested nine severe SVD patients, eight non-severe (i.e., moderate or mild) SVD patients, eleven healthy age-matched controls, and eight young adults. They were grouped according to Fazekas scale and by age. Participants performed horizontal line drawings with both hands simultaneously on two pen tablets. The movements consisted of rhythmic patterns where participants used both hands to draw horizontal lines in anti-phase on two pen tablets. Each participant underwent a series of neuropsychiatric assessments. Results showed that SVD patients exhibited in each hand smaller horizontal movement amplitudes with variability larger compared to the healthy age-matched controls. Only movement amplitudes appeared to decrease significantly with severity of SVD. Interestingly, we found no relevant differences between the age-matched, elderly controls and the young controls. Therefore, this effect appeared indicative of SVD. The variability of the lines orthogonal to the horizontal lines of the left, non-dominant hand differed only between the severe SVD group and the other groups. Furthermore, partial correlations demonstrated that the mean horizontal movement amplitude of the left hand was positively associated with the clock drawing test score, and the inter-manual asynchrony of the horizontal movements was positively associated with the Trail Making Test-B time. These results indicated that SVD patients show poor bimanual coordination, as reflected by spatial features such as movement amplitudes and variabilities, and abnormal bimanual coordination was associated with executive dysfunction.

Neuroimaging markers of dual impairment in cognition and physical performance following stroke: The Nor-COAST study

Background

Cognitive decline and decline in physical performance are common after stroke. Concurrent impairments in the two domains are reported to give increased risk of dementia and functional decline. The concept of dual impairment of physical performance and cognition after stroke is poorly investigated. Clinically accessible imaging markers of stroke and pre-existing brain pathology might help identify patients at risk.

Objective

The primary aim of this study was to investigate to which extent pre-stroke cerebral pathology was associated with dual impairment in cognition and physical performance at time of stroke. Secondary aims were to examine whether white matter hyperintensities, medial temporal lobe atrophy, and stroke lesion volume and location were associated with dual impairment.

Methods

Participants from the Norwegian Cognitive Impairment After Stroke (Nor-COAST) study with available MRI data at baseline were included in this cross-sectional study. Logistic regression analyses were conducted, with impairment status (no impairment, impaired cognition, impaired physical performance, and dual impairment) as the dependent variable and MRI markers as covariates. Pre-existing brain pathologies were classified into neurodegenerative, cerebrovascular, or mixed pathology. In addition, white matter hyperintensities and medial temporal lobe atrophy were included as independent covariates. Stroke volume and location were also ascertained from study-specific MRI scans.

Results

Participants' (n = 348) mean (SD) age was 72.3 (11.3) years; 148 (42.5%) were women. Participants with dual impairment (n = 99) were significantly older, had experienced a more severe stroke, and had a higher comorbidity burden and poorer pre-stroke function. Stroke lesion volume (odds ratio 1.03, 95%, confidence interval 1.00 to 1.05, p = 0.035), but not stroke location or pre-existing brain pathology, was associated with dual impairment, after adjusting for age and sex.

Conclusion

In this large cohort of stroke survivors having suffered mainly mild to moderate stroke, stroke lesion volume-but not pre-existing brain pathology-was associated with dual impairment early after stroke, confirming the role of stroke severity in functional decline.

Neuropsychiatric symptoms are associated with exacerbated cognitive impairment in covert cerebral small vessel disease

OBJECTIVES

Neuropsychiatric symptoms are related to disease progression and cognitive decline over time in cerebral small vessel disease (SVD) but their significance is poorly understood in covert SVD. We investigated neuropsychiatric symptoms and their relationships between cognitive and functional abilities in subjects with varying degrees of white matter hyperintensities (WMH), but without clinical diagnosis of stroke, dementia or significant disability.

METHODS

The Helsinki Small Vessel Disease Study consisted of 152 subjects, who underwent brain magnetic resonance imaging (MRI) and comprehensive neuropsychological evaluation of global cognition, processing speed, executive functions, and memory. Neuropsychiatric symptoms were evaluated with the Neuropsychiatric Inventory Questionnaire (NPI-Q, n = 134) and functional abilities with the Amsterdam Instrumental Activities of Daily Living questionnaire (A-IADL, n = 132), both filled in by a close informant.

RESULTS

NPI-Q total score correlated significantly with WMH volume (r_s = 0.20, p = 0.019) and inversely with A-IADL score (r_s = -0.41, p < 0.001). In total, 38% of the subjects had one or more informant-evaluated neuropsychiatric symptom. Linear regressions adjusted for age, sex, and education revealed no direct associations between neuropsychiatric symptoms and cognitive performance. However, there were significant synergistic interactions between neuropsychiatric symptoms and WMH volume on cognitive outcomes. Neuropsychiatric symptoms were also associated with A-IADL score irrespective of WMH volume.

CONCLUSIONS

Neuropsychiatric symptoms are associated with an accelerated relationship between WMH and cognitive impairment. Furthermore, the presence of neuropsychiatric symptoms is related to worse functional abilities. Neuropsychiatric symptoms should be routinely assessed in covert SVD as they are related to worse cognitive and functional outcomes.