Clinical correlates of cognitive decline in vascular dementia

Abnormal regional homogeneity in right caudate as a potential neuroimaging biomarker for mild cognitive impairment: A resting-state fMRI study and support vector machine analysis

Objective

Mild cognitive impairment (MCI) is a heterogeneous syndrome characterized by cognitive impairment on neurocognitive tests but accompanied by relatively intact daily activities. Due to high variation and no objective methods for diagnosing and treating MCI, guidance on neuroimaging is needed. The study has explored the neuroimaging biomarkers using the support vector machine (SVM) method to predict MCI.

Methods

In total, 53 patients with MCI and 68 healthy controls were involved in scanning resting-state functional magnetic resonance imaging (rs-fMRI). Neurocognitive testing and Structured Clinical Interview, such as Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) test, Activity of Daily Living (ADL) Scale, Hachinski Ischemic Score (HIS), Clinical Dementia Rating (CDR), Montreal Cognitive Assessment (MoCA), and Hamilton Rating Scale for Depression (HRSD), were utilized to assess participants' cognitive state. Neuroimaging data were analyzed with the regional homogeneity (ReHo) and SVM methods.

Results

Compared with healthy comparisons (HCs), ReHo of patients with MCI was decreased in the right caudate. In addition, the SVM classification achieved an overall accuracy of 68.6%, sensitivity of 62.26%, and specificity of 58.82%.

Conclusion

The results suggest that abnormal neural activity in the right cerebrum may play a vital role in the pathophysiological process of MCI. Moreover, the ReHo in the right caudate may serve as a neuroimaging biomarker for MCI, which can provide objective guidance on diagnosing and managing MCI in the future.

A clinical research of 11cases of human umbilical cord mesenchymal stem cells for curing senile vascular dementia

BACKGROUND

Patients affected by senile vascular dementia (VaD) suffer from a gradual deterioration in their cognitive expressions as well as the ability of taking care for themselves. This study aimed to investigate the clinical efficacy and safety of improving cognitive function and daily life activities of patients with VaD by transplanting human umbilical cord mesenchymal stem cells (HUCMSCs).

METHODS

A total number of 11 patients with senile VaD, who were admitted through outpatient treatment and hospitalized between February 2013 and February 2016, were selected. The diagnosis was based on CT and MRI examinations. The cultivated HUCMSCs (10⁶ /kg) were injected by intravenous (i.v.) infusion on three occasions. Patients were evaluated for the Mini-Mental State Examination (MMSE) with 25-30 as normal, 21-24 as mild dementia, 10-20 as moderate dementia, and 0-9 as severe dementia. In addition, the Barthel index (BI) was used for a standardized activities of daily living (ADLs) with 0-20 as total dependence, 21-60 as severe dependence, 61-90 as moderate dependence, and 91-95 slight dependence. The t-test was performed to compare statistical significance.

RESULTS

The study included 11 subjects, one of whom fell out due to an event unrelated to the study. The results show descriptive statistics at different time points. No matter MMSE score or Barthel index, the difference between before treatment and after treatment or follow-up was statistically significant (P < 0.001).Result interpretation: this intervention method has a significant therapeutic effect, and in the 3-month follow-up period, the intervention effect is still significant compared with that before treatment.

CONCLUSIONS

Our preliminary clinical observations suggest that the i.v. infusion of HUCMSCs significantly improved the cognitive function (MMSE) and daily life activities (BI) of patients with senile VaD. This approach may prove to be safe and relatively simple method to be applied for the treatment of senile VaD.

The Hachinski ischemic scale and cognition: the influence of ethnicity

OBJECTIVE

cardiovascular burden is considered a risk factor for the development of cognitive dysfunction and dementia. While this link is well established in the literature, implementing this work in primary care settings remains a challenge. The goal of this study is to examine the utility of the Hachinski Ischemic Scale (HIS) in identifying cognitive dysfunction and diagnosis of mild cognitive impairment (MCI) in an ethnically diverse sample.

METHODS

data were analysed on 517 participants (211 Mexican Americans and 306 non-Hispanic Whites) recruited from Project FRONTIER, a study of rural health. Neuropsychological measures were utilised to assess for cognitive functioning.

RESULTS

among non-Hispanic Whites, HIS scores were significantly related to poorer performance on tasks of global cognition [B (SE) = -0.13 (0.06), P = 0.02], immediate memory [B (SE) = -0.85 (0.26), P < 0.001], attention [B (SE) = -1.6 (0.36), P < 0.001] and executive functioning [B (SE) = 0.46 (0.12), P < 0.001], and significantly predicted diagnosis of MCI [odds ratio (OR) = 1.4; 95% confidence interval (CI) = 1.2-1.6]. For Mexican Americans, HIS scores were significantly related to immediate memory [B (SE) = -0.78 (0.28), P = 0.01], attention [B (SE) = -0.74 (0.36), P = 0.04] and executive functioning [B (SE) = 0.37 (0.14), P = 0.01]; however, HIS scores were not significantly related to diagnosis of MCI in Mexican Americans (OR = 1.2, 95% CI = 0.96-1.4, P = 0.116).

CONCLUSION

HIS scores were related to cognitive functioning; however, these results differed by ethnicity. It is possible that these findings indicate that vascular factors may increase risk for MCI among non-Hispanic Whites but not for Mexican Americans. These findings are consistent with past research that suggests risk factors for MCI may differ by ethnicity.

Citicoline protects against cognitive impairment in a rat model of chronic cerebral hypoperfusion

Background and purpose

Cerebral white matter (WM) lesions are frequently observed in human cerebrovascular diseases, and are believed to be responsible for cognitive impairment. Various neuroprotective agents can suppress this type of WM or neuronal damage. In this study, we investigated whether citicoline, a drug used to treat acute ischemic stroke, can attenuate WM lesions and cognitive decline caused by chronic hypoperfusion in the rat.

Methods

Animals were divided into immediate- and delayed-treatment groups. Those in the immediate-treatment group received a sham operation, citicoline (500 mg/kg/day), or phosphate buffered saline (PBS) treatment. Citicoline or PBS was administered intraperitoneally for 21 days after occluding the bilateral common carotid arteries. Rats in the delayed-treatment group were intraperitoneally administered with either 500 mg/kg/day citicoline or PBS for 21 days beginning on the 8th day after the operation. From the 17th day of administration, the rats were placed in an eight-arm radial maze to examine their cognitive abilities. After completing the administration, tissues were isolated for Klüver-Barrera and the terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) staining.

Results

In the immediate-treatment group, cognitive functions were preserved in the citicoline-treated group, and WM damage and TUNEL-positive cells differed significantly between the citicoline- and PBS-treated animals. In the delayed-treatment group, there was no decrease in WM damage and TUNEL-positive cells, but cognitive improvement was evident for citicoline treatment relative to PBS treatment.

Conclusions

These results show that citicoline can prevent WM damage and aid cognitive improvement, even after a certain extent of disease progression. Citicoline might be useful in patients with acute ischemic stroke as well as in chronic stroke accompanied with cognitive impairment.

Citicoline (Cognizin) in the treatment of cognitive impairment

Pharmacological treatment of cerebrovascular disorders was introduced at the beginning of the 20th Century. Since then, a multitude of studies have focused on the development of a consensus for a well defined taxonomy of these disorders and on the identification of specific patterns of cognitive deficits associated with them, but with no clear consensus. Nevertheless, citicoline has proved to be a valid treatment in patients with a cerebrovascular pathogenesis for memory disorders. A metanalysis performed on the entire database available from the clinical studies performed with this compound confirms the experimental evidence from the animal studies which have repeatedly described the multiple biological actions of citicoline in restoring both the cell lipid structures and some neurotransmitter functions.

Comparing Mattis Dementia Rating Scale--initiation/perseveration subset and frontal assessment battery in stroke associated with small vessel disease

Forty-two controls and 32 patients with stroke associated with small vessel disease (SSVD) were administered the Mattis Dementia Rating Scale Initiation / Perseveration subset (MDRS I/P) and Frontal Assessment Battery (FAB). Both tests showed comparably good ability in Receiver Operating Characteristics curves analysis (AUCMDRS I/P=0.887; AUC FAB=0.854, p=.833) in discriminating between controls and patients and correctly classified over 78% of subjects. Verbal fluency and motor programming contributed most to the discriminating power in the two tests. The MDRS I/P and FAB are useful in discriminating between controls and SSVD patients in a hospital setting.

Medial temporal atrophy rather than white matter hyperintensities predict cognitive decline in stroke survivors

Stroke is an important risk factor for dementia, but the exact mechanisms involved in cognitive decline remain unclear. In this study, we related baseline MRI brain measures with later cognitive decline. Seventy-nine stroke survivors aged 75+ years without dementia were recruited 3-month post-stroke. They underwent yearly neuropsychological assessments and had an MRI at baseline and 2 years. Medial temporal lobe atrophy (MTA) was scored and volume of white matter hyperintensities (WMH) was measured at baseline. The rate of ventricular enlargement was measured by comparing the baseline and repeat images. Linear regression indicated that memory loss was related to both baseline memory and MTA (p=0.001; standardized regression coefficient beta=-0.35) but not WMH volume. The only independent predictor of ventricular enlargement was MTA (p=0.003; beta=0.47). However, no baseline MRI variable differed between those who did (18%) and did not (82%) develop dementia. The association of MTA but not WMH with subsequent cognitive decline and increasing brain atrophy suggests a greater role for Alzheimer type than vascular pathology in delayed cognitive impairment after stroke.

Cognitive performance after first ever stroke related to progression of vascular brain damage: a 2 year follow up CT scan study

BACKGROUND

Stroke is one of the most common causes of cognitive impairment in the elderly. Ischaemic brain damage (white matter lesions and silent infarcts) progresses in a substantial number of stroke patients. The aim of this study was to investigate whether the progression of ischaemic brain damage is associated with cognitive functioning after first ever stroke.

METHODS

A total of 101 stroke patients were followed up for 2 years. Neuropsychological functioning was assessed at 1, 6, 12, and 24 months after stroke. Computed tomography was performed on all patients at baseline and 2 years after stroke. Progression in white matter lesions and (silent) infarcts was recorded.

RESULTS

Patients with progressive vascular brain damage performed worse on cognitive tasks, both 1 and 24 months after stroke, yet change in cognitive functioning was not different from that of patients without progressive vascular damage. During the follow up, improvement was noticed on most cognitive domains.

CONCLUSIONS

Although patients with progressive vascular brain damage after a first stroke performed somewhat worse on cognitive tests than those without such damage, both groups showed an improved or stable performance 2 years later. Thus, there is not a simple relation between progression of ischaemic brain damage and decline in cognitive functioning after first ever stroke.

Subcortical hyperintensities impact cognitive function among a select subset of healthy elderly

Previous studies have examined the impact of subcortical hyperintensities (SH), a proxy measure of cerebrovascular disease, on the cognitive abilities of otherwise healthy older adults. However, there remains a limited understanding as to what extent this MRI marker of pathological processes explains the decline in specific cognitive functions that occur nearly ubiquitously with advanced age, especially in relation to other age-related imaging markers. In the present study we compared cognitive abilities between a sample of 53 older healthy adults (age range=50-79) and a sample of 53 younger adults (age range=21-40). As expected, the older group performed significantly worse on most cognitive measures compared to the younger group. Frontal volume and total grey matter volume were also significantly reduced among the older individuals compared to the younger individuals. SH volume was consistently associated with cognitive function in older adults, though, this relationship was evident only for a relatively small subset of older individuals with the most severe SH. These data suggest that the relationship between SH and cognition in the elderly is driven by a subset of individuals who may be in the earliest stages of vascular cognitive impairment. Further, the findings suggest that cognitive aging is largely determined by factors other than SH for most older adults.

Neuroimaging and cardiac correlates of cognitive function among patients with cardiac disease

In the present study, we examined the relationships between whole brain volume (WBV), subcortical hyperintensities (SH), indices of cardiac disease and cognitive function in nondemented cardiac patients with evidence of mild cerebrovascular disease. A total of 27 individuals with evidence of cardiac disease underwent neuropsychological examination, neuroimaging, and cardiac assessment. Cognition was assessed with the Dementia Rating Scale-2 (DRS). WBV and SH were quantified using a semi-automated thresholding program based on MRI. Correlational analyses revealed that WBV predicted performance on the overall DRS score, the attention subscale and the initiation/perseveration scale. SH were significantly associated with performance on the attention subscale, and the initiation/perseveration subscale. Regression analyses revealed that SH accounted for most of the variance in the initiation/perseveration scale, whereas WBV accounted for most of the variance in the attention scale. The only cardiac structural or functional variable related to the neurological indices was aortic diameter, which was strongly related to both neuroimaging variables, as well as performances on the DRS attention and initiation/perseveration subscales. Our results highlight the importance of overall brain parenchyma in determining cognitive status among patients at risk for cognitive decline and suggest that select indices of structural cardiac morphology may be related to the early phases of cerebrovascular disease and cognitive status.