Magnitude Of Cognitive Impairment Research Articles

Abstract 168: Prevalence And Characterization Of Neuropsychological Deficits In Lacunar Stroke Patients. The Secondary Prevention Of Small Subcortical Strokes (sps3) Trial

Background: Though the important role of lacunar stroke in cognitive impairment and dementia is widely recognized, to date no well-characterized pattern of neuropsychological (NP) impairment has been defined in this stroke subtype. Methods: SPS3 is a multi-center international randomized trial that included a well-defined cohort of MRI proven lacunar stroke patients. For the purpose of this analysis we consider NP testing data collected at study entry for all English speaking participants enrolled in North America. The hour-long NPT was administered by a certified examiner and covered a wide range of domains. Raw test scores were converted to standardized scores using normative data which were then entered into a principal component analysis to identify distinct cognitive domains measured. NP status was defined as Not Cognitively Impaired (NCI) and Mild Cognitive Impairment (MCI) if there was impairment in memory and/or non-memory domains. Results: Of the 3020 SPS3 participants, 1632 were included in these analyses. Most (85%) scored ≥95 on the Barthel Index. Performances (z-scores) on all NPT were lower than normal for age, and for education and gender. The largest deficits were seen on tests of episodic memory (mean -0.92 to -0.68), verbal fluency (mean -0.89), and motor dexterity (median -2.5). The magnitude of cognitive impairment increased with higher Rankin scores (p < 0.001). Principal component analysis revealed memory and two non-memory domains (perceptual-verbal processing speed, executive functioning). Based on these domains, NP status was 53% NCI, 17% amnestic MCI, 17% amnestic multidomain MCI, and 13% non-amnestic MCI. Conclusion: In this large and well-defined cohort of lacunar stroke patients, MCI was present in half of the cohort. The most significant impairments were found on tests of processing speed, motor dexterity, executive function, and episodic memory. Episodic memory appears a central feature in this cohort and should be assessed carefully in future clinical studies and trials directed at subcortical stroke populations. NP deficits appear to be more prevalent than functional deficits (Barthel) in survivors of lacunar stroke.

Cognitive features in euthymic bipolar patients in old age

Studies of cognition in bipolar disorder (BD) have reported impairments in processing speed, working memory, episodic memory, and executive function, but they have primarily focused on young and middle-aged adults. In such studies, the severity of cognitive deficits increases with the duration of illness. Therefore, one would expect more pronounced deficits in patients with longstanding BD. The first aim of the present study was to determine the pattern and the magnitude of cognitive impairment in older euthymic BD patients. The second aim was to explore the interrelationship between these cognitive deficits and determine whether they reflect a single core impairment or the co-occurrence of independent cognitive deficits. Twenty-two euthymic elderly BD patients and 22 controls, matched for gender, age, and education, underwent a comprehensive neuropsychological assessment. Compared to controls, BD patients had significantly reduced performance in processing speed, working memory, verbal fluency, and episodic memory, but not in executive function. Hierarchical regression analyses showed that verbal fluency and working memory impairments were fully mediated by changes in processing speed. This was not the case for the episodic memory dysfunction. The cognitive profile in older euthymic BD cases is similar to the one described in younger BD cohorts. Our results further suggest that impaired processing speed plays a major role in the cognitive changes observed in BD patients except for deficits in episodic memory, thus providing strong evidence that processing speed and episodic memory are two core deficits in elderly BD patients.

Cognitive impairments in relapsing-remitting multiple sclerosis: a meta-analysis

There is debate in the literature regarding the magnitude, nature, and influence of cognitive impairment in individuals with relapsing-remitting multiple sclerosis (RRMS). Therefore, we conducted a meta-analysis that quantified the overall magnitude of cognitive impairment in individuals with RRMS and identified the domains of cognition and clinical/demographic variables that were moderators of the overall effect. We included 57 studies with 3891 participants that yielded a total of 755 effect sizes. Overall, there was a moderate decline in cognitive functioning in individuals with RRMS compared with healthy controls. Larger effects were observed in cognitive domains of motor functioning, mood status and memory and learning. Regarding demographic and clinical variables, age and gender were moderators of cognitive impairment in all cognitive domains, whereas neurological disability and disease duration primarily moderated performance on tasks assessing memory and learning.

The Effects of Type 1 Diabetes on Cognitive Performance

To investigate the exact nature and magnitude of cognitive impairments in patients with type 1 diabetes and the possible association with other disease variables, such as recurrent episodes of hypoglycemia and metabolic control. MedLine and PsycLit search engines were used to identify studies on cognitive performance in patients with type 1 diabetes. Effect sizes (Cohen's d), which are the standardized differences between the experimental and the control group, were calculated. In the meta-analysis, a combined d value was calculated, expressing the magnitude of associations across studies. A total of 33 studies were identified that met the inclusion criteria. Compared with nondiabetic control subjects, the type 1 diabetic group demonstrated a significantly lowered performance on the following cognitive domains: intelligence (d = -0.7), speed of information processing (d = -0.3), psychomotor efficiency (d = -0.6), visual (d = -0.4) and sustained attention (d = -0.3), cognitive flexibility (d = -0.5), and visual perception (d = -0.4). Lowered cognitive performance in diabetic patients appeared to be associated with the presence of microvascular complications but not with the occurrence of severe hypoglycemic episodes or with poor metabolic control. In patients with type 1 diabetes, cognitive dysfunction is characterized by a slowing of mental speed and a diminished mental flexibility, whereas learning and memory are spared.The magnitude of the cognitive deficits is mild to moderate, but even mild forms of cognitive dysfunction might hamper everyday activities since they can be expected to present problems in more demanding situations.