Impairment In Multiple Cognitive Domains Research Articles

Neuropsychiatric and Cognitive Symptoms in Spinocerebellar Ataxia: Relationship to Neuropathological Differences

The autosomal dominant spinocerebellar ataxias (SCA) are a heterogeneous group of disorders associated with progressive degeneration of the cerebellum and other brain regions to varying degrees. Neuropsychiatric and cognitive symptoms are now considered to be well established clinical features of the SCAs, and one central area of research is to examine clinical differences in neuropsychiatric and cognitive symptoms between SCA subtypes and their relationship to underlying neuropathological features. Among the most common SCA subtypes (SCA 1,2,3 and 6), memory impairment and depression occur most frequently in patients with SCA3, possibly related to relatively greater dysfunction of frontalsubcortical circuits through degeneration of the basal ganglia. In contrast, patients with SCA6 are less frequently depressed and demonstrate normal performance on measures of intelligence, attention, verbal and non-verbal memory, and executive functions. This implies that non-motor cognitive functions are less commonly affected in SCA6 possibly due to the more restricted expression pattern of the mutated calcium channel gene in this disorder. Patients with SCA2 demonstrate impairment in multiple cognitive domains including verbal memory and frontal lobe functions suggesting a more generalized process. These findings highlight the importance of evaluating all patients presenting with progressive ataxia for neuropsychiatric and cognitive symptoms.

Clinical Significance of Microbleeds in Subcortical Vascular Dementia

Despite many studies investigating the association between the ischemic changes and cognitive impairment in subcortical vascular dementia (SVaD), few studies correlated cognitive impairment with microbleeds (MBs) frequently seen in SVaD. Participants consisted of 86 patients with SVaD who fulfilled the criteria proposed by Erkinjuntti et al. MBs occurred in 73 of 86 (84.9%) patients with SVaD. MBs were most commonly distributed in the cortex, and the cortical MBs were most pronounced in the temporoparietal area. A multiple regression showed that the number of cerebral MB was an independent predictor of cognitive impairment in multiple domains and the severity of dementia even after controlling confounding factors such as age, education, ischemic severity, and number of lacunes. These results indicate that cerebral MB is one of the important factors that cause cognitive impairments in SVaD.

An investigation of the differential effect of self-generation to improve learning and memory in multiple sclerosis and traumatic brain injury

The generation effect (GE) is a phenomenon in which material that is produced by an individual is learned and remembered better than information that is provided to that individual. The current study examined the potential benefits of self-generation on learning and memory in individuals with traumatic brain injury (TBI) and multiple sclerosis (MS). The impact of cognitive impairment on the benefits of self-generation was also examined. Subjects consisted of 18 individuals with TBI and 31 individuals with clinically definite MS. Both the TBI and MS groups recalled significantly more words in the self-generated condition versus the provided condition. Those impaired in the domains of working memory, episodic memory, or executive functioning demonstrated a significant benefit from self-generation (all ps < .05). Furthermore, although individuals with impairments in multiple cognitive domains recalled fewer words overall compared to those with no or one impaired cognitive domain, this group demonstrated a large effect size in the difference in recall for generated versus provided words. Results demonstrate that people with cognitive impairments can benefit from self-generation to improve learning and memory. Future research should focus on how to amplify the benefit of the GE for impaired groups, apply it to everyday functional tasks, and sustain its effect over time.

Cognitive Changes in Parkinson’s Disease Patients with Visual Hallucinations

Objective: To evaluate the decline in specific neuropsychological functions in nondemented Parkinson’s disease (PD) patients with a history of visual hallucinations (VH). Methods: Twenty PD patients with VH, 20 PD patients without VH and 18 normal controls were followed up over a 1-year period and assessed for cognitive decline. Results: Forty-five percent of nondemented hallucinating PD patients developed dementia during the 1-year period between baseline and follow-up evaluations. Of the nondemented hallucinating PD patients nearly 70% showed impairment in multiple cognitive domains. The progressive decline in hallucinating PD patients affected mainly visual memory for faces and visuoperceptive-visuospatial functions. Conclusion: Our results support a fast impairment of complex visual functions in hallucinating PD patients, but also a progressive decline in multiple cognitive domains, which have been identified as a risk of developing dementia in PD.

Cognitive Function and Major Depression in Chronic Fatigue: The Apathy Construct

ABSTRACTObjective: The current study examined cognitive function, major depressive disorder (MDD), and apathy construct symptoms in a large multi-site surveillance study of chronic fatigue syndrome conducted by the Centers for Disease Control and Prevention. Method: Subjects underwent neuropsychological testing and were administered the Diagnostic Interview Schedule to establish psychiatric diagnoses. Questions in the Beck Depression Inventory relating to motivation were used to develop an apathy construct. Results: Neuropsychological test results showed impairment in multiple cognitive domains in over 25% of the cohort, and raised proportions of outliers in motor and executive function. Memory complaints were not associated with tests of memory function. The apathy construct rather than MDD was associated with impaired cognition. Conclusions: Impaired cognition in chronic fatigue does not appear to be associated with MDD but rather with endorsement of construct symptoms. Similar associations were reporte...

Is Cognitive Reserve Applicable to Epilepsy? The Effect of Educational Level on the Cognitive Decline After Onset of Epilepsy

The aim of this study was to know the effect of education level (EL) on the cognitive change after onset of epilepsy. The rationale is that people with high EL may have more cognitive reserve and show resistance to damage brought about by epilepsy. Patients were from an outpatient epilepsy clinic of a national university hospital. All received initial and repeated neuropsychological tests and the Cognitive Ability Screening Instrument (CASI), at an interval of 12 months. CASI consists of nine items, with a total score of 100. We compared the differences between the two tests, in terms of z-scores. The EL was divided into high and low with a cut-off at 12 years, and age at entry was divided with a cut-off at 38 years. Epilepsy severity was divided into intractable and nonintractable. A total of 64 patients completed the study, including 31 with high EL and 33 with low EL, with no differences in gender and epilepsy severity between groups. In general, patients had cognitive impairment in multiple domains. At the baseline, the effect of EL was found for all items except remote memory and orientation, whereas the effect of age was observed for remote and recent memory. At the 12-month follow-up, subjects with high EL showed deterioration in mental manipulation, whereas subjects with low EL showed improvement in verbal fluency but deterioration in attention. Patients with high EL have better cognitive functioning than those with low EL after epilepsy has developed, which supports the cognitive reserve theory. However, 1-year follow-up might be too short to see significant changes between groups.

Context Processing and Social Cognition in Schizophrenia

Recent empirical and theoretical work has conceptualized cognitive deficits in schizophrenia in terms of a deficit in the processing of contextual information [1, 2]. Context processing deficits have been shown to underlie impairments in multiple cognitive domains, and may thus represent a core disturbance in information processing in schizophrenia. Despite the increasing evidence for impaired context processing, there has been little research into the relevance of these deficits for an understanding of social cognition in schizophrenia. In the present paper, we argue that deficits in the processing of context may also be relevant for explanations of deficits in social cognition in schizophrenia. We review evidence to suggest that efficient context processing may be necessary for the acquisition and maintenance of social cognitive skills, such that deficits in context processing may be a common factor underlying deficits in both social and non-social cognition in schizophrenia. Future research should examine relationships between specific social cognitive skills (such as facial expression perception, mental state inference) in relation to context processing during non-social perceptual and cognitive tasks.

Multiple cognitive deficits during the transition to Alzheimer's disease.

The literature on cognitive markers in preclinical AD is reviewed. The findings demonstrate that impairment in multiple cognitive domains is typically observed several years before clinical diagnosis. Measures of executive functioning, episodic memory and perceptual speed appear to be most effective at identifying at-risk individuals. The fact that these cognitive domains are most implicated in normal cognitive aging suggests that the cognitive deficit observed preclinically is not qualitatively different from that observed in normal aging. The degree of cognitive impairment prior to the diagnosis of Alzheimer's disease (AD) appears to generalize relatively well across major study characteristics, including sample ascertainment procedures, age and cognitive status of participants, as well as time to diagnosis of dementia. In episodic memory, there is evidence that the size of the preclinical deficit increases with increasing cognitive demands. The global cognitive impairment observed is highly consistent with observations that multiple brain structures and functions are affected long before the diagnosis of AD. However, there is substantial overlap in the distribution of cognitive scores between those who will and those who will not be diagnosed with AD, hence limiting the clinical utility of cognitive markers for early identification of cases. Future research should consider combining cognitive indicators with other types of markers (i.e. social, somatic, genetic, brain-based) in order to increase prediction accuracy.

Increased risk of cognitive impairment 3 months after mild to moderate first-ever stroke: a Community-Based Prospective Study of Nonaphasic English-Speaking Survivors.

Results of hospital-based studies indicate a high risk of cognitive impairment 3 months after stroke. There are no comprehensive data on this issue from prospective community-based studies comparing first-ever stroke patients with stroke-free subjects. We administered a comprehensive neuropsychological battery to 99 community-based nonaphasic survivors of first-ever stroke at 3 months and 99 age- and sex-matched (1:1) stroke-free individuals. Domain-specific cognitive deficits were identified by blinded neuropsychological consensus. Stroke patients were more likely to suffer any cognitive impairment (relative risk [RR], 1.5; 95% CI, 1.1 to 2.1) attributable mainly to a greater risk of single-domain cognitive impairment (RR, 2.8; 95% CI, 1.5 to 5.3) but not multiple-domain cognitive impairment (RR, 1.2; 95% CI, 0.8 to 1.9). In this community-based study, a first-ever stroke of mild to moderate severity was associated with a significant risk of cognitive impairment at 3 months, even in the absence of clinical aphasia. This was due primarily to an increased risk of solitary deficits rather than generalized deficits.

The Trail Making Test, Part B: Cognitive Flexibility or Ability to Maintain Set?

The Trail Making Test (TMT) is a well-established test sensitive to impairment in multiple cognitive domains. There has been ambiguity about which cognitive demands are placed on the patient by TMT Part B over and above those required to perform TMT Part A. In particular, cognitive flexibility and ability to maintain a complex response set have been 2 competing hypotheses. This study preliminarily examined which of these 2 abilities primarily contributes to Part B performance. A total of 121 clinically referred Veterans Affairs patients were administered the TMT, as well as other tests of executive and other cognitive functions. Regression analyses were used to examine which tests predicted Part B performance above and beyond Part A performance. The results provide preliminary support for TMT Part B performance being more sensitive to cognitive flexibility (operationalized as Wisconsin Card Sorting Test [WCST], percent perseverative errors) than ability to maintain set (operationalized as WCST, failure to maintain set).

A Double-blind Placebo-controlled Case Study of the Use of Donepezil to Improve Cognition in a Schizoaffective Disorder Patient: Functional MRI Correlates.

Cognitive impairment in multiple domains is common in patients with schizophrenia and may be a powerful determinant of poor functional ability and quality of life. We report a double-blind, placebo-controlled, cross-over study of donepezil augmentation in a schizoaffective disorder patient stabilized on olanzapine pharmacotherapy. The patient showed significant improvements in several cognitive measures and increased activation of prefrontal cortex and basal ganglia on functional MRI during the donepezil augmentation. In addition, the donepezil augmentation resulted in a reduction of depressive symptoms and in significant improvements in functional abilities and quality of life. Further studies of donepezil augmentation of neuroleptics in schizophrenia are warranted.

A Double-blind Placebo-controlled Case Study of the Use of Donepezil to Improve Cognition in a Schizoaffective Disorder Patient: Functional MRI Correlates.

Cognitive impairment in multiple domains is common in patients with schizophrenia and may be a powerful determinant of poor functional ability and quality of life. We report a double-blind, placebo-controlled, cross-over study of donepezil augmentation in a schizoaffective disorder patient stabilized on olanzapine pharmacotherapy. The patient showed significant improvements in several cognitive measures and increased activation of prefrontal cortex and basal ganglia on functional MRI during the donepezil augmentation. In addition, the donepezil augmentation resulted in a reduction of depressive symptoms and in significant improvements in functional abilities and quality of life. Further studies of donepezil augmentation of neuroleptics in schizophrenia are warranted.

Brain structural and cognitive correlates of clock drawing performance in Alzheimer's disease.

The Clock Drawing Test (CDT) is widely used in the assessment of dementia and is known to be sensitive to the detection of deficits in neurodegenerative disorders such as Alzheimer's disease (AD). CDT performance is dependent not only on visuospatial and constructional abilities, but also on conceptual and executive functioning; therefore, it is likely to be mediated by multiple brain regions. The purpose of the present study was to identify component cognitive processes and regional cortical volumes that contribute to CDT performance in AD. In 29 patients with probable AD, CDT performance was significantly related to right-, but not left-hemisphere, regional gray matter volume. Specifically, CDT score correlated significantly with the right anterior and posterior superior temporal lobe volumes. CDT scores showed significant relationships with tests of semantic knowledge, executive function, and visuoconstruction, and receptive language. These results suggest that in AD patients, CDT performance is attributable to impairment in multiple cognitive domains but is related specifically to regional volume loss of right temporal cortex.