Differences in Neuropsychological Functioning Associated With Age, Education, Neurological Status, and Magnetic Resonance Imaging Findings In Neurologically Healthy Elderly Individuals

Assessing the impact of age on everyday cognitive function with a virtual environment task: The EcoKitchen

More realistic assessment tools are imperative for a better understanding of the impact of age-related cognitive deficits on functional status. With this in mind, we probed the ability of the EcoKitchen, a non-immersive virtual environment task with increasing executively demanding kitchen chores, to detect the effects of aging on the simulated everyday functioning of healthy adults. Fifty-three adults (age between 23 and 77 years) were assessed with the EcoKitchen and a set of conventional paper-and-pencil neuropsychological tests. The associations between the baseline features of study participants and each of the two different assessment methods were examined. The associations between the EcoKitchen variables and an executive composite score were also explored. Our results showed that older individuals present deficits in the performance of both the EcoKitchen task and standard assessment methods. Notably, we found that, unlike conventional tests, accuracy in the EcoKitchen task was not related to the education level and IQ score of participants. Moreover, the EcoKitchen performance time was significantly correlated with executive tests. We have demonstrated that the EcoKitchen task, an ecologically relevant computerized neuropsychological assessment tool, might be more suitable than classic paper-and-pencil tests to capture the impact of aging on everyday cognitive function, as it proved to be less prone to the influence of confounding factors. Additionally, we have shown that executive function plays an important role in the timely performance of cognitively challenging virtual environment tasks.

Mild Parkinsonian Signs: A Systematic Review of Clinical, Imaging, and Pathological Associations

Mild parkinsonian signs (MPS) have been widely studied during the past 3 decades and proposed as a risk marker for neurodegenerative disease. This systematic review explores the epidemiology, clinical and prognostic associations, radiological features, and pathological findings associated with MPS in older adults free from neurodegenerative disease. We find that MPS as currently defined are strongly associated with increasing age and increased risk of development of Parkinson's disease (PD), all-cause dementia, disability, and death. Positive associations with later PD are found mainly in younger populations and those with other features of prodromal PD. There are currently no consistent radiological findings for MPS, and pathological studies have shown that MPS, at least in the oldest old, are often underpinned by mixed neuropathologies, including those associated with Alzheimer's disease, cerebrovascular disease, nigral neuronal loss, and Lewy bodies. Different subcategories of MPS appear to convey varying risk and specificity for PD and other outcomes. MPS overall are not specific for parkinsonian disorders and, although associated with increased risk of PD, can reflect multiple pathologies, particularly in older individuals. "Mild motor signs" appears a more appropriate term to avoid prognostic and pathological implications, and larger future studies to prospectively examine outcomes and associations of specific MPS subcategories are required. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Descriptive Halstead-Reitan study of nonimpact mild traumatic brain injury

Patients subjected to severe acceleration forces in motor vehicle accidents that met criteria for uncomplicated mild traumatic brain injury (mTBI) in the absence of direct impact to the head were examined neuropsychologically using the Halstead-Reitan Neuropsychological Test Battery. The subjects were litigants and/or insurance claimants for whom there was psychometric evidence of acceptable test effort. The purpose of the study was to provide descriptive neuropsychological data for this particular clinical population. Individual test results were interpreted using inferential methods of level of performance, pathognomonic signs, score patterns, and right-left performance differences. These interpretive strategies yielded group data from which frequencies and percentages of atypical neuropsychological characteristics were calculated. The most salient clinical characteristics involved atypical right-left performance relationships on simple and more complex tests of motor function. Clinical data provided support for the possibility that a minority of nonimpact litigants or insurance claimants that sustain uncomplicated mTBI experience persistent diminishment in some neuropsychological abilities.

Voxel-based morphometry study on monozygotic twins discordant for Alzheimer's disease

OBJECTIVES

We set to investigate the possible role of genes and environment in developing Alzheimer's disease (AD) in monozygotic twin pairs discordant for AD.

METHODS

Three pairs of twins discordant for AD, who were enrolled in the Finnish Twin Cohort, were used in the study and compared with 13 controls. Gray matter changes were assessed with magnetic resonance images using voxel-based morphometry with statistical parametric mapping.

RESULTS

In the affected twins, the peaks of volume loss were located bilaterally in the temporal (including the hippocampus), the frontal, and the parietal lobes, while in the unaffected siblings, the peaks were located in the frontal gyri and in the parietal lobule. Thus, in the unaffected twins, the pattern of volume loss overlaps with the neocortical but not with the medial temporal areas.

DISCUSSION

These findings suggest that genetic factors more largely control neocortical regions, whereas environmental factors more strongly affect medial temporal regions.

Education-corrected CERAD identifies MCI and dementia in Parkinson's disease

OBJECTIVES

This study examined whether controlling for educational background in the CERAD cognitive screening battery would affect the likelihood of patients with Parkinson's disease to fulfill criteria for mild cognitive impairment (PD-MCI) and dementia (PDD).

MATERIALS & METHODS

One-hundred seventeen patients with PD were studied. Cognitive impairment was determined as two subtest scores falling below either the standard cutoff scores or education-corrected cutoff scores. The presence of dementia was determined by clinical interview or Clinical Dementia Rating. Patients were then classified as PD-MCI and PDD according to cognitive test performance and presence/absence of dementia.

RESULTS

The number of cognitively impaired patients (PD-MCI or PDD) was significantly higher when education-controlled cutoff scores were used (62.5% vs 38%). Correspondingly, the number of false negatives (demented PD patients performing normally in CERAD) was significantly lower when education-corrected cutoff scores were used (4% vs 10%).

CONCLUSIONS

Controlling for education increases the sensitivity of the CERAD for PD-MCI and PDD.

Use of objective psychomotor tests in health professionals

Evaluation of psychomotor skills is undertaken in a number of broad contexts. This includes testing of health professional populations as a measure of innate ability, to evaluate skill acquisition, or to compare professions. However, the use of psychomotor tests is frequently confounded by a lack of understanding of a particular tool's psychometric properties, strengths, and weaknesses. To identify and appraise the most commonly used tests on health professional populations, 86 articles were reviewed and the top nine tests identified. Few tests have had sufficient validity or reliability testing on health professionals. Based on the evidence available, use of the Grooved Pegboard Test, the Purdue Pegboard Test, or the Finger Tapping Test is recommended for the evaluation of dexterity in a health professional population; however, this choice may be dependent on the task(s) to which findings are generalised. More rigorous evaluation of validity and other psychometric properties is required.

Feasibility, internal consistency and covariates of TICS-m (telephone interview for cognitive status-modified) in a population-based sample: findings from the KORA-Age study

OBJECTIVE

Test the feasibility of the modified telephone interview for cognitive status (TICS-m) as a screening tool to detect cognitive impairment in a population-based sample of older subjects.

METHODS

Data were collected from 3,578 participants, age 65-94 years, of the KORA-Age study. We used analysis of covariance to test for significant sex, age and educational differences in raw TICS-m scores. Internal consistency was analysed by assessing Cronbach's alpha. Correction for education years was undertaken, and participants were divided in three subgroups following validated cut-offs. Finally, a logistic regression was performed to determine the impact of sex on cognition subgroups.

RESULTS

Internal consistency of the TICS-m was 0.78. Study participants needed approximately 5.4 min to complete the interview. Lower raw TICS-m scores were associated with male sex, older age and lower education (all p < 0.0001). After correction for education years, 2,851 (79%) had a non-impaired cognitive status (score >31). Male sex was independently associated with having a score equal to or below 27 and 31 (OR = 1.9, 95% CI 1.4-2.5 and OR = 1.5, 95% CI 1.2-1.7, respectively).

CONCLUSIONS

The TICS-m is a feasible questionnaire for community-dwelling older adults with normal cognitive function or moderate cognitive impairment. Lower cognitive performance was associated with being a man, being older, and having fewer years of formal education.

Geriatric syndromes--vascular disorders?

The term geriatric syndrome is used to characterize multifactorial clinical conditions among older people which are not subsumed readily into disease entities, but which nevertheless predispose older people to disability and death. Commonly included are frailty, dementia, delirium, incontinence, falls, and dizziness. Geriatric syndromes are common among older people: in a recent survey, 50% of those aged more than 65 had one or more of these conditions. Better methods for prevention and treatment are needed, but current strategies have lacked a coherent conceptual and diagnostic framework. Prevention and interventions need to be targeted at earlier ages, with geriatrics expertise needed in the definition and operationalization of these complex entities. In this review we consolidate evidence that vascular disorders, including vascular ageing and vascular diseases, are key etiological factors of geriatric syndromes. Identifying this vascular dimension would offer opportunities for more efficient preventive strategies and mandates earlier intervention, especially for women, among whom vascular disease is often expressed more insidiously than among men. This would entail a sensitization of the health care system to the systematic detection of the syndromes, which are currently underdiagnosed. Further disentangling of the mechanisms of vascular ageing may offer therapies for vascular diseases and geriatric syndromes alike.

Depression, cognitive reserve and memory performance in older adults

OBJECTIVES

The purpose of this research study was to examine the relationship between education and leisure, as markers of cognitive reserve, depressive symptoms and memory performance in a sample of cognitively normal Irish older adults.

METHODS

A cross-sectional survey style design was employed to gather data. A sample of 121 older adults in the Cork area was recruited through publicly advertising for volunteers. Only those volunteers who obtained a score of greater than 23 on the MMSE, and were not taking antidepressant or anxiolytic medications, were included. Data from 99 participants were included in the analysis.

RESULTS

Controlling for age and gender, depressive symptoms were found to be associated with poorer immediate recall performance, while greater than 12 years of education was positively associated with delayed recall and savings. Leisure did not emerge as being associated with any of the dimensions of memory assessed.

CONCLUSIONS

Depressive symptoms emerged as associated with immediate recall, even though few of the participants met the cut-off for caseness. This may indicate a need for intervention in cases of subclinical depression with associated memory complaints. The association between education level and both delayed recall and savings provides support for the cognitive reserve hypothesis, and may suggest useful non-pharmacological approaches to memory deficits in later life.

The effects of healthy aging on auditory processing in humans as indexed by transient brain responses

OBJECTIVE

The aim of the study was to investigate the effects of aging on human cortical auditory processing of rising-intensity sinusoids and speech sounds. We also aimed to evaluate the suitability of a recently discovered transient brain response for applied research.

METHODS

In young and aged adults, magnetic fields produced by cortical activity elicited by a 570-Hz pure-tone and a speech sound (Finnish vowel /a/) were measured using MEG. The stimuli rose smoothly in intensity from an inaudible to an audible level over 750 ms. We used both the active (attended) and the passive recording condition. In the attended condition, behavioral reaction times were measured.

RESULTS

The latency of the transient brain response was prolonged in the aged compared to the young and the accuracy of behavioral responses to sinusoids was diminished among the aged. In response amplitudes, no differences were found between the young and the aged. In both groups, spectral complexity of the stimuli enhanced response amplitudes.

CONCLUSIONS

Aging seems to affect the temporal dynamics of cortical auditory processing. The transient brain response is sensitive both to spectral complexity and aging-related changes in the timing of cortical activation.

SIGNIFICANCE

The transient brain responses elicited by rising-intensity sounds could be useful in revealing differences in auditory cortical processing in applied research.

Intelligence and medial temporal lobe function in older adults: a functional MR imaging-based investigation

BACKGROUND AND PURPOSE

The influence of general intelligence and formal education on functional MR imaging (fMRI) activation has not been thoroughly studied in older adults. Although these factors could be controlled for through study design, this approach makes sample selection more difficult and reduces power. This study was undertaken to examine our hypothesis that intelligence and education would impact medial temporal lobe (MTL) fMRI responses to an episodic memory task in healthy elderly subjects.

MATERIALS AND METHODS

Thirty-six women and 38 men, 50-83 years of age (mean, 63.4 +/- 7.9 years), completed an auditory paired-associates paradigm in a 1.5T magnet. The amplitude and volume of fMRI activation for both the right and left MTLs and MTL subregions were correlated with the intelligence quotients (IQs) and educational levels by using Pearson correlation coefficient tests and regression analyses.

RESULTS

The participants' mean estimated full scale IQ and verbal IQ scores were 110.4 +/- 7.6 (range, 92-123) and 108.9 +/- 8.7 (range, 88-123), respectively. The years of education showed a mean of 16.1 +/- 3.2 years (range, 8-25 years). The paradigm produced significant activation in the MTL and subregions. However, the volume and amplitude of activation were unrelated to either IQ or years of schooling in men and/or women.

CONCLUSIONS

We found no evidence of an effect of IQ or education on either the volume or amplitude of fMRI activation, suggesting that these factors do not necessarily need to be incorporated into study design or considered when evaluating other group relationships with fMRI.

Age differences in reaction time and attention in a national telephone sample of adults: education, sex, and task complexity matter

This study demonstrated effects of age, education, and sex on complex reaction time in a large national sample (N = 3,616) with a wide range in age (32-85) and education. Participants completed speeded auditory tasks (from the MIDUS [Midlife in the U.S.] Stop and Go Switch Task) by telephone. Complexity ranged from a simple repeated task to an alternating task that involved central executive processes including attention switching and inhibitory control. Increased complexity was associated with slower responses in older adults, those with lower education, and women, even after controlling for differences in health status. Higher levels of education were associated with greater central executive efficiency across adulthood: Overall, adults with college degrees performed on complex tasks like less educated individuals who were 10 years younger, up to age 75. These findings suggest that advanced education can moderate age differences on complex speeded tasks that require central executive processes, at least up to the point in old age at which biological declines predominate. The approach demonstrates the utility of combining laboratory paradigms with survey methods to enable the study of larger, more diverse and representative samples across the lifespan.

Heritability of cognitive functions in families with bipolar disorder

Bipolar disorder is highly heritable. Cognitive dysfunctions often observed in bipolar patients and their unaffected relatives implicate that these impairments may be associated with genetic predisposition to bipolar disorder and thus fulfill the criteria of a valid endophenotype for the disorder. However, the most fundamental criterion, their heritability, has not been directly studied in any bipolar population. This population-based study estimated the heritability of cognitive functions in bipolar disorder. A comprehensive neuropsychological test battery and the Structured Clinical Interview for DSM-IV were administered to a population-based sample of 110 individuals from 52 families with bipolar disorder. Heritability of cognitive functions as assessed with neuropsychological test scores were estimated using the Solar package. Significant additive heritabilities were found in verbal ability, executive functioning, and psychomotor processing speed. Genetic contribution was low to verbal learning functions. High heritability, in executive functioning and psychomotor processing speed suggest that these may be valid endophenotypic traits for genetic studies of bipolar disorder.

Cognitive and neurophysiological outcome of cardiac arrest survivors treated with therapeutic hypothermia

BACKGROUND AND PURPOSE

Cognitive deficits are common in survivors of cardiac arrest (CA). The aim of this study was to examine the effect of therapeutic hypothermia after CA on cognitive functioning and neurophysiological outcome.

METHODS

A cohort of 70 consecutive adult patients resuscitated from out-of-hospital ventricular fibrillation CA were randomly assigned to therapeutic hypothermia of 33 degrees C for 24 hours accomplished by external cooling or normothermia. Neuropsychological examination was performed to 45 of the 47 conscious survivors of CA (27 in hypothermia and 18 in normothermia group) 3 months after the incident. Quantitative electroencephalography (Q-EEG) and auditory P300 event-related potentials were studied on 42 patients at the same time point.

RESULTS

There were no differences between the 2 treatment groups in demographic variables, depression, or delays related to the resuscitation. No differences were found in any of the cognitive functions between the 2 groups. 67% of patients in hypothermia and 44% patients in normothermia group were cognitively intact or had only very mild impairment. Severe cognitive deficits were found in 15% and 28% of patients, respectively. All Q-EEG parameters were better in the hypothermia-treated group, but the differences did not reach statistical significance. The amplitude of P300 potential was significantly higher in hypothermia-treated group.

CONCLUSIONS

The use of therapeutic hypothermia was not associated with cognitive decline or neurophysiological deficits after out-of-hospital CA.

Pre-treatment factors related to cognitive functioning in women newly diagnosed with breast cancer

Women treated for breast cancer have shown cognitive deficits with reduced capacity to focus and concentrate or to direct attention. This study examined the relationship between cognitive function prior to any treatment for breast cancer and individual factors including age, education, menopausal status, chronic health problems, and distress. Women newly diagnosed with breast cancer (N=184), ages 27-86 years, were assessed with standardized attention tests, self-reports of effectiveness in cognitive functioning, and measures of distress at about 18 days before surgery. Measured performance on the cognitive tests was not significantly correlated to self-reports of effectiveness in cognitive functioning. Age, education, presence of a chronic health problem, and menopausal status, but not distress, were associated with performance on the cognitive tests. Only age and education, however, were significant (p<0.001) predictors of overall performance on the cognitive tests, when controlling covariates. In contrast, symptom and mood distress significantly (p<0.001) predicted perceptions of effectiveness in cognitive functioning. Thus, different factors were associated with measured performance versus self-reports of cognitive functioning. Individual factors that predispose to lowered effectiveness in cognitive functioning prior to treatment in women newly diagnosed with breast cancer are discussed.

MRI correlates of executive dysfunction in patients with ischaemic stroke

Executive dysfunction (ED) may lead to problem behaviour and impaired activities of daily living in many neuropsychiatric disorders, but the neuroanatomical correlates of ED are still not well known. Different aspects of executive functions were studied by widely used neuropsychological tests in 214 elderly patients 3 months after ischaemic stroke, and a sum score of eight different measures was counted in each patient. The number and site of brain infarcts as well as severity and location of white matter lesions (WMLs) and brain atrophy on magnetic resonance imaging were recorded and compared between patients with and without ED. ED was present in 73 (34.1%) of the 214 patients. The mean frequency of brain infarcts in the brain and in the left hemisphere was higher in the patients with ED. Lesions affecting the frontal-subcortical circuits (e.g. pallidum, corona radiata or centrum semiovale) were more frequent in patients with ED than in those without. Also, patients with pontine brain infarcts frequently had ED, but this may have been due to more extensive ischaemic changes in these patients in general. Mean number of brain infarcts affecting the pons and posterior centrum semiovale on the left side, moderate to severe medial temporal atrophy, the Fazekas white matter score, the Mini-Mental State Examination score and low education were independent correlates of ED. Brain infarcts and WML affecting the frontal-subcortical circuits or the pons may increase risk for ED in stroke patients.

Age, education and test performance on the Finnish CERAD

OBJECTIVES

The purpose of this study was to clarify the effects of age and education on CERAD (Consortium to Establish a Registry for Alzheimer's Disease) test performances.

MATERIAL AND METHODS

We present preliminary data on CERAD test results for a sample of elderly normal Finns (n = 40, age 58-85 years).

RESULTS

Our results show no significant correlation between age and CERAD test results. Significant differences were found between subjects with low versus high education in nine CERAD test scores. The mean scores in the low-education group were near the cut-off point in the naming test, whereas the mean scores of the high-education group nearly reached the ceiling on six test scores. These differences were evident in the wordlist learning test, which has previously been argued to be unaffected by educational level. Savings scores were unaffected by education.

CONCLUSION

The results underline the importance of taking into account the educational level of persons with subjective memory complaints when screening with CERAD for mild cognitive impairment and preclinical Alzheimer's disease.

Heritability and number of quantitative trait loci of neurocognitive functions in families with schizophrenia

Despite evidence for several chromosomal loci linked to schizophrenia, no susceptibility genes have been identified for the disorder. Using quantitative measures of phenotypic affection in place of clinical diagnostic categories or dichotomous classification of the affection status may be more effective in searching for susceptibility genes. Neurocognitive traits have been suggested as putative quantitative endophenotypes of the disorder, but their heritability estimates are not well known. We investigated the heritability of working memory, verbal declarative memory and its different components, and both verbal and visual ability functions in schizophrenia families with a well-ascertained pedigree structure. We also estimated the number of quantitative trait loci (QTLs) contributing to these neurocognitive functions. Additive genetic heritability of the neurocognitive functions was estimated in a sample of schizophrenia patients and their first-degree relatives (N = 264) from an isolated geographical subregion in Finland. The number of QTLs was analyzed using Markov chain Monte Carlo segregation analysis. Significant heritabilities were found in working memory and ability functions. Furthermore, the working memory functions revealed the most restricted number of QTLs. The mean numbers of loci for verbal and visual working memory were 1.2 and 1.0, respectively, with corresponding posterior probabilities of 73% and 70% for at least one locus. In declarative memory variables, the number of loci was more dispersed. Our results suggest that neurocognitive measures, particularly working memory, may provide valid quantitative phenotypic traits for linkage analyses searching predisposing genes for schizophrenia.

Education, age, and the Brown-Peterson technique

In this article, we discuss the effects of education level and age on short-term memory. The performance of young and elderly persons was compared on an adapted version of the Brown-Peterson procedure. Participants were asked to report consonant trigrams, after variable time periods, during which they performed a mental addition task or an articulation task. A control condition consisted of a no-interference task. Both age groups were divided according to individual educational level (greater or less than the median number of school years in each age group). The results revealed a significant effect of education. Moreover, the education effect interacted with the task: participants with less education were more impaired in mental addition than in articulation. However, neither the age effect nor the interactions involving age reached significance. These results indicate that education, to a greater extent than age, should be considered a determining factor of performance when interpolated tasks of high demand are used with the Brown-Peterson procedure.

Post-stroke depression, executive dysfunction and functional outcome

The early diagnosis of vascular cognitive impairment has been challenged and executive control function has been suggested to be a rational basis for the diagnosis of vascular dementia. We sought to examine the correlates of executive dysfunction in a well-defined stroke cohort. A group of 256 patients from a consecutive cohort of 486 patients with ischaemic stroke, aged 55-85 years, was subjected to a comprehensive neuropsychological examination 3-4 months after ischaemic stroke and 188 of them in addition to detailed psychiatric examination. Basic and complex activities of daily living (ADLs) (bADLs and cADLs) post-stroke were assessed. The DSM-III-R criteria were used for the diagnosis of the depressive disorders. Altogether 40.6% (n=104) of the patients had executive dysfunction. The patients with executive dysfunction were older, had lower level of education, were more often dependent, did worse in bADLs and cADLs, had more often DSM-III dementia, had worse cognition as measured by Mini Mental State Examination (MMSE) and were more depressed as measured by the BECK depression scale, but not with the more detailed psychiatric evaluation. They had more often stroke in the anterior circulation and less often in the posterior circulation. The independent correlates of executive dysfunction were cADLs (OR 1.1, 95% CI 1.03-1.16), each point of worsening in cognition by MMSE (OR 1.7, 95% CI 1.42-1.97) and stroke in the posterior circulation area (OR 0.4, 95% CI 0.18-0.84). Clinically significant executive dysfunction is frequent after ischaemic stroke and is closely connected with cADLs and to overall cognitive status but could be distinguished from depression by detailed neuropsychological examination. Executive measures may detect patients at risk of dementia and disability post-stroke.

Evaluation of various methods of assessing symptoms of cognitive impairment and dementia

BACKGROUND AND PURPOSE

The effect of different diagnostic criteria for detecting dementia in both epidemiological and stroke cohort studies has been shown, but comparison between different assessment methods has only seldom been done. We compared both assessment methods and diagnostic criteria for dementia in a large well-defined stroke cohort.

SUBJECT AND METHODS

A group of 227 of 486 patients aged 55 to 85 years who 3 months after ischemic stroke completed a comprehensive neuropsychological test battery, structured clinical mental status examination of defined cognitive domains with expanded Mini-Mental State Examination. The criteria for dementia were those of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III, DSM-III-R) and the National Institute of Neurological Disorders and Stroke-Associated Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN).

RESULTS

The main differences between clinical and neuropsychological examinations were seen in memory functions: clinically 24.7% and neuropsychologically 54.2% had impairment in short-term memory and 10.4% versus 5.3% in long-term memory. Accordingly, the prevalence of dementia varied greatly: It was clinically 14.1% by DSM-III, 9.7% by DSM-III-R and 8.4% by NINDS-AIREN criteria. The corresponding frequencies based on neuropsychological evaluation were 27.3%, 4.0% and 25.6%. Between these 3 diagnostic criteria the concordance varied in clinical testing between 59.4%-68.8% (kappa 0.72-0.79) and in neuropsychological testing between 14.5%-81.1% (kappa 0.20-0.86). The concordance between clinical and neuropsychological testing was 56.8% (kappa 0.42) by DSM-III, 31.6% (kappa 0.35) by DSM-III-R and 25.5% (kappa 0.24) by NINDS-AIREN.

CONCLUSIONS

The frequency of poststroke dementia and cognitive decline varied sharply when different systems of diagnostic classification and methods were used. This may have serious influences on investigation and treatment of patients. We underline the importance of further debate and studies to refine the categories of cognitive impairment used in the setting of CVD.

Executive functions and speed of mental processing in elderly patients with frontal or nonfrontal ischemic stroke

Impairments in executive functions have been related to aging and frontal lobe lesions. Aging also causes slowing of mental processing. We examined whether ischemic stroke in the frontal brain area results in dysexecutive syndrome, or whether the frontal stroke causes increased slowing of mental processing. Neurological, radiological and neuropsychological examinations were carried out 3 months post-stroke on 250 ischemic stroke patients (55-85 years) and on 39 healthy control subjects. Of the patients, 62 had frontal and 188 had nonfrontal lesions. The neuropsychological examination comprised several cognitive domains, including tests considered to measure executive functions. The frontal group was slower than the nonfrontal group in tasks measuring speed of mental processing which were time-limited (Trail Making A, Stroop dots and fluency). They were also inferior in the Digit Span backwards task. There were no differences between the groups in other cognitive domains, nor in some tests which are considered to be measures of executive functions (e.g. WCST). Impairments in executive functions were evident in both the frontal and the nonfrontal groups compared with the controls, but no dysexecutive syndrome specifically related to frontal lesions was found. Frontal stroke related mainly to the slowing of mental processing.