M.J.E. van Zandvoort

Cognitive Disorders in Acute Stroke: Prevalence and Clinical Determinants

Background: Although cognitive impairment early after stroke is a powerful predictor of long-term functional dependence and dementia, little is known about the characteristics and determinants of cognitive dysfunction in acute stroke. Methods: We administered a neuropsychological examination covering 7 cognitive domains to 190 patients within 3 weeks after a first stroke. We also assembled lesion characteristics, clinical factors at admission, demographic characteristics and vascular risk factors. Multivariate logistic regression adjusted for age, gender and education was performed to examine determinants of acute cognitive impairment. Results:Overall, 74% of patients with a cortical stroke, 46% with a subcortical stroke and 43% with an infratentorial stroke demonstrated acute cognitive impairment.Disorders in executive functioning (39%) and visual perception/construction (38%) were the most common. The prevalence and severity of deficits in executive functioning, language, verbal memory and abstract reasoning was more pronounced following left compared to right cortical stroke (all p < 0.05). Intracerebral haemorrhage (OR = 5.6; 95% CI = 1.2–25.4) and cortical involvement of the stroke (OR = 3.6; 95%, CI = 1.3–9.9) were independent determinants of acute cognitive impairment, whereas premorbid moderate alcohol consumption exerted a protective effect (OR = 0.4; 95% CI = 0.1–1.1). Conclusions:Cognitive impairment is common in the first weeks after stroke, with executive and perceptual disorders being the most frequent. Intracerebral haemorrhage, cortical involvement of the lesion and premorbid moderate alcohol consumption are independently associated with acute cognitive impairment.

The prognostic value of domain-specific cognitive abilities in acute first-ever stroke

Objective: To evaluate the prognostic value of domain-specific cognitive abilities in acute stroke with respect to long-term cognitive and functional outcome in addition to neurologic and demographic predictors. Methods: The authors evaluated 168 patients within the first 3 weeks after first-ever stroke. The prevalence of neuropsychological impairment was calculated vs 75 matched healthy controls. The authors also recorded demographic data, vascular risk factors, lesion characteristics, and clinical factors at admission. Independent predictor variables associated with long-term cognitive impairment (assessed with a follow-up neuropsychological examination) and functional impairment (assessed with the modified Barthel Index and the Frenchay Activities Index) were identified with stepwise multiple logistic regression. Areas under receiver operator characteristic curves were used to compare the predictive value of three models, i.e., a standard medical model, a purely cognitive model, and a model consisting of both medical and cognitive predictors. Results: Thirty-one percent of patients showed long-term cognitive impairment. Basic and instrumental ADL disturbances remained present in 19% and 24% of patients. Domain-specific cognitive functioning predicted cognitive and functional outcome better than any other variable. Moreover, the prediction of instrumental ADL functioning improved when cognitive predictors were added to the standard medical model (p < 0.05). Impairments in abstract reasoning and executive functioning were independent predictors of long-term cognitive impairment. Inattention and perceptual disorders were more important in predicting long-term functional impairment. Conclusion: Domain-specific cognitive abilities in the early phase of stroke are excellent independent predictors of long-term cognitive and functional outcome.

Origin of superoxide production by endothelial nitric oxide synthase

Using fluorescence optical and electron spin resonance spectroscopy, we have investigated the production of superoxide by bovine endothelial nitric oxide synthase (NOS). In contrast to neuronal NOS, the heme moiety is identified as the exclusive source of superoxide production by endothelial NOS. Thus, calmodulin‐mediated enzyme regulation affects production of nitric oxide and superoxide simultaneously and inseparably. The balance between the nitric oxide/superoxide reaction pathways may be shifted by addition of exogenous heme‐specific agents, such as tetrahydrobiopterin. Our results have direct relevance for the pathophysiology of atherosclerosis.

Early cognitive impairment predicts long-term depressive symptoms and quality of life after stroke

OBJECTIVE The aim of the present study was to examine the predictive value of cognitive impairment in the acute phase after stroke as a risk factor for long-term (six to ten months after stroke) depressive symptoms (DS) and a reduced quality of life (QOL), independent of demographic and neurological predictors. METHODS We evaluated 143 patients within the first 3 weeks post-stroke. Predictor variables included domain-specific cognitive function, demographic data, vascular risk factors, lesion characteristics, and clinical factors. Predictor variables associated with long-term DS (Montgomery Asberg Depression Rating Scale >or=7) and QOL (Stroke-Specific Quality of Life Scale) were identified with multiple logistic and linear regression. RESULTS Long-term DS were independently predicted by cognitive impairment at baseline, DS at baseline, female sex, diabetes mellitus, and previous TIA(s). Cognitive impairment, increasing age, and functional dependence predicted a reduced QOL, whereas hypercholesterolaemia predicted a better QOL. Among all cognitive disorders, unilateral neglect was the greatest risk factor for DS after 6 months, whereas a disorder in visual perception and construction affected QOL the most. CONCLUSIONS Cognitive impairment and vascular risk factors are important predictors of long-term DS and QOL after stroke. The prognostic value of cognition suggests a reactive component in the development or continuation of long-term DS.

Early depressive symptoms after stroke: neuropsychological correlates and lesion characteristics

OBJECTIVE To examine the relation between depressive symptoms and specific cognitive functions in patients with a recent stroke and to examine associations with lesion characteristics. METHODS We studied 126 of 183 consecutive patients within 3 weeks after a first-ever symptomatic stroke (mean interval, 8.3+/-4.3 days). Presence and severity of depressive symptoms was assessed with the Montgomery Asberg Depression Rating Scale. Neuropsychological functioning was examined by means of a detailed neuropsychological examination covering six cognitive domains. We included a healthy control group (N=75) to obtain normative data for the neuropsychological examination. Functional impairment was measured with the modified Barthel Index and the modified Rankin Scale. Symptomatic and preexistent lesion characteristics were determined on CT or MRI. RESULTS Of the included patients, 40% demonstrated mild and 12% moderate to severe depressive symptoms. Severity of depressive symptoms was related to lesion volume (p=0.008), functional impairment (all p<0.004), and degree of overall cognitive impairment (p=0.005). After adjustment for lesion size, a specific neuropsychological profile emerged in patients with moderate to severe depressive symptoms, affecting primarily memory, visual perception, and language (all p<0.05). No association was found between severity of depressive symptoms and lesion location, presence of preexistent lesions (white matter lesions and silent infarcts), and demographic factors (age, education, and gender). CONCLUSIONS Moderate or severe symptoms of depression in the early stage poststroke are associated with a specific pattern of cognitive impairment, lesion size, and functional status. We suggest that depressive symptoms early after stroke are, at least in part, a reactive phenomenon secondary to severe cognitive and functional deficits.

Decreased capacity for mental effort after single supratentorial lacunar infarct may affect performance in everyday life

OBJECTIVES The long term outcome after a single symptomatic lacunar infarct may be less favourable than is generally assumed. Patients often present with complaints such as fatigue or “being different from before the stroke”, for which there are no obvious physical explanations. Although cognitive functioning is considered normal in most patients with lacunar infarction in the internal capsule or corona radiata, a study was carried out to determine if subclinical changes in mental or emotional function can explain these vague complaints characteristic for their disablement. METHODS Sixteen patients, each with a single symptomatic supratentorial lacunar infarct, and 16 matched healthy controls were examined with an extensive neuropsychological screening battery and a standardised questionnaire aimed at emotional problems. The mean number of correct responses was calculated for each subject and averaged within each group. RESULTS Although, on the whole, there were no differences in performance, patients’ results on the following tasks in different modalities showed evidence for decreased performance under relatively more demanding conditions: line orientation task (mean difference (MD) 261 ms; 95% confidence interval (95%CI) 94 to 428), Rey-Osterrieth delayed recall (MD−3.8, 95% CI −7.5 to 0.0), visual elevator subtest of the everyday attention task (EAT) (MD −0.7, 95% CI −1.5 to 0.1), lottery subtest of the EAT (MD −0.6, 95% CI −1.3 to 0.1) and WAIS similarities (MD −3.2 95% CI −6.3 to 0.1). Patients also more often had emotional disturbances than controls. CONCLUSION Both subtle cognitive impairments and emotional disturbances may play a part in the decreased competence in everyday life of patients with a supratentorial lacunar infarct.

Domain-specific cognitive recovery after first-ever stroke. A follow-up study of 111 cases.

The objective of this study is to examine the prognosis of acute cognitive disorders post-stroke, and to evaluate which clinical factors predict domain-specific cognitive recovery. We followed the course of cognitive functioning in 111 stroke patients and 77 healthy controls by administering two neuropsychological examinations with a 6 to 10 month interval (mean interval, 7.5 +/- 1.3 months). The baseline examination was administered within three weeks post-stroke (mean interval, 7.9 +/- 4.2 days). To examine determinants of domain-specific cognitive recovery, we recorded vascular risk factors, clinical variables, and lesion characteristics. Recovery in visual perception/construction (83%) and visual memory (78%) was the most common. An acute cognitive disorder predicted a long-term disorder in the same domain (all p < .05), except for visual perception/construction. Factors associated with poor cognitive recovery were age (all p < .01), preexistent verbal ability (all p < .005), lesion locations involving the temporal (all p < .05), frontal (p < .05) and occipital lobe (allp < .05), lesion volume (p < or = .001), and diabetes mellitus (p < .01). An early neuropsychological examination provides valuable information on long-term cognitive performance. The prognosis of higher-level visual disorders is the most favorable. Cognitive recovery is associated with age, preexistent ability, lesion volume, lesion location, and diabetes mellitus.

A long-lasting improvement of somatosensory function after prism adaptation, a case study

Previous studies have observed a reduction of visual and representational neglect symptoms after visuo-manual adaptation to rightward displacing prisms. Recently, improvements have also been observed on somatosensory tasks, such as locating the centre of a haptically explored circle and tactile double simultaneous stimulation. In the current single case study we assessed whether prism adaptation with the ipsilesional hand improved two aspects of contralesional somatosensory function, pressure sensitivity and proprioception. After the first application of prism adaptation improvements in pressure sensitivity and proprioception were observed. A second prism adaptation confirmed the improvements in contralesional somatosensory function. The effects of prism adaptation on position sense were longer lasting than have been reported previously, but consistent with reductions of visual neglect symptoms after prism adaptation. The current findings suggest that prism adaptation can have a non-spatial effect on neglect-related supra-modal deficits.

Prevalence and Determinants of Cognitive Complaints after Aneurysmal Subarachnoid Hemorrhage

Background: To investigate the prevalence of cognitive complaints after subarachnoid hemorrhage (SAH) and the relationships between cognitive complaints and cognitive impairments, disability and emotional problems. Methods: Cognitive complaints were assessed with the Checklist for Cognitive and Emotional Consequences following stroke (CLCE-24) in 111 persons who visited our outpatient clinic 3 months after SAH. Associations between cognitive complaints and cognitive functioning, demographic characteristics, disability and emotional problems were examined using Spearman correlations and linear regression analysis. Results: In this study group, 105 patients (94.6%) reported at least one cognitive or emotional complaint that hampered everyday functioning. The most frequently reported cognitive complaints were mental slowness, short-term memory problems and attention deficits. All cognitive domains, disability, depressive symptoms and feelings of anxiety were significantly associated with the CLCE-24 cognition score. In the final regression model, memory functioning (β value –0.21), disability (–0.28) and depressive symptoms (0.40) were significant determinants of cognitive complaints, together explaining 35.4% of the variance. Conclusion: Cognitive complaints are common after SAH and associated with memory deficits, disability and depressive symptoms. Rehabilitation programs should focus on these symptoms and deficits.

Cognition after carotid endarterectomy or stenting A randomized comparison

Objective: To compare the effect on cognition of carotid artery stenting (CAS) and carotid endarterectomy (CEA) for symptomatic carotid artery stenosis. Methods: Patients randomized to CAS or CEA in the International Carotid Stenting Study (ICSS; ISRCTN25337470) at 2 participating centers underwent detailed neuropsychological examinations (NPE) before and 6 months after revascularization. Ischemic brain lesions were assessed with diffusion-weighted imaging before and within 3 days after revascularization. Cognitive test results were standardized into z scores, from which a cognitive sumscore was calculated. The primary outcome was the change in cognitive sumscore between baseline and follow-up. Results: Of the 1,713 patients included in ICSS, 177 were enrolled in the 2 centers during the substudy period, of whom 140 had an NPE at baseline and 120 at follow-up. One patient with an unreliable baseline NPE was excluded. CAS was associated with a larger decrease in cognition than CEA, but the between-group difference was not statistically significant: −0.17 (95% CI −0.38 to 0.03; p = 0.092). Eighty-nine patients had a pretreatment MRI and 64 within 3 days after revascularization. New ischemic lesions were found twice as often after CAS than after CEA (relative risk 2.1; 95% CI 1.0 to 4.4; p = 0.041). Conclusions: Differences between CAS and CEA in effect on cognition were not statistically significant, despite a substantially higher rate of new ischemic lesions after CAS than after CEA. Classification of Evidence: This study provides Class III evidence that any difference between the effects of CAS and CEA on cognition at 6 months after revascularization is small.