***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Background Delirium after cardiac surgery is a serious complication , increasing morbidity and mortality . Despite its high expectations , off-pump coronary artery bypass grafting ( OPCAB ) has largely failed to reduce the incidence of postoperative neurological complications . To further investigate the reasons for this failure , we used perioperative brain magnetic resonance imaging ( MRI ) to determine the relation between MRI findings and postoperative delirium . Methods Altogether , 98 patients undergoing elective OPCAB were enrolled in this prospect i ve observational study . Patients underwent brain MRI and magnetic resonance angiography ( MRA ) before and after surgery to identify cerebral infa rct ion , white matter lesions , and intracranial artery stenosis . Postoperative delirium in the intensive care unit was measured using the delirium rating scale . The relation between postoperative delirium and MRI findings was examined using logistic regression . Results Magnetic resonance imaging and MRA was completed in 88 ( 90 % ) of the patients . New ischemic lesions were present in seven ( 7.9 % ) patients . Delirium rating scale scores of 0 , 1 - 7 , and ≥ 8 were found in 25 ( 31 % ) , 48 ( 60 % ) , and seven ( 9 % ) patients , respectively . Multivariate logistic regression analysis revealed that new ischemic lesions ( odds ratio [ OR ] 11.07 , 95 % confidence interval [ CI ] : 1.53 to 80.03 ; P = 0.017 ) , carotid artery stenosis ( OR 7.06 , 95 % CI : 1.59 to 31.13 ; P = 0.010 ) , history of myocardial infa rct ion ( OR 3.78 , 95 % CI : 1.05 to 13.65 ; P = 0.043 ) , and deep subcortical white matter hyperintensity ( OR 3.04 , 95 % CI : 1.14 to 8.12 ; P = 0.027 ) were significantly associated with postoperative delirium . Conclusions Magnetic resonance imaging findings of new cerebral ischemic lesions , carotid stenosis , and deep subcortical white matter hyperintensity correlated significantly with postoperative delirium in patients who had undergone OPCAB surgery . Résumé Context eLa survenue d’un délirium après chirurgie cardiaque est une complication grave , augmentant la morbidité et la mortalité . En dépit des fortes attentes , le pontage coronarien à cœur battant ( OPCAB ) a largement échoué à démontrer qu’il pouvait réduire l’incidence des complications neurologiques postopératoires . Pour approfondir l’étude des raisons de cet échec , nous avons utilisé une imagerie par résonance magnétique ( IRM ) périopératoire du cerveau pour déterminer la relation entre les constations de l’IRM et le délirium postopératoire . MéthodesUn ensemble de 98 patients subissant un OPCAB électif a été inclus dans cette étude observationnelle prospect i ve . Les patients ont subi une IRM cérébrale et une angiographie par résonance magnétique ( ARM )  avant et après l’intervention chirurgicale afin d’identifier un infa rct us cérébral , des lésions de la substance blanche et une sténose d’une artère intracrânienne . Le délirium postopératoire a été mesuré dans l’unité de soins intensifs au moyen de l’échelle d’évaluation du délirium . La relation entre le délirium postopératoire et les constatations de l’IRM a été analysée par régression logistique . RésultatsL’imagerie par résonance magnétique et l’ARM ont été effectuées chez 88 ( 90 % ) patients . De nouvelles lésions ischémiques ont été retrouvées chez sept ( 7,9 % ) patients . Les scores de l’échelle d’évaluation du délirium étaient de 0 , 1 à 7 , et ≥ 8 chez , respectivement , 25 ( 31 % ) , 48 ( 60 % ) , et 7 ( 9 % ) patients . Analyse de régression logistique multifactorielle a révélé que les nouvelles lésions ischémiques ( rapport de cotes [ RC ] 11,07 , intervalle de confiance [ IC ] à 95 % : 1,53 à 80,03 ; P = 0,017 ) , une sténose carotidienne ( RC 7,06 , IC à 95 % : 1,59 à 31,13 ; P = 0,010 ) , un antécédent d’infa rct us du myocarde ( RC 3,78 , IC à 95 % : 1,05 à 13,65 ; P = 0,043 ) , et une hyperintensité de la substance blanche sous-corticale profonde ( RC 3,04 , IC à 95 % : 1,14 à 8,12 ; P = 0,027 ) étaient significativement associés au délirium postopératoire . Conclusions La constatation par imagerie cérébrale par résonance magnétique de nouvelles lésions ischémiques cérébrales , d’une sténose carotidienne et d’une hyperintensité de la substance blanche sous-corticale profonde est significativement corrélée au délirium postopératoire chez des patients ayant subi une intervention pour OPCAB Background Sepsis-associated brain dysfunction has been linked to white matter lesions ( leukoencephalopathy ) and ischemic stroke . Our objective was to assess the prevalence of brain lesions in septic shock patients requiring magnetic resonance imaging ( MRI ) for an acute neurologic change . MethodS eventy-one septic shock patients were included in a prospect i ve observational study . Patients underwent daily neurological examination . Brain MRI was obtained in patients who developed focal neurological deficit , seizure , coma , or delirium . Electroencephalogy was performed in case of coma , delirium , or seizure . Leukoencephalopathy was grade d and considered present when white matter lesions were either confluent or diffuse . Patient outcome was evaluated at 6 months with the Glasgow Outcome Scale ( GOS ) . Results We included 71 patients with median age of 65 years ( 56 to 76 ) and SAPS II at admission of 49 ( 38 to 60 ) .  MRI was indicated on focal neurological sign in 13 ( 18 % ) , seizure in 7 ( 10 % ) , coma in 33 ( 46 % ) , and delirium in 35 ( 49 % ) .  MRI  was normal in 37 patients ( 52 % ) and showed cerebral infa rcts in 21 ( 29 % ) , leukoencephalopathy in 15 ( 21 % ) , and mixed lesions in 6 ( 8 % ) . EEG malignant pattern was more frequent in patients with ischemic stroke or leukoencephalopathy . Ischemic stroke was independently associated with disseminated intravascular coagulation ( DIC ) , focal neurologic signs , increased mortality , and worse GOS at 6 months . Conclusions Brain MRI in septic shock patients who developed acute brain dysfunction can reveal leukoencephalopathy and ischemic stroke , which is associated with DIC and increased mortality Three-dimensional Arterial Spin Labeling ( ASL ) MRI was performed before surgery in a cohort of 146 prospect ively enrolled subjects ≥ 70 years old scheduled to undergo elective surgery . We investigated the prospect i ve association between ASL-derived measures of cerebral blood flow ( CBF ) before surgery with postoperative delirium incidence and severity using whole-brain and globally normalized voxel-wise analysis . We also investigated the cross-sectional association of CBF with patients ’ baseline performance on specific neuropsychological tests , and with a composite general cognitive performance measure ( GCP ) . Out of 146 subjects , 32 ( 22 % ) developed delirium . We found no significant association between global and voxel-wise CBF with delirium incidence or severity . We found the most significant positive associations between CBF of the posterior cingulate and precuneus and the Hopkins Verbal Learning Test – Revised total score , Visual Search and Attention Test ( VSAT ) score and the GCP composite . VSAT score was also strongly associated with right parietal lobe CBF . ASL can be employed in a large , well-characterized older cohort to examine associations between CBF and age-related cognitive performance . Although ASL CBF measures in regions previously associated with pre clinical Alzheimer ’s Disease were correlated with cognition , they were not found to be indicators of baseline pathology that may increase risk for delirium Delirium is an acute change in cognition which occurs frequently after coronary artery bypass graft ( CABG ) surgery . Cerebral microemboli , from plaque , air , or thrombus , have been hypothesized to contribute to delirium and cognitive decline after CABG . The purpose of this study was to determine if there was an association between cerebral microemboli and delirium after cardiac surgery . Non-delirious patients ( n=68 ) were prospect ively enrolled and underwent intraoperative monitoring of the middle cerebral arteries with transcranial Doppler ( TCD ) . TCD signals were saved and analyzed postoperatively for microemboli manually , according to established criteria . Postoperatively , patients were assessed for delirium with a st and ardized battery . Thirty-three patients ( 48.5 % ) developed delirium after surgery . Microemboli counts ( mean ± SD ) were not significantly different in those with and without delirium ( 303 ± 449 vs. 299 ± 350 ; p=0.97 ) . While intraoperative microemboli were not associated with delirium after CABG , further investigation into the source and composition of microemboli can further eluci date the long-term clinical impact of microemboli OBJECTIVE To develop and vali date a new st and ardized confusion assessment method ( CAM ) that enables nonpsychiatric clinicians to detect delirium quickly in high-risk setting s. DESIGN Prospect i ve validation study . SETTING Conducted in general medicine wards and in an outpatient geriatric assessment center at Yale University ( site 1 ) and in general medicine wards at the University of Chicago ( site 2 ) . PATIENTS The study included 56 subjects , ranging in age from 65 to 98 years . At site 1 , 10 patients with and 20 without delirium participated ; at site 2 , 16 patients with and 10 without delirium participated . MEASUREMENTS AND MAIN RESULTS An expert panel developed the CAM through a consensus building process . The CAM instrument , which can be completed in less than 5 minutes , consists of nine operationalized criteria from the Diagnostic and Statistical Manual of Mental Disorders ( DSM-III-R ) . An a priori hypothesis was established for the diagnostic value of four criteria : acute onset and fluctuating course , inattention , disorganized thinking , and altered level of consciousness . The CAM algorithm for diagnosis of delirium required the presence of both the first and the second criteria and of either the third or the fourth criterion . At both sites , the diagnoses made by the CAM were concurrently vali date d against the diagnoses made by psychiatrists . At sites 1 and 2 values for sensitivity were 100 % and 94 % , respectively ; values for specificity were 95 % and 90 % ; values for positive predictive accuracy were 91 % and 94 % ; and values for negative predictive accuracy were 100 % and 90 % . The CAM algorithm had the highest predictive accuracy for all possible combinations of the nine features of delirium . The CAM was shown to have convergent agreement with four other mental status tests , including the Mini-Mental State Examination . The interobserver reliability of the CAM was high ( kappa = 0.81 - 1.0 ) . CONCLUSIONS The CAM is sensitive , specific , reliable , and easy to use for identification of delirium Introduction Postoperative delirium is an important problem in patients undergoing major surgery .  Cerebral oximetry is a non-invasive method to detect imbalances in the cerebral oxygen supply/dem and -ratio . Low preoperative cerebral oxygen saturation ( ScO2 ) levels have been associated with postoperative delirium in non-cardiac surgery patients . The present prospect i ve observational study determines the relationship between pre- and intra-operative ScO2 levels and postoperative delirium in patients undergoing on-pump cardiac surgery . Methods After approval of the local ethical committee and written informed consent , N = 231 patients scheduled for elective/urgent cardiac surgery were enrolled .  Delirium was assessed by the confusion- assessment - method for the intensive care unit ( CAM-ICU ) on the first three days after surgery .  ScO2 was obtained on the day before surgery , immediately before surgery and throughout the surgical procedure . Preoperative cognitive function , demographic , surgery related , and intra- and post-operative physiological data were registered . Results Patients with delirium had lower pre- and intra-operative ScO2 readings , were older , had lower mini-mental-status-examination(MMSE ) scores , higher additive EuroScore and lower preoperative haemoglobin-levels . The binary logistic regression identified older age , lower MMSE , neurological or psychiatric disease and lower preoperative Sc 
    Output:
    
Despite heterogeneity in study design , delirium was associated with WMH , lower brain volume , atrophy , dysconnectivity , impaired cerebral autoregulation , reduced blood flow and cerebral oxygenation and glucose hypometabolism .
There was evidence of long-term brain changes following intensive care unit delirium .