A hospital-wide evaluation of delirium prevalence and outcomes in acute care patients - a cohort study.

BACKGROUND: Delirium is a well-known complication in cardiac surgery and intensive care unit (ICU) patients. However, in many other settings its prevalence and clinical consequences are understudied. The aims of this study were: (1) To assess delirium prevalence in a large, diverse cohort of acute care patients classified as either at risk or not at risk for delirium; (2) To compare these two groups according to defined indicators; and (3) To compare delirious with non-delirious patients regarding hospital mortality, ICU and hospital length of stay, nursing hours and cost per case. METHODS: This cohort study was performed in a Swiss university hospital following implementation of a delirium management guideline. After excluding patients aged < 18 years or with a length of stay (LOS) < 1 day, 29'278 patients hospitalized in the study hospital in 2014 were included. Delirium period prevalence was calculated based on a Delirium Observation Scale (DOS) score ≥ 3 and / or Intensive Care Delirium Screening Checklist (ICDSC) scores ≥4. RESULTS: Of 10'906 patients admitted, DOS / ICDSC scores indicated delirium in 28.4%. Delirium was most prevalent (36.2-40.5%) in cardiac surgery, neurosurgery, trauma, radiotherapy and neurology patients. It was also common in geriatrics, internal medicine, visceral surgery, reconstructive plastic surgery and cranio-maxillo-facial surgery patients (prevalence 21.6-28.6%). In the unadjusted and adjusted models, delirious patients had a significantly higher risk of inpatient mortality, stayed significantly longer in the ICU and hospital, needed significantly more nursing hours and generated significantly higher costs per case. For the seven most common ICD-10 diagnoses, each diagnostic group's delirious patients had worse outcomes compared to those with no delirium. CONCLUSIONS: The results indicate a high number of patients at risk for delirium, with high delirium prevalence across all patient groups. Delirious patients showed significantly worse clinical outcomes and generated higher costs. Subgroup analyses highlighted striking variations in delirium period-prevalence across patient groups. Due to the high prevalence of delirium in patients treated in care centers for radiotherapy, visceral surgery, reconstructive plastic surgery, cranio-maxillofacial surgery and oral surgery, it is recommended to expand the current focus of delirium management to these patient groups.

Neurologic Injury With Severe Adult Respiratory Distress Syndrome in Patients Undergoing Extracorporeal Membrane Oxygenation: A Single-Center Retrospective Analysis.

This retrospective single-center study investigated the incidence of neurologic injury as determined by autopsy or cerebral imaging in 74 patients undergoing extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome. Seventy-three percent of patients were treated with venovenous and 27% with venoarterial ECMO. ECMO-associated intracerebral hemorrhage was diagnosed in 10.8% of patients. There were no cases of ischemic stroke. Clinical characteristics did not differ between patients with and without neurologic injury. Six-month survival was 13% (Wilson confidence interval, 2%-47%) in patients with severe intracerebral hemorrhage compared to an overall survival rate of 57% (Wilson confidence interval, 45%-67%).

The effect of sampling rate and lowpass filters on saccades - A modeling approach.

The study of eye movements has become popular in many fields of science. However, using the preprocessed output of an eye tracker without scrutiny can lead to low-quality or even erroneous data. For example, the sampling rate of the eye tracker influences saccadic peak velocity, while inadequate filters fail to suppress noise or introduce artifacts. Despite previously published guiding values, most filter choices still seem motivated by a trial-and-error approach, and a thorough analysis of filter effects is missing. Therefore, we developed a simple and easy-to-use saccade model that incorporates measured amplitude-velocity main sequences and produces saccades with a similar frequency content to real saccades. We also derived a velocity divergence measure to rate deviations between velocity profiles. In total, we simulated 155 saccades ranging from 0.5° to 60° and subjected them to different sampling rates, noise compositions, and various filter settings. The final goal was to compile a list with the best filter settings for each of these conditions. Replicating previous findings, we observed reduced peak velocities at lower sampling rates. However, this effect was highly non-linear over amplitudes and increasingly stronger for smaller saccades. Interpolating the data to a higher sampling rate significantly reduced this effect. We hope that our model and the velocity divergence measure will be used to provide a quickly accessible ground truth without the need for recording and manually labeling saccades. The comprehensive list of filters allows one to choose the correct filter for analyzing saccade data without resorting to trial-and-error methods.

Cognitive performance in high-altitude climbers: a comparative study of saccadic eye movements and neuropsychological tests.

Impairment of cognitive performance during and after high-altitude climbing has been described in numerous studies and has mostly been attributed to cerebral hypoxia and resulting functional and structural cerebral alterations. To investigate the hypothesis that high-altitude climbing leads to cognitive impairment, we used of neuropsychological tests and measurements of eye movement (EM) performance during different stimulus conditions. The study was conducted in 32 mountaineers participating in an expedition to Muztagh Ata (7,546 m). Neuropsychological tests comprised figural fluency, line bisection, letter and number cancellation, and a modified pegboard task. Saccadic performance was evaluated under three stimulus conditions with varying degrees of cortical involvement: visually guided pro- and anti-saccades, and visuo-visual interaction. Typical saccade parameters (latency, mean sequence, post-saccadic stability, and error rate) were computed off-line. Measurements were taken at a baseline level of 440 m and at altitudes of 4,497, 5,533, 6,265, and again at 440 m. All subjects reached 5,533 m, and 28 reached 6,265 m. The neuropsychological test results did not reveal any cognitive impairment. Complete eye movement recordings for all stimulus conditions were obtained in 24 subjects at baseline and at least two altitudes and in 10 subjects at baseline and all altitudes. Measurements of saccade performances showed no dependence on any altitude-related parameter and were well within normal limits. Our data indicates that acclimatized climbers do not seem to suffer from significant cognitive deficits during or after climbs to altitudes above 7,500 m. We demonstrated that investigation of EMs is feasible during high-altitude expeditions.

Subacute bilateral visual loss in methylmalonic acidemia.

A 23-year-old woman known to have methylmalonic acidemia (MMA) since birth suffered bilateral visual loss within 5 days. Multiple sclerosis, Leber hereditary optic neuropathy, vasculitis, infections (in particular treponema), and vitamin deficiency were ruled out. The optic nerve head changed from normal in appearance to atrophic. Treatment attempts with high-dose intravenous steroids and coenzyme Q10 combined with vitamin E were ineffective. The patient's underlying disease was metabolically well controlled by strict diet and carnitine supplementation. Toxic damage of both optic nerves due to MMA is the most likely mechanism. MRI showed moderate enhancement of both optic nerves. To our knowledge, this is the first report of a morphological correlate on MRI.

Treatment of resistant fever: new method of local cerebral cooling.

BACKGROUND: Fever in neurocritical care patients is common and has a negative impact on neurological outcome. The purpose of this prospective observational study was (1) to evaluate the practicability of cooling with newly developed neck pads in the daily setting of neurointensive care unit (NICU) patients and (2) to evaluate its effectiveness as a surrogate endpoint to indicate the feasibility of neck cooling as a new method for intractable fever. METHODS: Nine patients with ten episodes of intractable fever and aneurysmal subarachnoid hemorrhage were treated with one of two different shapes of specifically adapted cooling neck pads. Temperature values of the brain, blood, and urinary bladder were taken close meshed after application of the cooling neck pads up to hour 8. RESULTS: The brain, blood, and urinary bladder temperatures decreased significantly from hour 0 to a minimum in hour 5 (P < 0.01). After hour 5, instead of continuous cooling in all the patients, the temperature of all the three sites remounted. CONCLUSION: This study showed the practicability of local cooling for intractable fever using the newly developed neck pads in the daily setting of NICU patients.

Increased protocol adherence and safety during controlled normothermia as compared to hypothermia after cardiac arrest.

PURPOSE: This study aims to compare protocol adherence, neurological outcome and adverse effects associated with a controlled hypothermia versus a controlled normothermia protocol in patients successfully resuscitated after cardiac arrest. METHODS: In this retrospective single-center study in a university intensive care unit in Switzerland, post-cardiac arrest patients were compared before and after a protocol change from targeted temperature management at 33 °C (TTM-33) to 36 °C (TTM-36) using an intravascular cooling device. Protocol adherence was assessed as the primary outcome. Secondary outcomes were in-hospital mortality, neurological outcome and adverse effects. RESULTS: 373 patients after cardiac arrest were screened, of whom a total of 133 patients were included. Protocol adherence was lower in the TTM-33 group (47% vs 87% of patients, p < 0.01). In-hospital mortality (59% vs 45%, p = 0.15) and neurological outcome (modified Rankin Score < 4 in 33% vs 39% and CPC-Score < 3 in 33% vs 39% of patients, p = 0.60 and 0.97) were similar. Overall incidence of adverse effects was comparable, with bradycardic arrhythmias occurring more frequently in the TTM-33 group. CONCLUSION: Protocol adherence was higher in the TTM-36 group. In-hospital mortality and neurological outcome were similar, while bradycardic arrhythmias were encountered more often in TTM-33.

Comparison of spectral entropy and bispectral index electroencephalography in coronary artery bypass graft surgery.

OBJECTIVE: The study's aim was to compare response entropy (RE) and state entropy (SE) with bispectral index (BIS) electroencephalography (EEG) as an alternative cerebral monitoring tool in patients scheduled for coronary artery bypass graft surgery. DESIGN: Prospective, observational single-center study. SETTING: University hospital. PARTICIPANTS: Thirty patients undergoing coronary artery bypass graft surgery receiving remifentanil-propofol anesthesia. INTERVENTIONS: Surgery was performed with cardiopulmonary bypass (CPB) and cardiac arrest in 15 patients, with CPB without cardiac arrest in 9 patients and without CPB in 6 patients. MEASUREMENTS AND MAIN RESULTS: RE, SE, BIS, burst suppression ratio (BSR), and frontal electromyography (f-EMG) were detected simultaneously. RE and SE compared favorably with BIS and their correlations were strong (r(2) = 0.6, r(2) = 0.55, respectively). The mean bias of RE and BIS was -1.8, but limits of agreement were high (+20.5/-24.1). RE and SE tended to be lower than the BIS values in the CPB subgroups. The detection of BSR was similar with RE and SE and the BIS. A strong correlation existed between BIS and f-EMG (r(2) = 0.62) in contrast to RE (r(2) = 0.45) and SE (r(2) =0.39). BIS monitoring was significantly more disturbed than RE and SE with 9.1% +/-10.9% and 0.1% +/- 0.2% of the total anesthesia time, respectively. Neither implicit nor explicit memory was shown. CONCLUSION: RE and SE are comparable with the BIS but showed significantly less interference from f-EMG and superior resistance against artifacts. Thus, spectral entropy is more suitable than the BIS during propofol-remifentanil anesthesia in cardiac surgery patients.

Implementation of a multiprofessional, multicomponent delirium management guideline in two intensive care units, and its effect on patient outcomes and nurse workload: a pre-post design retrospective cohort study.

AIM OF THE STUDY: Delirium is a frequent intensive care unit (ICU) complication, affecting 26% to 80% of ICU patients, often with serious consequences. This study aimed to evaluate the effectiveness, costs and benefits of following a standardised multiprofessional, multicomponent delirium guideline on eight outcomes: delirium prevalence and duration, lengths of stay in ICU and hospital, in-hospital mortality, duration of mechanical ventilation, and cost and nursing hours per case. It also aimed to explore the associations of delirium with length of ICU stay, length of hospital stay and duration of mechanical ventilation. METHODS: This retrospective cohort study used a pre-post design. ICU patients in an historical control group (n = 1608) who received standard ICU care were compared with a postintervention group (n = 1684) who received standardised delirium management – delirium risk identification, preventive measures, screening and treatment – with regard to eight outcomes. The delirium management guideline was developed and implemented in 2012 by a group of experts from the study hospital. As appropriate, descriptive statistics and multivariate, multilevel models were used to compare the two groups and to explore the association between delirium occurrence and the selected outcomes. RESULTS: Twelve percent of the 1608 historical controls and 20% of the 1684 postintervention patients were diagnosed with delirium according to the ICD-10 delirium diagnosis codes. Patients being treated for heart disease, and those with septic shock, ARDS, renal insufficiency (acute or chronic), older age and higher numbers of comorbidities were significantly more likely to develop delirium during their stay. Multivariate models comparing the historical controls with the post intervention group indicated significant differences in delirium period prevalence (odds ratio 1.68, 95% confidence interval [CI] 1.38–2.06; p <0.001), length of stay in the ICU (time ratio [TR] 0.94, CI 0.89–1.00; p = 0.048), cost per case (median difference 3.83, CI 0.54–7.11; p = 0.023) and duration of mechanical ventilation (TR 0.84, CI 0.77–0.92; p <0.001). The observed differences in the other four outcomes – in-hospital mortality, delirium duration, length of stay in the hospital, and nursing hours per case – were not significant. Delirium was a significant predictor for prolonged duration of mechanical ventilation and for both ICU and hospital stay. CONCLUSION: Standardised delirium management, specifically delirium screening, supports timely detection of delirium in ICU patients. Increased awareness of delirium after the implementation of standardised multiprofessional, multicomponent management leads to increased therapeutic attention, a prolongation of ICU stay and increased costs, but with no influence on mortality.

Starting a carotid artery stenting program is safe.

BACKGROUND: Little is known on the performance of newly initiated carotid artery stenting (CAS) programs. The safety of the procedure is being questioned following the publication of the EVA-3S trial, a study criticized for the limited interventional experience required to enroll patients. METHODS: Within a newly started academic CAS program, patient data and outcomes were collected prospectively. The outcomes of the first 100 consecutive patients treated are reported. A CAS-fellowship-trained interventionalist was involved in all procedures. All patients underwent clinical assessment by a neurologist before and after the procedure, and serial ECG and cardiac enzymes were routinely obtained. Primary outcome measures included 30-day major adverse events (MAE), defined as death, stroke, or myocardial infarction, while on follow-up deaths and ipsilateral strokes were added. RESULTS: Between July 2003 and November 2006, 92 patients had a single internal carotid artery treated, while 7 underwent staged bilateral CAS. In one patient, the procedure was aborted prior to lesion treatment. The 30-day MAE rate per procedure was 1.9% (one major and one minor stroke). By a mean follow-up of 16 months (range 2-42 months), one patient had died of refractory heart failure, while one patient had a minor ipsilateral stroke and three had minor contralateral strokes, corresponding to total MAE per patient of 4%. The rate of any stroke or death was 7%. The rate of restenosis >or=50% per lesion by ultrasound was 3.8%. CONCLUSION: This single center experience suggests that it is safe to start a CAS program following dedicated fellowship.

Retinal microangiopathy and rapidly fatal cerebral edema in a patient with adult-onset Still's disease and concurrent macrophage activation syndrome.

Hemophagocytic lymphohistiocytosis (HLH) is a complex inflammatory disease with multiple diagnostic and therapeutic pitfalls. The congenital form, referred to as familial hemophagocytic lymphohistiocytosis (FHL), is often associated with cerebromeningeal involvement, whereas neurological complications are not characteristic of the adult form of secondary HLH (sHLH). Here we report the case of a 20-year-old woman with adult-onset Still's disease (AOSD), retinal microangiopathy and concurrent macrophage activation syndrome (MAS), in the context of sHLH. Following treatment with etanercept, ibuprofen, methylprednisolone, and phenylbutazone for 3 weeks, MAS deteriorated and fatal cerebral edema occurred within only 24 h. The clinical signs and neuropathological findings are discussed with special emphasis on possible relationships between the aggravation of MAS and therapeutic interventions for AOSD. In conclusion, even the slightest sign of mental decline in a patient with AOSD must be considered central nervous system MAS which can be rapidly fatal.

Neurological adverse events to voriconazole: evidence for therapeutic drug monitoring.

BACKGROUND: Voriconazole shows a considerable interpatient variation of serum concentrations. METHODS AND RESULT: In an analysis of 28 treatment courses, 6 patients presented with neurological adverse events (hallucination, encephalopathy, and visual disturbance). The hazard ratio per 0.1 mg/mL voriconazole serum level (sVL) increase was 2.27 (95% CI: 1.45-3.56, p <0.001). There was no correlation between sVL and creatinine (r = 0.12, p = 0.114), ALT (r = -0.14, p = 0.072), AST (r = 0.003, p = 0.964), alkaline phosphatase (r = 0.03, p = 0.723). CONCLUSIONS: Our findings demonstrate that elevated sVL is associated with neurological adverse events, and measurement of its serum concentration could improve voriconazole treatment and safety.

Changes in cerebral glucose metabolism after an expedition to high altitudes.

The possibility of persistent cerebral impairment due to exposure to extreme altitude and resulting hypoxic conditions is of great concern to both high altitude mountaineers and researchers. The aim of the present study was to investigate the effect of prolonged exposure to hypoxia on cerebral glucose metabolism, which probably precedes structural and functional impairment. Positron emission tomography (PET) employing [18F]-2-deoxy-2-fluoro-D-glucose (FDG) was performed, and the normobaric hypoxic ventilatory response (HVR) was assessed in 11 mountaineers before (pre) and after (post) climbing Mount Shisha Pangma (8048 m). During the climb, acute mountain sickness (AMS) symptoms were recorded and heart rate and oxygen saturation (SaO2) were measured daily. Neuropsychological evaluations were conducted at different heights. The difference FDGpost- FDGpre was analyzed voxel by voxel using statistical parametric mapping (SPM) and volumes of interest (VOI). SPM revealed two areas of increased cerebral FDG uptake after the expedition, one localized in the left cerebellum (+9.4%) and one in the white matter lateral of the left thalamus (+8.3%). The VOI analysis revealed increased postexpeditional metabolism in an area of the right cerebellum (+11%) and of the thalamus bilaterally (+3.7% on the left, +4.6% on the right). FDG-PET alterations did not correlate with changes in SaO2, HVR, or AMS scores. All neuropsychological test results during the climb were unremarkable. We conclude that a prolonged stay at an extreme altitude leads to regional specific changes in the cerebral glucose metabolism without any signs of neuropsychological impairment during the climb.

Saccadic eye movement performance as an indicator of driving ability in elderly drivers.

OBJECTIVE: Regular checking of the fitness to drive of elderly car-license holders is required in some countries, and this will become increasingly important as more countries face aging populations. The present study investigated whether the analysis of saccadic eye movements could be used as a screening method for the assessment of driving ability. METHODS: Three different paradigms (prosaccades, antisaccades, and visuovisual interactive (VVI) saccades) were used to test saccadic eye movements in 144 participants split into four groups: elderly drivers who came to the attention of road authorities for suspected lack of fitness to drive, a group of elderly drivers who served as a comparison group, a group of neurology patients with established brain lesion diagnoses, and a young comparison group. The group of elderly drivers with suspected deficits in driving skills also underwent a medical examination and a practical on-road driving test. The results of the saccadic eye tests of the different groups were compared. RESULTS: Antisaccade results indicated a strong link to driving behaviour: elderly drivers who were not fit to drive exhibited a poor performance on the antisaccade task and the performance in the VVI task was also clearly poorer in this group. CONCLUSIONS: Testing saccadic eye movements appears to be a promising and efficient method for screening large numbers of people such as elderly drivers. This study indicated a link between antisaccade performance and the ability to drive. Hence, measuring saccadic eye movements should be considered as a tool for screening the fitness to drive.

Serial EEG findings in sporadic and iatrogenic Creutzfeldt-Jakob disease.

OBJECTIVE: To study temporal and spatial development of EEG patterns in sporadic and iatrogenic Creutzfeldt-Jakob disease patients. METHODS: Temporal and spatial development of EEG patterns in 4 patients with sporadic Creutzfeldt-Jakob disease and 2 patients with iatrogenic Creutzfeldt-Jakob disease due to implantation of contaminated brain depth electrodes were investigated. A total of 56 EEGs were analyzed, over time spans ranging from 1272 to 3 days prior to death. RESULTS: Frontal intermittent rhythmical delta activity (FIRDA) was seen at early timepoints in 4/6 patients and might represent an early EEG pattern that is associated, with human prion diseases. EEG patterns associated with CJD are sensitive to midazolam. Initial EEG changes were seen at the site of prion exposure in iatrogenic Creutzfeldt-Jakob disease patients, before they could be observed at distant sites, suggesting that prion disease was initiated at the site of prion exposure. CONCLUSIONS: Serial EEG recordings are a valuable tool not only in the early diagnosis of sporadic CJD, but also in the determination of prion exposure in iatrogenic Creutzfeldt-Jakob disease. SIGNIFICANCE: FIRDA occur at an early stage of CJD and are progressively replaced by the classical PSWC. The EEG patterns of CJD are sensitive to midazolam. The initial EEG changes in iatrogenic CJD are seen at the site of prion exposure.

Neuroophthalmology: a brief Vademecum.

The stunning, intricate interaction between the visual, vestibular and optomotor systems--each a miracle on its own--ensures maintenance of orientation in space as well as visual recognition and target selection despite a host of sensory conflicts and adversary disturbances. Their main goals are to keep a target of interest on the fovea by either maintaining or shifting the direction of gaze in order to produce an accurate internal representation of the visual surroundings, in particular the selected target, and to continuously mirror the spatial relationship between these various visual elements and the self. Not surprising, the implementation of this host of elaborate neural networks encompasses almost every part of the brain, including the brainstem, cerebellum, extrapyramidal system and many areas of the cerebral cortex. Thus far, these systems are among the best investigated in brain research; and enormous knowledge was amassed over the last century employing a variety of techniques, including single cell recordings, eye movement studies, functional imaging and neuropsychological observations. In addition, this prolific line of research has enlightened many fundamental principles of neural and neuronal processing, which have subsequently enriched other fields of brain research as well as computational neuroscience, e.g. the discovery of receptive fields, which have now become a ubiquitous concept in many other areas of neurophysiology. This (improperly) brief, fractional and undoubtedly biased Vademecum is meant to accompany the reader into this marvellous field of neurophysiology and neurology. In particular, it stresses the clinical application of its functional neuroanatomy at the bedside, which, in many respects, is superior to other means of investigating a patient.

Amyotrophic lateral sclerosis after embolization of cerebral arterioveneous malformations.

Cerebral arterioveneous malformations (AVM) can cause neurological symptoms and carry a risk of hemorrhage. Therapeutic options to cure or reduce AVM include surgery, embolization, irradiation, and combinations thereof. Prompted by three index cases treated in our center, we studied whether AVM embolization is associated with an increased risk of subsequent amyotrophic lateral sclerosis (ALS). In a monocenter series, we retrospectively analyzed the new development of ALS in patients who had been treated with embolization of cerebral AVM from 1986 to 2010 (n = 1,114). After a median follow-up of 11 years (range, 0-25 years) after first embolization, seven patients developed ALS with a median latency of 14 years (range, 12-17 years) and a median age of ALS onset of 38 years (range, 28-52 years). In all cases, the initial limb of ALS symptom onset was ipsilateral to the AVM. Five patients died within the follow-up period, with a range of 1-4 years after the onset of ALS symptoms. The seven patients belonged to a subgroup of 34 patients who had in common a rare AVM architecture characterized by significant perinidal angiogenesis. All cases were partially treated by at least three embolization sessions. As there is no known association between AVM and ALS, AVM embolization must be taken into account to have contributed to the development of ALS in the seven patients with this rare AVM architecture. Searching for underlying mechanisms, we compared frozen serum samples that were available from four of the patients who developed ALS, from eight patients with AVM of other architecture, and less than three embolizations who did not develop ALS, and of 20 controls. The concentration of vascular endothelial growth factor (VEGF) in the serum was lowest in AVM patients who developed ALS (245 ± 154 pmol/l) and highest in controls (409 ± 178 pmol/l). Although this difference was not statistically significant in the small sample, it suggests that low VEGF production by AVM with significant angiogenesis, possibly due to multiple embolization procedures, might have contributed to ALS development. ALS should be considered as a late complication of multiple embolizations of cerebral AVM characterized by significant perinidal angiogenesis.

Complete graft dehiscence 8 months after repair of acute type A aortic dissection.

Acute type A aortic dissection is a dreaded differential diagnosis of acute chest pain. Long-term outcome mainly depends on pre-existing comorbidities and post-operative complications. We present a patient with aortic graft dehiscence and subsequent severe aortic regurgitation due to fungal graft infection 8 months after repair of acute type A aortic dissection. Redo aortic surgery had to be delayed for 28 days due to intracerebral haemorrhage caused by septic embolism and clipping of a mycotic left middle cerebral artery aneurysm. Surgery revealed a circumferentially detached graft at the site of the proximal anastomosis thereby forming a massive pseudoaneurysm. The patient underwent successful aortic root replacement using a Freestyle porcine root bioprosthesis (25 mm), followed by re-anastomosis of the coronary arteries and partial replacement of the ascending aorta with a 28 mm Dacron graft. The patient was discharged on day 67 in stable cardiac condition with persistent neurological deficits. This case highlights the challenging management of patients with aortic graft infection and neurological dysfunction after redissection of the ascending aorta who require redo cardiac surgery.