Timing for fever-related brain damage in acute ischemic stroke

Update in the management of acute ischemic stroke

Acute ischemic stroke is the fourth leading cause of death and the leading cause of disability in the United States. Stroke is a medical emergency. The development of stroke systems of care has changed the way practitioners view and treat this devastating disease. Ample evidence has shown that patients presenting early and receiving intravenous thrombolytic therapy have the best chance for significant improvement in functional outcome, particularly if they are transported to specialized stroke centers. Early detection and management of medical and neurologic complications is key at preventing further brain damage in patients with acute ischemic stroke.

Hypothermia protects human neurons

BACKGROUND AND AIMS

Hypothermia provides neuroprotection after cardiac arrest, hypoxic-ischemic encephalopathy, and in animal models of ischemic stroke. However, as drug development for stroke has been beset by translational failure, we sought additional evidence that hypothermia protects human neurons against ischemic injury.

METHODS

Human embryonic stem cells were cultured and differentiated to provide a source of neurons expressing β III tubulin, microtubule-associated protein 2, and the Neuronal Nuclei antigen. Oxygen deprivation, oxygen-glucose deprivation, and H2 O2 -induced oxidative stress were used to induce relevant injury.

RESULTS

Hypothermia to 33°C protected these human neurons against H2 O2 -induced oxidative stress reducing lactate dehydrogenase release and Terminal deoxynucleotidyl transferase dUTP nick end labeling-staining by 53% (P ≤ 0·0001; 95% confidence interval 34·8-71·04) and 42% (P ≤ 0·0001; 95% confidence interval 27·5-56·6), respectively, after 24 h in culture. Hypothermia provided similar protection against oxygen-glucose deprivation (42%, P ≤ 0·001, 95% confidence interval 18·3-71·3 and 26%, P ≤ 0·001; 95% confidence interval 12·4-52·2, respectively) but provided no protection against oxygen deprivation alone. Protection (21%) persisted against H2 O2 -induced oxidative stress even when hypothermia was initiated six-hours after onset of injury (P ≤ 0·05; 95% confidence interval 0·57-43·1).

CONCLUSION

We conclude that hypothermia protects stem cell-derived human neurons against insults relevant to stroke over a clinically relevant time frame. Protection against H2 O2 -induced injury and combined oxygen and glucose deprivation but not against oxygen deprivation alone suggests an interaction in which protection benefits from reduction in available glucose under some but not all circumstances.

Relationship between Chinese medicine pattern types, clinical severity, and prognosis in patients with acute cerebral infarct

We investigated the relationship between Chinese medicine pattern (CMP) types, their severity, and prognosis in patients (n = 187) with acute cerebral infarct (ACI). Six CMPs (wind, phlegm, fire-heat, blood stasis, qi deficiency, and yin deficiency and yang hyperactivity) were evaluated according to inspection, listening and smelling, inquiry, and palpitation. The severity and prognosis of each pattern type was determined according to the Glasgow Coma Scale (GCS), Modified Rankin Scale (MRS), National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), and Functional Independence Measure (FIM), recorded at stroke onset and 12 weeks after stroke onset. The phlegm pattern (PP) patients displayed lower GCS, BI, and FIM scales scores, and higher MRS and NIHSS scales scores, than the nonphlegm pattern (N-PP) patients at, and 12 weeks after stroke onset, suggesting the clinical severity is greater and the prognosis is worse in PP patients with ACI than in non-PP patients with ACI.

Is higher body temperature beneficial in ischemic stroke patients with normal admission CT angiography of the cerebral arteries?

Background

Low body temperature is considered beneficial in ischemic stroke due to neuroprotective mechanisms, yet some studies suggest that higher temperatures may improve clot lysis and outcomes in stroke patients treated with tissue plasminogen activator (tPA). The effect of increased body temperature in stroke patients treated with tPA and with normal computed tomography angiography (CTA) on admission is unknown. We hypothesized a beneficial effect of higher body temperature in the absence of visible clots on CTA, possibly due to enhanced lysis of small, peripheral clots.

Methods

Patients with ischemic stroke admitted to our Stroke Unit between February 2006 and April 2013 were prospectively registered in a database (Bergen NORSTROKE Registry). Ischemic stroke patients treated with tPA with normal CTA of the cerebral arteries were included. Outcomes were assessed by the modified Rankin Scale (mRS) after 1 week. An excellent outcome was defined as mRS=0, and a favorable outcome as mRS=0–1.

Results

A total of 172 patients were included, of which 48 (27.9%) had an admission body temperature ≥37.0°C, and 124 (72.1%) had a body temperature <37.0°C. Body temperature ≥37.0°C was independently associated with excellent outcomes (odds ratio [OR]: 2.8; 95% confidence interval [CI]: 1.24–6.46; P=0.014) and favorable outcomes (OR: 2.8; 95% CI: 1.13–4.98; P=0.015) when adjusted for confounders.

Conclusion

We found an association between higher admission body temperature and improved outcome in tPA-treated stroke patients with normal admission CTA of the cerebral arteries. This may suggest a beneficial effect of higher body temperature on clot lysis in the absence of visible clots on CTA.

Ellagic acid-induced thrombotic focal cerebral ischemic model in rats

INTRODUCTION

Ischemic stroke is a common cause of human disability and death. Animal models of focal cerebral ischemia are widely utilized to mimic human ischemic stroke. Although models of focal cerebral ischemia have been well established, very few evidence is based on triggering the intrinsic coagulation system to induce focal cerebral ischemia. Ellagic acid (EA) has been identified to trigger the intrinsic coagulation system via activating coagulation factor XII. However, it remains unknown whether EA can serve as a novel pharmacological approach to induce a new model of focal cerebral ischemia in rats.

METHODS

EA was used for inducing focal cerebral ischemia in adult rats. The dose- and time-dependent effects of EA were characterized. The cerebral infarction ratio was determined with triphenyltetrazolium chloride staining, and the histopathological analysis of the brain tissue was performed under light microscopy. The neurological deficit score was evaluated by a modified method of Bederson. Malondialdehyde (MDA) level and lactate dehydrogenase (LDH) and superoxide dismutase (SOD) activities in serum were determined by spectrophotometry.

RESULTS

Injection of EA into the middle cerebral artery of rats was able to generate focal cerebral infarction and increased the neurological deficit score and the brain weight to body weight ratio in dose- and time-dependent manners. Furthermore, EA raised serum LDH activity and MDA level and decreased serum SOD activity in a dose-related fashion.

DISCUSSION

This is the first evidence to show that EA induces focal cerebral ischemia in rats, which is similar to human ischemia stroke in pathogenesis. This model holds promise for pathological, pharmacological and clinical studies of ischemic stroke.

Treatment of arterial ischemic stroke in children

Stroke is a rare but increasingly recognized disorder in children. Current therapies for arterial ischemic stroke include thrombolytic, antithrombotic and antiplatelet agents, blood transfusion and surgery. Adult studies, pediatric case studies and expert opinion form the basis for these treatment strategies. Thrombolytic agents are increasingly used but, as in adults, the majority of arterial ischemic strokes in children are treated with antiplatelet and antithrombotic agents. Sickle-cell patients, a distinct subset of the pediatric stroke population, are treated primarily with transfusion therapy. Pediatric arterial ischemic stroke studies are needed to determine the most appropriate course of treatment. An international study is currently in progress to formally study the incidence, risk factors, treatment strategies and outcomes of stroke in children.

Management of Fever, Hyperglycemia, and Swallowing Dysfunction following Hospital Admission for Acute Stroke in New South Wales, Australia

Background

Fever, hyperglycemia, and swallow dysfunction poststroke are associated with significantly worse outcomes. We report treatment and monitoring practices for these three items from a cohort of acute stroke patients prior to randomization in the Quality in Acute Stroke Care trial.

Method

Retrospective medical record audits were undertaken for prospective patients from 19 stroke units. For the first three-days following stroke, we recorded all temperature readings and administration of paracetamol for fever (≥37.5°C) and all glucose readings and administration of insulin for hyperglycemia (>11 mmol/L). We also recorded swallow screening and assessment during the first 24 h of admission.

Results

Data for 718 (98%) patients were available; 138 (19%) had four hourly or more temperature readings and 204 patients (29%) had a fever, with 44 (22%) receiving paracetamol. A quarter of patients ( n = 102/412, 25%) had six hourly or more glucose readings and 23% (95/412) had hyperglycemia, with 31% (29/95) of these treated with insulin. The majority of patients received a swallow assessment ( n = 562, 78%) by a speech pathologist in the first instance rather than a swallow screen by a nonspeech pathologist ( n = 156, 22%). Of those who passed a screen ( n = 108 of 156, 69%), 68% ( n = 73) were reassessed by a speech pathologist and 97% ( n = 71) were reconfirmed to be able to swallow safely.

Conclusions

Our results showed that acute stroke patients were: undermonitored and undertreated for fever and hyperglycemia; and underscreened for swallowing dysfunction and unnecessarily reassessed by a speech pathologist, indicating the need for urgent behavior change.

Brain Injury as a Risk Factor for Fever Upon Admission to the Intensive Care Unit and Association With In-Hospital Case Fatality

Purpose:

To test the hypothesis that fever was more frequent in critically ill patients with brain injury when compared to nonneurological patients and to study its effect on in-hospital case fatality.

Methods:

Retrospective matched cohort study utilizing a single-center prospectively compiled registry. Critically ill neurological patients ≥18 years and consecutively admitted to the intensive care unit (ICU) with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), and traumatic brain injury (TBI) were selected. Patients were matched by sex, age, and Acute Physiology and Chronic Health Evaluation II (APACHE-II) to a cohort of nonneurological patients. Fever was defined as any temperature ≥37.5°C within the first 24 hours upon admission to the ICU. The primary outcome measure was in-hospital case fatality.

Results:

Mean age among neurological patients was 65.6 ± 15 years, 46% were men, and median APACHE-II was 15 (interquartile range 11-20). There were 18% AIS, 27% ICH, and 6% TBI. More neurological patients experienced fever than nonneurological patients (59% vs 47%, P = .007). The mean hospital length of stay was higher for nonneurological patients (18 ± 20 vs 14 ± 15 days, P = .007), and more neurological patients were dead at hospital discharge (29% vs 20%, P < .0001). After risk factor adjustment, diagnosis (neurological vs nonneurological), and the probability of being exposed to fever (propensity score), the following variables were associated with higher in-hospital case fatality: APACHE-II, neurological diagnosis, mean arterial pressure, cardiovascular and respiratory dysfunction in ICU, and fever (odds ratio 1.9, 95% confidence interval 1.04-3.6, P = .04).

Conclusion:

These data suggest that fever is a frequent occurrence after brain injury, and that it is independently associated with in-hospital case fatality.

Relationships between brain and body temperature, clinical and imaging outcomes after ischemic stroke

Pyrexia soon after stroke is associated with severe stroke and poor functional outcome. Few studies have assessed brain temperature after stroke in patients, so little is known of its associations with body temperature, stroke severity, or outcome. We measured temperatures in ischemic and normal-appearing brain using (1)H-magnetic resonance spectroscopy and its correlations with body (tympanic) temperature measured four-hourly, infarct growth by 5 days, early neurologic (National Institute of Health Stroke Scale, NIHSS) and late functional outcome (death or dependency). Among 40 patients (mean age 73 years, median NIHSS 7, imaged at median 17 hours), temperature in ischemic brain was higher than in normal-appearing brain on admission (38.6°C-core, 37.9°C-contralateral hemisphere, P=0.03) but both were equally elevated by 5 days; both were higher than tympanic temperature. Ischemic lesion temperature was not associated with NIHSS or 3-month functional outcome; in contrast, higher contralateral normal-appearing brain temperature was associated with worse NIHSS, infarct expansion and poor functional outcome, similar to associations for tympanic temperature. We conclude that brain temperature is higher than body temperature; that elevated temperature in ischemic brain reflects a local tissue response to ischemia, whereas pyrexia reflects the systemic response to stroke, occurs later, and is associated with adverse outcomes.

Persistent middle cerebral artery occlusion associated with lower body temperature on admission

BACKGROUND

Low body temperature is considered neuroprotective in ischemic stroke, yet some studies suggest that low body temperature may also inhibit clot lysis and recanalization. We hypothesized that low body temperature was associated with persistent proximal middle cerebral artery (MCA) occlusion in patients with acute ischemic stroke presenting with symptoms of proximal MCA occlusion, suggesting a possible detrimental effect of low body temperature on recanalization.

METHODS

All patients with acute ischemic stroke admitted to our Stroke Unit between February 2006 and August 2012 were prospectively registered in a database. Computed tomography (CT) angiography was performed in patients admitted <6 hours after stroke onset. Based on presenting symptoms, patients were classified according to the Oxford Community Stroke Project classification (OCSP). Patients with symptomatic proximal MCA occlusion were compared to patients with total anterior circulation infarct (TACI) without MCA occlusion on CT angiography.

RESULTS

During the study period, 384 patients with acute ischemic stroke were examined with CT angiography. A total of 79 patients had proximal MCA occlusion and 31 patients had TACI without MCA occlusion. Median admission body temperatures were lower in patients with MCA occlusion compared to patients without occlusion (36.3°C versus 36.7°C, P = 0.027). Admission body temperature <36.5°C was independently associated with persistent MCA occlusion when adjusted for confounders in multivariate analyses (odds ratio 3.7, P = 0.007).

CONCLUSION

Our study showed that low body temperature on admission was associated with persistent proximal MCA occlusion. These results may support a possible detrimental effect of low body temperature on clot lysis and recanalization.

Continuous versus intermittent physiological monitoring for acute stroke

BACKGROUND

Explanations for the effectiveness of stroke units compared with general wards in reducing mortality, institutionalisation and dependence of people with stroke remain undetermined, and the discussion on the most effective stroke unit model is still up for debate. The intensity of non-invasive mechanical monitoring in many western countries is one of the main issues regarding the different models. This is because of its strong impact on the organisation of the stroke unit in terms of the number of personnel, their expertise, the infrastructure and costs.

OBJECTIVES

To assess whether continuous intensive monitoring compared with intermittent monitoring of physiological variables in people with acute stroke can change their prognosis in terms of mortality or disability.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (November 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 8), MEDLINE (1966 to November 2012), EMBASE (1980 to November 2012), CINAHL (1982 to November 2012) and the British Nursing Index (1985 to November 2012). In an effort to identify further published, unpublished and ongoing trials we searched trials registers (November 2012) and reference lists, handsearched conference proceedings and contacted trial authors.

SELECTION CRITERIA

We included all randomised, cluster randomised and quasi-randomised controlled trials comparing continuous monitoring with intermittent monitoring in people within three days of stroke onset. We excluded studies confounded by the delivery of care in different settings (that is studies in which the location of the intervention was not in the same ward in the two arms of the trial).

DATA COLLECTION AND ANALYSIS

Three review authors independently selected studies for inclusion, assessed methodological quality and extracted data. We sought original data from trialists in two trials and verified the inclusion criteria in another four trials (three presented at conferences and one was from the Chinese Clinical Trial Registry). Where possible, we extracted data on the threshold level of abnormality that triggered intervention for a given physiological variable, the specific intervention given to correct the abnormality and compliance with the allocated therapy.

MAIN RESULTS

Three studies, involving a total of 354 participants, met our inclusion criteria for the primary outcome. Compared with intermittent monitoring, continuous monitoring significantly reduced death and disability at three months or discharge (odds ratio (OR) 0.27, 95% confidence interval (CI) 0.13 to 0.56) and was associated with a non-significant reduction in deaths from any cause at discharge (OR 0.72, 95% CI 0.28 to 1.85). These significant results depend on one study that has a high risk of bias.Continuous monitoring was associated with a non-significant reduction of dependency (OR 0.79, 95% CI 0.30 to 2.06), death from vascular causes (OR 0.48, 95% CI 0.10 to 2.39), neurological complications (OR 0.81, 95% CI 0.46 to 1.43), length of stay (mean difference (MD) -5.24, 95% CI -10.51 to 0.03) and institutionalisation (OR 0.83, 95% CI 0.04 to 15.72) (secondary outcomes). For the last two outcomes we detected consistent heterogeneity across trials.Cardiac complications (OR 8.65, 95% CI 2.52 to 29.66), fever (OR 2.17, 95% CI 1.22 to 3.84) and hypotension (OR 4.32, 95% CI 1.68 to 14.38) were detected significantly more often in participants who received continuous monitoring (surrogate outcomes).We detected no significant increase in adverse events due to immobility (pneumonia, other infections or deep vein thrombosis) in participants who were continuously monitored compared with those allocated to intermittent monitoring.

AUTHORS' CONCLUSIONS

Continuous monitoring of physiological variables for the first two to three days may improve outcomes and prevent complications. Attention to the changes in physiological variables is a key feature of a stroke unit, and can most likely be aided by continuous monitoring without complications related to immobility or to treatments triggered by the relief of abnormal physiological variables. Well-designed, high-quality studies are needed because many questions remain open and deserve further research. These include when to start continuous monitoring, when to interrupt it, which people should be given priority, and which treatments are most appropriate after the identification of abnormalities in physiological variables.

Body Temperature, Blood Infection Parameters, and Outcome of Thrombolysis-Treated Ischemic Stroke Patients

Background and Aims

Body temperature, inflammation, and infections may modify response to thrombolytic therapy. We studied their associations with clinical improvement after intravenous thrombolysis and three-month outcome.

Methods

We included 985 consecutive acute ischemic stroke patients treated with intravenous thrombolysis at the Helsinki University Central Hospital during 1995–2008. Body temperature, blood leukocyte count, and C-reactive protein levels were analyzed on arrival and at day one. Clinical improvement was defined as National Institutes of Health Stroke Scale score decrease of ≥4 points or a score of 0 at 24 h. Functional outcome was assessed at three-months with the modified Rankin Scale dichotomized at 0–2 (good) vs. 3–6 (poor). Associations were tested with multivariable logistic regression analysis.

Results

Of the baseline variables, lower C-reactive protein independently predicted clinical improvement at 24 h (odds ratio 0·94 per 5 mg/L; 95% confidence interval 0·89–1·00; P = 0·03), whereas higher leukocyte count (odds ratio 1·10 per E9/L; 1·03–1·17; P < 0·01) and C-reactive protein (odds ratio 1·07 per 5 mg/L; 1·01–1·14; P = 0·02) were associated with poor three-month outcome. When body temperature increased over the first 24 h, clinical improvement after thrombolysis was unlikely (odds ratio 0·66 per °C; 0·45–0·95; P = 0·03) and poor outcome more common (odds ratio 1·63 per °C; 1·24–2·14; P < 0·001). Elevated leukocytes at baseline increased the risk of symptomatic intracerebral hemorrhage (odds ratio 1·07 per E9/L; 1·00–1·13; P= 0·04).

Conclusion

A lower level of systemic inflammation at time of thrombolysis may be associated with clinical improvement and good outcome at three-months. Increase in body temperature during the first 24 h associates with lack of clinical improvement and worse patient outcome.

Effectively managing intractable central hyperthermia in a stroke patient by bromocriptine: a case report

Central hyperthermia is characterized by a rapid onset, high temperature, marked temperature fluctuation, and poor response to antipyretics and antibiotics. Although poststroke central hyperthermia is common, prolonged instances are rare. We report a case of prolonged central fever after an intracranial hemorrhage. Before the accurate diagnosis and management of central fever, the patient underwent long-term antibiotic use that led to pseudomembranous colitis. Bromocriptine was used to treat the prolonged central hyperthermia, after which the fever did not exceed 39°C. A week later, the body temperature baseline was reduced to 37°C and a low-grade fever with minor temperature fluctuation occurred only a few times. No fever occurred in the month following the treatment. After the fever subsided, the patient could undergo an aggressive rehabilitation program.

Clinical-radiological severity mismatch phenomenon: patients with severe neurological deficits without matching infarction on computed tomographic scan

OBJECTIVE

The objective was to determine the long-term outcome of patients with severe persistent neurological deficits without a large infarction on computed tomographic (CT) scan.

METHODS

We analyzed the prospectively collected data as part of the randomized, placebo controlled trial in patients with ischemic stroke presenting within 3 hours of symptom onset. Volume of infarction was measured from CT scan acquired at 3 months. Favorable outcome defined by no significant or slight disability on a modified Rankin scale at 12 months. We determined the outcome of patients with National Institutes of Health Stroke Scale score (NIHSS score) ≥ 10 at 24 hours.

RESULTS

Of the 277 patients with NIHSS score ≥ 10 at 24 hours, 88 (32%) met the criteria of clinical-radiological severity mismatch. Compared with patients with NIHSS score ≥ 10 with infarct volume ≥ 20 cc, the patients with NIHSS score ≥ 10 and infarct volume <20 cc were older but there were no differences in the gender, race or vascular risk factors. Patients with clinical-radiological severity mismatch were more likely to have a favorable outcome at 12 months compared with those without mismatch (odd ratio 4.3, 95% confidence interval 1.5-12.6, P = .0063) after adjusting for potential confounders.

CONCLUSIONS

We observed that approximately one-fourth of patients with severe neurological deficits have clinical-radiological severity mismatch. Such patients appear to have a high rate of favorable outcomes at 1 year.

A magnetic resonance (MR) compatible selective brain temperature manipulation system for preclinical study

There is overwhelming evidence that hypothermia can improve the outcome of an ischemic stroke. However, the most widely used systemic cooling method could lead to multiple side effects, while the incompatibility with magnetic resonance imaging of the present selective cooling methods highly limit their application in preclinical studies. In this study, we developed a magnetic resonance compatible selective brain temperature manipulation system for small animals, which can regulate brain temperature quickly and accurately for a desired period of time, while maintaining the normal body physiological conditions. This device was utilized to examine the relationship between T1 relaxation, cerebral blood flow, and temperature in brain tissue during magnetic resonance imaging of ischemic stroke. The results showed that this device can be an efficient brain temperature manipulation tool for preclinical studies needing local hypothermic or hyperthermic conditions.

Temporal profile of body temperature in acute ischemic stroke: relation to stroke severity and outcome

Background

Pyrexia after stroke (temperature ≥37.5°C) is associated with poor prognosis, but information on timing of body temperature changes and relationship to stroke severity and subtypes varies.

Methods

We recruited patients with acute ischemic stroke, measured stroke severity, stroke subtype and recorded four-hourly tympanic (body) temperature readings from admission to 120 hours after stroke. We sought causes of pyrexia and measured functional outcome at 90 days. We systematically summarised all relevant previous studies.

Results

Amongst 44 patients (21 males, mean age 72 years SD 11) with median National Institute of Health Stroke Score (NIHSS) 7 (range 0–28), 14 had total anterior circulation strokes (TACS). On admission all patients, both TACS and non-TACS, were normothermic (median 36.3°C vs 36.5°C, p=0.382 respectively) at median 4 hours (interquartile range, IQR, 2–8) after stroke; admission temperature and NIHSS were not associated (r²=0.0, p=0.353). Peak temperature, occurring at 35.5 (IQR 19.0 to 53.8) hours after stroke, was higher in TACS (37.7°C) than non-TACS (37.1°C, p<0.001) and was associated with admission NIHSS (r²=0.20, p=0.002). Poor outcome (modified Rankin Scale ≥3) at 90 days was associated with higher admission (36.6°C vs. 36.2°C p=0.031) and peak (37.4°C vs. 37.0°C, p=0.016) temperatures. Sixteen (36%) patients became pyrexial, in seven (44%) of whom we found no cause other than the stroke.

Conclusions

Normothermia is usual within the first 4 hours of stroke. Peak temperature occurs at 1.5 to 2 days after stroke, and is related to stroke severity/subtype and more closely associated with poor outcome than admission temperature. Temperature-outcome associations after stroke are complex, but normothermia on admission should not preclude randomisation of patients into trials of therapeutic hypothermia.

Differential temporal evolution patterns in brain temperature in different ischemic tissues in a monkey model of middle cerebral artery occlusion

Brain temperature is elevated in acute ischemic stroke, especially in the ischemic penumbra (IP). We attempted to investigate the dynamic evolution of brain temperature in different ischemic regions in a monkey model of middle cerebral artery occlusion. The brain temperature of different ischemic regions was measured with proton magnetic resonance spectroscopy (¹H MRS), and the evolution processes of brain temperature were compared among different ischemic regions. We found that the normal (baseline) brain temperature of the monkey brain was 37.16°C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16°C higher than the baseline; however, this increase was region dependent, with 1.72°C in the IP, 1.08°C in the infarct core, and 0.62°C in the oligemic region. After recanalization, the brain temperature of the infarct core showed a pattern of an initial decrease accompanied by a subsequent increase. However, the brain temperature of the IP and oligemic region showed a monotonously and slowly decreased pattern. Our study suggests that in vivo measurement of brain temperature could help to identify whether ischemic tissue survives.

Thoracoscopic correction and placement of anterior instrumentation for scoliotic deformity. Case report

Correction of rigid scoliotic deformities involving the thoracic spine has required that a thoracotomy be performed to obtain anterior release to mobilize the deformity, as well as placement of corrective spinal instrumentation either via a separate posterior or anterior thoracic approach. To the best of the author's knowledge, this is the first published report of a case in which anterior correction of a deformity was achieved endoscopically. A 27-year-old man presented with a rigid 85 degrees thoracic kyphoscoliotic deformity that had developed over several years. He had previously undergone a C7-T12 laminectomy to decompress the spinal cord from a lipoma. Using thoracoscopic techniques, the author performed an anterior release and interbody fusion. Endoscopically, an anterior screw/rod system applied from T-5 to T-9 corrected the deformity to 55 degrees . There were no surgery-related complications. At follow-up examiniation 1.5 years after surgery, the patient had developed a solid fusion and the correction was maintained at an angle of 58 degrees . It is feasible to use thoracoscopic techniques to perform an anterior release and to apply anterior corrective spinal instrumentation to treat thoracic scoliotic deformities, thereby avoiding the need for an open posterior approach in which instrumentation is placed.

Non-infectious hyperthermia in acute brain injury patients: relationships to mortality, blood pressure, intracranial pressure and cerebral perfusion pressure

The present study was conducted to investigate the frequency of hyperthermia during the first 72 h after acute brain injury, and to compare subjects that developed hyperthermia with those that did not with respect to blood pressure, intracranial pressure (ICP), cerebral perfusion pressure (CPP), Glasgow Coma Scale (GCS) score and mortality. This study was conducted by performing a retrospective medical record review of 126 brain injury patients admitted to the neurological intensive care unit of a university hospital located in Incheon, South Korea. Our results showed that 25.4% of the subjects had hyperthermia for at least 1 day during the first 3 days of hospitalization. Hyperthermic subjects demonstrated higher mortality and ICP, and lower CPP and GCS scores than non-hyperthermic subjects, indicating a reduced cerebral blood flow. The findings may provide a possible explanation for poor clinical outcome and offer justification for the careful monitoring of body temperature in patients with acute brain injury.

Critical care management of acute ischemic stroke

PURPOSE OF REVIEW

Acute ischemic stroke (AIS) can have profound and devastating effects on the CNS and several other organs. Approximately 15% to 20% of patients with AIS are admitted to an intensive care unit and cared for by a multidisciplinary team. This article discusses the critical care management of patients with AIS.

RECENT FINDINGS

Patients with AIS require attention to airway, pulmonary status, blood pressure, glucose, temperature, cardiac function, and, sometimes, life-threatening cerebral edema.

SUMMARY

The lack of disease-specific data has led to numerous management approaches and limited guidance on choosing among them. Existing guidelines emphasize risk factors, prevention, natural history, and prevention of bleeding but provide little discussion of the complex critical care issues involved in caring for patients with AIS.

Glutamate excitoxicity is the key molecular mechanism which is influenced by body temperature during the acute phase of brain stroke

Glutamate excitotoxicity, metabolic rate and inflammatory response have been associated to the deleterious effects of temperature during the acute phase of stroke. So far, the association of temperature with these mechanisms has been studied individually. However, the simultaneous study of the influence of temperature on these mechanisms is necessary to clarify their contributions to temperature-mediated ischemic damage. We used non-invasive Magnetic Resonance Spectroscopy to simultaneously measure temperature, glutamate excitotoxicity and metabolic rate in the brain in animal models of ischemia. The immune response to ischemia was measured through molecular serum markers in peripheral blood. We submitted groups of animals to different experimental conditions (hypothermia at 33°C, normothermia at 37°C and hyperthermia at 39°C), and combined these conditions with pharmacological modulation of glutamate levels in the brain through systemic injections of glutamate and oxaloacetate. We show that pharmacological modulation of glutamate levels can neutralize the deleterious effects of hyperthermia and the beneficial effects of hypothermia, however the analysis of the inflammatory response and metabolic rate, demonstrated that their effects on ischemic damage are less critical than glutamate excitotoxity. We conclude that glutamate excitotoxicity is the key molecular mechanism which is influenced by body temperature during the acute phase of brain stroke.

Mitochondrial dysfunction induced by heat stress in cultured rat CNS neurons

Previous work demonstrated that hyperthermia (43°C for 2 h) results in delayed, apoptotic-like death in striatal neuronal cultures. We investigated early changes in mitochondrial function induced by this heat stress. Partial depolarization of the mitochondrial membrane potential (ΔΨ(m)) began about 1 h after the onset of hyperthermia and increased as the stress continued. When the heat stress ended, there was a partial recovery of ΔΨ(m), followed hours later by a progressive, irreversible depolarization of ΔΨ(m). During the heat stress, O(2) consumption initially increased but after 20-30 min began a progressive, irreversible decline to about one-half the initial rate by the end of the stress. The percentage of oligomycin-insensitive respiration increased during the heat stress, suggesting an increased mitochondrial leak conductance. Analysis using inhibitors and substrates for specific respiratory chain complexes indicated hyperthermia-induced dysfunction at or upstream of complex I. ATP levels remained near normal for ∼4 h after the heat stress. Mitochondrial movement along neurites was markedly slowed during and just after the heat stress. The early, persisting mitochondrial dysfunction described here likely contributes to the later (>10 h) caspase activation and neuronal death produced by this heat stress. Consistent with this idea, proton carrier-induced ΔΨ(m) depolarizations comparable in duration to those produced by the heat stress also reduced neuronal viability. Post-stress ΔΨ(m) depolarization and/or delayed neuronal death were modestly reduced/postponed by nicotinamide adenine dinucleotide, a calpain inhibitor, and increased expression of Bcl-xL.

Low body temperature associated with severe ischemic stroke within 6 hours of onset: The Bergen NORSTROKE Study

Background

Hypothermia is considered neuroprotective and a potential treatment in cerebral ischemia. Some studies suggest that hyperthermia may promote clot lysis. We hypothesized that low body temperature would prolong time to spontaneous clot lysis resulting in an association between low body temperature and severe neurological deficits in the early phase of ischemic stroke.

Methods

In this prospective study, patients (n = 516) exhibiting ischemic stroke with symptom onset within 6 hours were included. Body temperature and National Institute of Health Stroke Scale (NIHSS) score were registered on admission. Because low body temperature on admission may be secondary to immobilization due to large stroke, separate analyses were performed on patients with cerebral hemorrhage admitted within 6 hours (n = 85).

Results

Linear regression showed that low body temperature on admission was independently associated with a high NIHSS score within 6 hours of stroke onset in patients with ischemic stroke (P < 0.001). The association persisted when NIHSS was measured at 24 hours after admission. No such associations were found in patients with cerebral hemorrhage admitted within 6 hours of stroke onset.

Conclusion

Our study suggests that low body temperature within 6 hours of symptom onset is associated with severe ischemic stroke. This is in support of our hypothesis, although other contributing mechanisms cannot be excluded.

[Stroke care in the ICU: general supportive treatment. Experts' recommendations]

The French Society of Intensive Care (SRLF) requested medical experts to publish recommendations on the management of stroke in the ICU for adult and pediatric patients. The following article describes the underlying evidence used by the experts to elaborate recommendations for general supportive treatment. Such treatment is fundamental for victims of acute stroke to avoid neurological worsening. Oxygen delivery in a normoxic patient is useless. However, if saturation is below 92 %, oxygen supplementation is needed. Hyper- and hypoglycemia worsen the neurological prognosis. As no glycemic target is known, administration of insulin is required for glucose levels higher that 10 mmol/l. Body temperature above 37.5° is associated with poorer outcome. In the acute phase of stroke, high blood pressure should not be lowered except in life-threatening situations, and if so the lowering should be done cautiously. The current consensus is to lower blood pressure if the systolic pressure is above 220 mmHg or if the diastolic pressure is above 120 mmHg for ischemic stroke. For hemorrhagic stroke and after thrombolysis, treatment is needed if systolic pressure rises above 180 mmHg and if diastolic pressure is above 105 mmHg. Small doses of heparin decrease the risk of deep venous thrombosis and pulmonary embolism without increasing cerebral bleeding. There is no consensus on the treatment of epileptic crises after stroke and no dedicated treatment. Further studies are needed to define adequate blood pressure and glycemic target values in order to limit secondary worsening after an acute stroke as well as the appropriate modalities for the treatment of epilepsy.

Hyperthermia worsens ischaemic brain injury through destruction of microvessels in an embolic model in rats

PURPOSE

Basal lamina is a major part of the microvascular wall and plays a critical role in the integrity of microvasculature. The aim of this study is to determine whether hyperthermia worsens the destruction of microvascular integrity in the ischaemic injured brain.

MATERIALS AND METHODS

Focal cerebral ischaemia was induced by embolising a pre-formed clot into the middle cerebral artery (MCA). Rats received either normothermic or hyperthermic treatment. Neurological score and infarct size were evaluated at 24 h after the MCA occlusion. Microvascular collagen type IV and laminin were measured with fluorescence microscopy. The activities of matrix metalloproteinases (MMP-2 and MMP-9) and plasminogen activators (tPA and uPA) were determined by zymography.

RESULTS

Treatment with hyperthermia significantly increased infarct volume (p<0.01), cortex swelling (p<0.01), striatum swelling (p<0.05) and neurologic score (p<0.01) at 24 h after the MCA occlusion. Compared to the normothermic groups, hyperthermia significantly worsened the losses of microvascular basal lamina structure proteins, collagen type IV and laminin, at 6 h (p<0.001) and 24 h (p<0.01) after MCA occlusion. Hyperthermia increased the MMP-9 activity at 6 and 24 h after MCA occlusion compared with normothermia (p<0.05), whereas increased the MMP-2 activity at 6 h only (p<0.05). Hyperthermia also elevated uPA activity significantly at 6 and 24 h after MCA occlusion compared to normothermia (p<0.05).

CONCLUSIONS

These results demonstrate that hyperthermia exacerbates the destruction of microvascular integrity possibly by increasing the activities of MMP-2, MMP-9 and uPA in the ischaemic cerebral tissues.

Keep the brain cool--endovascular cooling in patients with severe traumatic brain injury: a case series study

BACKGROUND

As brain temperature is reported to be extensively higher than core body temperature in traumatic brain injury (TBI) patients, posttraumatic hyperthermia is of particular relevance in the injured brain.

OBJECTIVE

To study the influence of prophylactic normothermia on brain temperature and the temperature gradient between brain and core body in patients with severe TBI using an intravascular cooling system and to assess the relationship between brain temperature and intracranial pressure (ICP) under endovascular temperature control.

METHODS

Prospective case series study conducted in the neurologic intensive care unit of a tertiary care university hospital. Seven patients with severe TBI with a Glasgow Coma Scale score of 8 or less were consecutively enrolled. Prophylactic normothermia, defined as a target temperature of 36.5°C, was maintained using an intravascular cooling system. Simultaneous measurements of brain and urinary bladder temperature and ICP were taken over a 72-hour period.

RESULTS

The mean bladder temperature in normothermic patients was 36.3 ± 0.4°C, and the mean brain temperature was determined as 36.4 ± 0.5°C. The mean temperature difference between brain and bladder was 0.1°C. We found a significant direct correlation between brain and bladder temperature (r = 0.95). In 52.4% of all measurements, brain temperature was higher than core body temperature. The mean ICP was 18 ± 8 mm Hg.

CONCLUSION

Intravascular temperature management stabilizes both brain and body core temperature; prophylactic normothermia reduces the otherwise extreme increase of intracerebral temperature in patients with severe TBI. The intravascular cooling management proved to be an efficacious and feasible method to control brain temperature and to avoid hyperthermia in the injured brain. We could not find a statistically significant correlation between brain temperature and ICP.

Treatment of fever after stroke: conflicting evidence

Approximately 50% of patients hospitalized for stroke develop fever. In fact, experimental evidence suggests that high body temperature is significantly correlated to initial stroke severity, lesion size, mortality, and neurologic outcome. Fever occurring after stroke is associated with poor outcomes. We investigated the etiology of fever after stroke and present evidence evaluating the efficacy and safety of interventions used to treat stroke-associated fever. Oral antipyretics are only marginally effective in lowering elevated body temperature in this population and may have unintended adverse consequences. Nonpharmacologic approaches to cooling have been more effective in achieving normothermia, but whether stroke outcomes can be improved remains unclear. We recommend using body temperature as a biomarker and a catalyst for aggressive investigation for an infectious etiology. Care must be taken not to exceed the new standard of a maximum acetaminophen dose of 3 g/day to avoid patient harm.

A higher body temperature is associated with haemorrhagic transformation in patients with acute stroke untreated with recombinant tissue-type plasminogen activator (rtPA)

Higher body temperature is a prognostic factor of poor outcome in acute stroke. Our aim was to study the relationship between body temperature, HT (haemorrhagic transformation) and biomarkers of BBB (blood-brain barrier) damage in patients with acute ischaemic stroke untreated with rtPA (recombinant tissue-type plasminogen activator). We studied 229 patients with ischaemic stroke <12 h from symptom onset. Body temperature was determined at admission and every 6 h during the first 3 days. HT was evaluated according to ECASS II (second European Co-operative Acute Stroke Study) criteria in a multimodal MRI (magnetic resonance imaging) at 72 h. We found that 55 patients (34.1%) showed HT. HT was associated with cardioembolic stroke (64.2% against 23.0%; P<0.0001), higher body temperature during the first 24 h (36.9°C compared with 36.5°C; P<0.0001), more severe stroke [NIHSS (National Institutes of Health Stroke Scale) score, 14 (9-20) against 10 (7-15); P=0.002], and greater DWI (diffusion-weighted imaging) lesion volume at admission (23.2 cc compared with 13.2 cc; P<0.0001). Plasma MMP-9 (matrix metalloproteinase 9) (187.3 ng/ml compared with 44.2 ng/ml; P<0.0001) and cFn (cellular fibronectin) levels (16.3 μg/ml compared with 7.1 μg/ml; P=0.001) were higher in patients with HT. Body temperature within the first 24 h was independently associated with HT {OR (odds ratio), 7.3 [95% CI (confidence interval), 2.4-22.6]; P<0.0001} after adjustment for cardioembolic stroke subtype, baseline NIHSS score and DWI lesion volume. This effect remained unchanged after controlling for MMP-9 and cFn. In conclusion, high body temperature within the first 24 h after ischaemic stroke is a risk factor for HT in patients untreated with rtPA. This effect is independent of some biological signatures of BBB damage.

Implementation of evidence-based treatment protocols to manage fever, hyperglycaemia, and swallowing dysfunction in acute stroke (QASC): a cluster randomised controlled trial

BACKGROUND

We assessed patient outcomes 90 days after hospital admission for stroke following a multidisciplinary intervention targeting evidence-based management of fever, hyperglycaemia, and swallowing dysfunction in acute stroke units (ASUs).

METHODS

In the Quality in Acute Stroke Care (QASC) study, a single-blind cluster randomised controlled trial, we randomised ASUs (clusters) in New South Wales, Australia, with immediate access to CT and on-site high dependency units, to intervention or control group. Patients were eligible if they spoke English, were aged 18 years or older, had had an ischaemic stroke or intracerebral haemorrhage, and presented within 48 h of onset of symptoms. Intervention ASUs received treatment protocols to manage fever, hyperglycaemia, and swallowing dysfunction with multidisciplinary team building workshops to address implementation barriers. Control ASUs received only an abridged version of existing guidelines. We recruited pre-intervention and post-intervention patient cohorts to compare 90-day death or dependency (modified Rankin scale [mRS] ≥2), functional dependency (Barthel index), and SF-36 physical and mental component summary scores. Research assistants, the statistician, and patients were masked to trial groups. All analyses were done by intention to treat. This trial is registered at the Australia New Zealand Clinical Trial Registry (ANZCTR), number ACTRN12608000563369.

FINDINGS

19 ASUs were randomly assigned to intervention (n=10) or control (n=9). Of 6564 assessed for eligibility, 1696 patients' data were obtained (687 pre-intervention; 1009 post-intervention). Results showed that, irrespective of stroke severity, intervention ASU patients were significantly less likely to be dead or dependent (mRS ≥2) at 90 days than control ASU patients (236 [42%] of 558 patients in the intervention group vs 259 [58%] of 449 in the control group, p=0·002; number needed to treat 6·4; adjusted absolute difference 15·7% [95% CI 5·8-25·4]). They also had a better SF-36 mean physical component summary score (45·6 [SD 10·2] in the intervention group vs 42·5 [10·5] in the control group, p=0·002; adjusted absolute difference 3·4 [95% CI 1·2-5·5]) but no improvement was recorded in mortality (21 [4%] of 558 in intervention group and 24 [5%] of 451 in the control group, p=0·36), SF-36 mean mental component summary score (49·5 [10·9] in the intervention group vs 49·4 [10·6] in the control group, p=0·69) or functional dependency (Barthel Index ≥60: 487 [92%] of 532 patients vs 380 [90%] of 423 patients; p=0·44).

INTERPRETATION

Implementation of multidisciplinary supported evidence-based protocols initiated by nurses for the management of fever, hyperglycaemia, and swallowing dysfunction delivers better patient outcomes after discharge from stroke units. Our findings show the possibility to augment stroke unit care.

FUNDING

National Health & Medical Research Council ID 353803, St Vincent's Clinic Foundation, the Curran Foundation, Australian Diabetes Society-Servier, the College of Nursing, and Australian Catholic University.

[Neuroprotection with hypothermia in the newborn with hypoxic-ischaemic encephalopathy. Standard guidelines for its clinical application]

Standardisation of hypothermia as a treatment for perinatal hypoxic-ischaemic encephalopathy is supported by current scientific evidence. The following document was prepared by the authors on request of the Spanish Society of Neonatology and is intended to be a guide for the proper implementation of this therapy. We discuss the difficulties that may arise when moving from the strict framework of clinical trials to clinical daily care: early recognition of clinical encephalopathy, inclusion and exclusion criteria, hypothermia during transport, type of hypothermia (selective head or systemic cooling) and side effects of therapy. The availability of hypothermia therapy has changed the prognosis of children with hypoxic-ischaemic encephalopathy and our choices of therapeutic support. In this sense, it is especially important to be aware of the changes in the predictive value of the neurological examination and the electroencephalographic recording in cooled infants. In order to improve neuroprotection with hypothermia we need earlier recognition of to recognise earlier the infants that may benefit from cooling. Biomarkers of brain injury could help us in the selection of these patients. Every single infant treated with hypothermia must be included in a follow up program in order to assess neurodevelopmental outcome.

Infections and ischemic stroke outcome

Background. Infections increase the risk of ischemic stroke (IS) and may worsen IS prognosis. Adverse effects of in-hospital infections on stroke outcome were also reported. We aimed to study the prevalence of pre- and poststroke infections and their impact on IS outcome. Methods. We analysed clinical data of 2066 IS patients to assess the effect of pre-stroke and post-stroke infections on IS severity, as well as short-term (up to 30 days) and long-term (90 days) outcome. The independent impact of infections on poor outcome (death, death/dependency) was investigated by use of logistic regression analysis. The effect of antibiotic therapy during hospitalization on the outcome was also assessed. Results. Pre-stroke infections independently predicted worse short-term outcome. In-hospital infections were associated with worse short-term and long-term IS prognosis. Antibacterial treatment during hospitalization did not improve patients' outcome. Conclusions. Prevention of infections may improve IS prognosis. The role of antibiotic therapy after IS requires further investigations.

Bilateral middle cerebral artery thromboembolic occlusion. Could maternal hyperthermia be a detrimental factor?

We describe a six-month-old girl with microcephaly, developmental delay, truncal hypotonia, left pyramidal signs, partial seizures and myoclonic spasms, born to a feverish mother. MRI showed bilateral vascular lesions in the territory of the middle cerebral arteries, prevalent in the right hemisphere, together with hypoplasia of the posterior part of the corpus callosum and Wallerian degeneration of the cerebral peduncle. There may be many reasons for these lesions. In the reported patient the presence of maternal hyperthermia could have exacerbated cerebral thromboembolic occlusion.

Mild-to-moderate neurogenic pyrexia in acute cerebral infarction

BACKGROUND

Pyrexia is often associated with unfavorable stroke outcomes. However, limited information is available on the relationship between the causes of poststroke hyperthermia and stroke prognosis, especially for mild-to-moderate neurogenic pyrexia in acute cerebral infarction.

AIMS

To compare the differences in the clinical features and characteristics of pyrexia as well as its prognosis among acute cerebral infarction patients with mild-to-moderate neurogenic pyrexia, with infectious pyrexia, and without pyrexia. The focus was on mild-to-moderate neurogenic pyrexia.

METHODS

A total of 709 patients with acute cerebral infarction were prospectively recruited and their clinical data were analyzed.

RESULTS

No significant difference was detected in age, gender, history of smoking, hypertension, or diabetes among the 3 groups (p > 0.05). Patients with mild-to-moderate neurogenic pyrexia and those with infectious pyrexia had higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (15.1 ± 6.7, p = 0.003; 14.3 ± 8.1, p = 0.002, respectively), lower 3-month Barthel index (BI) values (64.2 ± 40.7, p < 0.001; 61.9 ± 49.3, p < 0.001, respectively) and higher 3-month mortality rates (13%, p = 0.026; 16%, p < 0.001, respectively) than patients without pyrexia (NIHSS score 11.4 ± 7.9; BI 82.6 ± 39.8, and mortality rate 6%, respectively). No difference existed in these parameters between the 2 pyrexia groups (p > 0.05), but mild-to-moderate neurogenic pyrexia had an earlier onset and a shorter duration than infectious pyrexia (p < 0.001).

CONCLUSIONS

Acute cerebral infarction patients with mild-to-moderate neurogenic pyrexia had a similar prognosis compared to those with infectious pyrexia. Mild-to-moderate neurogenic pyrexia is possibly associated with stroke severity.

Inverse relationship of baseline body temperature and outcome between ischemic stroke patients treated and not treated with thrombolysis: the Bergen stroke study

BACKGROUND

High body temperature may promote clot lysis whereas low body temperature is neuroprotective in patients with cerebral infarction. We hypothesized that high body temperature is associated with favorable outcome in patients treated with tissue plasminogen activator (tPA) and that low body temperature is associated with favorable outcome in patients not treated with tPA.

METHODS

Patients (n = 111) who were treated with tPA and patients (n = 139) who were not treated with tPA, but presented within 6 h of stroke onset were included. Patients with no temperature measurements within 6 h of stroke onset were excluded. National Institute of Health Stroke Scale (NIHSS) score was obtained on admission. Modified Rankin score (mRS) was obtained after 1 week. Favorable outcome was defined as mRS 0-2 and unfavorable outcome as mRS 3-6.

RESULTS

On logistic regression analysis, high body temperature was independently associated with favorable outcome among patients treated with tPA (OR = 3.7, P = 0.009) and low body temperature was independently associated with favorable prognosis among patients not treated with tPA (OR = 2.0, P = 0.042).

CONCLUSIONS

Our study suggests that the effect of high body temperature on clot lysis is more important than the neuroprotective effect of low body temperature in the early phase after cerebral infarction treated with tPA.

Fever is associated with doubling of odds of short-term mortality in ischemic stroke: an updated meta-analysis

OBJECTIVE

Association between fever and ischemic stroke mortality is known, but the magnitude and independence of the association is controversial. This paper aims to determine the size of independent effect of fever on short term mortality in acute ischemic stroke.

METHODS

We searched the Medline and Cochrane library databases for papers studying the relationship between fever in acute ischemic stroke and short term mortality from January, 1990 to November, 2008. Two authors independently selected the studies for inclusion in the review using explicit criteria. Data was entered into software Revman 4.2.8. Heterogeneity was assessed using I² and chi-square statistics. Odds ratios (OR) from logistic regression were combined. Magnitude of association was determined using meta-analysis of the adjusted odds ratio using fixed effects model.

RESULTS

Six cohort studies involving 2986 patients were included. There was no significant heterogeneity among studies reporting short-term mortality (I² = 21.2%, P = 0.28). Meta-analysis yielded a combined OR of 2.20 (95% CI 1.59-3.03, P < 0.00001).

CONCLUSIONS

This meta-analysis suggests that fever within first 24 h of hospitalization in patients with ischemic stroke is associated with doubling of odds of mortality within one month of the onset of stroke.

An early rise in body temperature is related to unfavorable outcome after stroke: data from the PAIS study

Subfebrile temperature or fever is present in about a third of patients on the first day after stroke onset and is associated with poor outcome. However, the temporal profile of this association is not well established. We aimed to assess the relationship between body temperature on admission as well as the change in body temperature from admission to 24 h thereafter and functional outcome and death. We analyzed data of 1,332 patients admitted within 12 h of stroke onset. The relation between body temperature on admission or the change in body temperature from admission to 24 h thereafter (adjusted for body temperature on admission) on the one hand and unfavorable outcome (death, or a modified Rankin Scale score >2) at 3 months on the other were expressed as odds ratio per 1.0°C increase in body temperature. Adjustments for potential confounders were made with a multiple logistic regression model. No relation was found between admission body temperature and poor outcome (aOR 1.06; 95% CI 0.85-1.32) and death (aOR 1.23; 95% CI 0.95-1.60). In contrast, increased body temperature in the first 24 h after stroke onset was associated with poor outcome (aOR 1.30; 95% CI 1.05-1.63) and death (aOR 1.51; 95% CI 1.15-1.98). An early rise in body temperature rather than high body temperature on admission is a risk factor for unfavorable outcome in patients with acute stroke.

Hyperacute ischemic stroke management: reperfusion and evolving therapies

Management of acute ischemic stroke patients is organized around several priorities aimed at ensuring optimal patient outcomes, the first of which is reperfusion therapy, followed by determination of pathogenic mechanism by provision of a comprehensive workup to determine probable cause of the ischemic stroke or transient ischemic attack, for the purpose of providing appropriate prophylaxis for subsequent events. Provision of secondary prevention measures along with therapies that prevent complications associated with neurologic disability, and evaluation for the most appropriate level of rehabilitation services are the final priorities during acute hospitalization. This article provides an overview of reperfusion therapies and emerging hemodynamic treatments for hyperacute ischemic strokes. Gaps in the scientific evidence that are driving current blood flow augmentation research are identified.

Fever control in the neuro-ICU: why, who, and when?

PURPOSE OF REVIEW

Fever in the neurocritical care setting is very common and has a negative impact on outcome of all disease types. Recent advances have made eliminating fever and maintaining normothermia feasible. However, important questions regarding indications and timing remain. The purpose of this review is to analyze the data surrounding the impact of fever across a range of neurologic injuries to better understand the optimal timing and duration of fever control.

RECENT FINDINGS

Meta-analyses have demonstrated that fever at onset and in the acute setting after ischemic brain injury, intracerebral hemorrhage, and cardiac arrest have a negative impact on morbidity and mortality. There are data to support that the impact of fever is sustained for longer durations after subarachnoid hemorrhage and traumatic brain injury. However, there are currently no prospective randomized trials demonstrating the benefit of fever control in these patient populations.

SUMMARY

The negative impact of fever after neurologic injury is well understood. Prospective randomized trials are needed to determine whether the beneficial impact of secondary injury prevention is outweighed by the potential infectious risk of prolonged fever control.

Hyperthermia Exacerbates Ischaemic Brain Injury

Hyperthermia frequently occurs in stroke patients. Hyperthermia negatively correlates with clinical outcome and adversely effects treatment regiments otherwise successful under normothermic conditions. Preclinical studies also demonstrate that hyperthermia converts salvageable penumbra to ischaemic infarct. The present article reviews the knowledge accumulated from both clinical and preclinical studies about hyperthermia and ischaemic brain injury, examines current treatment strategies and discusses future research directions.