Deformation of the ventrolateral medulla oblongata by subarachnoid hemorrhage from ruptured vertebral artery aneurysms causes neurogenic pulmonary edema

Neurogenic pulmonary edema and Takotsubo cardiomyopathy in aneurysmal subarachnoid hemorrhage

PURPOSE

Neurogenic pulmonary edema (NPE) combined with Takotsubo cardiomyopathy (TCM) is a rare condition associated with aneurysmal subarachnoid hemorrhage (aSAH). Although several mechanisms have been proposed, the pathophysiology and management strategies are not yet fully established. We aimed to determine the radiological and clinical outcomes of patients with NPE and with TCM after aSAH to propose management strategies.

METHODS

We analyzed the data of 564 patients with aSAH recorded at a single medical center from February 2015 to July 2022. This study retrospectively investigated the incidence and demographics of SAH combined with both NPE and TCM and the clinical outcomes of the patients. Correlating factors, independently associated with NPE-TCM, were also investigated.

RESULTS

During the 7 years, 11 (2.0%) of 564 patients had NPE complicated with TCM after aSAH. Seven of 11 (63.6%) patients had poor-grade SAH (Hunt-Hess Grade 4 to 5). Three of 11 patients had a posterior circulation in the NPE-TCM group. The most prevalent treatment option was endovascular coil embolization, except for one case of clip. Long-term outcomes were favorable in 6 of 11 patients, and there was one case of mortality. Age, troponin I level, and alveolar-arterial oxygen gradient were correlating factors of NPE-TCM.

CONCLUSION

Although NPE-TCM represents a rare complication associated with aSAH, achieving active resolution of underlying neurological causes through early and appropriate treatment may contribute to a favorable prognosis. Considering the limited incidence of SAH complicated with NPE-TCM, a multi-center study may be needed.

Respiratory Parameters as Predictors of Balance and Gait Ability in Patients with Stroke at Discharge

Pulmonary complications are frequent in stroke, contributing to both mortality and morbidity rates. Respiratory parameters in such patients encompass both pulmonary function and respiratory muscle strength. Identifying respiratory function variables that influence the balance and gait ability of patients with stroke is crucial for enhancing their recovery in these aspects. However, no study has assessed predictions for a comprehensive array of balance and gait abilities in such patients. We aimed to examine whether initial respiratory muscle strength and pulmonary function can predict balance and gait ability at discharge from a rehabilitation program. Thirty-one patients with stroke were included in this prospective observational study. Multiple regression models with a forward selection procedure were employed to identify respiratory parameters (including peak expiratory flow and maximal expiratory pressure) that contributed to the results of balance assessments and gait evaluations at the time of discharge. The peak expiratory flow (PEF) served as a predictor explaining 42.0% of the variance. Similarly, the maximal expiratory pressure (MEP) was a predictor variable explaining 32.0% of the variance. PEF and MEP assessments at the initial stage as predictive factors for both balance and gait ability are important in stroke management.

Prevalence, in-hospital mortality, and factors related to neurogenic pulmonary edema after spontaneous subarachnoid hemorrhage: a systematic review and meta-analysis

Neurogenic pulmonary edema (NPE) is a life-threatening and severe complication in patients with spontaneous subarachnoid hemorrhage (SAH). The prevalence of NPE varies significantly across studies due to differences in case definitions, study populations, and methodologies. Therefore, a precise estimation of the prevalence and risk factors related to NPE in patients with spontaneous SAH is important for clinical decision-makers, policy providers, and researchers. We conducted a systematic search of the PubMed/Medline, Embase, Web of Science, Scopus, and Cochrane Library databases from their inception to January 2023. Thirteen studies were included in the meta-analysis, with a total of 3,429 SAH patients. The pooled global prevalence of NPE was estimated to be 13%. Out of the eight studies (n = 1095, 56%) that reported the number of in-hospital mortalities of NPE among patients with SAH, the pooled proportion of in-hospital deaths was 47%. Risk factors associated with NPE after spontaneous SAH included female gender, WFNS class, APACHE II score ≥ 20, IL-6 > 40 pg/mL, Hunt and Hess grade ≥ 3, elevated troponin I, elevated white blood cell count, and electrocardiographic abnormalities. Multiple studies showed a strong positive correlation between the WFNS class and NPE. In conclusion, NPE has a moderate prevalence but a high in-hospital mortality rate in patients with SAH. We identified multiple risk factors that can help identify high-risk groups of NPE in individuals with SAH. Early prediction of the onset of NPE is crucial for timely prevention and early intervention.

Role of autonomic system imbalance in neurogenic pulmonary oedema

Neurogenic pulmonary oedema (NPE) is a life-threatening complication that develops rapidly and dramatically after an injury to the central nervous system (CNS). The autonomic system imbalance produced by severe brain damage may play an important role in the development of NPE. Activation of the sympathetic nervous system and inhibition of the vagus nerve system are essential prerequisites for autonomic system imbalance. The more severe the damage, the more pronounced the phenomenon. Sympathetic hyperactivity is associated with increased release of catecholamines from peripheral sympathetic nerve endings, which can cause dramatic changes in haemodynamics and cause pulmonary oedema. On the other hand, the abnormal inflammatory response caused by vagus nerve inhibition may also play an important role in the pathogenesis of NPE. The perspective of autonomic system imbalance seems to perfectly integrate the existing pathogenesis of NPE and can explain the entire development progression of NPE.

Brain-lung interactions and mechanical ventilation in patients with isolated brain injury

During the last decade, experimental and clinical studies have demonstrated that isolated acute brain injury (ABI) may cause severe dysfunction of peripheral extracranial organs and systems. Of all potential target organs and systems, the lung appears to be the most vulnerable to damage after brain injury (BI). The pathophysiology of these brain–lung interactions are complex and involve neurogenic pulmonary oedema, inflammation, neurodegeneration, neurotransmitters, immune suppression and dysfunction of the autonomic system. The systemic effects of inflammatory mediators in patients with BI create a systemic inflammatory environment that makes extracranial organs vulnerable to secondary procedures that enhance inflammation, such as mechanical ventilation (MV), surgery and infections. Indeed, previous studies have shown that in the presence of a systemic inflammatory environment, specific neurointensive care interventions—such as MV—may significantly contribute to the development of lung injury, regardless of the underlying mechanisms. Although current knowledge supports protective ventilation in patients with BI, it must be born in mind that ABI-related lung injury has distinct mechanisms that involve complex interactions between the brain and lungs. In this context, the role of extracerebral pathophysiology, especially in the lungs, has often been overlooked, as most physicians focus on intracranial injury and cerebral dysfunction. The present review aims to fill this gap by describing the pathophysiology of complications due to lung injuries in patients with a single ABI, and discusses the possible impact of MV in neurocritical care patients with normal lungs.

Anterior Spinal Artery Steal Syndrome Complicated by Ruptured Flow-Related Aneurysm of the Anterior Radiculomedullary Artery

BACKGROUND

Anterior spinal artery steal syndrome, radiculomedullary artery aneurysms, and pulmonary arteriovenous malformations with a systemic origin are each, considered individually, exceptional conditions.

CASE DESCRIPTION

We describe the coexistence of all these conditions and their pathophysiologic relationship by presenting the case of a woman who referred to the emergency department for loss of consciousness and a history of 2 days of medullary symptoms and a subsequent acute respiratory failure. Detailed imaging revealed a subarachnoid hemorrhage due to the rupture of a spinal aneurysm located in a C8 radiculomedullary artery that had its flow reversed toward the deep cervical artery from which a systemic to pulmonary arteriovenous malformation originated.

CONCLUSIONS

Eventually, the lesion was treated with the exclusion of the left C8 spinal segmental branch and embolization of the arteriovenous malformation.

Crosstalk between brain, lung and heart in critical care

Extracerebral complications, especially pulmonary and cardiovascular, are frequent in brain-injured patients and are major outcome determinants. Two major pathways have been described: brain-lung and brain-heart interactions. Lung injuries after acute brain damages include ventilator-associated pneumonia (VAP), acute respiratory distress syndrome (ARDS) and neurogenic pulmonary œdema (NPE), whereas heart injuries can range from cardiac enzymes release, ECG abnormalities to left ventricle dysfunction or cardiogenic shock. The pathophysiologies of these brain-lung and brain-heart crosstalk are complex and sometimes interconnected. This review aims to describe the epidemiology and pathophysiology of lung and heart injuries in brain-injured patients with the different pathways implicated and the clinical implications for critical care physicians.

Clinical Features of Neurogenic Pulmonary Edema in Patients with Subarachnoid Hemorrhage

OBJECTIVE

Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by acute onset after central nervous system injury. Here, we investigated the clinical features of NPE in patients with subarachnoid hemorrhage (SAH).

METHODS

We retrospectively analyzed a total of 350 patients with SAH who were treated at our hospital from April 2014 to September 2017. Patient demographics, aneurysm size and location, clinical characteristics, and patient outcomes were reviewed and compared between an NPE and a non-NPE group.

RESULTS

Sixteen patients (4.6%) presented with NPE at admission. Ten of these (62.5%) recovered from NPE immediately, and ventilatory support was withdrawn within 2 days from onset. A univariate analysis showed that patients with NPE were younger (P = 0.04), had a higher rate of vertebral artery dissection (P < 0.01), more severe World Federation of Neurosurgical Societies (WFNS) grades (P = 0.01), and lower systolic blood pressure on admission (P = 0.01). A multivariate analysis revealed significant differences in the frequency of vertebral artery dissection (odds ratio 4.83, 95% confidence interval 1.50-15.56, P < 0.01) and in WFNS grades (odds ratio 3.73, 95% confidence interval 1.02-13.66, P = 0.04) between the groups. No significant group differences were found in other factors including heart rate, radiographic sign (Fisher grade), aneurysm size and location, blood sample tests on admission, and neurologic outcomes.

CONCLUSIONS

Vertebral artery dissection and severe WFNS grade on admission were confirmed as significant risk factors for NPE. However, neurologic outcomes at discharge did not differ between groups, suggesting that poor outcomes due to NPE could be reduced by appropriate diagnosis and treatment.

Pulmonary Complications After Spontaneous Aneurysmal Subarachnoid Hemorrhage: Experience from Barrow Neurological Institute

OBJECTIVE

Because the clinical course of spontaneous aneurysmal subarachnoid hemorrhage (aSAH) can be compromised by pulmonary complications, we sought to review posttreatment outcomes in aSAH patients with and without pulmonary complications.

METHODS

Patient demographic, clinical, and outcome data (March 2003-January 2007) were analyzed retrospectively. Patients underwent microsurgical or endovascular treatment for aSAH; pulmonary complications were reported. Outcomes were assessed using the Glasgow Outcome Scale (GOS) scores at the 1-year, 3-year, and 6-year follow-up visits.

RESULTS

The cohort comprised 471 patients (mean age, 53.7 ± 12.4 years; men, 332/471 [70%]). The mean Glasgow Coma Scale (GCS) score at presentation was 11.9 ± 3.0. Of 471 patients, 47% (n = 223) presented with a Hunt and Hess score of ≥3 and 76% (n = 357) with a Fisher grade of 3. Treatment was clipping for 69% (279/407) and coiling for 31% (128/407) of patients. Pulmonary complications occurred in 210 of 471 (45%) patients. Nearly one-half of patients were discharged to home (215/471, 46%), and more than one-half had a good outcome defined as a GOS score of 5 at their 1-year (226/403, 56%), 3-year (217/397, 55%), and 6-year (203/380, 53%) follow-up visits. Logistic regression showed age and GCS scores as outcome predictors at all time points, whereas pulmonary complications predicted poor outcome only at the 1-year follow-up visit.

CONCLUSIONS

Pulmonary problems represent the most common nonneurologic medical complications after aSAH. Despite advances in critical care, pulmonary complications represented predictors of short-term poor outcome only at the 1-year follow-up visit, whereas the medical history of the patient became more relevant for prognosis in long-term follow-up.

Neurogenic pulmonary oedema secondary to vertebral artery dissection while playing tennis

We present a case of a patient who developed vertebral artery dissection (VAD) while playing tennis and presented with neurogenic pulmonary oedema. The case highlights two important points: acute pulmonary oedema as an unusual presenting feature of VAD and VAD, an important cause of stroke in young people, as being associated with playing low-impact sports such as tennis. These associations, independent of each other, are under-recognised and can lead to a delay in diagnosis.

Could cardiac biomarkers predict neurogenic pulmonary edema in aneurysmal subarachnoid hemorrhage?

BACKGROUND

Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by the acute onset of pulmonary edema after a significant central nervous system (CNS) insult. NPE occurs as a result of release of catecholamines into the blood immediately after aneurysm rupture. The aim of this study is to investigate the connection between the value of cardiac biomarkers on admission and incidence of NPE in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

A total of 262 SAH patients (162 women, 100 men) were prospectively included in the study. Clinical characteristics, electrocardiographic (ECG) changes, serum cardiac and inflammatory biomarkers were measured on admission and on the day of development of NPE. These data were analyzed in order to predict the development NPE.

RESULTS

Nineteen patients (7.25%) developed NPE. Comparison revealed that patients who subsequently developed NPE, sustained more severe SAH. Cardiac damage was more severe in these patients, as represented by significantly higher mean values of all examined cardiac biomarkers (P = 0.000), except for troponin I value that was significantly lower (P = 0.000). Multivariate regression analysis revealed that elevated troponin I (OR, 4.980; 95% CI, 1.27-19.49; P = 0.021) and white blood cell count (OR, 22.195; 95% CI, 3.99-123.50; P = 0.000) are predictors of NPE.

CONCLUSIONS

Significantly higher values of cardiac biomarkers were observed in SAH patients complicated with NPE. Elevated values of cardiac biomarkers appear to play an active role in prediction of NPE, although white blood cell count may be involved in the prediction of NPE. There is an influence of SAH therapy on predictors of NPE.

Neuropulmonology

Neuropulmonology refers to the complex interconnection between the central nervous system and the respiratory system. Neurologic injury includes traumatic brain injury, hemorrhage, stroke, and seizures, and in each there are far-reaching effects that can result in pulmonary dysfunction. Systemic changes can induce impairment of pulmonary function due to changes in the core structure and function of the lung. The conditions and disorders that often occur in these patients include aspiration pneumonia, neurogenic pulmonary edema, and acute respiratory distress syndrome, but also several abnormal respiratory patterns and sleep-disordered breathing. Lung infections, pulmonary edema - neurogenic or cardiogenic - and pulmonary embolus all are a serious barrier to recovery and can have significant effects on outcomes such as hospital course, prognosis, and mortality. This review presents the spectrum of pulmonary abnormalities seen in neurocritical care.

Neurogenic Pulmonary Edema in Aneurysmal Subarachnoid Hemorrhage

Neurogenic pulmonary edema (NPE) is observed in cerebral injuries and has an impact on treatment results, being a predictor of fatal prognosis. In this study we retrospectively reviewed medical records of 250 consecutive patients with aneurysmal subarachnoid hemorrhage (SAH) for the frequency and treatment results of NPE. The following factors were taken under consideration: clinical status, aneurysm location, presence of NPE, intracranial pressure (ICP), and mortality. All patients had plain- and angio-computer tomography performed. NPE developed most frequently in case of the aneurysm located in the anterior communicating artery. The patients with grades I-III of SAH, according to the World Federation of Neurosurgeons staging, were immediately operated on, while those with poor grades IV and V had only an ICP sensor's implantation procedure performed. A hundred and eighty five patients (74.4 %) were admitted with grades I to III and 32 patients (12.8 %) were with grade IV and V each. NPE was not observed in SAH patients with grade I to III, but it developed in nine patients with grade IV and 11 patients with grade V. Of the 20 patients with NPE, 19 died. Of the 44 poor grade patients (grades IV-V) without NPE, 20 died. All poor grade patients had elevated ICP in a range of 24-56 mmHg. The patients with NPE had a greater ICP than those without NPE. Gender and age had no influence on the occurrence of NPE. We conclude that the development of neurogenic pulmonary edema in SAH patients with poor grades is a fatal prognostic as it about doubles the death rate to almost hundred percent.

Neurogenic pulmonary edema caused by spontaneous cerebellar hemorrhage: A fatal case report

Background:

Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by an acute increase of pulmonary interstitial and alveolar fluid. It could result from a significant central nervous system (CNS) insult such as intracranial hemorrhage. However, NPE as a major presenting manifestation of cerebellar hemorrhage was seldom reported.

Case Description:

We introduce a rare case of a 34-year-old woman suffering from a fulminant NPE in parallel with a spontaneous cerebellar hemorrhage. Although appropriate supportive measures were taken in the neuroscience care unit, the patient failed to survive hypoxemia within 28 h after hospital admission.

Conclusion:

Pathological lesions of the cerebellum may initiate a cascade of reactions including massive sympathetic discharge and catecholamine storm, leading to a dysfunction of both cardiovascular and respiratory systems. By far, no effective therapeutic strategies have been utilized to treat such a situation. Our present report would shed light on the underlying mechanism of NPE.

Impact of aneurysm location on cardiopulmonary dysfunction after subarachnoid hemorrhage

BACKGROUND

Cardiopulmonary dysfunction may occur after aneurysmal subarachnoid hemorrhage (SAH), but its characteristics have not been fully clarified. We investigated the impact of aneurysm location on systemic hemodynamics after SAH.

METHODS

This multicenter prospective cohort study measured hemodynamic parameters in relation to aneurysm location in patients with SAH using a single-indicator transpulmonary thermodilution system (PiCCO) on days 1-14.

RESULTS

Of 204 subjects enrolled, 58 had aneurysms of the anterior communicating artery (ACA), 61 of the middle cerebral artery (MCA), 57 of the internal carotid artery (ICA), and 28 of the vertebrobasilar artery (VA/BA). Patient characteristics were similar except for predominance of coiling in the VA/BA. Patients with ACA aneurysm had a lower systemic vascular resistance index (SVRI) in the acute phase and afterload mismatch (lower cardiac index [CI] and higher SVRI) in the spasm phase. Those with ICA aneurysm had a lower CI in the acute phase, and those with VA/BA aneurysm had a warm shock-like condition (higher CI and lower SVRI) in the spasm phase. Patients with MCA aneurysm showed no specific characteristics in CI and SVRI with a significant improvement in B-type natriuretic peptide. Extravascular lung water index was high independent of left cardiac dysfunction. In multivariate analysis, age and ACA were independently related to poor global ejection fraction after SAH.

CONCLUSIONS

Aneurysm location affects cardiac output, vascular resistance, and pulmonary edema in biphasic fashion. Patient age and location of aneurysm in the ACA may be risk factors for cardiac failure after SAH.

Early endovascular treatment of aneurysmal subarachnoid hemorrhage complicated by neurogenic pulmonary edema and Takotsubo-like cardiomyopathy

Aneurysmal subarachnoid hemorrhage (SAH) may be associated with acute cardiopulmonary complications, like neurogenic pulmonary edema (NPE) and Takotsubo-like cardiomyopathy (TCM). These dysfunctions seem to result from a neurogenically induced overstimulation of the sympathetic nervous system through the brain-heart connection and often complicate poor grade aneurysmal SAH. The optimal treatment modality and timing of intervention in this clinical setting have not been established yet. Early endovascular therapy seems to be the fitting treatment in this particular group of patients, in which surgical clipping is often contraindicated due to the added risk of craniotomy. Herein we describe the case of a woman admitted to the emergency department with aneurysmal SAH complicated by NPE-TCM, in which early endovascular coiling was successfully performed. Our case, characterized by a favorable outcome, further supports the evidence that early endovascular treatment should be preferred in this peculiar clinical scenario.

Unilateral neurogenic pulmonary oedema: An unusual cause for post-operative respiratory dysfunction following clipping of ruptured intracranial aneurysm

A variety of central nervous system lesions like stroke, subarachnoid haemorrhage, trauma and seizure activity can result in neurogenic pulmonary oedema (NPE). Unilateral neurogenic pulmonary oedema is very rare. There are no reports of unilateral NPE with aneurysmal vasospasm. We present the case of a 55-year-old female who developed respiratory distress with unilateral pulmonary oedema and mild left ventricular dysfunction in the context of postoperative cerebral vasospasm following clipping of ruptured intracranial aneurysm. Neurogenic pulmonary oedema should always be in the differential diagnosis when patients with presumed neurogenic pathology develop respiratory compromise. The diagnosis of unilateral neurogenic pulmonary oedema requires a high index of suspicion. Early initiation of supportive treatment results in good outcome.

The role of sympathetic nervous system in the development of neurogenic pulmonary edema in spinal cord-injured rats

The pronounced activation of sympathetic nervous system is a necessary prerequisite for the development of neurogenic pulmonary edema (NPE) in rats with balloon compression of spinal cord. In this study we examined whether this is a consequence of rapid activation of spinal pathways leading to sympathetic venoconstriction, blood pressure rise, and reflex bradycardia. We found that NPE development can be prevented by epidural upper thoracic anesthesia or by transection of the upper spinal cord. This indicates an important role of spinal pathways activation. NPE development can also be prevented by moderate blood loss, supporting the role of blood redistribution to pulmonary circulation. In rats developing NPE the catecholamine surge following spinal cord compression involved not only a dramatic increase of circulating norepinephrine but also of epinephrine levels. The pretreatment of rats with α-1 adrenoceptor blocker prazosin, α-2 adrenoceptor blocker yohimbine, or calcium channel blocker nifedipine prevented NPE development, whereas the effect of β-adrenoceptor blockade with propranolol was less convincing. In conclusion, considerable activation of thoracic spinal pathways, followed by marked catecholamine secretion, play a major role in the development of NPE in spinal cord-injured rats. Enhanced α-adrenergic nifedipine-sensitive vasoconstriction is responsible for observed blood pressure changes, subsequent baroreflex bradycardia, and blood volume redistribution, which represent major pathogenetic mechanisms of NPE development.

Clinical significance of elevated natriuretic peptide levels and cardiopulmonary parameters after subarachnoid hemorrhage

Daily changes in serum concentrations of natriuretic peptides and various cardiopulmonary parameters were measured after the onset of subarachnoid hemorrhage (SAH) to investigate the pathogenesis of the cardiac and pulmonary consequences in 15 patients with acute phase SAH, divided into the control group (n = 5) with consciousness continuously preserved from SAH onset to admission, and the consciousness disturbance group (n = 10). Daily changes in serum A-type and B-type natriuretic peptides (ANP and BNP, respectively) were measured for 10 days, and intrathoracic blood volume index and extravascular lung water index (EVLWI) were measured for 5 days by the single transpulmonary thermodilution method. Natriuretic peptides in the consciousness disturbance group showed significantly higher values during the 10-day period, with ANP 119.2 +/- 12.4 pg/ml (mean +/- standard error of the mean, p = 0.005) on day 2 and BNP 354.1 +/- 80.3 pg/ml (p = 0.009) on day 1. EVLWI showed higher values in the consciousness disturbance group compared to the control group throughout the 5-day period. The increases in natriuretic peptide levels and increase in pulmonary extravascular water content found in SAH patients with consciousness disturbance show that load on the left ventricle or atrium as well as pulmonary capillary pressure are increased immediately after onset, supporting the contention that excessive release of catecholamines occurs at this time.

Neurogenic pulmonary edema in patients with subarachnoid hemorrhage

Neurogenic pulmonary edema (NPE), leading to cardiopulmonary dysfunction, is a potentially life-threatening complication in patients with aneurysmal subarachnoid hemorrhage (SAH). We sought to assess the clinical presentation and risk factors for the development of NPE after SAH. The database contained prospectively collected information on 477 patients with SAH. Baseline characteristics, clinical and radiologic severity of the bleeding, localization of the ruptured aneurysm, and clinical outcome of patients with NPE were compared with those of patients without NPE. Further, in patients with NPE, intracranial pressure, serum cardiac biomarkers, and hemodynamic parameters during the acute phase were evaluated retrospectively. The incidence of NPE was 8% (39 of 477 patients). Most patients with NPE were severely impaired and all of them presented with radiologically severe hemorrhage. The incidence of NPE was significantly higher in patients with ruptured aneurysm in the posterior circulation. Elevated intracranial pressure was found in 67%, pathologically high cardiac biomarkers in up to 83% of patients with NPE. However, no patient suffered from persistent cardiac dysfunction. Compared with patients without NPE, patients with NPE showed poor neurologic outcome (Glasgow outcome scale 1 to 3 in 25% vs.77% of patients). In conclusion, patients with NPE have a high mortality rate more likely due to their severity grade of the bleeding. Morbidity and mortality due to cardiopulmonary failure might be reduced by appropriate recognition and treatment. The awareness of and knowledge about occurrence, clinical presentation, and treatment of NPE, are essential for all those potentially confronted with patients with SAH in the acute phase.

Sudden death in toddlers with viral meningitis, massive cerebral edema, and neurogenic pulmonary edema and hemorrhage: report of two cases

Viral (lymphocytic) meningitis typically does not cause sudden death, especially in the absence of severe inflammation in the brain or other organs. We report 2 toddlers with clinical evidence of a viral infection who died unexpectedly and were found at autopsy to have lymphocytic meningitis associated with severe brain edema, transtentorial herniation, neurogenic pulmonary edema and hemorrhage, and cardiomegaly. Influenza A virus, demonstrated in tracheal epithelium by immunocytochemistry, is the presumed cause of the mild meningitis in 1 case; adenovirus was cultured from swabs of the brain and anus in the 2nd case. Current concepts of neurogenic pulmonary edema and acute cardiac dysfunction associated with intracranial disease are discussed in considering the mechanism of sudden death in these toddlers. These cases emphasize the possibility that mild intracranial viral infections may be a rare cause of sudden death via lethal cardiopulmonary complications. They also underscore the importance of a comprehensive autopsy, including detailed neuropathologic examination and viral testing, in determining of the cause of unexpected death in toddlers.

The systemic implications of aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is analogous to a pathophysiological watershed, disrupting brain integrity and function and precipitating an array of systemic derangements including cardiovascular, respiratory, endocrine, hematological, and immune dysfunction. Extracerebral organ dysfunction is closely linked to the magnitude of the primary neurological insult, suggesting neurogenic, neuroendocrine and neuroimmunomodulatory mechanisms. Systemic organ involvement is associated with increased mortality and neurological impairment, even after adjustment for other outcome predictors such as the severity of the initial neurological injury. This may be a reflection of secondary brain injury precipitated by hypoxemia, circulatory failure, fever, or hyperglycemia, all of which have been linked to adverse clinical outcomes. Interventions to avert or reverse these and other perturbations need to be tested in clinical trials as they represent opportunities to improve survival and neurological recovery in patients with SAH.

Low Concentration of Isoflurane Promotes the Development of Neurogenic Pulmonary Edema in Spinal Cord Injured Rats

Anesthetics can either promote or inhibit the development of neurogenic pulmonary edema (NPE) after central nervous system (CNS) injury. The influence of isoflurane was examined in male Wistar rats using 1.5%, 2%, 2.5%, 3%, 4%, or 5% isoflurane in air. Epidural balloon compression of the thoracic spinal cord was performed. The development of NPE was examined in vivo and on histologic sections of lung tissue. Animals anesthetized with 1.5% or 3% isoflurane were behaviorally monitored using the BBB and plantar tests for 7 weeks post-injury. The spinal cord was examined using MRI and morphometry of the spared white and gray matter. All animals from the 1.5% and 2% groups developed NPE. Almost 42% of the animals in the 1.5% group died of severe pulmonary hemorrhage and suffocation; x-rays, the pulmonary index, and the histological picture revealed a massive NPE. More than 71% of the animals from the 2.5% and 3% groups did not develop any signs of NPE. Blood pressure after spinal cord compression rose more in the 1.5% group than in the 3% one. In the 1.5% group, the sympathetic ganglionic blockade prevented the neurogenic pulmonary edema development. Animals from the 3% group recovered behaviorally more rapidly than did the animals from the 1.5% group; morphometry and MRI of the lesions showed no differences. Thus, low levels of isoflurane anesthesia promote NPE in rats with a compressed spinal cord and significantly complicates their recovery. The optimal concentration of anesthesia for performing a spinal cord compression lesion is 2.5-3% isoflurane in air.

Neurogenic pulmonary edema

Neurogenic pulmonary edema (NPE) is usually defined as an acute pulmonary edema occurring shortly after a central neurologic insult. It has been reported regularly for a long time in numerous and various injuries of the central nervous system in both adults and children, but remains poorly understood because of the complexity of its pathophysiologic mechanisms involving hemodynamic and inflammatory aspects. NPE seems to be under-diagnosed in acute neurologic injuries, partly because the prevention and detection of non-neurologic complications of acute cerebral insults are not at the forefront of the strategy of physicians. The presence of NPE should be high on the list of diagnoses when patients with central neurologic injury suddenly become dyspneic or present with a decreased P(a)o(2)/F(i)o(2) ratio. The associated mortality rate is high, but recovery is usually rapid with early and appropriate management. The treatment of NPE should aim to meet the oxygenation needs without impairing cerebral hemodynamics, to avoid pulmonary worsening and to treat possible associated myocardial dysfunction. During brain death, NPE may worsen myocardial dysfunction, preventing heart harvesting.

Extracerebral organ dysfunction in the acute stage after aneurysmal subarachnoid hemorrhage

In patients with aneurysmal subarachnoid hemorrhage (SAH), secondary complications are an important cause of morbidity and case fatality. Delayed cerebral ischemia and hydrocephalus are important intracranial secondary complications. Potentially treatable extracranial complications are also frequently observed, and some are related to the occurrence of delayed cerebral ischemia and outcome. In addition to the occurrence of an inflammatory response and metabolic derangements, cardiac and pulmonary complications are the most common extracranial complications. This article provides an overview of the most common extracranial complications in patients with SAH and describes their effects on outcome and delayed cerebral ischemia.

Terson's Syndrome as the Initial Symptom of Subarachnoid Hemorrhage Caused by Ruptured Vertebral Artery Aneurysm-Case Report-

A 61-year-old male initially presented to the ophthalmology department complaining of sudden visual loss. Fundus photography and ultrasonography followed by computed tomography identified Terson's syndrome caused by subarachnoid hemorrhage (SAH). Cerebral angiography revealed a dissecting aneurysm of the left vertebral artery. Other than obtunded visual acuity, his neurological examination was normal and he denied any headache. He was treated conservatively with pain and blood pressure control. He complained of headache associated with rerupture of the aneurysm on day 5. The patient died of rerupture on day 14. The clinical course of this patient indicates that Terson's syndrome may occur without sudden increase of intracranial pressure. Terson's syndrome may occur as a rare initial clinical sign of SAH caused by ruptured cerebral aneurysm.

Neurogenic pulmonary edema during intracranial endovascular therapy

Neurogenic pulmonary edema (NPE) is a well-known complication of acute brain injury. Neurogenic stunned myocardium (NSM) occurs clinically in a significant subset of patients with NPE. A 49-year-old woman developed refractory cerebral vasospasm requiring angioplasty following a subarachnoid hemorrhage. During angioplasty, NPE with NSM manifested as acute pulmonary edema associated with elevated pulmonary artery occlusion pressure and reduced cardiac output. Evaluations disclosed a right insular infarction, cardiac wall motion abnormalities, and electrocardiographic characteristics of NSM. The NSM completely resolved, and the neurological outcome was good. A 56-year-old woman developed NPE during complicated coil embolization of an internal carotid artery aneurysm. Cardiac function was normal, and the NPE resolved with a brief period of mechanical ventilation and diuresis. The delayed appearance of NSM and NPE during endovascular therapy in these patients implies a degree of risk for sympathetically mediated cardiopulmonary dysfunction during complex intracranial endovascular procedures.

Spontaneous subarachnoid hemorrhage and serious cardiopulmonary dysfunction--a systematic review

INTRODUCTION

: The association between the degree of neurological deficit and cardiopulmonary dysfunction in patients with spontaneous subarachnoid hemorrhage (SAH) is poorly understood.

METHOD

A systematic search (MEDLINE, bibliographies, to 9.2004) was performed for prospective studies (any architecture; > or = 10 patients with SAH), reporting on neurological deficit and cardiopulmonary dysfunction. Neurological deficit was graded according to the Hunt-Hess or Botterell scores as minimal (1 or 2 points), moderate (3), or severe (4 or 5), and tested for an association with cardiopulmonary dysfunction (Chi-square test).

RESULTS

Relevant data came from two randomized trials, four case control studies, and 31 uncontrolled series. In eight studies (386 patients), ECG abnormalities were found in 32% of patients with minimal, 55% with moderate, and 58% with severe neurological deficit (P < 0.0001). In six studies (135), echocardiographic abnormalities were found in 4% of patients with minimal, 30% with moderate, and 52% with severe neurological deficit (P = 0.0001). In two trials (63), creatinine phosphoskinase was increased in 18% of patients with minimal, 71% with moderate, and 100% with severe neurological deficit (P < 0.0001). In three trials (309), troponin-I was increased in 10% of patients with minimal, 20% of patients with moderate, and 46% with severe neurological deficit (P < 0.0001). In five trials (163), pulmonary edema was found in 4% of patients with minimal, 12% with moderate, and 35% with severe neurological deficit (P < 0.0001). Seventeen studies reported on mortality; 26% of the patients died, 80% of deaths were directly related to SAH.

CONCLUSIONS

In patients with spontaneous SAH, cardiopulmonary dysfunction is more likely to occur with increasing neurological deficit.