CT and CT-Perfusion Findings of Reversible Leukoencephalopathy During Triple-H Therapy for Symptomatic Subarachnoid Hemorrhage-Related Vasospasm

Pediatric Posterior Reversible Encephalopathy Syndrome: A Review With Emphasis on Neuroimaging Characteristics

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by the sudden onset of seizures, headaches, and visual disturbances. Its exact cause is unknown, but several triggers and associated conditions are identified, including high blood pressure, kidney dysfunction, and various medications. Magnetic resonance imaging (MRI) plays a crucial role in diagnosis due to its high sensitivity and specificity for detecting characteristic features. Pediatric PRES exhibit age-dependent differences in triggers, radiological findings, and clinical course. The lesions typically involve the posterior cortical and subcortical white matter, but atypical locations and features are also observed. While generally reversible with appropriate treatment, PRES carries a risk of permanent neurological damage. Despite increasing cases, the current literature on pediatric PRES remains limited. This review highlights the need for further research to understand the mechanisms, delineate distinct clinical and radiological features, and develop precise diagnostic and management strategies for pediatric patients.

Perfusion Deficits in Patients with Posterior Reversible Encephalopathy Syndrome: a Retrospective, Two-Center Study

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is manifested by acute neurological symptoms in patients with varied predisposing factors and characteristic findings on brain imaging. Cerebrovascular autoregulation is thought to be altered in PRES. However, it remains unclear whether cerebral hypoperfusion or hyperperfusion is the initiating event. We aimed to describe the brain perfusion status in untreated patients with PRES.

METHODS

Patients with PRES who underwent cerebral perfusion studies on presentation were retrospectively identified from (1) a prospective database of patients with PRES admitted to Saint Mary's Hospital, Mayo Clinic, Rochester from January 2005 to December 2021 and (2) University of Nebraska Medical Center electronic database from January 2010 to December 2021. Demographics, past medical history, presenting symptoms, cause of PRES, and clinical outcomes were recorded. Brain imaging studies were reviewed. We recorded the location of brain lesions, the time from symptoms onset to perfusion study, blood pressure at the time of the perfusion study, and blood pressure lowering treatments.

RESULTS

Five patients (four women, median age 66 years) were included. Causes of PRES were acute hypertension (n = 3), perioperative blood pressure fluctuations, and treatment with pazopanib. Four patients had chronic hypertension. Presenting symptoms were encephalopathy (n = 5), focal neurological symptoms (n = 4), and seizures (n = 2). All patients underwent computed tomography (CT) perfusion performed within 12 h of symptoms onset. All but one patient was hypertensive at the time of CT perfusion. Scans showed diffuse cerebral hypoperfusion, more pronounced in the corona radiata and areas with brain edema. No patient had critical cerebral ischemia or arterial vasoconstriction on CT angiogram.

CONCLUSIONS

Patients with PRES can have cerebral hypoperfusion despite severe hypertension. A perfusion study in the acute setting may be helpful to better understand the perfusion status and guide blood pressure treatment.

Cerebral perfusion in posterior reversible encephalopathy syndrome measured with arterial spin labeling MRI

BACKGROUND AND PURPOSE

The pathophysiologic basis of posterior reversible encephalopathy syndrome (PRES) remains controversial. Hypertension (HTN)-induced autoregulatory failure with subsequent hyperperfusion is the leading hypothesis, whereas alternative theories suggest vasoconstriction-induced hypoperfusion as the underlying mechanism. Studies using contrast-based CT and MR perfusion imaging have yielded contradictory results supporting both ideas. This work represents one of the first applications of arterial spin labeling (ASL) to evaluate cerebral blood flow (CBF) changes in PRES.

MATERIALS AND METHODS

After obtaining Institutional Review Board approval, MRI reports at our institution from 07/2015 to 09/2020 were retrospectively searched and reviewed for mention of "PRES" and "posterior reversible encephalopathy syndrome." Of the resulting 103 MRIs (performed on GE 1.5 Tesla or 3 Tesla scanners), 20 MRIs in 18 patients who met the inclusion criteria of clinical and imaging diagnosis of PRES and had diagnostic-quality pseudocontinuous ASL scans were included. Patients with a more likely alternative diagnosis, technically non-diagnostic ASL, or other intracranial abnormalities limiting assessment of underlying PRES features were excluded. Perfusion in FLAIR-affected brain regions was qualitatively assessed using ASL and characterized as hyperperfusion, normal, or hypoperfusion. Additional quantitative analysis was performed by measuring average gray matter CBF in abnormal versus normal brain regions.

RESULTS

HTN was the most common PRES etiology (65%). ASL showed hyperperfusion in 13 cases and normal perfusion in 7 cases. A hypoperfusion pattern was not identified. Quantitative analysis of gray matter CBF among patients with visually apparent hyperperfusion showed statistically higher perfusion in affected versus normal appearing brain regions (median CBF 100.4 ml/100 g-min vs. 61.0 ml/ 100 g-min, p < 0.001).

CONCLUSION

Elevated ASL CBF was seen in the majority (65%) of patients with PRES, favoring the autoregulatory failure hypothesis as a predominant mechanism. Our data support ASL as a practical way to assess and noninvasively monitor cerebral perfusion in PRES that could potentially alter management strategies.

Asymmetric posterior reversible encephalopathy syndrome secondary to epilepsy occurring in the chronic phase of subarachnoid hemorrhage

Background:

Posterior reversible encephalopathy syndrome (PRES) is a rare clinical syndrome that refers to a disorder with reversible subcortical vasogenic brain edema involving the parieto-occipital lobe, temporal lobe, basal ganglia, and its surroundings. Radiologically, it is characterized by symmetrical lesions; however, atypical findings have sometimes been reported.

Case Description:

A 79-year-old woman experienced subarachnoid hemorrhage (SAH) a year and a half previously before this hospitalization. She presented with sudden-onset coma, dacryorrhea, and moderate right hemiparesis and was taken to our hospital. Computed tomography showed no apparent abnormal acute lesions. Electroencephalography confirmed periodic lateralized epileptiform discharges in the left hemisphere. First, based on the findings, she was diagnosed with nonconvulsive status epilepticus and started antiepileptic therapy. Six days after admission, however, multiple asymmetric lesions were confirmed on magnetic resonance imaging. Considering that findings subsequently improved, we finally diagnosed her with asymmetric PRES secondary to epilepsy occurring in the chronic phase of SAH. Aphasia and right hemispatial neglect persisted as sequelae and she was transferred to a rehabilitation hospital with a modified Rankin scale of 3.

Conclusion:

Excessive elevation of blood flow in the hemisphere is inferred to lead to blood–brain barrier collapse and subsequent asymmetric PRES.

The management of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a rare event affecting relatively young patients therefore leading to a high social impact. The management of SAH follows a biphasic course with early brain injuries in the first 72 hours followed by a phase at risk of secondary deterioration due to delayed cerebral ischemia (DCI) in 20 to 30% patients. Cerebral infarction from DCI is the most preventable cause of mortality and morbidity after SAH. DCI prevention, early detection and treatment is therefore advocated. Formerly limited to the occurrence of vasospasm, DCI is now associated with multiple pathophysiological processes involving for instance the macrocirculation, the microcirculation, neurovascular units, and inflammation. Therefore, the therapeutic targets and management strategies are also evolving and are not only focused on proximal vasospasm. In this review, we describe the current knowledge of DCI pathophysiology. We then discuss the diagnosis strategies that may guide physicians at the bedside with a multimodal approach in the unconscious patient. We will present the prevention strategies that have proven efficient as well as future targets and present the therapeutic approach that is currently being developed when a DCI occurs.

Cerebral Autoregulation in Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating stroke subtype with a high rate of mortality and morbidity. The poor clinical outcome can be attributed to the biphasic course of the disease: even if the patient survives the initial bleeding emergency, delayed cerebral ischemia (DCI) frequently follows within 2 weeks time and levies additional serious brain injury. Current therapeutic interventions do not specifically target the microvascular dysfunction underlying the ischemic event and as a consequence, provide only modest improvement in clinical outcome. SAH perturbs an extensive number of microvascular processes, including the “automated” control of cerebral perfusion, termed “cerebral autoregulation.” Recent evidence suggests that disrupted cerebral autoregulation is an important aspect of SAH-induced brain injury. This review presents the key clinical aspects of cerebral autoregulation and its disruption in SAH: it provides a mechanistic overview of cerebral autoregulation, describes current clinical methods for measuring autoregulation in SAH patients and reviews current and emerging therapeutic options for SAH patients. Recent advancements should fuel optimism that microvascular dysfunction and cerebral autoregulation can be rectified in SAH patients.

Posterior reversible encephalopathy syndrome after induced hypertension therapy for delayed cerebral ischemia after subarachnoid hemorrhage: A case-control study

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is associated with arterial hypertension. Our aim was to investigate whether induced hypertension (IH) as therapy for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) is associated with PRES and to identify risk factors for PRES.

MATERIAL AND METHODS

We retrospectively searched our database for patients with SAH and IH in our institution between 2009 and 2018 and identified additional cases of PRES after SAH with IH from the literature. We then analyzed demographic findings and clinical features of these patients.

RESULTS

172 patients with acute SAH received IH. PRES was diagnosed in 3/172 (1.7%) patients. Our literature search revealed 17 additional cases. The pooled PRES group (n = 20) was non-significantly older than the non-PRES group (n = 169) (median, 62.5 years vs. 52 years, p = 0.06). No significant differences were found between both groups with regard to sex (p = 0.73), Hunt & Hess-Score (p = 0.9), aneurysm treatment (p = 0.13), and time from diagnosis of SAH to the start of IH (p = 0.14).

CONCLUSIONS

PRES after IH in SAH patients occurred in 1.7% of our patients. Our results imply that it is important to be aware of a possible development of a PRES in older SAH patients with IH, irrespective of sex, initial clinical status, and treatment modality.

Posterior Reversible Encephalopathy Syndrome Caused by Induced Hypertension to Treat Cerebral Vasospasm Secondary to Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

The aim of the present study was to describe the case of a patient who had presented to a university hospital with induced-hypertension (IH) posterior reversible encephalopathy syndrome (PRES). We also reviewed all other reports of such patients.

METHODS

We have described the clinical course of a patient who had presented to the university hospital neurosurgical department. We also performed a systematic review of studies related to the incidence of PRES caused by the use of IH in the treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

RESULTS

The patient had presented with an acute-onset headache and found to have a subarachnoid hemorrhage due to anterior communicating artery aneurysm rupture. She underwent coiling the next day. During the subsequent days, she demonstrated fluctuating clinical examination findings, aphasia, and decreased levels of arousal. Digital subtraction angiography was performed, and the findings were concerning for mild vasospasm of the anterior and middle cerebral arteries. The systolic blood pressure goal was increased to 180-220 mm Hg for an IH trial, which had initially resulted in some transient clinical improvements in her level of arousal. However, the improvement was not sustained. During the next 36 hours, the patient worsened, and she developed left middle cerebral artery syndrome. Given the concern for a possible ischemic event, magnetic resonance imaging was performed, which demonstrated interval development of multiple areas of cortical-based fluid-attenuated inversion recovery hyperintensity consistent with PRES. The systolic blood pressure goal was relaxed to normotension, and ~48 hours later, the patient's clinical status had significantly improved.

CONCLUSION

IH-PRES is a rare complication that should be remembered in the differential diagnosis for at-risk patients.

Posterior Reversible Encephalopathy Syndrome (PRES): Pathophysiology and Neuro-Imaging

Posterior reversible encephalopathy syndrome (PRES) represents a unique clinical entity with non-specific clinical symptoms and unique neuroradiological findings. This syndrome may present with a broad range of clinical symptoms from headache and visual disturbances to seizure and altered mentation. Typical imaging findings include posterior-circulation predominant vasogenic edema. Although there are many well-documented diseases associated with PRES, the exact pathophysiologic mechanism has yet to be fully elucidated. Generally accepted theories revolve around disruption of the blood-brain barrier secondary to elevated intracranial pressures or endothelial injury. In this article, we will review the clinical, typical, and atypical radiological features of PRES, as well as the most common theories behind the pathophysiology of PRES. Additionally, we will discuss some of the treatment strategies for PRES related to the underlying disease state.

Advanced Imaging Techniques in Diagnosis of Posterior Reversible Encephalopathy Syndrome (PRES)

Diagnosis of Posterior Reversible Encephalopathy Syndrome (PRES) in some circumstances can be challenging and structural imaging may not be sufficient to distinguish it from other differential diagnostic considerations. Advanced imaging techniques, such as MR spectroscopy or positron emission tomography (PET) can provide additional information to determine the diagnosis. Other techniques, such as susceptibility weighted imaging (SWI) improves detection of hemorrhage which has prognostic role. CT or MR Perfusion as well as Single-Photon Emission Computed Tomography (SPECT) are more useful to understand the underlying vasculopathic changes in PRES and may answer some of the unresolved controversies in pathophysiology of this complex disease. In this review we summarized the findings of previous studies using these advanced methods and their utilities in diagnosis or prognosis of PRES.

Transcranial Doppler Sonography Defined Vasospasm, Ischemic Brain Lesions, and Delayed Ischemic Neurological Deficit in Younger and Elderly Patients after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Vasospasm, delayed ischemic neurologic deficit (DIND), and ischemic brain lesions after acute subarachnoid hemorrhage (SAH) are associated with increased morbidity and mortality. The purpose of this study was to analyze age cutoffs for vasospasm, DIND, and ischemic brain lesions after SAH.

METHODS

This study included 292 aneurysmal SAH patients from January 2005 to December 2015. Patients' data were extracted from a prospective database with measurements of transcranial Doppler sonography. Any vasospasm was defined as a maximum mean flow velocity (MMFV) >120 cm/sec. Severe vasospasms were defined as at least 2 measurements of MMFVs >200 cm/sec or an increase of MMFV >50 cm/sec/24 hours over 2 consecutive days or a new neurologic deficit. All MMFVs >120 cm/sec in absence of severe vasospasm criteria were defined as mild vasospasm. Age-related cutoff values were calculated using receiver operating curve analysis.

RESULTS

Any vasospasms occurred in 142 patients and thereof mild vasospasm in 86/142 (60.6%) patients and severe vasospasm in 56/142 patients (39.4%). Significantly higher incidences of any vasospasm (P = 0.005), severe vasospasm (P = 0.003), DIND (P = 0.031), and ischemic brain lesions (P = 0.04) were observed in patients aged <50 years. According to receiver operating curve analysis, the optimal age cutoff was 50 years for the presence of overall vasospasms, severe vasospasms, DIND, and ischemic brain lesions and 65 years for mild vasospasms.

CONCLUSIONS

Higher incidences of any vasospasms, severe vasospasms, DIND, and ischemic brain lesions were observed in younger SAH patients.

A Case of Posterior Reversible Encephalopathy Syndrome After Surgical Clipping of Unruptured Cerebral Aneurysm

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible edematous lesions on imaging examinations, along with symptoms of altered consciousness disorder and seizures. Various factors associated with PRES have been reported. However, we encountered a very rare case that developed after clipping surgery for unruptured cerebral aneurysm.

CASE DESCRIPTION

A 74-year-old man with a history of hypertension presented with an unruptured right middle cerebral artery aneurysm and underwent cranial clipping surgery. After surgery, he developed consciousness disorder and epilepsy after delayed awakening from general anesthesia. Radiological examinations revealed multiple edematous lesions, strongly suggesting PRES, and excluding asymmetry consistent with the area of craniotomy. With conservative treatment, symptoms and radiological findings almost disappeared. Symptoms and imaging findings remaining at the area of craniotomy were attributed to the severe difference in cerebral perfusion pressure due to craniotomy.

CONCLUSIONS

Based on the literature, this case was considered to represent PRES caused by rapid blood pressure fluctuations accompanying general anesthesia for clipping surgery. Practitioners must keep PRES in mind as a rare complication after clipping for unruptured cerebral aneurysms. PRES developing after craniotomy shows unilaterality and may become severe in the craniotomy area and leave sequelae.

Posterior reversible encephalopathy syndrome (PRES) and infection: a systematic review of the literature

Posterior reversible encephalopathy syndrome (PRES) is an encephalopathy characterized by a rapid onset of symptoms including headache, seizures, confusion, blurred vision, and nausea associated with a typical magnetic resonance imaging appearance of reversible subcortical vasogenic edema prominent and not exclusive of parieto-occipital lobes. Vasogenic edema is caused by a blood-brain barrier leak induced by endothelial damage or a severe arterial hypertension exceeding the limits of cerebral blood flow autoregulation. Although the exact pathophysiological mechanism is still unclear, frequent conditions that may induce PRES include severe hypertension, eclampsia/pre-eclampsia, acute kidney diseases and failure, immunosuppressive therapy, solid organ, or bone marrow transplantation. Conversely to other conditions, which may induce PRES, the link between severe infection or sepsis and PRES, often associated with gram-positive bacteria, is still poorly understood and less well known. Clinicians from multiple disciplines, such as neurologists and internists, may encounter during their profession patients with severe infection or sepsis and should consider the possible association between PRES and these conditions. We systematically reviewed the literature about this association in order to provide a helpful clinical insight of such complex pathophysiological mechanism, highlighting the importance of recognizing PRES in such a complex clinical scenario.

Protective effect of unilateral vasospasm in the setting of HHH-associated posterior reversible encephalopathy syndrome: case report, review of the literature, and treatment considerations

Background

Hyperdynamic therapy, also called triple-H therapy, is the standard treatment and prophylaxis for aneurysmal-associated vasospasm. In patients who are able to tolerate cardiopulmonary stressors induced by this therapy, it is of benefit as a modality for prevention and treatment of delayed ischemic neurologic deficit. However, it can be a cause of significant cardiopulmonary or neurologic sequelae. In rare cases, it can be associated with posterior reversible encephalopathy syndrome (PRES), secondary to prolonged vasopressor and hypertensive therapies.

Case presentation

We present the case of a patient with right-sided aneurysmal-associated vasospasm who, after 10 days of triple-H therapy, experienced a seizure and was found to have left-sided PRES. Right-sided vasospasm served as a protective mechanism from triple-H therapy-associated PRES. It presented a treatment conundrum due to contradictory perfusion requirements. Hypertensive therapy was curtailed and in efforts to preserve local cerebral perfusion and vasodilation, local therapy with intrathecal nicardipine was initiated. We present our case, a review of the literature, and management considerations.

Conclusions

Therapies that have conventionally functioned as second line treatments for aneurysmal subarachnoid hemorrhage (intra-arterial vasodilators and intrathecal vasodilators) may be beneficial as earlier treatments in the setting of vasospasm given the systemic difficulties and complications associated with HHH therapy in patients with PRES.

Changes in Cerebral Perfusion with Induced Hypertension in Aneurysmal Subarachnoid Hemorrhage: A Pilot and Feasibility Study

BACKGROUND

The effects of induced hypertension (IH) on cerebral perfusion after subarachnoid hemorrhage (SAH) are unclear. The objectives of this investigation are to: (1) determine whether there are differences in cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) measured with computed tomography perfusion (CTP) before and after IH; (2) evaluate differences in the presence of infarction and clinical outcome between patients with and without IH.

METHODS

We performed a retrospective cohort analysis of 25 aneurysmal SAH patients. IH was initiated as per the standard institutional protocol when patients showed clinical symptoms of delayed cerebral ischemia (DCI). Differences in CBF, CBV, and MTT between early (<72 h after aneurysm rupture) and late (7-10 days after aneurysm rupture) CTP were quantified in patients with (n = 13) and without IH (n = 12). Outcome measures included cerebral infarction and clinical outcome at 3 months.

RESULTS

Early MTT was significantly greater in the IH group compared to the no-IH group. There was no difference in early or late CBV or CBF between the two groups. In patients that received IH, there was a significant decrease in MTT between the early (7.0 ± 1.2 s) and late scans (5.8 ± 1.6 s; p = 0.005). There was no difference in the incidence of infarction (5/13 vs. 2/11) or poor outcome (3/11 vs. 6/13) between the IH and no-IH groups, respectively (p > 0.05).

CONCLUSIONS

Elevated MTT is a significant factor for the development of DCI in patients eventually requiring IH therapy and is improved by IH treatment. Therapies to prevent DCI and improve clinical outcome may need to be initiated earlier, when cerebral perfusion abnormalities are first identified.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Rapid intracranial pressure drop as a cause for posterior reversible encephalopathy syndrome: Two case reports

Background:

Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible edematous lesions on radiological examinations as well as symptoms of altered consciousness and seizures. To date, the underlying mechanism remains largely unknown.

Case Descriptions:

Case 1 is a 72-year-old man with a history of hypertension presented with a subarachnoid hemorrhage. Fourteen days after the successful clipping of a ruptured aneurysm; he experienced inadvertent overdrainage via the intraventricular drain. Nine hours later, he started to have seizures followed by disturbances in consciousness. An emergency magnetic resonance imaging showed multiple high-intensity lesions in the frontal, temporal, parietal, and occipital lobes, basal ganglia, brainstem, and cerebellar hemispheres bilaterally, which are compatible with typical magnetic resonance findings in PRES patients. He was treated conservatively and recovered well. Case 2 is a 68-year-old woman with a mild history of hypertension and a ventriculo-peritoneal shunt for obstructive hydrocephalus, who underwent a cysto-peritoneal shunt placement because of an enlarging symptomatic arachnoid cyst. Immediately following surgery, she experienced disturbances in consciousness and developed status epilepticus. Radiological examinations revealed remarkable shrinkage of the arachnoid cyst and multiple edematous lesions, which led us to strongly suspect PRES. With conservative treatment, her symptoms and the radiological abnormalities disappeared.

Conclusion:

Based on the previous literature and our cases, we believe that the association between rapid reduction of intracranial pressure (ICP) and the development of PRES should be recognized because most neurosurgical procedures such as craniotomy or cerebrospinal fluid diversion present a potential risk of rapid reduction of ICP.

Blood Pressure Management in Intracranial Hemorrhage: Current Challenges and Opportunities

OPINION STATEMENT

Non-traumatic intracranial hemorrhage (i.e. intracerebral hemorrhage [ICH] and subarachnoid hemorrhage [SAH]) are more life threatening and least treatable despite being less common than ischemic stroke. Elevated blood pressure (BP) is a strong predictor of poor outcome in both ICH and SAH. Data from a landmark clinical trial INTERACT 2, wherein 2839 participants enrolled with spontaneous ICH were randomly assigned to receive intensive (target systolic BP <140 mmHg) or guideline recommended BP lowering therapy (target systolic BP <180 mmHg), showed that intensive BP lowering was safe, and more favorable functional outcome and better overall health-related quality of life were seen in survivors in the intensive treatment group. These results contributed to the shift in European and American guidelines towards more aggressive early management of elevated BP in ICH. In contrast, the treatment of BP in SAH is less well defined and more complex. Although there is consensus that hypertension needs to be controlled to prevent rebleeding in the acute setting, induced hypertension in the later stages of SAH has questionable benefits.

Posterior Reversible Encephalopathy Syndrome as an Overlooked Complication of Induced Hypertension for Cerebral Vasospasm

Background and Purpose—

Delayed cerebral ischemia associated with cerebral vasospasm is a common cause of secondary neurological decline after aneurysmal subarachnoid hemorrhage (SAH). Triple-H therapy, induced hypertension, hypervolemia, and hemodilution, is often used to treat cerebral vasospasm. However, hypertensive treatment may carry significant medical morbidity, including cardiopulmonary, renal, and intracranial complications. Posterior reversible encephalopathy syndrome (PRES) is a reversible intracranial complication that has rarely been reported in the setting of induced hypertension.

Methods—

We present an illustrative case of PRES in a patient with induced hypertension for SAH-related cerebral vasospasm and performed a systematic review. Furthermore, the electronic database MEDLINE was searched for additional data in published studies of PRES after induced hypertension.

Results—

Overall, 7 case reports presenting 10 patients who developed PRES secondary to induced hypertension were found. Eighty-two percent of the patients were women. In all cases, the clinical symptoms were attributed to cerebral vasospasm before the diagnosis of PRES. The time from onset of induced hypertension to the development of PRES was 7.8±3.8 days. After the diagnosis of PRES and careful taper down of the blood pressure, the neurological symptoms resolved almost completely within a few days in all patients.

Conclusions—

PRES in the setting of SAH is an overlooked complication of hypertensive therapy for the treatment of vasospasm. However, the diagnosis of this phenomenon is crucial given the necessity to reverse hypertensive therapy, which is contrary to the usual management of patients with vasospasm.

Posterior reversible encephalopathy syndrome with thalamic involvement during vasopressor treatment of vertebrobasilar vasospasm after subarachnoid hemorrhage

Hemodynamic augmentation is the primary medical intervention employed to reverse neurological deficits associated with vasospasm and delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage. Failure to improve despite induced hypertension (IH) may raise concern for persistent hypoperfusion and prompt even more aggressive blood pressure augmentation. However, posterior reversible encephalopathy syndrome (PRES) is a hyperperfusion syndrome reported as a rare complication of IH that may confound this picture. We report a case of PRES with prominent thalamic involvement and impaired level of consciousness secondary to blood pressure augmentation for the treatment of symptomatic vertebrobasilar vasospasm. Recognition of this syndrome in distinction to worsening ischemia is particularly critical, as normalization of blood pressure should lead to rapid clinical improvement.

Posterior reversible encephalopathy syndrome with thalamic involvement during vasopressor treatment of vertebrobasilar vasospasm after subarachnoid hemorrhage

Hemodynamic augmentation is the primary medical intervention employed to reverse neurological deficits associated with vasospasm and delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage. Failure to improve despite induced hypertension (IH) may raise concern for persistent hypoperfusion and prompt even more aggressive blood pressure augmentation. However, posterior reversible encephalopathy syndrome (PRES) is a hyperperfusion syndrome reported as a rare complication of IH that may confound this picture. We report a case of PRES with prominent thalamic involvement and impaired level of consciousness secondary to blood pressure augmentation for the treatment of symptomatic vertebrobasilar vasospasm. Recognition of this syndrome in distinction to worsening ischemia is particularly critical, as normalization of blood pressure should lead to rapid clinical improvement.

Unilateral reversible posterior leukoencephalopathy syndrome after coiling of an aneurysm

Background

Reversible posterior leukoencephalopathy syndrome (RPLS) is radiologically characterized by symmetrical subcortical areas of vasogenic edema that are preferentially parieto-occipital, and it typically resolves after appropriate treatment.

Case Report

We present a patient with strikingly unilateral RPLS that developed 21 days after coiling of an anterior communicating artery aneurysm and several days of triple-H therapy. Cortical and subcortical vasogenic edema and enhancement developed only in the left hemisphere, with a pattern suggesting RPLS. After 7 months the lesions had nearly completely resolved.

Conclusions

The pathophysiological mechanism underlying RPLS is still not well understood, which makes it difficult to explain the unilateral appearance in this case. Since the imaging findings may be confused with other conditions such as ischemia, recognition of RPLS after coiling is necessary in order to avoid inadequate treatment.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a recently proposed cliniconeuroradiologic entity with several well-known causes, such as hypertensive encephalopathy, eclampsia, and the use of cytotoxic and immunosuppressive drugs, as well as some causes more recently described. PRES is characterized by neuroimaging findings of reversible vasogenic subcortical edema without infarction. The pathogenesis is incompletely understood. Two opposing hypotheses are commonly cited, but the issue is controversial: (1) the current more popular theory suggests that severe hypertension exceeds the limits of autoregulation, leading to breakthrough brain edema; (2) the earlier original theory suggests that hypertension leads to cerebral autoregulatory vasoconstriction, ischemia, and subsequent brain edema. The clinical syndrome of PRES typically involves headache, encephalopathy, visual symptoms, and seizures. The clinical presentation is often nonspecific, and therefore the diagnosis of PRES has come to increasingly rely on magnetic resonance imaging (MRI) abnormalities consistent with PRES with documented recovery clinically and on repeated neuroimaging. The diagnosis has important therapeutic and prognostic implications because the reversibility of the clinical and radiologic abnormalities is contingent on the prompt control of blood pressure and/or discontinuing the offending drug.

Hyperperfusion syndrome after stent/coiling of a ruptured carotid bifurcation aneurysm

The authors report a syndrome of regional, symptomatic cerebral hyperperfusion, and edema mimicking infarction in a 54-year-old woman following coiling of a ruptured right carotid bifurcation aneurysm and stenting of the right middle cerebral artery. The patient presented with a Hunt and Hess grade III subarachnoid hemorrhage 7 days after developing thunderclap headache. She underwent successful coiling under general anesthesia of the 1.6 × 1.5 × 1.6 cm aneurysm, but immediately after the coil was placed occlusion of the proximal M1 segment was developed. This occlusion was stented after ~5-min delay, and flow restored without angiographic evidence of distal emboli. Following the procedure, she was extubated and noted to have left hemiparesis, neglect, and mutism without a CT correlate. Cerebral infarction was suspected, but urgent repeat angiography demonstrated patent cerebral vasculature. On the following day, symptoms persisted, and non-contrast head CT now showed cerebral edema localized to the right middle cerebral artery territory mimicking subacute infarction. CT perfusion imaging and angiography showed a widely patent MCA circulation, and suggested a regional hyperperfusion syndrome. The blood pressure was incrementally lowered, with rapid and sustained neurological improvement. Hyperperfusion events following aneurysm repair and related circumstances are reviewed.

European Stroke Organization guidelines for the management of intracranial aneurysms and subarachnoid haemorrhage

BACKGROUND

Intracranial aneurysm with and without subarachnoid haemorrhage (SAH) is a relevant health problem: The overall incidence is about 9 per 100,000 with a wide range, in some countries up to 20 per 100,000. Mortality rate with conservative treatment within the first months is 50-60%. About one third of patients left with an untreated aneurysm will die from recurrent bleeding within 6 months after recovering from the first bleeding. The prognosis is further influenced by vasospasm, hydrocephalus, delayed ischaemic deficit and other complications. The aim of these guidelines is to provide comprehensive recommendations on the management of SAH with and without aneurysm as well as on unruptured intracranial aneurysm.

METHODS

We performed an extensive literature search from 1960 to 2011 using Medline and Embase. Members of the writing group met in person and by teleconferences to discuss recommendations. Search results were graded according to the criteria of the European Federation of Neurological Societies. Members of the Guidelines Committee of the European Stroke Organization reviewed the guidelines.

RESULTS

These guidelines provide evidence-based information on epidemiology, risk factors and prognosis of SAH and recommendations on diagnostic and therapeutic methods of both ruptured and unruptured intracranial aneurysms. Several risk factors of aneurysm growth and rupture have been identified. We provide recommendations on diagnostic work up, monitoring and general management (blood pressure, blood glucose, temperature, thromboprophylaxis, antiepileptic treatment, use of steroids). Specific therapeutic interventions consider timing of procedures, clipping and coiling. Complications such as hydrocephalus, vasospasm and delayed ischaemic deficit were covered. We also thought to add recommendations on SAH without aneurysm and on unruptured aneurysms.

CONCLUSION

Ruptured intracranial aneurysm with a high rate of subsequent complications is a serious disease needing prompt treatment in centres having high quality of experience of treatment for these patients. These guidelines provide practical, evidence-based advice for the management of patients with intracranial aneurysm with or without rupture. Applying these measures can improve the prognosis of SAH.

Unilateral posterior reversible encephalopathy syndrome with hypertensive therapy of contralateral vasospasm: case report

BACKGROUND AND IMPORTANCE

Hemodynamic treatment of subarachnoid hemorrhage-induced vasospasm is associated with a number of systemic and cerebral risks. However, hypertensive encephalopathy has rarely been reported in the setting of induced hypertension. Recognition of this complication is nonetheless critical because failure to lower blood pressure may lead to worsening of deficits and even permanent injury.

CLINICAL PRESENTATION

This report details a case of unilateral hypertensive encephalopathy (also referred to as posterior reversible encephalopathy syndrome [PRES]) in a subarachnoid hemorrhage patient who was being treated with induced hypertension for symptomatic vasospasm affecting the contralateral hemisphere. This patient developed right hemispheric deficits associated with angiographic vasospasm of the right middle cerebral artery, which responded to induced hypertension. However, within 24 hours of raising blood pressure, the patient deteriorated with new left hemispheric deficits that paradoxically worsened when blood pressure was raised further in response. Computed tomography imaging was suspicious for evolving infarction in the left hemisphere, but on reevaluation, concern for PRES was raised. Magnetic resonance imaging confirmed left hemispheric PRES, and a dramatic neurological improvement occurred almost immediately after lowering blood pressure. Repeat CT showed resolution of the left hemispheric edema.

CONCLUSION

This is the first reported case of unilateral PRES in the setting of subarachnoid hemorrhage. It likely occurred because right-sided vasospasm attenuated ipsilateral distal perfusion pressures, leaving the left hemisphere vulnerable to the consequences of induced hypertension. Hypertensive encephalopathy should be considered in patients with unilateral or asymmetric vasospasm when neurological worsening occurs in the contralateral hemisphere during induced hypertension and/or the patient paradoxically worsens despite raising blood pressure.

Posterior reversible encephalopathy syndrome associated with hemodynamic augmentation in aneurysmal subarachnoid hemorrhage

BACKGROUND

Cerebral vasospasm has become the most concerning complication in patients with aneurysmal subarachnoid hemorrhage (aSAH) seen in the neurosciences intensive care unit (NSICU). Hemodynamic augmentation is frequently used to treat cerebral ischemia from vasospasm. In the last 5 years, posterior reversible encephalopathy syndrome (PRES) has been reported in three single case reports as a complication of hemodynamic augmentation. We describe an additional three patients seen in our institution.

METHODS

Description of clinical course of three patients with a secured aneurysm treated with hemodynamic augmentation for cerebral vasospasm.

RESULTS

We identified three patients (two female and one male), ranged in age from 62 to 70 years who developed PRES after treatment with induced or permissive arterial hypertension. During their NSICU stay, case 1 had worsening headache and confusion, case 2 and 3 had a decline in level of consciousness. Neuroimaging was compatible with vasogenic edema characteristic of PRES. Arterial blood pressure was reduced with a complete clinical and imaging resolution of PRES.

CONCLUSIONS

PRES can be a cause of deterioration in patients with aSAH treated with hemodynamic augmentation. PRES should be differentiated from evolving infarctions due to cerebral vasospasm. Clinical manifestations and neuroimaging findings are reversible after gradual normalization of blood pressure.

Lower Incidence of Transcranial Doppler and Symptomatic Vasospasm After Aneurysmal Subarachnoid Hemorrhage and Aneurysm Clipping in the Elderly Patient?

BACKGROUND:

Vasospasm is the major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage. It is well known that the vasoreactivity decreases with advancing age, but it is not well investigated in a large patient cohort whether, as a consequence, the incidence of vasospasm is lower in elderly patients.

OBJECTIVE:

To investigate whether transcranial Doppler vasospasm, delayed ischemic neurological deficits, and vasospasm-associated ischemic lesions are less frequent in older patients.

METHODS:

Seven hundred fifty-eight patients who suffered from subarachnoid hemorrhage were included in this study. Clinical presentation, Hunt and Hess score, Fisher grade, incidence of vasospasm, neurological deficits and ischemic lesions on radiographic imaging, transcranial Doppler blood flow velocities, medical complications, and outcome were registered.

RESULTS:

Four hundred seventy-eight patients &lt; 60 years of age and 280 patients ≥ 60 years of age were identified; 55.2% of the younger and 25.7% of the older age group developed post-hemorrhagic vasospasm (P &lt; .001). Older patients developed less vasospasm (P = .00), fewer neurological deficits (P &lt; .001), and fewer ischemic lesions on computed tomography imaging (P = .06). On the other hand, older patients had significantly worse outcomes than younger patients (P = .01) and more frequently died of medical complications (P = .01).

CONCLUSION:

Vasospasm, delayed ischemic neurological deficits, and vasospasm-associated ischemic lesions are more likely to occur in patients &lt; 60 years of age than in older patients. The lower incidence of vasospasm and vasospasm-related ischemia in the elderly patient does not translate into better outcome because of the higher rate of fatal medical complications in patients ≥ 60 years of age.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual disturbances, and seizures. Radiological features typically include edema of the posterior cerebral regions, especially of the parietooccipital lobes. Atypical imaging features, such as involvement of anterior cerebral regions, deep white matter, and the brain stem are also frequently seen. Vasoconstriction is common in vascular imaging. Different conditions have been associated with PRES, but toxemia of pregnancy, solid organ or bone marrow transplantation, immunosuppressive treatment, cancer chemotherapy, autoimmune diseases, and hypertension are most commonly described. The pathophysiology of PRES is unclear and different hypotheses are being discussed. Posterior reversible encephalopathy syndrome is best managed by monitoring and treatment in the setting of a neurointensive care unit. The prognosis is usually benign with complete reversal of clinical symptoms within several days, when adequate treatment is immediately initiated. Treatment of severe hypertension, seizures, and withdrawal of causative agents represent the hallmarks of specific therapy in PRES. Delay in diagnosis and treatment may lead to permanent neurological sequelae. Therefore, awareness of PRES is of crucial importance for the intensivist.

Posterior reversible encephalopathy syndrome associated with hemorrhage

BACKGROUND

Posterior Reversible Encephalopathy Syndrome (PRES) is a clinico-radiological entity characterized by headache, encephalopathy, visual disturbances, and seizures in association with reversible vasogenic edema on neuroimaging. Intracerebral hemorrhage associated with PRES (PRES-ICH) is generally considered an atypical finding.

METHODS

Retrospective case series.

RESULTS

Seven patients were identified with PRES-ICH, four males and three females. The presenting clinical symptoms included headache (2), encephalopathy (5), vision changes (2), seizures (2), and hemiparesis (1). The co-morbid conditions included acute renal dysfunction (3), solid organ transplantation (3), bone marrow transplant (1), use of calcineurin inhibitor agents (4), and pre-eclampsia (1). Neuroimaging revealed intraparenchymal hemorrhage in six patients and subarachnoid hemorrhage in one patient. Six of the seven patients with PRES-related ICH had underlying bleeding diathesis, including one patient who was anti-coagulated with a heparin drip. The mean platelet count was 82.1 x 10(3)/microl (range, 4-232 x 10(3)/microl), and the mean INR value was 2.18 (range, 0.9-6.7). Two patients died during the acute hospitalization. Among the five survivors, only two patients had good functional outcome (pre-defined as mRS < or = 1).

CONCLUSION

In our series, the majority of patients with PRES-ICH (85%) had an underlying bleeding diathesis or coagulopathy. Although PRES is typically considered to have a favorable prognosis, the clinical outcome of PRES with associated ICH can be more variable.

Medical Management of Patients with Aneurysmal Subarachnoid Haemorrhage

Treating patients with aneurysmal subarachnoid haemorrhage is taking care of acutely ill patients, and should be performed in centres where a multidisciplinary team is available 24 hours a day 7 days a week, and where enough patients are managed to maintain and improve standards of care. There is no medical management that improves outcome by reducing the risk of rebleeding, therefore occlusion of the aneurysm, nowadays preferably by means of coiling, remains an important goal in treating patients with aneurysms. Because the poor outcome after subarachnoid haemorrhage is caused to a large extent by complications other than rebleeding, proper medical management to prevent and treat these complications is therefore essential. On basis of the available evidence, oral (not intravenous) nimodipine should be standard care in patients with subarachnoid haemorrhage. It is rational to refrain from treating hypertension unless cardiac failure develops and to aim for normovolaemia, even in case of hyponatraemia. There is no evidence for prophylactic hypervolaemia, and the strategy of hypervolaemia and hypertension in patients with secondary cerebral ischaemia is based on case reports and uncontrolled observational series of patients. Magnesium sulphate and statins are promising therapies, and large trials on effectiveness in improving clinical outcome are underway. There is no evidence for prophylactic use of anti epileptic drugs, and routine use of corticosteroids should be avoided.

Posterior reversible encephalopathy syndrome: an emerging clinical entity in adult, pediatric, and obstetric critical care

PURPOSE

To describe the signs, symptoms, causative factors, and treatment for posterior reversible encephalopathy syndrome (PRES), an emerging clinical neuroradiologic entity which may be encountered by nurse practitioners in almost any clinical setting.

DATA SOURCES

Extensive review of worldwide literature, including peer-reviewed medical specialty journals, supplemented by an actual case study. Currently, a paucity of information exists in the nursing literature.

CONCLUSIONS

PRES occurs as a result of disordered cerebral circulatory autoregulation and/or endothelial dysfunction, usually as a result of acute, intermittent hypertension. Clinical manifestations include mental status change, headache, visual disturbance, and seizures. Characteristic abnormalities in the posterior cerebral white matter, seen best on diffusion-weighted magnetic resonance imaging, confirm the presence of the syndrome. PRES has been documented worldwide among a diverse patient population, yet many clinicians are still unfamiliar with this diagnosis.

IMPLICATIONS FOR PRACTICE

PRES is a clinical-radiographic diagnosis that requires close collaboration between the clinician and interpreting radiologist. Rapid identification and appropriate diagnostics are essential, as prompt treatment usually results in reversal of symptoms; permanent neurologic injury or death can occur with treatment delay.

Reversible posterior encephalopathy syndrome in systemic lupus erythematosus and lupus nephritis

Reversible posterior encephalopathy syndrome (RPES) is a clinical entity characterized with headache, nausea, vomiting, seizures, consciousness disturbance, and frequently visual disorders associated with neuroradiological findings, predominantly white matter abnormalities of the parieto-occipital lobes. The central nervous system manifestations of systemic lupus erythematosus (SLE) are highly diverse. However, SLE-associated RPES has been seldom reported. Here, we report a case with RPES in SLE and lupus nephritis with exclusive involvement of parietal and occipital cortices. A systematic review of the literature on the pathogenesis and treatment of SLE-associated RPES is included.

Reversible posterior leukoencephalopathy syndrome in a patient with multiple system atrophy: A possible association with oral midodrine treatment

We describe a 51-year-old man with a 3-year history of multiple system atrophy, who developed a reversible posterior leukoencephalopathy syndrome (RPLS) after receiving prescription midodrine for therapeutic treatment of orthostatic hypotension. Typical reversible magnetic resonance imaging findings, following treatment with midodrine, suggested a possible relationship between midodrine treatment, supine hypertension, and RPLS, although a cause-and-effect relationship cannot be confirmed.